BACKGROUND: Persistent pain is grossly undertreated in older adult sufferers, despite its high prevalence in this age group. Because of its multidimensional impacts, including depression, sleep disruption and physical disability, patients with persistent pain often benefit from interdisciplinary pain clinic treatment. This treatment is expensive, however, and may not be required by all patients. The Multiaxial Assessment of Pain (MAP) has demonstrated value in predicting response to treatment in younger adults with persistent pain.OBJECTIVE: To examine the feasibility of a MAP taxonomy for community-dwelling adults age 65 years or older.PARTICIPANTS AND PROCEDURES: One hundred eight subjects with persistent pain (mean age 73.8 years, SD=8.4 years) were interviewed and data collected on demographics, pain intensity, depressive symptoms, sleep disruption, pain interference with performance of basic and instrumental activities of daily living, frequency of engagement in advanced activities of daily living, cognitive function and comorbidity. A subset of these subjects underwent physical capacities testing, including maximal isometric lift strength, dynamic lifting endurance, timed chair rise and balance.RESULTS: Analyses derived three primary clusters of patients. Cluster 1 (24&#x25;) reported less intense pain, less depression and sleep disruption, and higher activity levels. Cluster 3 (30&#x25;) suffered from more pain and were more functionally disabled. Cluster 2 (46&#x25;) had characteristics of cluster 1 and cluster 3, but with some characteristics that were clearly unique.CONCLUSIONS: While these results are preliminary and require further validation, they indicate that older adults are heterogeneous in their response to persistent pain. Future studies should be performed to examine whether the MAP taxonomy is applicable to older adults regardless of medical diagnosis. Ultimately, this information may have meaning with regard to both treatment prescribing, and the design and interpretation of intervention studies.

Debra K Weiner

Thomas E Rudy

Swati Gaur

Are all Older Adults with Persistent Pain Created Equal? Preliminary Evidence for a Multiaxial Taxonomy

BACKGROUND: Pain perception is known to depend on integrated cognitive processing. Alzheimer's disease affects 5&#x25; to 10&#x25; of older adults, but the impact of this disease on pain sensitivity and report has yet to be fully investigated.AIM OF INVESTIGATION: The present study examined pain threshold, the reliability of pain report and the central nervous system processing of noxious input, as indexed by cerebral event-related potentials (CERP).METHODS: Carbon dioxide laser detection and heat pain thresholds were determined on the hand dorsum of 15 healthy older adults (Mini-Mental State Examination [MMSE] score 29.9&#xb1;0.3) and 15 persons with cognitive impairment (MMSE score 12.7&#xb1;6.1). Using an array of 15 silver/silver chloride scalp electrodes, the CERP and subjective rating of stimulus intensity were recorded after fixed intensity, 25 W laser stimuli.RESULTS: Compared with age-matched controls, the detection threshold for just noticeable sensation was significantly increased in elderly adults suffering from Alzheimer's disease. There was no difference in pain threshold intensity between persons with cognitive impairment and controls, although the former group was less reliable in reporting detection and pain threshold sensations. The subjective rating of a 25 W stimulus was virtually identical in both groups, and the amplitude of the major CERP component (P400) was similar; however, cognitively impaired adults exhibited a significant increase in the latency of the P400 response.CONCLUSION: The present findings indicate that pain perception in response to an acute heat pain stimulus is not diminished in older persons with cognitive impairment. Patients with Alzheimer's disease may be slightly less reliable in threshold pain report, although the subjective rating of evoked pain and the level of poststimulus cortical activation following noxious stimulation were found to be similar to those of controls. A longer latency of the CERP may suggest slower cortical processing of nociceptive input by persons with Alzheimer's disease.

Stephen J Gibson

Xenophon Voukelatos

David Ames

Leon Flicker

Robert D Helme

An Examination of Pain Perception and Cerebral Event-Related Potentials following Carbon Dioxide Laser Stimulation in Patients with Alzheimer&#x2019;s Disease and Age-Matched Control Volunteers

BACKGROUND: There is little information available on the rates of pain in institutionalized elderly persons, and this is particularly true for Canada.OBJECTIVES: To provide information about the prevalence and clinical correlates of pain in a sample of Canadian nursing homes, to determine whether residents with cognitive impairment experience lower rates of health conditions associated with pain (eg, arthritis) than residents without cognitive impairment and to determine whether the associations (ie, odds ratios) for pain with such health conditions vary as a function of cognitive status.DESIGN: The study is based on a secondary analysis of data collected with the minimum data set (MDS 2.0).SETTING AND PARTICIPANTS: The study comprised 3195 nursing home residents in Ontario, Manitoba and Saskatchewan.SUBJECTS AND METHODS: All residents were assessed with the MDS 2.0 by trained clinicians (usually nurses). Pain was documented if it had occurred within the seven days before the assessment. Assessors were trained to look for overt signs of discomfort, such as wincing or verbalizations. Self-report ratings were obtained when possible.RESULTS: The overall prevalence of pain in this sample was 49.7&#x25;, and 23.7&#x25; of residents experienced pain daily. Persons with and persons without cognitive impairments did not differ with respect to the prevalence of conditions likely to cause pain and the associations of pain with such health conditions. Regional differences were found, with Ontario residents having a higher frequency and intensity of pain than their counterparts in Saskatchewan and Manitoba. This may be due, at least in part, to regional differences in nursing home admission criteria.CONCLUSIONS: The findings suggest that the prevalence of identified pain is lower among nursing home residents with higher levels of cognitive impairment. These results do not support the notion that this is a function of lower prevalence rates of pain-causing conditions in nursing home residents with dementia. Furthermore, the results do not support the view that residents with cognitive impairments are less sensitive to pain. This study highlights the need for more comprehensive tools to assess pain in persons with cognitive impairments. Nonetheless, the MDS may be a useful instrument for detecting pain in such populations, because it does not rely exclusively on self-report.

Wendey R Proctor

John P Hirdes

Pain and Cognitive Status among Nursing Home Residents in Canada

Thomas Hadjistavropoulos

Pain and Aging

OBJECTIVE: Judgments about an individual's pain can be profoundly important to sufferers. Relatively few studies have examined variables that may affect observers' judgments of the pain of others. The present article reports two studies investigating the relationship between different kinds of exposure to pain problems and observers' ratings of the pain intensity of patients.DESIGN: In the first study, 82 observers were classified into groups with positive and negative family histories of chronic pain. They viewed a videotape showing the facial expressions of shoulder pain patients undergoing physiotherapy assessments and rated the pain experienced by the subjects. In the second study, the data from observers having no experience with pain problems were compared with data collected from therapists having considerable experience with pain problems.RESULTS: Observers with a positive family history of chronic pain attributed greater pain to the patients than those with a negative family history of chronic pain. Professionals' pain judgments were lower than those of control subjects.CONCLUSIONS: Together, the findings imply that one's experiences with the different problems of pain patients may affect pain judgments. Alternative interpretations of the findings are considered.

Kenneth M Prkachin

Patty Solomon

Teresa Hwang

Susan R Mercer

Does Experience Influence Judgements of Pain Behaviour? Evidence from Relatives of Pain Patients and Therapists

The effect of cannabimimetic agents on the function of immune cells such as T and B lymphocytes, natural killer cells and macrophages has been extensively studied over the past several decades using human and animal paradigms involving whole animal models as well as tissue culture systems. From this work, it can be concluded that these drugs have subtle yet complex effects on immune cell function and that some of the drug activity is mediated by cannabinoid receptors expressed on the various immune cell subtypes. However, the overall role of the cannabinoid system of receptors and ligands in human health and disease is still unclear and requires extensive elucidation. Further studies will define the precise structure and function of the putative immunocannabinoid system, the potential therapeutic usefulness of these drugs in chronic diseases such as acquired immune deficiency syndrome and multiple sclerosis, the effects of these agents on tumour growth and induction of apoptosis, and the potential anti-inflammatory and proinflammatory properties of cannabimimetic compounds. It is likely that the cannabinoid system, along with other neuroimmune systems, has a subtle but significant role in the regulation of immunity and that this role can eventually be exploited in the management of human disease.

Thomas W Klein

Catherine A Newton

Herman Friedman

Cannabinoids and the Immune System

OBJECTIVE: To provide an overview of the history and pharmacology of cannabis in relation to current scientific knowledge concerning actual and potential therapeutic uses of cannabis preparations and pure cannabinoids.METHODS: The literature on therapeutic uses of cannabis and cannabinoids was assessed with respect to type of study design, quality and variability of data, independent replications by the same or other investigators, magnitude of effects, comparison with other available treatments and reported adverse effects. The results of this review were also compared with those of major international reviews of this topic in the past five years.CONCLUSIONS: Pure tetrahydrocannabinol and several analogues have shown significant therapeutic benefits in the relief of nausea and vomiting, and stimulation of appetite in patients with wasting syndrome. Recent evidence clearly demonstrates analgesic and antispasticity effects that will probably prove to be clinically useful. Reduction of intraocular pressure in glaucoma and bronchodilation in asthma are not sufficiently strong, long lasting or reliable to provide a valid basis for therapeutic use. The anticonvulsant effect of cannabidiol is sufficiently promising to warrant further properly designed clinical trials. There is still a major lack of long term pharmacokinetic data and information on drug interactions. For all the present and probable future uses, pure cannabinoids, administered orally, rectally or parenterally, have been shown to be effective, and they are free of the risks of chronic inflammatory disease of the airways and upper repiratory cancer that are associated with the smoking of crude cannabis. Smoking might be justified on compassionate grounds in terminally ill patients who are already accustomed to using cannabis in this manner. Future research will probably yield new synthetic analogues with better separation of therapeutic effects from undesired psychoactivity and other side effects, and with solubility properties that may permit topical administration in the eye, or aerosol inhalation for rapid systemic effect without the risks associated with smoke inhalation.

Harold Kalant

Medicinal Use of Cannabis: History and Current Status

Cannabinoids have been used to treat pain for many centuries. However, only during the past several decades have rigorous scientific methods been applied to understand the mechanisms of cannabinoid action. Cannabinoid receptors were discovered in the late 1980s and have been found to mediate the effects of cannabinoids on the nervous system. Several endocannabinoids were subsequently identified. Many studies of cannabinoid analgesia in animals during the past century showed that cannabinoids block all types of pain studied. These effects were found to be due to the suppression of spinal and thalamic nociceptive neurons, independent of any actions on the motor systems. Spinal, supraspinal and peripheral sites of cannabinoid analgesia have been identified. Endocannabinoids are released upon electrical stimulation of the periaqueductal gray, and in response to inflammation in the extremities. These observations and others thus suggest that a natural function of cannabinoid receptors and their endogenous ligands is to regulate pain sensitivity. The therapeutic potential of cannabinoids remains an important topic for future investigations, with previous work suggesting utility in clinical studies of cancer and surgical pain. New modes of delivery and/or new compounds lacking the psychotropic properties of the standard cannabinoid ligands offer promise for cannabinoid therapeutics for pain.

J Michael Walker

Nicole M Strangman

Susan M Huang

Cannabinoids and Pain

George V Rossie

R Daun Gretzinger

Toward making 'IMEs' Independent

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<p>Pain Research and Management publishes research focusing on laboratory and clinical findings in the field of pain research and the prevention and management of pain.</p>


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<p>Chief Editor&nbsp;Professor Valeriani specialises in clinical neurophysiology with a particular interest in pain and headaches in children and adults, and is currently a neurologist who works at the Bambi Gesu Children’s Hospital in Rome.</p>


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Pain Research and Management - Table of contents 2001

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Pain Research and Management publishes research focusing on laboratory and clinical findings in the field of pain research and the prevention and management of pain.

Pain Research and Management