Disclaimer: English Kinda Thing

The sole purpose of the "English Kinda Thing" is to document my attempts to correct my own mistakes in standard English usage and to share the resources I find. In no way do I attempt to teach nobody English through these blurbs--just as I intend not to teach nobody to be a neurotic and psychotic handicap in Ratology Reloaded or Down with Meds! :-)

Sunday, July 12, 2009

Are Patients With Schizophrenia Insensitive to Pain? A Reconsideration of the Question (Bonnot, Anderson, Cohen, Willer, & Tordjman, 2009)

Bonnot, O., Anderson, G., Cohen, D., Willer, J. C., & Tordjman, S. (2009). Are Patients With Schizophrenia Insensitive to Pain? A Reconsideration of the Question. The clinical journal of pain, 25(3), 244-252.

OK… one thing I have to say is that this is the 3rd or 4th review paper I have gone through about pain in psychotics… I am starting to feel that much of the information is redundant and will only do a brief notation on this article…

International Association for the Study of Pain (IASP): "(J)ust because someone cannot verbally communicate their state of being doesn't mean they are not experiencing pain and requires no interventions." Schizophrenia, for instance, is a type of mental disease that could involve communication problems and cognitive impairments.

This article reviewed 57 selected articles which could be classified as case reports, clinical and epidemiologic studies, experimental studies and previous review papers.

Discussion

Insensitivity or less reactivity?

I believe the authors' opinion is that the reported pain insensitivity is a result of altered mode of pain expression rather than endogenous analgesia. In addition, the authors also mentioned the assessment problems: the pain measures were not comparable, psychophysical methods are potentially unreliable and, even with signal detection theory, what is intended to measure the sensory discrimination might end up measuring some other processes.

Biochemical Dysfunction?

The opioid and N-methyl-D-aspartate theories of Schizophrenia have been proposed. However, research concerning both hypotheses provided conflicting results.

Decreased behavioral pain expression and stress vulnerability model

The experience of pain results in stress. In ordinary people, the reactions to pain stimuli could be released through normal pain behavior, psychologically or physically. Patients with schizophrenia, on the other hand, can not release the invoked stress through normal reaction channel. As a result, stress might get built up and results in the worsening of psychotic conditions.

Saturday, July 11, 2009

review papers

If you ask me why I am going so much into details with these review papers...

Well, I guess that is the process involved in establishing a mental model about pain in psychosis... Given the dearth of literature available for this topic, I shall be able to get a pretty good idea about the "state of the art" literature in this line of research... This will also help me to narrow the topic down...

When I move on to the actual report papers, I would primarily focus on the assessment tools used to measure pain...

Hypoalgesia in schizophrenia is independent of antipsychotic drugs: A systematic quantitative review of experimental studies (Potvin & Marchand, 2008)

Potvin, S., & Marchand, S. (2008). Hypoalgesia in schizophrenia is independent of antipsychotic drugs: A systematic quantitative review of experimental studies. Pain, 138(1), 70-78.

This meta-analysis study containing 12 studies aims to investigate whether patients of schizophrenia have lower pain response when comparing to the normal control groups. In addition, the authors also attempts to examine the impacts of confounding factors on the results of experimental studies; these factors include the nature of pain stimuli, the use of antipsychotic medications, the nature of the psychiatric condition (e.g., process or acute type) and the validity of diagnosis.

The studies about hypoalgelsia fall into four different groups:

  • Clinical case reports
  • Population studies examining the prevalence of pain in patients with schizophrenia
  • Population studies examining the prevalence of schizophrenia in patients with chronic pain
  • Experimental studies

While mixed findings are found in existing literature about pain perception, there is also a lack of satisfactory explanation for the observations of pain insensitivity in schizophrenia.

The author provides the following as an explanation for the inconclusive findings: "(T)he heterogeneity of patients and the heterogeneity of experimental conditions (, which) may account for heterogeneity of results.

I absolutely agree with this comment because, personally, I have been diagnosed as having delusion disorder, bipolar disorder, schizophrenia, schizoaffective disorder, depression disorder etc. In addition, the diagnosis of schizophrenia has this garbage bag nature—all else don't fit too well.. let's label it schizophrenia… Moreover, what is the nature of pain and how is pain measured? If the notion of pain insensitivity holds true, is it true for all types of pain (e.g., electric shock, thermal stimuli) or is it truer for certain types of stimuli over the others? For instance, although I seem to have fairly high tolerance or threshold for electrical stimuli, I find myself having very low tolerance for heat or thermal stimuli. In addition, taking a multi-dimensional view of pain and different measures might be applied to assess pain of different dimensions (or even same dimensions)… will the results be consistent and why would results on different dimensions have to be consistent?

The studies retained in the analyses of this study have the following characteristics:

  • It contained a group of schizophrenia patients
  • The study contained a control group of healthy people
  • It was an experimental study where stimuli were given and pain was measured
  • The study was published between 1952 and 2007

The statistics

The reported mean and standard deviation from each study were used to calculate effect size estimate- Hedges' g, which also adjust for sample size, for the schizophrenia patients and the healthy control groups using D-STAT. In this analysis, positive effect size indicates diminished pain response in schizophrenia patients.

The authors also aggregated effect size estimates for each pain measure to generate a mean effect size estimate for each study, which, then, were pooled together to produce a composite effect size estimates. Additional mean effect size estimates were also calculated (see table).




In addition, this study did not find gender and age differences.

The conclusions

Results of this study provide supporting evidence for the notion that schizophrenia patients might have diminished pain responses when compared to health people.

Since analgesic effects were found both in patients medicated with antipsychotic drugs and those not taking medication, such finding casts doubts on the notion that analgesia is a mere artifacts of antipsychotic medications. In addition, some early report on analgesia in psychotic patients were actually published before the introduction of antipsychotic medications.

Since patients with schizophrenia have been found to have blunt response to more than pain (e.g., basic emotion), it is possible that the blunt response is not pain-specific and is more global.

The results found larger effect size when pain is induced using electric stimuli than using thermal stimuli. In other words, all pains are not equal in their effects on patients with schizophrenia.

The authors further provided a critic/recommendations on the short-comings of existing research:

  • Future research should take on a multi-dimensional view about pain and use multiple pain assessments to measure "pain."
  • More electrophysiological studies examining the spinal, autonomic and cortical components of pain are needed.
  • More studies needed to investigate the relationship between pain perception and schizophrenia.
  • More studies needed to examine the relationship between the endogenous pain modulation system in schizophrenia.

Friday, July 10, 2009

Pain insensitivity in schizophrenia: Trait or state marker? (Singh, Giles, & Nasrallah, 2006)

Singh, M. K., Giles, L. L., & Nasrallah, H. A. (2006). Pain insensitivity in schizophrenia: Trait or state marker? : Journal of Psychiatric Practice Vol 12(2) Mar 2006, 90-102.

This study aims to provide a description for the phenomena of pain insensitivity in schizophrenic patients. It also tries to identify whether pain insensitivity is a trait or a state. In addition, the authors also attempts to propose a "multi-factorial model" based on the analyses of this article. The literature reviewed includes case reports, population-based studies and case series as well as empirical data.

Case reports

All of the patients mentioned in this class of articles did not report the perception of pain. Due to such distorted pain perceptions, their conditions were either misdiagnosed and treatments were delayed, which resulted in the worsening of the morbidity and mortality.





Population-based studies and case series

Prevalence of pain insensitivity in patients with schizophrenia

This type of studies provides a percentage value concerning the lack of pain complaints in conditions where pain should be present. Although many studies emphasized the lower

prevalence of pain complaints, studies have also shown that pain reports are not absent in schizophrenic patients (e.g., Ballenger et al, 1977, and Torrey, 1979). I can attest to this since I have had really bad pains that were incorporated into my delusional system (e.g., thinking I was being attacked by people remotely) when the conditions were so bad that I actually was institutionalized. An absence of pain and decreased pain reaction were also reported in young children who were institutionalized. This type of research could be used as evidence for the trait theory instead of state theory. At the same time, there also exists research that fails to report the decreased sensitivity towards pain in schizophrenic patients. Varsamis and Adamson (1976), for instance, had concluded that only the subgroup of patients marked to be withdrawal failed to report pain. One thing should be noted is that these studies did not utilize comparable pain assessments.




Prevalence of schizophrenia in people with pain

For people with chronic pain and referred to psychiatric treatment, the diagnosis of schizophrenia is far less prevalent than other diagnosis such as anxiety disorder and depression disorder. Some of the studies cited in the article actually found no patients with chronic pain with the comorbidity of schizophrenia. On the other hand, there are also studies finding no evidence of pain insensitivity in schizophrenic patients although more studies are needed to replicate these results.





Empirical data

Currently, there are two methods in this line of studies: psychophysical method and signal detection theory. The psychophysical method involves having subjects reporting the intensity and unpleasantness of the pain signal using words, numbers, line length or handgrip (Gracely, 1984). The major drawbacks of this method is the lack of reliability (Fernandez & Turk, 1992) especially in patients with limited verbal ability.

The second and more recent mode of investigation is the method of signal detection, which attempts to differentiate between the sensory (i.e., sensory discrimination) and affective (i.e., the report that the sensory experiences are painful) perspectives of pain. In this paradigm, patients with schizophrenia are first subjected to thermal, electrical, pinprick, cold pressor and pressured pain. Thereafter, their ability to discriminate the stimuli and their attitudes towards the perceptions of the stimuli are measured. This is considered as the accepted method in measuring pain in psychiatric patients because this is the only method separating the assessment of pain sensory and affect. Yet, this method also has its drawbacks. While what is assumed to measure sensory discrimination might actually be measuring non-sensory process, there is no telling whether the response criteria selected by the researchers really represent what is intended to be measured. Essentially, these are issues concerning the validity of the assessments.

Among the cited literature, following are some of the key findings that catch my eye:

  • One study found that schizophrenic patients' reaction to electrical stimuli were "ambivalent" and "dissociated"; such response pattern is similar to that of people with "brain lesion."—No wonder I feel brain dead most of the times. 8-O In addition, this reminds me of the time when I was receiving TENS (transcutaneous electrical nerve stimulation). It did not take me too much time before I hit the top intensity of the signal strength. Moreover, in my much younger years, I went for TENS kind of sessions for "weight loss" purposes. I also hit the top intensity in no time and it was even before the onset of my psychotic symptoms, which seems to speak for the trait theory concerning pain perception. The fact that I seemed to have higher tolerance or higher threshold towards electrical shocks before the onset of my psychosis seem to correspond with the line of research examining the pain sensitivity in health students with family psychiatric history.
  • Patients with paranoia were less sensitive to pain when comparing patients with other types of schizophrenia.—Since I am so very well endowed with paranoia (whether you believe it or not), am I not supposed to have less sensitivity to pain? In this case, how could I be with chronic pain? On a second thought, what is the possibility that I am actually enduring more pain than I know? 8-O
  • It is found that patients with chronic schizophrenia are less sensitive to electrical shocks and thermal pain when comparing to those with acute schizophrenia. Am I chronic or not?
  • Researchers have also tried to figure out the molecular basis for the presumed insensitivity to pain in schizophrenic patients. It has been suggested that there might be abnormal level of serotonin, dopamine, prostaglandins and endorphins in the brain for schizophrenics. Unfortunately, current literature yield conflicting results.
  • One study found that schizophrenic patients had worsening ability in sensory discrimination but did not differ from the control group in the response criteria required for the reports of pain. Higher response criteria were found to be more correlated with higher degree of flattening affect. The authors thus concluded that the observed insensitivity to pain might have more to do with affective abnormality.

It has been suggested, though, that earlier literature were loaded with methodological flaws including issues concerning sample size, diagnostic reliability and the use of control groups. Despite of the presumed methodological improvement in recent studies, there is still a lack of solid literature supporting the "hypoalgesia" in schizophrenic populations.



The author of this review then provided their thoughts about directions for future research etc.

The most important conclusion they had, at least for me, would be that… pain insensitivity seems to be a trait rather than a state. In addition, pain is a multi-dimensional phenomena or, in the authors' words, there need to be a multi-factorial integrated approach to pain perception.

Thursday, July 9, 2009

Schizophrenia and pain reactivity (Bonnot & Tordjman, 2008)

Bonnot, O., & Tordjman, S. (2008). Schizophrenia and pain reactivity. La Presse Médicale, 37(11), 1561-1568.


Since this article is actually in French and I don't really read French, following are some of the simple notes I could take about this article.


This is one of the review articles investigating the relationship between psychosis and pain perception. The authors used Medline to search from relevant literature published between the year of 1950 and 2007 and identified 50 articles for further analyses. Among these articles, 5 were previous review papers, 21 were clinical and epidemiological studies and 9 were case reports. One important conclusion of this review is that, although the patients with schizophrenia might exhibit a decreased level of Behavioral Reactivitiy to Pain (BRP), there doesn't seem to be sufficient evidence to prove the notion of insensitivity or anagelsia, which is a neurologic or pharmacologic state within which painful stimuli are perceived but not interpreted as pain.

The definition of pain according to l'Association internationale pour l'étude de la douleur (IASP), French version: « La douleur est une expérience sensorielle et émotionnelle désagréable associée à un dommage tissulaire présent ou potentiel ».

In any case, this would be a good source of references, to.

Monday, July 6, 2009

An appreciation of yoga-therapy in the treatment of schizophrenia. (Machleidt & Ziegenbein, 2008) Abstract

Just found this interesting article speaking of the use of Yoga (or perhpas acupuncture) as a treatment for schizophrenia. Personally, I would stay on my meds until a whole body of literature proves it true.... 8-O

Since I don't have the time to go into the real articles, following is the abstract for the paper..

An appreciation of yoga-therapy in the treatment of schizophrenia. (Machleidt & Ziegenbein, 2008)

Comments on an article by Duraiswamy and colleagues (see record 2007-11830-010). Arun Jha comments in the Letter above on the study by Duraiswamy and colleagues published in the Acta Psychiatrica Scandinavica September issue 2007 reporting unexpectedly positive results. In the Indian cultural environment patients suffering from schizophrenia can possibly be more easily motivated to undergo a yoga therapy than they may be in Europe or South America, as Indian patients are well versed culturally in this method. In Central Europe, in Germany for example, autogenic training has been successfully recommended to patients with schizophrenia for stress reduction. Active physical measures such as running, swimming and cycling, for example, have also been increasingly advocated. The transcultural superiority of yoga therapy over all other CAM may be confirmed some day, as has been the case with acupuncture treatment for pain, but at the moment this open question necessitates a great deal of systematic research across cultural boundaries. It would not be found unwelcome should yoga therapy for schizophrenics come to be accorded the same world wide recognition that acupuncture enjoys for the treatment of pain.

Psychological Causes of Schizophrenia (MacPherson, 2009)

MacPherson, M. (2009). Psychological Causes of Schizophrenia. Schizophrenia Bulletin, 35(2), 284-286.


As I try to look for articles concerning the assessment tools used to evaluate pain in patients with psychosis, I came across this article based on the first person account of a schizophrenic patient in the academic journal titled "Schizophrenia Bulletin."

In this article, the author shares with us the lessons he or she learned for the past 32 years. Through his accounts, the author provides us with a positive example about how patients actually could lead an independent and eventful life through consciously and constantly working on developing coping skills in general as well as in managing additional demands imposed by being a schizophrenic.

It was stated in this article: "In the discharge planning process, I made a conscious decision to return to work." In addition, "One needs to grow in life's experience and cognitive functioning. The help and support of a specialized vocational program…" I cannot agree more.

Ever since the onset of my psychosis about 10 years ago, my psychiatrist and I have been working on keeping me "vocationally functional" if possible. One thing people might not understand is that, the impacts of all health conditions are generally two-folded. One the one hand, you deal with the symptoms associated with the disorders; on the other hand, you also have to deal with the side effects of the treatment such as medication. Interestingly, over two years ago, I would have told you that the above is applicable to mental health condition. It was not until I became a handicapped in chronic pain did I realized that such is applicable to all health conditions.

I have been very lucky in this perspective because my employers have been very accommodating and I have always been able to return or remain at work even when I just got discharged from the psychiatric ward… sustaining high level of psychotic symptoms such as hallucination and delusions as well as having limited cognitive capacity due to both the symptoms and the side effects of the high-dose medications.

However, I do not quite agree with the author concerning the role of parents in the development or maintenance of schizophrenia. Personally, this sounds a bit too much like the classical attachment theory to me… What I believe, instead, is that the development and maintenance of our symptoms are very much dependent on our modus operandi in dealing with all relationships including those with our parents.

I also do not really agree with the statement that "Paranoia and paranoid states and reactions are simply child-like sates similar to a child's temper tantrum." While it is true that some parts of our delusions and hallucinations might have a more childish presence, others do take on a more adult presence. At the same time, some part of the interactions in our delusional worlds might simulate the characteristics of adult-child relationship. However, I don't feel that "a child's temper tantrum could sufficiently explain all symptoms.

I do agree with the notion that "delusions are also based in fear and paranoia and represent a false belief but have a basis in reality." I would also add "guilt" as well. Such opinion is based on my personal experiences. Coincidentally, I have come to this conclusion myself earlier this year or late last year after realizing the "horror" components of my visions, hallucinations and delusions. I have been since pondering about where to start from to resolve issues in me which might have contributed to the manifestation of my psychotic symptoms. Unfortunately, I have yet to find out how to go about doing it.

One thing I cannot stress enough is that… the psychotic symptoms we experience are or could be idiosyncratic to us. For instance, my immigration status to remain in the United States has been an issue for me for a long time, and, the immigration status has also been a major theme in my psychotic symptom. Apparently, such might not be one of the themes for those who are American or who are not aliens wishing to stay in the US.

Most importantly, I am only a fledgling psychotic in that I have only spent about 10 years of experiences dealing with psychotic symptoms etc. There is a high possibility that, as the time goes on and as the learning progress, I might eventually come to fully appreciate what the author tries to convey.

In addition, I am mostly appreciative to both the author and the editors of the journal Schizophrenia Bulletin in the efforts they put forth to publish a case study base the personal account of a Schizophrenic patient. So has it been one of my most deep-seated bias… at point, patients might have something to offer…. at least for the fellow patients...

This writing is cross-posted in the Ratology Reloaded blog.



Thursday, July 2, 2009

Evaluation of the pain patient (Leo, 2007)


I think this is a very nice diagram showing the three major components of pain history (Leo, 2007).

Leo, R. J. (2007). Evaluation of the pain patient. In Clinical manual of pain management in psychiatry (pp. 35-62). Washington DC: American Psychiatric Publishing, Inc.

Monday, June 22, 2009

Sensory pathways of pain and acute versus chronic pain (Leo, 2007)

Leo, R. J. (2007). Sensory pathways of pain and acute versus chronic pain. In Clinical manual of pain management in psychiatry (pp. 11-33). Washington DC: American Psychiatric Publishing, Inc


It has been suggested that pain is a multidimensional concept, incorporating the biological, psychological and social dimensions.



Pain-relaying pathways and mechanisms


Conventionally, the pain relay pathway is considered to involve three sets of neurons:


First order neurons: noxious information is transmitted from the peripheral to the spinal cord particularly ending in dorsal horns.



Second order neurons: Information in the spinal cord is sent to thalamus. At this level, fibers go all the way up to the brain stem and ending in the countralateral thalamus while a small number of them go into the ipsilateral thalamus. Within the spinothalamic system, the pathways diverge into two pain pathways: the paleospinothalamic (affective-motivational) pathway and the neospinothalamic (sensory discrimination) pathway.



Third order neurons: these neurons reside in the thalamus and beyond.



  • The involvement of somatosensory cortex (parietal lobe) makes possible the discriminative aspects of pain, localization of the pain and motor-coordination response to pain.
  • Information from the paleospinothalamic pathway lands in reticular formation, media thalamus, hypothalamus and prefrontal cortex—resulting in painful sensory information in the the affect, attention, cognition and memory domains.
  • Stress reactions involve hypothalamic-pituitary axis and autonomic nervous system.
  • The affective quality and pain experiences involve information landing in both cortices.
  • The experiences of pain are shaped by the affective influences (e.g., anger, alarm, surprise) due to the involvement of limbic system; mood state, for instance, can affect the cognitive strategies one takes to deal with pain.
  • The cognitive processing (e.g., identify, evaluation, decision making) of pain stimuli involves the frontal lobe.

Pain-Modulating Process within the Nervous system


  • Neurochemicals in pain processing


  • Endogenous Opiates: β-endorphin, enkephalins and dynorphins
  • Pain-reducing pathways:

    • Four regions of the CNS functions to reduce the sensation of pain or to make the individual be aware of the pain:
      • the cortex and the limbic structure
      • the midbrain
      • the rostral ventromedial medulla
      • the spinal dorsal horn (and yes, I thought I might have dorsal horn reorganization)
    • If my understanding is correct, neurochemicals are required for these regions to modulate pain perception such as the following

  • Opiate receptors and descending inhibitions of pain pathways: 4 classes of opiate receptors have been recognized to date.
  • The rise of chronic pain
    • Essentially, one thing leads to the other… towards the end, the more dysfunctional your pathways become, the harder it is to break the hardwired habit of pain.


Hansen's disease: people with no pain….


Acute vs. Chronic pain




Categories of chronic pain: Chronic pain could be categorized as nociceptive, neuropathic or psychogenic.


The impact of pain on the quality of life


Friday, June 19, 2009

Introduction: Clinical Manual of pain management in psychiatry (Leo, 2007)

Leo, R. J. (2007). Introduction Clinical Manual of pain management in psychiatry (pp. 1-10). Washington, DC: American Psychiatric Publishing, Inc.

Following is the ideas I find of special interest to me on a day when my head is aching, body hurts and ears can't stand sounds if not noises... 8-O lol sigh

In this chapter, the author provided an analysis about the problems associated with the tradition model about pain. Essentially, underlying the traditional model is a dualist view about pain: pain is either organic or psychogenic. When patients do not respond to treatment and when the reported pain experiences seem to be disproportional to the physical evidence, the belief that the pain is psychological emerges. However, for many patients, the dualistic notion seems inadequate (Boisservain & McCAIN, 1991; Lynch 1992).

It was also suggested that, driven by the frustration that they could not pin point a cause for patients' pain or the lack of improvement in patients' condition, some doctors might start to discount patients' complaint and consider patients' condition as psychic in nature rather than somatic.

So what kind of impact does it have when pain patients are referred to a psychiatrist and, perhaps, like me, whenever I complaint about my condition, that doctor of mine would tell me to go back and talk to my psychiatrist? Apparently, patients might feel that the doctor has given them up, their condition is no longer taken seriously, or, they are blamed for their lack of responsiveness to treatments because it is all in their head (Gamsa 1994). (Page 4-5)

What I find most interesting about the above is interaction among "patient condition," doctor's belief system, and, patients' belief system.

Wednesday, June 17, 2009

Chapter 14: Disability Evaluation in Painful Conditions (Robinson, 2001)

Robinson, J. P. (2001). Disability Evaluation in Painful Conditions. In D. C. Turk & R. Melzack (Eds.), Handbook of Pain Assessment. New York: The Guilford Press.

  1. Disability: "Disability refers to an inability to carry out necessary tasks in any important domain of life because of a medical condition.
  2. Impairment: impairment is "a deviation from normal in a body part or organ system and its functioning."

Issues addressed in disability evaluation

  1. Diagnosis
  2. Causation
  3. Maximal medical improvement
  4. Impairment rating
  5. Ability to work







Problems associated with the evaluation of disability in painful condition:

  1. How do you measure impairment publically and objectively?
  2. How well does the mechanical failure model of impairment explain activity limitations?
  3. How do you resolve the dilemma between mechanical failure model and patients' appraisal about their condition?

Practical strategies for disability evaluation


The author is a physician and also serves as an IME. The information provided in this section is based on his own experiences since data on the reliability of disability evaluations are scanty (Clark et al., 1988; Clark & Halderman, 1993) and there is also a lack of validity for the evaluations. The author also cautioned practitioners to not fall into believing their judgments are absolutely valid while the act of making an evaluation actually is based on a whole bunch of biases.

The ethics of disability evaluation

The practitioners need to ask themselves the following questions:
What are your attitudes towards disability? Do you empathize with these people or to you think they are con artists?


  1. In addition, research have found that regardless the level of medical condition, it is better to keep people at work for when people are separated from their workplace, they and their families are at a higher risk of suffering from outcomes such as depression, anxiety, substance abuse, social isolation, family dissolution… etc (Atkinson, Liem, & Liem, 1986; Hammarstrom & Janlert, 1997; Kaplan et al., 1987; Mrazek & Haggerty, 1994; Rahmqvist & Carstensen, 1998).
  2. In addition, when one is out of work, they also suffer severe economic loss… tell me about it…
  3. Studies have also shown that people often develop "dysfunctional beliefs and attitudes" as time goes by as they adapt the role of someone disabled. For instance, people who were more upbeat about their condition soon after the injuries have been found to be more resistant to rehabilitation efforts. This is what they call as the disability syndrome, which is a concept that is really hard to validate (Krause & Ragland, 1994; Robinson et al; 1997).

How do you know about the disability agencies with which you interact? Please be knowledgeable about the policy of the disability agencies.

How do you integrate disability evaluation into an overall strategy of disability management?

How much importance do you give to the subjective appraisals that patients make regarding their ability to work? Essentially, believe them and not believe them…. People with chronic pain often have distorted views of their capabilities and these views are modifiable (Alaranta et al., 1994; Estlander et al., 1991; Jensen, Turner, & Romano, 1994; Lipchik, Milles, & Covington, 1993)--- I will have to read up this line of research.. Didn't they read the article….

Mechanics

In this section, the author provides an overview about how Disability evaluations could be conducted systematically.




In this chapter, they also provided a sample list of risk factors for prolonged disability issued by the Washington State Department of Labor and Industries (1999).



A sample list of "characteristics Associated with High Patient Credibility:



Psychogenic pain: every time I read about psychogenic pain, I feel like to scream and I know it is my bias…

People who report chronic pain and restriction in their activities sometimes have no biomedical abnormality to support their complaint.

  1. Studies have found high level of psychopathology and psychological distress in patients with chronic pain… (Hey, remember, correlation is no causation.)


After finish reading this, if you ask me why anyone who is non-medical professional shall learn about anything written in this chapter, I would say that... at least now you have a better idea how the system work... for instance, how do we represent ourselves as a patient with high credibility... Too late for me... 8-O lol

In addition, although this chapter doesn't really tell me much about the psychometric properties of anything specific... At least, one thing I learned is that there ain't too much of them evidence about the validity if not reliability of them disability evaluations.... 8-O lol sigh


Tuesday, June 16, 2009

Multidimensional scaling of painful and innocuous electrocutaneous stimuli: reliability and individual differences. (Janal, Clark, & Carroll, 1991)

Janal, M. N., Clark, W. C., & Carroll, J. D. (1991). Multidimensional scaling of painful and innocuous electrocutaneous stimuli: reliability and individual differences. Perception & Psychophysics, 50(2), 108-116.

Abstract

Multidimensional scaling was used to explore whether a single intensity dimension underlies the perception of both nonpainful and painful electrical stimuli, or whether separate dimensions are required. For the scaling (INDSCAL) procedure, 41 healthy volunteers judged the similarity between all pairs of 16 intensities, which ranged from imperceptible levels to pain tolerance. For the property mapping (PREFMAP) analysis, they rated each intensity on each of 16 property scales. INDSCAL revealed four dimensions that showed high levels of both test-retest and split-half reliability. The first dimension scaled stimuli from the lowest intensity to the pain threshold. This dimension was related to property scales of sensation, affect, and arousal, but not pain, suggesting a sensory magnitude dimension. The second dimension ordered the stimuli from mildly to severely painful and was related to the painful property scale, suggesting a pain intensity dimension. Third and fourth dimensions, which refined the scaling of nonpainful stimuli, were also found. Variability in the subjects' use of the painful and nonpainful dimensions was related to their choice of stimulus descriptors. Like clinical pain, laboratory pain requires multidimensional assessment.

This study involves 41 male participants who were given electric shocks and responded to psychological tests such as the McGill Pain Questionnaire (MPQ) items.

To begin with, the Ascending method of limits (AML) was applied within which subjects were requested to respond to electric stimuli with increasing intensity with 4 V difference between steps using the following intensity scale: no sensation, slight sensation, moderate sensation, strong sensation, uncomfortable, faint pain, moderate pain and severe pain. The participants were allowed to stop the increase of electric stimuli when they consider the pain to be intolerable. The information gather through this stage is used to label the plots of the INNDSCAL results.

Participants were asked to rate the similarity between 120 pairs of stimuli with one extreme of the rating scale as "not similar" and the other end as "extremely similar". This part of the data was analyzed using the INDSCAL model.

Participants were also asked to rate eight of the stimuli intensities using 16 property scales and this part of data were analyzed using PREFMAP.

In addition, the authors ran some regression analyses to relate subject weights on different dimension to MPQ descriptors.

The authors also collected additional data from 25 of the 41 participants on a different day to reconfirm the 4 dimensional structure obtained through the INDSCAL analyses. In addition to finding similarity in the dimensional structure, high correlations of the stimuli coordinates between days were found for each of the dimensions.

In addition, the authors also calculated split-half and test-retest reliability.

Apparently, previous work had indicated the existence of independent painful and nopainful intensity dimensions. Results of this study reconfirm the existence of those two dimension and two additional nonpain dimensions.

One thing strange about this paper is that—while this is a lab study, at the very last sentence, the authors all of a sudden claimed that the model is also well suited to the study of clinical pain for no good reason… I am not quite sure whether there is some part of the writing that I am missing since this statement seemed to have come out from no where and, of course, it might have something to do with my over-drugged kind of state of mind... oops... 8-O lol sigh

This study is very much similar to the one I finished yesterday also about lab-studies on pain. Both studies speaks of the multidimensional nature of pain experiences. The paper I finished yesterday is actually a sequel of this one...

Monday, June 15, 2009

How separate are the sensory, emotional, and motivational dimensions of pain? A multidimensional scaling analysis. (Clark, Janal, Hoben, & Carroll, 2001)

Clark, W. C., Janal, M. N., Hoben, E. K., & Carroll, J. D. (2001). How separate are the sensory, emotional, and motivational dimensions of pain? A multidimensional scaling analysis. Somatosensory and motor research, 18(1), 31-39.

Abstract

To map the structure of the space generated by verbal descriptors of pain, 41 male college students made pairwise similarity judgments to all possible pairings of 16 words that describe experiences commonly associated with noxious electrical stimulation. Individual Differences Scaling (INDSCAL) yielded four dimensions (D) in the group stimulus space: D-1, Intense to Moderate Experiences, contained two attributes: Strong Sensations and Strong Emotions; D-2, Moderate to Weak Experiences, exhibited two attributes: Moderate Sensations and Moderate Emotions; D-3, Motivational State, possessed two attributes: Pain and Arousal Level; D-4, Sensory Qualities, exhibited two attributes: Pain and Somatosensory Qualities. The interpretation of the dimensions was supported by Preference Mapping (PREFMAP) and by correlations between subject weights and (a) psychological tests and (b) responses to noxious electrical stimuli. Conclusion: semantically, the pain attribute or component of the total pain-suffering experience pervades emotional, motivational and somatosensory attributes. Pain is not an independent dimension. This means that a score on a pain rating scale is not a pure measure of the patient's pain, but is heavily influenced in unknown ways by the patient's emotional and motivational state.

There is been a lot of controversies concerning the dimensionality of pain. For instance, the affect theory of Marshall considers pains as merely an emotional arousal (Schneider and Karoly, 1983). On the other hand, Melzack and Casey consider pain as three-dimensional phenomena involving dimensions such as: Sensory-discriminative, motivational-affective and cognitive-evaluative.


When considering the multidimensionality of pain, another question to be addressed is whether the dimensions are independent of each other. After a review of the topic, Fernandez and Turk (1992) concluded that it is not necessary for the dimensions to be independent of each other.

Studies employing MDS or cluster analyses to investigate the dimensionality of pain have identified intensity, affect, motivation and somatosensory as the common components of pain.

  • INDSCAL: The underlying assumption is that the group members shares the dimensions in the stimulus space and each individual have different weights for the different dimensions.
  • PREFMAP: Using semantic anchors to assist the interpretations of the stimulus space.

The goals of the study

  1. Individual Differences Scaling Model (INDSCAL) is used to assess the number of dimensions while results of PREFMAP is used to confirm the results. Validity was determined using split group comparison and test-retest reliability was also assessed.
  2. Assess the relationship among the dimensions.

Methods


Subjects: no women used because the use of analgesics and ansiolytics in a later study. Test-retest reliability: 1 week apart.

Procedure

  • INDSCAL:
    • 16 descriptors
    • Pair them all
    • Similarity judgement on a 10 point scale
  • PREFMAP
    • Subjects rated the similarity of 16 descriptions to the 16 scales above based on a 10 point scale
  • The brief Symptom Inventory (BSI)
  • Participants' Attitude Toward the Study (PAT): PAT has been found to reflect the euphoric state related to the increase of endorphin after running and dysphoria related to naloxone.
  • Visual analogue scale (VAS)
  • Sensory Decision Theory (SDT): Participants were given electric shock and related the stimuli on a 9 point category scale ranging from No Sensation to Severe Pain.
  • MPQ: Sensory, Affective and Evaluative scales were used.

Results

Results of INDSCAL analysis yielded a four-dimension structure. The indentified dimensions are Intense to Moderate Experiences, Moderate to Weak Experiences, Motivational State and Sensory Qualities.







The PREFMAP analyses confirmed the interpretation of the dimensions. Split-group analyses confirmed the validity of the results.

Test-retest reliability provides evidence for the consistency of the results. Correlations were calculated to understand the relationship between group membership and other tests of psychological traits.


This is an experimental study which gave male participants electric shocks to simulate pain. In other words, the participants weren't patients with real pain. This study employed INDSCAL to identify the dimensionality of pain. The correlations between the personal weight and a) psychological tests and b) responses to the electric shocks were used to reconfirmation of INDSCAL results. The most important finding of this study is that it supports the view of Fernandez and Turk (1992) that pain could be considered a multi-dimensional construct with the dimensions not necessarily independent of each other.

Wednesday, June 10, 2009

Medically incongruent chronic back pain: physical limitations, suffering, and ineffective coping (Reesor & Craig, 1988)

Reesor, K. A., & Craig, K. D. (1988). Medically incongruent chronic back pain: physical limitations, suffering, and ineffective coping. Pain, 32(1), 35-45.


Abstract

Chronic low back pain (CLBP) patients with pain and symptomatology incongruent with physical pathology have been found to have a poorer outcome to medical treatment and rehabilitation, and to use health care resources excessively. To examine possible psychological and behavioral bases for this pattern, this investigation contrasted 40 CLBP patients who displayed non-organic physical signs, inappropriate symptoms, and/or anatomically incongruent pain drawings with 40 'control' CLBP patients without incongruent pain criteria. Multivariate analyses revealed that the incongruent CLBP group reported greater pain intensity and depression, received higher observer ratings of pain, displayed more ambulatory/postural pain behavior, and reported more dysfunctional cognitions during pain. Incongruent CLBP patients also were found to have greater physical impairment and disability. When group differences on physical impairment/disability were controlled statistically, all the afore-mentioned differences disappeared, with one exception. Incongruent CLBP patients still displayed more maladaptive and dysfunctional cognitions. These findings indicate that incongruent CLBP patients may be conceptualized as ineffective and overwhelmed in their attempts to cope and as more physically disabled as a result of their pain. The role of cognitive factors, reasons for failure of physically based interventions, and implications for patient management are discussed.

Yesterday we spoke of idiopathic pain… today we encounter a new term… Incongruent pain…

Incongruent pain: the behavioral pattern of the pain sufferers inconsistent with expectations established through findings of medical examinations.

Incongruent pain in CLBP is defined as:

  • The observed behaviors during orthopedic examination do not match with the anatomical principle (non-organic sigh)
  • Reported symptom severity is exaggerated and does not correspond to either the anatomy or the disease course (non-organic symptoms).
  • Exaggerated and non-anatomical drawings patients produce to represent the areas of pain

I especially love the word "exaggeration".... Even if them pains were associated with hallucinations and delusions... Does it mean they don't hurt? 8-O lol sigh

People identified as having incongruent pain seem to be less responsive to treatments.

This study used 40 men and 40 women with the complaints of persistent lower back pain. The patients have been given numerous assessments to evaluate their state of being. Fore information about some of the instruments could be find here.

  • The sensory, affective and evaluate pain components of the McGill Pain Questionnaire (MPQ)
  • The use of the Descriptor Differential Scales about pain sensation and pain unpleasantness
  • Pain drawing was coded using Ransford et al's scoring system to quantify the non-anatomical or exaggeration in patients drawing of pain area.
  • The Inappropriate Symptom Scale
  • Coping Strategy Questionnaire (CSQ) consisted of 7 scales related to pain coping activity and 2 scale concerning coping effectiveness.
  • Beck Depression Inventory (BDI)
  • Oswestry Low Back Pain Disability Questionnaire includes 10 scales addressing problems concerning pain-related disability
  • Non-organic signs: Signs of pain reports which deviates from anatomical principles.
  • Physical impairment contains a set of indices related to organic impairment and physical limitations
  • Behavior assessment procedure: Patients were videotaped and pain behaviors are coded.
  • Pain induction assessment: Pain was induced using a pressure pain apparatus. Immediate after the pain induction trial, the patients were given a semi-structured interview with responses coded for the following categories of cognitive activities: 1. Use coping strategies such as dissociation, relaxation, imagery and non imagery distraction; 2) expression for sense of control; and, 3) catastrophizing.
  • Determination on whether a patients fall into the medically incongruent pain group is based on the following criteria: 1. The presence of 2 or more non-organic physical sighs, 2) the presence of 3 of more inappropriate symptoms; and 3) the presence of 3 or more inappropriate drawing.

Something interesting about the analyses concerning pain and depression measure is that the authors went through great length in describing and interpreting the significance of the results while, in reality, the results of MANOVA did not even reach the significant level or was on "marginally significant."


The following are my favorite paragraphs from the paper…. Apparently, this must have been how the doctors have had in their eyes about me and my condition… Following is my response to the writing by assuming myself as a patient with incongruent pain…


"Chronic pain patients whose illness behavior and symptom report were anatomically inconsistent, vague, poorly localized, and exaggerated or disproportionate to their back pain condition. "—this is why that neurologist thought I might have conversion disorder…


"The absence of cognitions reflecting perceived control or self-efficacy during exposure to a pain stimulus discriminated incongruent pain patient from control patient groups."—Damn… thought I was working hard trying to reflect all that time… How else should I have thought and acted.... 8-O 8-X


"Incongruent chronic pain patients also appeared to engage in more maladaptive, dysfunctional, and anxiety-laden cognitions (i.e., catastrophizing) concerning their pain."--- 8-O It did feel catastrophizing though at times… the pain, the spasm, the inability to recover… shall you be in my shoes please check how well you would fair… 8-O


Sort of like what the authors commented later…

"the degree of subjective and expressed pain may be more a function of the level to which mobility and behavior are compromised because of the pain." Finally something that sounds more like music to my ears... speaking of internal biase.... 8-O lol


"Thus, the subjective pain experience tended to be perceived and judged to be more disturbing, distressing, and debilitating by incongruent pain patients in comparison to control patients." Poor patients with incongruent pain… why can't you simply be like them control group patients?


What do incongruent patients have the tendency to not respond to treatment? One theory the authors came up with was that these patients might have more severe physical impairment and disability; as a result, they need more care than the non-incongruent patients. Another theory is that they need to be taught more adaptive coping cognitive style… (whatever that means.)


Another point I really appreciate from this paper…

"Clinicians may be more likely to conclude incorrectly that these patients have minimal organic basis for pain and that they are malingering. Health care providers may even inadvertently prompt more exaggerated pain and distress on the part of the patient, since a more 'dramatic' presentation may be needed to convince the clinician of the 'reality' of the pain problem. in actuality, incongruent pain patients, in this investigation. appeared to have had a more severe organic pain problem. It is important to note in this regard that incongruent indicators may not necessarily be associated with psychopathology or efforts to receive financial compensation. "

Man, doesn't this paragraph remind me of the time when the doctor I was seeing telling me to talk to my psychiatrist every time I made a complaint or asked the question, "Why am I so in pain?" And, how they refused to believe that I had pain in the neck because the only radiological evidence was the herniation in the lumbar area... because I only had MRI done in the lumbar area... Without the MRI evidence, they wouldn't believe I have problems in the cervical area; at the same time, the doctor refused to prescribe an MRI scan to the cervical spine.... and later, thoracic... And other similar scenarios… again and again… to the extent that I have to wonder to myself... Maybe what they have been insinuating is right.... What it be like if it really is all in my head? And, on a second thought, no wonder the associated experiences are catastrophising since, at some point, it starts to appear to you that, including you yourself, no one really seems to believe in the validity of your condition... 8-O lol sigh

Of course, as the authors have pointed out… never forget that correlations are not causations… All depends on the interpretations…

Tuesday, June 9, 2009

In Pain and Of Mental

I have a dream... one day, I am going to find a world of literature showing chronic pain could lead to the worsening of psychotic symptoms with the underlying model in human all figured out...

Yet, to date, the only thing I could find is a case study reporting how a lady who initially reported tick bites eventually had a full-blown psychotic episode... Good luck to her and wish her a full recovery and no more relapses...

When scanning through the Chapter Assessment of Psychiatric Disorder in the Handbook for Pain Assessment, the authors did a, presumably, comprehensive review of pain-related psychiatric disorders including Depressive Disorder, Anxiety Disorders, Somatiform Disorders as well as Substance Abuse and Dependence. Yet, there is not much mentioning about psychosis.

In line with the structure of the above chapter, when searching for literature concerning pain and psychosis, it appears to me that the consensus the experts has achieved so far is that people with psychosis are insensitive to pain and have high pain threshold..... 8-O

I do have to mention that there do exist literature looking into the the pain perceptions of pain as part of the delusions and hallucinations.

Granted, much has been written about how depression often follows the onset of chronic pain and how patients with depression have the propensity to report worse pain level in various dimensions (as long as you don't ask me how they come up with the baseline since I have not had the chance yet to go much into the original research papers).

Of course, despite of my idiopathic pain, one thing I am trying to accomplish is to understand how my psychiatric condition, namely, although Schizo (psychotic) also affective (neurotic), might have had an impact on the unfolding of my recovery process from my spinal injuries and chronic pain, and, how pain might have had an impact on my psychiatric condition, be it Schizo (psychotic) or affective (neurotic).

As you could tell through them purple texts, it appears that more studies have done and theories have been formed concerning the association between depressive symptoms and pain.

Maybe it has something to do with the garbage-can nature of da Schizo syndrome, there seems to be far less research done in examining psychotics in excruciating pain.

This leads me to wonder...

How does my being both psychotic and neurotic, or, both the propensity for insensitivity and sensitivity to pain, have an impact on my pain experiences? Is there an additive effect when they simply cancel each other out or might there be an interaction effect although I am not quite sure how they might interact? Unless, it is simply choosing the more miserable outcome effect I am pondering about and speaking of.... 8-O lol sigh

And, perhaps, the specific topic I have in mind concerning pain assessment would be around the alley of the assessment of pain for people with some kind of mental health condition(s).... with the pain, perhaps, neuropathic?

(This writing is cross-posted in my Ratology Reloaded Blog)

Synopsis: Workshop on Idiopathic Low-Back Pain (White & Gordon, 1982)

White, A. A. I., & Gordon, S. L. (1982). Synopsis: Workshop on Idiopathic Low-Back Pain. Spine, 7(2), 141-149.


Following are some part of the writing that I find relevant to my interest….

Existing research has only found a moderate correlation between structural abnormality and the symptomatology. Many people with structural abnormalities such as disc degeneration have no complaints while others who complaints might not have apparent structural abnormality based on radiologic evidences.

It was suggested that subtle abnormalities might have developed before the body eventually, due to additional factors, gave way to the state of pain.


By the way, in case you wonder what idiopathic pain means... it simply means... pain without a cause... and are there ever pains with good causes? 8-O lol sigh

Painful Hallucinations and Somatic Delusions in a Patient With the Possible Diagnosis of Neuroborreliosis (Bar, Jochum, Hager, Meissner, & Sauer, 2005)


Bar, K.-J., Jochum, T., Hager, F., Meissner, W., & Sauer, H. (2005). Painful Hallucinations and Somatic Delusions in a Patient With the Possible Diagnosis of Neuroborreliosis. The Clinical Journal of Pain, 21(4), 362-363.


This is the first study I have encountered concerning chronic pain and psychosis. This is a case study about a 61-year-old lady who sustained a severe pain syndrome for 2 years after bitten by ticks and treated for neuroborreliosis, a tick-borne infection of the nervous system. At the beginning, depressive symptoms including suicidal ideology and hypochondria were the dominant psychiatric symptoms although she also reported delusional ideology thinking her gastrointestinal tract was no longer working. Her symptoms improved substantially after she was treated with antidepressant and neuroleptic medication. However, 6 months after, the patient went into a relapse of psychotic episode where psychotic symptoms such as referential ideology and delusions of persecution were reported.


Essentially, the key point of this study is that, the doctors were not sure whether the psychosis was the primary or secondary condition. 8-O lol sigh

Monday, June 8, 2009

tardive dyskinesia and Vitamins

Found this article published in the American Journal of Psychiatry online.

The authors conducted a study to examine the effects of Vitamin B-6 in treating schizophrenia patients with tardive dyskinesia. The patients were randomly assigned to either the experimental group, who receive Vitamin B-6, or the control group, who receives the placebo.

The symptom severity was measured using Extrapyramidal Symptom Rating Scale. Results seems to suggest the beneficial effect of Vitamin B-6 at the dosage of 300 mg per day in treating the tardive dyskinesia conditions. It was suggested that the observed effects might have something to do with the antioxidant and free radical scavenger activities of vitamin B6 although the authors aren't not quite sure how it works exactly....

In case you wonder, many free radicals have been found to be associated with the development of psychopathologic symptoms and movement disorders. I guess it is the free radical scavenger activities that ate up them free radicals runnin around in our systems. In addition, I can't quite tell you whether there were other studies replicating similar results since I haven't gotten the chance to do more research on the topic...

In addition, somewhere out there I read that that Vitamine E might also be helpful in treatment tardive dyskinesia although I haven't had the chance to review the original articles yet....

The moral of the lesson... gotta make sure I take my vitamin Bs and E from now on.... whether the theory holds true or not in my scenario...

In addition, the following page provides a list of food high high on Vitamin E.... and Vitaim B...

So... after I read about them research studies, I took a trip down to buy me some Almonds since it is on discount at Rite Aid this week... Almonds are supposed to be one of the greatest source for vitamin E... secon to Wheat Germ only...

(This writing is cross-posted in my Ratology Reloaded Blog)

Self-Report Scales and Procedures for Assessing Pain in Adults (Jensen & Karoly, 2001)

Jensen, M. P., & Karoly, P. (2001). Self-Report Scales and Procedures for Assessing Pain in Adults. In D. C. Turk & R. Melzack (Eds.), Handbook of Pain Assessment (2 ed.). New York: The Guilford Press.


Self-Report Scales and Procedures for Assessing Pain in Adults (Jensen & Karoly, 2001)
In this chapter, the authors adopted the pain context model within which pain is considered as a latent construct, similar to depression or anxiety that cannot be observed directly and can only be inferred. At the same time, when it comes to the measurement of latent constructs, all too often, even the best measures or indicators might not be closely related. It is because the components of the same construct might not always occur synchronously or in the same configuration.


For instance, some people might report pain but not manifest non-verbal pain behavior; other people might manifest non-verbal pain behavior but do not report pain; still others might show non-verbal pain behavior and report pain at the same time.


Due to the multidimensional nature of pain, we have to identify the relevant dimensions before we could proceed with its measurement. Despite the discrepancies among the different measures available in the market, four dimensions are currently assessed in all patients including the intensity (e.g., 7 on a 10 point scale), affect (e.g., distress), quality (e.g., dull, sharp) and location (e.g., cervical, lumbar, finger) of pain. Among these four dimensions, pain affect is possibly more complex than the rest. It is because pain affect is a mental state triggered by the individual appraisal of the threat; it, thus, could be manifested as a heterogeneous group of emotional reactions.



Assessing pain intensity


Most of measures of pain intensity are highly correlated with the others


Verbal Rating Scales (VRSs)




Patients are given a list of adjectives describing pain. They are supposed to rank the adjectives based on pain severity and assign each with a score. For instance, 0 indicating no pain, 1 indicating mild pain, 2 indicating moderate pain and 3, severe pain.


Cross-modality matching procedure has been used to transform VRS ratings to ratings involving other modalities that are more likely to have ratio properties (e.g., loudness of a tone).


The problems of VRS



  1. Time consuming

  2. Standardized scores are developed using non-patients in reaction to experimental pain while it has been found that patient with chronic pain might rate the adjectives differently from those sustaining acute pain

VRSs have demonstrated their validity based on the high correlation they have with other pain intensity measures. They also demonstrate their sensitivity to treatment having substantial impacts on pain intensity.


The problem was VRSs is that patients need to be familiar with the list of adjectives, the task is time-consuming and it is difficult to tell the level of understanding the patients have with listing. Sometimes, patients might not be able to find an adjective to describe their condition. In addition, the VRSs are found to be less reliable for illiterate patients.


Visual Analogues Scales (VASs)


A VAS consist of a line with one end indicating “no pain” and the other end indicating “Pain as bad as it could be” When a VAS have points and labels associated with these points, it is called a graphic rating scale (GRS). Existing research has substantiated the validity of the VASs through studies measuring the association between pain intensity and pain behavior, sensitivity to treatment effects and how distinct the scale is from other components of pains. In addition, VASs have been found to be more sensitive to changes especially when comparing to scales with limited response category.




An alternative version of VASs was designed to counteract the issue of scoring complexity. With the mechanical VAS, participants use a sliding marker on one side of a paper or plastic to provide their responses while the researchers use the other side of the paper or plastic to get the intensity score. Mechanical VASs have been found to correlate highly with paper-and-pencil VASs and has good test-retest reliability within a two-hour window.


The VASs also have various drawbacks. For instance, participants need to have a minimal level of motor ability as well as a certain level of cognitive ability. For people with cognitive difficulties, the use of VAS is not suggested.

Numerical Rating Scale (NRS)


With NRS, patients are simply asked to rate their pain experiences based on either a scale of 0 to 10, 0 to 20, or, 0 to 100 with 0 indicating no pain and 10, 20 or 100 indicating the worst level of pain possible. While NRS could be done verbally, it is also available in paper and pencil format.
The validity of NRS has been well-documented. They correlate well with other measures of pain intensity. They are sensitive to treatment effect. It can be used on a greater range of patients.
The weakness of NRS is that it does not have the quality of a ratio scale. In other words, when a patient’s rating drop from 9 to 6, it doesn’t mean that the intensity of pain has decreased by 33%.

Picture of Face Scale




With this method, each person has shown pictures and is asked to indicate which one of the pictures best represent their experiences with pain while each picture is associate with a score. This scale is great for patients who might be illiterate. Yet, the pictures still need to be explained to patients when might be cognitively impaired or who might be young children.

Descriptor Differential Scale of Pain Intensity (DDS-I)




DDS-I contains a list of adjectives describing levels of pain intensity. Patients are asked to rate whether their experience is more or less than what is described in the word.
DDS-I has high internal consistency as well as test-retest stability. It also correlate highly with other pain intensity measure and is sensitive to changes in the state including treatment effect and experimental stimulation. The DDS-I also has the quality of ratio scale.


One major drawback of DDS-I is that it is too complex and time consuming.

Assessing pain affect

Pain intensity could be defined as how much one hurts; pain affect is defined as “the emotional arousal and disruption engendered by the pain experience. Pain affect has been considered as a multidimensional construct with the dimensions either correlated or uncorrelated. However, to date, there exists no multidimensional measure of pain affect. Overall, there are 5 general methods of pain affect assessment: The affective subscale of the McGill Pain Questionnaire (MPQ), the Verbal Rating Scales (VRSs), the Visual Analogues Scales (VASs), the Descriptor Differential Scale of Pain Affect (DDS-A) and the Affective Scale of the Pain-O-Meter (POM).

Verbal Rating Scales (VRSs)





VRSs for pain affect consist of descriptors for increased discomfort and suffering (e.g., bearable, excruciating). They are scored in three ways: ranking, cross-modality matching or standardized score method. There are mixed findings in the validity of VRSs. On one hand, when used to evaluate treatments designed to impact the emotional component of pain, VRSs have been found to be more sensitive than pain intensity. However, various studies found that pain affect and pain intensity are very often overlapped; in other words, while pain affect and pain intensity might be two distinct constructs, they are not completely independent from the others and, actually, the interdependence might be needed.

Visual Analogues Scales (VASs)



The extremes response used in VAS affect measure could be “not bad at all” and “the most unpleasant feeling for me.” In terms of the validity of VASs, VASs affect measures seem to be sensitive to treatment effect and more sensitive to treatment than that of intensity as well. In addition, they have the quality of ratio scale. Unfortunately, VASs affect scale doesn’t discriminate from the intensity measure and most of the research was done on younger populations (as opposed to the older adults). Because VASs affect measures are single item scales, they might be less reliable and valid when comparing to measures containing multiple items and examining a full range of responses. No studies have been done, though, to compare the VAS affect measure that that of others.

Descriptor Differential Scale of Pain Affect (DDS-A)



DDS-A is a multi-item scale and provides more reliable and valid assessment than single-item scales such as VASs. Existing research has also demonstrated its test-retest reliability and internal consistency. A special merit of DDS-A is that respondents could not only indicate whether their affect response is higher or lower than the descriptor as well as by how much more.

Affective Scale of the Pain-O-Meter (POM)


The POM includes a VAS and two lists of 11 pain descriptor selected from MPQ. Patients indicate which of the 11 descriptors describe their experience as well as the intensity value. Although the scale has been found to be reliable and demonstrate the ability to discriminate between patients of different disorders. There is still a need for scale validation.


Questions to be answered:



  1. Global measure or separate indices?

  2. Are single-item measure less reliable than multi-item measure?

Assessing pain Quality



  1. The sensory scale from the McGill Pain Questionnaire (MPQ)

  2. The Neuropathic Pain Scale (NPS)

NPS


Patients are requested to rate the severity of the pain descriptors with 0 indicating “no pain” and 10 “the most intense pain sensation imaginable). The NPS also allow the patients to indicate the fluctuation of the pain over time. Because many of the indicators seem to correlate poorly, it has been suggested that the use of a composite score might have limited meaning and a profiling approach might yield more meaningful information. On the other hand, the NPS has been developed to assess neuropathic pain, it might be less meaningful for other types of pain conditions.


Assessing Pain Location




  1. Line drawing to present the localized pain

  2. Shading areas

  3. Symbols to represent different pains
    o Internal "I" or external "E"
    o Numbness "--"
    o Pins and needles “oo”
    o Burning pain “xx”
    o Stabbing pain “//”

Usefulness
The correlation between lower back pain and interferences with life’s activities

Tuesday, May 26, 2009

The measurement of Pain and the Assessment of People Experiencing pain (Turk & Melzack, 2001)

Turk, D. C., & Melzack, R. (2001). The measurement of Pain and the Assessment of People Experiencing pain. In D. C. Turk & R. Melzack (Eds.), Handbook of Pain Assessment (pp. 3-11). New York: The Guilford Press.


"Just as 'my pain' belongs in a unique way only to me, so I am utterly alone with it. I cannot share it. I have no doubt about the reality of the pain experience, but I cannot tell anybody what I experience. I surmise that others have 'their' pain, even though I cannot perceive what they mean when they tell me about them." (Illich, 1976 cited in D.C. Turk & R. Melzack, 2001)

The associations between reported pain and physical abnormality are fairly weak. Studies have found that, while patients with significant pathology might sustain only little pain or no pain (e.g., Boden, Davis, Dina, Patronas & Wiesel, 1990; Jensen, Brant-Zawadski, Wiesel, Tsourmas, & Malkasian, Ross, 1994) there are other patients who suffered from unproportional amount of pain despite the limited amount of identified pathology (e.g., White & Gordon, 1982). In a lot of patients, physical pathology underlies their pain actually could not be identified.

Some experts suggested that results of lab tests and imaging techniques should be used as the basis of pain assessments. Again, even with techniques sophisticated like MRI scans, research studies remain to find weak associations between physical pathology and pain.

In addition, weak associations have also be reported between the degree of physical disability and functionality, of returning to work and, of treatment outcomes. It has been suggested that the observed weak correlation between "pathology, symptoms and outcome" might have something to do with the reliability of the examination procedure.

The weak correlations between pathology and pain led experts to consider whether personal factor, such as a "pain-prone personality" or "psychogenic pain" might have contributed to such a weak association. Existing research provided little evidence supporting such an argument although there might be promises associated with this area of research.

The differences among nociception, pain, pain behavior and suffering

  • Nociception: the processing of stimuli that are defined as related to the stimulation of nociceptors and capable of being interpreted as pain.
  • Pain: A perceptual process involving multiple perspectives.
  • Suffering: the interpretation and subsequent response to the perception of pain.

Interesting study by Reesor and Craig (1988): cognitive process seems to distort or amplify patients' pain experiences and suffering. Unfotunately, since I have not read this paper, I can't quite tell you yet how they came up with this conclusion about "distortion" and "amplification". One naive question I have now is... how do you come up with a baseline to make such an argument?

It is important to realize that disability is not solely a function of the extent of physical pathology or the level of pain. Disability is a complex phenomenon that multiple factors such as the physical pathology and the environmental factor. (Check the disability related articles for more information).

Like the instruments used to assess functional disability, currently, there is no single measure that has been used to assess pain and there are too many competing instruments. These instruments have often been developed for particular group of people or for particular diagnosis. In addition, even if an instrument has been validated for certain population, researchers and practitioners often select items of their interest from existing instruments to develop their own assessment. This practice, thus, would result in problems with the scale validity and reliability; in addition, it also makes it difficult to compare the results yielded by different studies.

Thursday, May 21, 2009

Pain

An interesting quotation I encounter in the opening chapter of the Handbook of Pain Assessment...

"Just as 'my pain' belongs in a unique way only to me, so I am utterly alone with it. I cannot share it. I have no doubt about the reality of the pain experience, but I cannot tell anybody what I experience. I surmise that others have 'their' pain, even though I cannot perceive what they mean when they tell me about them." (Illich, 1976 cited in D.C. Turk & R. Melzack, 2001)

So very true... I could only appropriate the pains others suffer by referencing to the experiences of my own.... There is no object measure such as a pain thermometer... and it is also difficult to equate our idiosyncratic scales...

At the same time, if only our beliefs about our experiences could be so very strong...

For... many a time, we go back to revisit this plausibility...

Is it simply in my head-- a manifestation of psychosomatisation?

Even so--- how would it matter and what does it inform us about how to to move forward?