Acute and chronic pain syndromes in multiple sclerosis. A 5-year follow-up study

Depression and anxiety amongst multiple sclerosis patients

The aim of this study was to investigate the prevalence of symptoms of depression and anxiety amongst multiple sclerosis (MS) patients, and the associations with demographic and clinical characteristics. The current treatment for depression and anxiety was also evaluated amongst the MS patients. A total of 140 MS patients from Eastern Norway underwent neuropsychiatric and clinical examinations, with registration of symptoms of depression and anxiety (Hopkins Symptom Checklist-25), as well as information about any help seeking for depression were obtained. A total of 31.4% patients reported symptoms of depression, whilst 19.3% reported anxiety; both symptoms were significantly higher than that amongst the general population (P < 0.001). Fatigue and younger age at onset were significantly associated with symptoms of depression, whilst fatigue and pain, lower Expanded Disability Status Scale score and younger age at onset were associated with symptoms of anxiety. The proportion of reported treatment of depression was 15.9% and for anxiety 11.1%. Of untreated patients with symptoms, 18.2% expressed the need for treatment. A greater focus on depression and anxiety amongst MS patients is needed to establish the appropriate treatment for patients suffering from MS.

Pain associated with multiple sclerosis: systematic review and proposed classification

Pain is common in patients with multiple sclerosis (MS), but estimates of its prevalence have varied widely. The literature describing pain in MS patients spans four decades and has employed a range of different methodologies. We undertook a systematic review in order to summarize current understanding of the association between MS and pain and provide a basis for the design and interpretation of future studies. The point prevalence of pain in patients with MS is nearly 50%, and approximately 75% of patients report having had pain within one month of assessment. Pain adversely affects most aspects of health-related quality of life, including functional domains such as the ability to work. The presence of pain in patients with MS is associated with increased age, duration of illness, depression, degree of functional impairment, and fatigue. Several different types of pain are found in patients with MS, including extremity pain, trigeminal neuralgia, Lhermitte's sign, painful tonic spasms, back pain, and headache. Putative mechanisms of pain in patients with MS are discussed, and a classification of pain in MS is proposed. Few randomized clinical trials of treatments for MS pain have been conducted, and the limitations of current knowledge regarding approaches for treating MS pain are discussed. Suggestions for future studies that would increase understanding of the natural history, mechanisms, and treatment of pain in patients with MS are presented.

Analysis of nociception, sex and peripheral nerve innervation in the TMEV animal model of multiple sclerosis

Although pain was previously not considered an important element of multiple sclerosis (MS), recent evidence indicates that over 50% of MS patients suffer from chronic pain. In the present study, we utilized the Theiler's murine encephalomyelitis virus (TMEV) model of MS to examine whether changes in nociception occur during disease progression and to investigate whether sex influences the development of nociception or disease-associated neurological symptoms. Using the rotarod assay, TMEV infected male mice displayed increased neurological deficits when compared to TMEV infected female mice, which mimics what is observed in human MS. While both male and female TMEV infected mice exhibited thermal hyperalgesia and mechanical allodynia, female mice developed mechanical allodynia at a faster rate and displayed significantly more mechanical allodynia than male mice. Since neuropathic symptoms have been described in MS patients, we quantified sensory nerve fibers in the epidermis of TMEV-infected and non-infected mice to determine if there were alterations in epidermal nerve density. There was a significantly higher density of PGP9.5 and CGRP-immunoreactive axons in the epidermis of TMEV-infected mice versus controls. Collectively these results indicate that the TMEV model is well suited to study the mechanisms of MS-induced nociception and suggest that alterations in peripheral nerve innervation may contribute to MS pain.

Chronic Pain in Multiple Sclerosis: Prevalence, Characteristics, and Impact on Quality of Life in an Australian Community Cohort

This cross-sectional study describes chronic pain in 94 persons with multiple sclerosis residing in the community. The characteristics of chronic pain, pain-related disability, pain treatments, barriers to health care, and impact on quality of life were examined. Sixty-four percent of participants reported chronic pain; of these, 60% had dysesthetic pain and 70% had episodic increases in pain. The mean numerical pain intensity rating score was moderate (5). Chronic Pain Grade was used to classify severity of pain, using scores for items for pain intensity and pain-related disability. Those in the higher pain grades had more disability and recorded more health care visits (P = .06) (not significant because of small sample size). Effective pain management techniques included analgesic medication and physical measures as reported by 54% and 44% participants, respectively. Participants' perceived barriers to health care included environmental and personal factors. Those with multiple sclerosis and pain, compared with those with no pain, showed a significant difference in the domain of psychological well-being scores (P = .01) on the Assessment of Quality of Life scale. Additionally, the domains of independent living (P = .009) and total scores (P = .04) showed better quality of life in participants with lower pain grades. Improved understanding of chronic pain in this population may facilitate early identification for timely intervention and minimize pain-related disability.

PERSPECTIVE

This article describes chronic pain in persons with multiple sclerosis living in the community. The information regarding pain prevalence, pain-related disability, and impact on quality of life provides insight into the complex multidimensional pain experience. Improved understanding of pain and early intervention may contribute to the overall well-being and decrease pain-related disability in this population.

Multiple Sclerosis as A Painful Disease

Pain is a common problem of patients with multiple sclerosis (MS) and may be due to central/neuropathic or peripheral/somatic pathology. Rarely MS may present with pain, or pain may herald an MS exacerbation, such as in painful tonic spasms or Lhermitte's sign. In other patients, pain may become chronic as a long-term sequela of damage to nerve root entry zones (trigeminal neuralgia) or structures in central sensory pathways. Migraine headache may develop as a consequence of MS, and headache can also be a side effect of interferon treatment. The pathophysiology of pain in MS may be linked to certain plaque locations which disrupt the spinothalamic and quintothalamic pathways, abnormal impulses through motor axons, development of an acquired channelopathy in affected nerves, or involve glial cell inflammatory immune mechanisms. At this time, the treatment of pain in MS employs the use of antiepileptic drugs, muscle relaxers/antispasmodic agents, anti-inflammatory drugs, and nonpharmacological measures. Research concerning cannabis-based treatments shows promising results, and substances which block microglial or astrocytic involvement in pain processing are also under investigation.

Chronic Pain in Persons with Multiple Sclerosis

The MS literature clearly indicates that chronic pain is a significant problem for many, although not all, persons with MS. The rates of pain have been found to vary in different studies, from 44% to 80%, depending on the sample and the specific questions used to assess the incidence and severity of pain. What is not clear is the proportion of persons who have acute pain relative to chronic pain. Although the specific frequency of pain problems in patients with MS may not be clear, there is a subgroup of patients (about 38% of those with pain in one sample) who report experiencing severe pain [8]. Preliminary research suggests that chronic pain can have a significant negative impact on a number of aspects of functioning in persons with MS, such as the ability to engage in household work and psychologic functioning. A biopsychosocial model of chronic pain, which has proved to be useful in understanding chronic pain as a primary condition and chronic pain in persons with other physical disabilities, may also be useful for understanding pain in persons with MS. Research,however, has not yet tested the utility of this model among MS populations. Longitudinal research is needed to help us learn how MS-related pain may fluctuate over time and with changes in disease status. There also is a strong need for research that examines access to pain treatment and that evaluates the efficacy of currently available pain treatments in persons with MS. The results of such research, as it is applied to help patients with MS, should contribute to an overall increase in well-being and a decrease in suffering among persons with MS and chronic pain.

Central pain in multiple sclerosis--prevalence and clinical characteristics

Pain is more common in multiple sclerosis (MS) than has previously been recognised. In the present study we have investigated the occurrence of central pain (CP) in MS and defined its characteristics. Questionnaires were sent to all 429 patients with definite MS in the patient register at our neurology department. All admitting to pain were interviewed and offered an extended interview and examination. Three hundred and sixty four patients responded (86%), of whom 57.5% reported pain during the course of their disease (21% nociceptive, 2% peripheral neuropathic and 1% related to spasticity). One hundred patients (27.5%) had CP, including 18 patients (4.9%) with trigeminal neuralgia. The non-trigeminal CP was, in 87%, located in the lower and in 31% in the upper extremities. It was mostly bilateral (76%) and constant, with 88% experiencing daily pain. Only 2% had paroxysmal attacks. Aching, burning, pricking were the commonest qualities. The pain was intense with small to moderate spontaneous variation. In 5.5% of all patients (20% of the patients with CP), pain was a presenting symptom, alone or in combination with other symptoms. The most common neurological symptoms/signs besides CP were sensory abnormalities (98%, dominated by abnormal sensibility to painful stimulus and temperature). Trigeminal neuralgia in MS started later in life and after longer disease duration than non-trigeminal pain. Both types of CP existed either chronically or as a feature of relapse. Central pain is thus an important symptom in MS (around 30%) and causes much suffering.

Chronic pain in a large community sample of persons with multiple sclerosis

INTRODUCTION

This study examined the prevalence, intensity, interference, and biopsychosocial correlates of pain in a large community-based sample of persons with multiple sclerosis (MS).

METHODS

Mail surveys were returned by 442 members of the King County (WA) MS Association. Average pain intensity, pain-related activity interference, depressive symptoms and severity of MS were assessed.

RESULTS

Forty-four percent reported persistent, bothersome pain in the three months prior to completing the survey. Participants with pain reported an average pain intensity rating of 5.2 (SD = 2.3) on the 0 (no pain) to 10 (pain as bad as could be) scale. Twenty-seven percent reported severe pain (score of 7-10), while 51% of those with pain rated the interference of their pain with daily activities as none to minimal. Twenty percent reported severe interference in activities as a result of pain. In multivariate modeling, MS illness severity, marital status, and self-ratings of overall health were significantly associated with pain-related interference with activities.

CONCLUSIONS

Approximately a fourth of this sample described having a chronic pain problem characterized by severe pain intensity and significant pain-related interference with activities. Disability due to pain may be more important than previously recognized for the MS population.

Symptom management and adjustment of patients with multiple sclerosis: a 4-year longitudinal intervention study

The researchers studied the effectiveness of a nursing intervention in promoting adjustment and symptom management in individuals with multiple sclerosis (MS). This was a 4-year longitudinal study to determine whether the 4-week intensive outpatient program was effective in increasing adjustment to MS and if the treatment effect would last over time. A sample of 27 individuals with MS participated in the study. Treatment participants had significant improvements in symptom management at the 4-year follow up. This improvement was attributable to signficant improvements in sleep and fatigue levels. Although adjustment and self-efficacy scores improved in the treatment group over time, this improvement was not superior to the control group. This was anticipated because the behavioral changes would precede improvement in adjustment to life following the diagnosis of MS.

Chronic pain secondary to disability: a review

BACKGROUND

Until recently, very little has been written regarding chronic pain as a secondary problem in persons who already have a physical disability, despite the potential for pain to increase the negative impact of what may already be a very disabling condition. The purpose of this review is to summarize what is currently known concerning the nature and scope of chronic pain as a secondary condition to disability, specifically spinal cord injury, acquired amputations, cerebral palsy, multiple sclerosis, neuromuscular disease, and postpolio syndrome.

METHOD

What is known concerning the frequency, severity, impact, and treatment of pain in these specific conditions is reviewed, as are the factors that contribute to, or are associated with, adjustment to chronic pain in these disability groups. The authors conclude with several research questions that emerge from this knowledge, the answers to which will contribute to the long-term goal of the reduction of pain and suffering in persons with disabilities.

CONCLUSIONS

The existing literature clearly documents that many persons with disabilities experience chronic pain. Many questions remain unanswered regarding the scope, severity, and treatment of chronic pain in these groups.