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

Risk factors of neuropathic pain in multiple sclerosis: a retrospective case-cohort study

Background

Pain is a common symptom in multiple sclerosis (MS), especially neuropathic pain, which has a significant impact on patients' mental and physical health and quality of life. However, risk factors that related to neuropathic pain, still remain unclear.

Objective

The study aimed to explore the risk factors of neuropathic pain among MS patients.

Materials and methods

This retrospective study examined the consecutive patients diagnosed with MS in the Department of Neurology of Guangdong Provincial Hospital of Chinese Medicine between August 2011 and October 2022. Neuropathic pain was defined as "pain arising as a direct consequence of a lesion or disease affecting the somatosensory system". Demographic and clinical features were obtained from the electronic system of the hospital.

Results

Our cohort revealed that the prevalence of patients with neuropathic pain in MS was 34.1%. The results indicated that the longer the spinal lesions, the greater the neuropathic pain risks (2-4: OR, 13.3(2.1-82), >5: OR, 15.2(2.7-86.8), p for tread: 0.037). Meanwhile, multivariate regression analysis showed that cervical and thoracic lesions (OR 4.276, 95% CI 1.366-13.382, P = 0.013), upper thoracic lesions (T1-T6) (OR 3.047, 95% CI 1.018-9.124, P = 0.046) were positively correlated with neuropathic pain, while basal ganglia lesions (OR 0.188, 95% CI 0.044-0.809, P = 0.025) were negatively correlated with neuropathic pain among MS patients.

Conclusion

Extended spinal lesions (≥3 spinal lesions), cervical and thoracic lesions, upper thoracic lesions were independent risk factors of neuropathic pain among MS patients. Furthermore, our study found that the longer the spinal lesions, the greater the neuropathic pain risks.

Targeting N-type calcium channels in young-onset of some neurological diseases

Calcium (Ca ²⁺) is an important second messenger in charge of many critical processes in the central nervous system (CNS), including membrane excitability, neurotransmission, learning, memory, cell proliferation, and apoptosis. In this way, the voltage-gated calcium channels (VGCCs) act as a key supply for Ca²⁺ entry into the cytoplasm and organelles. Importantly, the dysregulation of these channels has been reported in many neurological diseases of young-onset, with associated genetic factors, such as migraine, multiple sclerosis, and Huntington's disease. Notably, the literature has pointed to the role of N-type Ca²⁺ channels (NTCCs) in controlling a variety of processes, including pain, inflammation, and excitotoxicity. Moreover, several Ca²⁺ channel blockers that are used for therapeutic purposes have been shown to act on the N-type channels. Therefore, this review provides an overview of the NTCCs in neurological disorders focusing mainly on Huntington's disease, multiple sclerosis, and migraine. It will discuss possible strategies to generate novel therapeutic strategies.

Headache in multiple sclerosis - pharmacological aspects

For decades, headache was not considered a typical symptom of multiple sclerosis (MS) and was construed as a "red flag" for important differential diagnoses such as cerebral vasculitis. Meanwhile, several studies have demonstrated an increased prevalence of headache in MS compared to the general population. This is due to the heterogeneity of headache genesis with frequent occurrence of both primary and secondary headaches in MS. On the one hand, MS and migraine are often comorbid. On the other hand, secondary headaches occur frequently, especially in the course of MS relapses. These are often migraine-like headaches caused by inflammation, which can improve as a result of MS-specific therapy. Headaches are particularly common in the early stages of chronic inflammatory CNS disease, where inflammatory activity is greatest. In addition, headache can also occur as a side effect of disease-modifying drugs (DMDs). Headache can occur with most DMDs and is most frequently described with interferon-beta therapy. The aim of this work is to present the prevalence of headache and describe the heterogeneity of possible causes of headache in MS. In addition, important therapeutic aspects in the treatment of MS patients in general will be presented as well as different approaches to the treatment of headache in MS depending on the etiological classification.

Comprehensive Approach to Management of Multiple Sclerosis: Addressing Invisible Symptoms-A Narrative Review

Multiple sclerosis (MS) is a chronic autoimmune inflammatory disease of the central nervous system, leading to neurodegeneration and manifesting as a variety of symptoms. These can include "invisible" symptoms, not externally evident to others, such as fatigue, mood disorders, cognitive impairments, pain, bladder/bowel dysfunction, sexual dysfunction, and vision changes. Invisible symptoms are highly prevalent in people living with MS, with multifactorial etiology and potential to impact the disease course. Patient experiences of these symptoms include both physical and psychosocial elements, which when unaddressed negatively influence many aspects of quality of life and perception of health. Despite the high impact on patient lives, gaps persist in awareness and management of these hidden symptoms. The healthcare provider and patient author experiences brought together here serve to raise the profile of invisible symptoms and review strategies for a team-based approach to comprehensive MS care. We summarize the current literature regarding the prevalence and etiology of invisible symptoms to convey the high likelihood that a person living with MS will contend with one or more of these concerns. We then explore how open communication between people living with MS and their care team, stigma mitigation, and shared decision-making are key to comprehensive management of invisible symptoms. We recommend validated screening tools and technological advancements that may be incorporated into MS care to regularly monitor these symptoms, offering insight into how healthcare providers can both educate and listen to patients, with the goal of improved patient quality of life. By pairing clinical knowledge with an understanding and consideration of the patient perspective, providers will be equipped to foster a patient-centered dialogue that encourages shared decision-making. Invisible symptoms of MS.

Longitudinal prevalence and determinants of pain in multiple sclerosis: results from the German National Multiple Sclerosis Cohort study

Pain is frequent in multiple sclerosis (MS) and includes different types, with neuropathic pain (NP) being most closely related to MS pathology. However, prevalence estimates vary largely, and causal relationships between pain and biopsychosocial factors in MS are largely unknown. Longitudinal studies might help to clarify the prevalence and determinants of pain in MS. To this end, we analyzed data from 410 patients with newly diagnosed clinically isolated syndrome or relapsing-remitting MS participating in the prospective multicenter German National MS Cohort Study (NationMS) at baseline and after 4 years. Pain was assessed by self-report using the PainDETECT Questionnaire. Neuropsychiatric assessment included tests for fatigue, depression, and cognition. In addition, sociodemographic and clinical data were obtained. Prevalence of pain of any type was 40% and 36% at baseline and after 4 years, respectively, whereas prevalence of NP was 2% and 5%. Pain of any type and NP were both strongly linked to fatigue, depression, and disability. This link was even stronger after 4 years than at baseline. Moreover, changes in pain, depression, and fatigue were highly correlated without any of these symptoms preceding the others. Taken together, pain of any type seems to be much more frequent than NP in early nonprogressive MS. Moreover, the close relationship between pain, fatigue, and depression in MS should be considered for treatment decisions and future research on a possible common pathophysiology.

Pain Characteristics and Associations with Quality of Life in Patients with Multiple Sclerosis in Lithuania

Background and objectives: Even though pain in multiple sclerosis (MS) patients is common and possibly associated with reduced quality of life, its exact prevalence and characteristics remain vaguely understood. We aimed to estimate the true extent of pain and its associations with quality of life in Lithuanian MS patients and to compare this data with that of a control group. Materials and Methods: Data were collected prospectively at the Department of Neurology, Lithuanian University of Health Sciences Kaunas Clinics. A face-to-face structured interview and a questionnaire were used to collect demographic and clinical data of the MS (n = 120) and control (n = 120) groups. The Expanded Disability Status Scale (EDSS) was used to quantify disability in the MS group. Scores ≥4/10 in the Douleur Neuropathique 4 questionnaire were classified as neuropathic pain. Patients were evaluated using the anxiety and depression subsets of the Hospital Anxiety and Depression Scale (HADS-A and HADS-D), the physical and mental component subsets of the Short Form-12 questionnaire (PSC-12 and MSC-12). Results: The MS and control groups did not differ in pain prevalence (76.7% vs. 65.9%, p = 0.064) or intensity. Lhermitte sign, lower limb, and face pain were more common in the MS group, whereas subjects in the control group were more often affected by lower back, neck, and joint pain. Neuropathic pain and pain lasting longer than 2 years were more common among pain-affected MS patients than among controls. MS patients with pain had higher EDSS, HADS-D, and HADS-A and lower PSC-12 scores than those without pain; however, no difference was found regarding the duration of MS or age. Males with MS and pain had higher MSC-12 and HADS-D scores in comparison to the same subset of females. Conclusions: Pain affects approximately three out of four patients with MS in Lithuania and is negatively associated with the mental and physical aspects of quality of life.

Low back pain in patients with multiple sclerosis: A systematic review and the prevalence in a French multiple sclerosis population

PURPOSE

The prevalence and management of back pain in MS patients was assessed by a systematic review, and the results of a survey on the characteristics of low back pain in a sample of French MS patients are reported.

METHODS

A systematic search was conducted according to the PRISMA guidelines. The outcomes of interest included the prevalence of back pain, severity of pain and impact on daily activities. Moreover, the prevalence of low back pain and its consequences on daily living in a large French MS population were assessed.

RESULTS

Fourteen studies were included in the systematic review. The prevalence of back pain in MS patients ranged from 8.6 to 50%, but that of low back pain in particular ranged from 41.6 to 52.4%. Concerning the survey, 237 patients participated in the online questionnaire. The prevalence of low back pain in the French MS patients was 76.4%. The patients with chronic low back pain had more limitations in their daily life activities than those without chronic low back pain.

CONCLUSION

Patients with MS commonly suffer from low back pain, but it is still an underdiagnosed cause of pain that reduces one's ability to perform activities in daily life.

Clinical perspective on pain in multiple sclerosis

Pain is an important and frequent symptom in multiple sclerosis (MS), which leads to a low quality of life, increased disability level, and lack of employment and mental health. Recently, studies have shown increased interest in pain in MS and there is a growing evidence of its prevalence. However, the literature suffers from lack of experimental studies focusing on pain reduction. This topical review summarizes the current knowledge about pain in MS with its definitions, assessments, treatments and rehabilitation within a holistic perspective.

Measurement of Pain in Multiple Sclerosis

life is pain. It is important to determine the features and the measurement of pain. Common types of pain are described in multiple sclerosis. One-dimensional and multi-dimensional pain scales, which are also used in different painful diseases, are used in the measurement of these pain. Scoring and recording in one-dimensional pain scales are easy and a better measurement is achieved in acute pain. However, the disadvantage of these scales is that they do not give detailed information about the nature of the pain. Multidimensional pain scales are used in chronic and complex pain. Multidimensional scales have some disadvantage about application by patients because of complexity. The development of specific scales for the better measurement of pain in multiple sclerosis is important for the effective treatment of pain in patients.

Temperature sensitivity in multiple sclerosis: An overview of its impact on sensory and cognitive symptoms

Multiple sclerosis (MS) is an autoimmune neurodegenerative disease characterized by demyelination of the central nervous system (CNS). The exact cause of MS is still unknown; yet its incidence and prevalence rates are growing worldwide, making MS a significant public health challenge. The heterogeneous distribution of demyelination within and between MS patients translates in a complex and varied array of autonomic, motor, sensory and cognitive symptoms. Yet a unique aspect of MS is the highly prevalent (60-80%) temperature sensitivity of its sufferers, where neurological symptoms are temporarily exacerbated by environmental- or exercise-induced increases (or decreases) in body temperature. MS temperature sensitivity is primarily driven by temperature-dependent slowing or blocking of neural conduction within the CNS due to changes in internal (core) temperature; yet changes in skin temperature could also contribute to symptom exacerbation (e.g. during sunlight and warm ambient exposure). The impact of temperature sensitivity, and particularly of increases in core temperature, on autonomic (e.g. thermoregulatory/cardiovascular function) and motor symptoms (e.g. fatigue) is well described. However, less attention has been given to how increases (and decreases) in core and skin temperature affect sensory and cognitive symptoms. Furthermore, it remains uncertain whether changes in skin temperature alone could also trigger worsening of symptoms. Here we review the impact of temperature sensitivity on MS sensory and cognitive function and discuss additional factors (e.g. changes in skin temperature) that potentially contribute to temperature-induced worsening of symptoms in the absence of alteration in core temperature.

Psychiatric and physical comorbidities and pain in patients with multiple sclerosis

Background

It has been observed that patients with multiple sclerosis (MS), who have psychiatric and physical comorbidities such as depression and COPD, have an increased risk of experiencing more pain. In this study, we have distinguished between pain intensity and pain affect, as the latter, particularly, requires treatment. Furthermore, while pain and comorbidities have been assessed using questionnaires, this is possibly a less reliable method for those who are cognitively vulnerable.

Objective

The aim of this study was to determine whether psychiatric and physical comorbidities can predict pain intensity and pain affect in MS patients, susceptible to cognitive impairment.

Methods

Ninety-four patients with MS and 80 control participants participated in this cross-sectional study. Besides depression and anxiety, 47 additional comorbidities were extracted from patients’ medical records. Depression and anxiety were assessed using the Beck Depression Inventory and the Symptom Check List-90. Pain was assessed using the Number of Words Chosen Affective, Coloured Analog Scale, and the Faces Pain Scale. Cognitive functions, for example, memory and executive functions, were assessed using several neuropsychological tests.

Results

The main findings indicate that psychiatric comorbidities (depression and anxiety) predict both pain intensity and pain affect and that total physical comorbidity predicts only pain affect in MS patients, susceptible to cognitive impairment.

Conclusion

Both psychiatric and physical comorbidities predict pain affect. All three clinical outcomes enhance MS patients’ suffering.

Chronic pain in multiple sclerosis: A 10-year longitudinal study

BACKGROUND AND PURPOSE

Pain is a common symptom associated with multiple sclerosis (MS), and has lasting effects on an individual's functional capacity and quality of life. A wide range of prevalence rates of pain (between 23% and 90%)have been reported in MS and this is mainly due to the methodological differences amongst the studies such as variability in patient sources, method of sampling and the definition of pain used. Chronic pain in MS, defined as pain lasting for greater than 3-6 months, can have a significant impact on their biopsychosocial health, including negative impact on activities of daily living, relationships and social participation. The long-term course of MS-related pain and its impact in an Australian cohort over a 7-year period has been investigated earlier. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period. The aim of this longitudinal study was to describe the impact of chronic pain, pain-related disability and carer burden in persons with MS over a 10-year period.

METHODS

This was a prospective longitudinal study conducted at the Rehabilitation Department of Royal Melbourne Hospital (RMH), a tertiary referral hospital in Victoria and Australia. The source of participants was from the RMH MS database and contains detailed MS patient information including demographic data, diagnosis details (using McDonald's criteria), pain characteristics. Structured face-face interviews and validated measures were used, which include the visual analogue scale (VAS); chronic pain grade (CPG); the assessment of quality of life (AQoL) and the carer strain index (CSI). The mean age of the participants (n=70) was 55.3 years and majority (70%) were female.

RESULTS

The mean age of the participants (n=70) was 55.3 years and majority (70%) were female. The findings show that over time (10 years), participants report having greater bilateral bodily pain and greater description of pain as 'worse as it could be'. Pain types were similar to 7-years follow-up but remained higher than baseline. There was a significant deterioration in quality of life in those with more severe CPG over time. Almost half of the participants 31 (44%) required care either from a private carer, institution or from a family member. Although fear of taking medications and side effects were common barriers to treatment for pain, there was an increase in the use of pharmacological treatment over time and an increase in the use of healthcare services, mainly neurologists and general practitioners.

CONCLUSIONS

The pain measures reported by the participants were similar to those at the 7-year follow-up except there was a greater representation of bilateral pain locations (limb, trunk and facial pain) compared to baseline and 7-year follow-up. At 10-year follow-up, more participants used medications compared to 7-year follow-up and there was an increase in the use of health professionals at the 10-year follow-up. At the 10-year follow up QoL of the participants deteriorated significantly and more participants had progressed to higher CPG III and CPG IV. This study demonstrates that chronic pain is a significant issue over time in MS, with clinical and health implications, impact on quality of life, disability and healthcare utilization.

IMPLICATIONS

Greater awareness of chronic pain in pwMS, cognitive classifications and an interdisciplinary approach is required to improve long-term patient outcomes and well-being.

Prevalence of neuropathic pain in early multiple sclerosis

Background:

Pain is considered a frequent symptom in multiple sclerosis. Neuropathic pain is the type of pain most closely related to the pathology of multiple sclerosis and its prevalence estimates vary largely.

Objective:

We prospectively assessed the prevalence of neuropathic pain in patients with early multiple sclerosis and investigated the association of neuropathic pain with other clinical parameters.

Methods:

A total of 377 outpatients with multiple sclerosis at an early disease stage were included in this prospective study. Mean disease duration was 4.2 years, mean Expanded Disability Status Scale (EDSS) score was 1.6, 96.8% of patients were classified as having relapsing–remitting multiple sclerosis. Neuropathic pain was assessed using the PainDETECT questionnaire (PDQ). Depression, fatigue and cognition were assessed using the Beck Depression Inventory (BDI), the Fatigue Scale for Motor and Cognitive Functions (FSMC) and the Paced Auditory Serial Addition Test.

Results:

PDQ scores indicative of neuropathic pain were found in 4.2% of patients. Regression analysis revealed EDSS, BDI and FMSC scores as strongest predictors of PDQ scores.

Conclusions:

Neuropathic pain appears to be less frequent in early multiple sclerosis than expected and is significantly associated with disability, depression and fatigue. The assessment and therapy of pain in multiple sclerosis should thus take into account neuropsychiatric symptoms already at early disease stages.

The scope and nature of pain in persons with multiple sclerosis

Much remains unknown about the scope, nature, and impact of pain on the lives of persons with multiple sclerosis (MS). In the present study, 180 community dwelling adults with MS completed a postal survey that included demographic measures, MS disease measures, and several standardized measures of pain, including pain intensity, variability, location, and pain-related interference. Some 66% of the sample reported pain, 25% of whom reported severe pain. Persons with pain reported an average of 6.6 distinct pain sites. Using the Brief Pain Inventory Interference Scale, the average level of overall pain interference was 3.33 (0- 10 scale) in the group reporting pain. The highest levels of pain interference were reported for sleep, recreational activities, and work in and outside the home. Persons with pain were more likely to report greater MS disease severity, poorer psychological functioning, and poorer health than persons with MS but not pain. Persons with pain were also less likely to be employed. These findings are consistent with previous research that shows that pain is common in MS, that it is severe in a substantial subset of these individuals and has the potential to negatively impact physical and psychosocial functioning over and above the effects of MS itself.

Pain and affective memory biases interact to predict depressive symptoms in multiple sclerosis

A large literature supports a direct relationship between pain and depressive symptoms among various patient populations. Patients with multiple sclerosis (MS) frequently experience both pain and depression. Despite this, no relationship between pain and depression has been found in MS. The present investigation explored the relationship between pain and depression in a sample of patients with MS. Consistent with cognitive theories of depression, results supported the hypothesis that pain would only contribute to depression when MS patients exhibited a concomitant cognitive vulnerability. Cognitive vulnerability to depression was measured using a performance based affective memory bias (AMB) task. Patients with high levels of pain and negative AMB reported more depressive symptoms compared to patients with pain and positive AMB. Implications for the identification and treatment of depression in MS are discussed.

Chronic Pain in Multiple Sclerosis Patients: Utility of Sensory Quantitative Testing in Patients with Fibromyalgia Comorbidity

BACKGROUND

Lower thermal and discomfort thresholds may predispose multiple sclerosis (MS) patients to chronic pain, but a possible effect of fibromyalgia (FM) comorbidity has never been investigated. Aims were to investigate the thermal and discomfort thresholds in the evaluation of pain intensity between MS patients with FM (PFM+) and MS patients with pain not associated to FM (PFM-).

METHODS

One hundred thirty three MS patients were investigated for chronic pain. FM was assessed according to the 1990 ACR diagnostic criteria. An algometer was used to measure the thresholds in the patients and 60 matched healthy subjects.

RESULTS

Chronic pain was present in 88 (66.2%) patients; 12 (13.6%) had neuropathic pain, 22 (17.3%) were PFM+ and 65 (48.9%) PFM-. PFM+ were predominantly female (p = 0.03) and had a greater EDSS (p = 0.01) than NoP; no other significant differences emerged than PFM-. The thresholds were lower in MS patients than controls (p < 0.01), mainly in the PFM+. FM severity influenced the thermal threshold (p < 0.001), while the female gender influenced the discomfort threshold (p < 0.001).

CONCLUSION

Thermal and discomfort thresholds were lower in patients than controls and were the lowest in PFM+. Their more severely impaired thermal threshold supports a neurophysiological basis of such association.

Inflammation triggers production of dimethylsphingosine from oligodendrocytes

Neuropathic pain is a chronic, refractory condition that arises after damage to the nervous system. We previously showed that an increased level of the endogenous metabolite N,N-dimethylsphingosine (DMS) in the central nervous system (CNS) is sufficient to induce neuropathic pain-like behavior in rats. However, several important questions remain. First, it has not yet been demonstrated that DMS is produced in humans and its value as a therapeutic target is therefore unknown. Second, the cell types within the CNS that produce DMS are currently unidentified. Here we provide evidence that DMS is present in human CNS tissue. We show that DMS levels increase in demyelinating lesions isolated from patients with multiple sclerosis, an autoimmune disease in which the majority of patients experience chronic pain. On the basis of these results, we hypothesized that oligodendrocytes may be a cellular source of DMS. We show that human oligodendrocytes produce DMS in culture and that the levels of DMS increase when oligodendrocytes are challenged with agents that damage white matter. These results suggest that damage to oligodendrocytes leads to increased DMS production which in turn drives inflammatory astrocyte responses involved in sensory neuron sensitization. Interruption of this pathway in patients may provide analgesia without the debilitating side effects that are commonly observed with other chronic pain therapies.

Chronic pain in multiple sclerosis: is there also fibromyalgia? An observational study

Background

Chronic pain is common in persons with multiple sclerosis (MS), but the co-morbidity of fibromyalgia (FM) has yet to be investigated in MS. Objectives of the study were to evaluate, among the various types of chronic pain, the frequency of FM in MS and its impact on MS patients’ health-related quality of life (HRQoL).

Material/Methods

133 MS patients were investigated for the presence and characterization of chronic pain within 1 month of assessment. A rheumatologist assessed the presence FM according to the 1990 ACR diagnostic criteria. Depression, fatigue, and HRQoL were also assessed by means of specific scales.

Results

Chronic pain was present in 66.2% of patients (musculoskeletal in 86.3%; neuropathic in 13.7%; absent in 33.8% [called NoP]). Pain was diagnosed with FM (PFM+) in 17.3% of our MS patients, while 48.9% of them had chronic pain not FM type (PFM−); the prevalence of neuropathic pain in these 2 sub-groups was the same. PFM+ patients were prevalently females and had a higher EDSS than NoP. The PFM+ patients had a more pronounced depression than in the NoP group, and scored the worst in both physical and mental QoL.

Conclusions

In our sample of MS patients we found a high prevalence of chronic pain, with those patients displaying a higher disability and a more severe depression. Moreover, FM frequency, significantly higher than that observed in the general population, was detected among the MS patients with chronic pain. FM occurrence was associated with a stronger impact on patients’ QoL.

Mechanisms and pharmacology of neuropathic pain in multiple sclerosis

The neuropathic pain of multiple sclerosis is quite prevalent and severely impacts quality of life. A few randomized, placebo-controlled, blinded clinical trials suggest that cannabis- and anticonvulsant-based treatments provide partial pain relief, but at the expense of adverse events. An even smaller, but emerging, number of translational studies are using rodent models of experimental autoimmune encephalomyelitis (EAE), which exhibit pain-like behaviors resembling those of Multiple sclerosis (MS) patients. These studies not only support the possible effectiveness of anticonvulsants, but also compel further clinical trials with serotonin-norepinephrine reuptake inhibitors, the immunosuppressant drug rapamycin, or drugs which interfere with glutamatergic neurotransmission. Future behavioral studies in EAE models are essential toward a new pharmacotherapy of multiple sclerosis pain.

Pharmacological treatment of pain in multiple sclerosis

Pain is a common symptom in multiple sclerosis (MS) and was recently estimated to be experienced by up to 75% of patients. Nociceptive and neuropathic pain in MS may be present concurrently and at different stages of the disease and may be associated with other symptoms. Evidence for treating pain in MS is limited. Many clinical features of pain are often unrecognized by clinicians and are difficult for patients to describe. Treatment is often based on anecdotal reports and clinical experience. We present a review of treatment options for pain in MS that should serve to update current knowledge, highlight shortcomings in clinical research and provide indications towards achieving evidence-based treatment of pain in MS.

Symptomatic treatment and management of multiple sclerosis

The range of symptoms which occur in multiple sclerosis (MS) can have disabling functional consequences for patients and lead to significant reductions in their quality of life. MS symptoms can also interact with each other, making their management challenging. Clinical trials aimed at identifying symptomatic therapies have generally been poorly designed and have tended to be underpowered. Therefore, the evidence base for the management of MS symptoms with pharmacologic therapies is not strong and tends to rely upon open-label studies, case reports, and clinical trials with small numbers of patients and poorly validated clinical outcome measures. Recently, there has been a growing interest in the management of MS symptoms with pharmacologic treatments, and better-designed, randomized, double-blind, controlled trials have been reported. This chapter will describe the evidence base predominantly behind the various pharmacologic approaches to the management of MS symptoms, which in most, if not all, cases, requires multidisciplinary input. Drugs routinely recommended for individual symptoms and new therapies, which are currently in the development pipeline, will be reviewed. More interventional therapies related to symptoms that are refractory to pharmacotherapy will also be discussed, where relevant.

Does pain in individuals with multiple sclerosis affect employment? A systematic review and meta-analysis

BACKGROUND

Individuals with multiple sclerosis (MS) experience some of the highest unemployment rates among all groups of chronic illnesses. Pain has been found to be a common reason for sick leave or early retirement in healthy populations or other groups with chronic illness; however, there is little awareness regarding the effect of pain on the work status of individuals with MS.

OBJECTIVES

To estimate the extent to which individuals with pain differ in employment status compared with those without pain among MS patients.

METHODS

An extensive systematic review of the scientific literature was performed within the framework of the Cochrane Collaboration to identify studies focusing on the effect of pain on employment in individuals with MS. The following databases were searched: PubMed, EMBASE, PsychInfo, Web of Science, MD Consult and Elsevier, and Science Direct. The methodological quality of studies was assessed using the McMaster Critical Review Form.

RESULTS

Ten articles met the inclusion criteria and were included in the systematic review. Of these studies, five that exhibited clinical, methodological and statistical homogeneity were included in the meta-analysis. The between-groups (pain + versus pain -) pooled random OR of being employed was 0.7 (strong), and was significantly different from unity (95% CI 0.5 to 0.9; P=0.001).

CONCLUSIONS

The results of the present study indicated that individuals with MS who experience pain were significantly more likely to report a decreased employment rate than individuals with MS who were pain free.

Age and the role of restricted activities in adjustment to disability-related pain

Chronic pain is common in individuals with multiple sclerosis and spinal cord injury and is associated with depressed mood. This may be because pain creates interference in performing and enjoying valued activities. The importance of pain interference may also vary with age, since older adults may have lowered expectations regarding function. This study analyzed relationships among pain variables, age, and mood in 521 individuals with multiple sclerosis or spinal cord injury. As predicted, pain interference mediated the relationship between pain severity and depressed mood. There was no evidence that older adults were less distressed by pain interference than were younger adults.

Poor sleep in patients with multiple sclerosis

Background

Poor sleep is a frequent symptom in patients with multiple sclerosis (MS). Sleep may be influenced by MS-related symptoms and adverse effects from immunotherapy and symptomatic medications. We aimed to study the prevalence of poor sleep and the influence of socio-demographic and clinical factors on sleep quality in MS- patients.

Methods

A total of 90 MS patients and 108 sex-and age- matched controls were included in a questionnaire survey. Sleep complaints were evaluated by Pittsburgh Sleep Quality Index (PSQI) and a global PSQI score was used to separate good sleepers (≤5) from poor sleepers (>5). Excessive daytime sleepiness, the use of immunotherapy and antidepressant drugs, symptoms of pain, depression, fatigue and MS-specific health related quality of life were registered. Results were compared between patients and controls and between good and poor sleepers among MS patients.

Results

MS patients reported a higher mean global PSQI score than controls (8.6 vs. 6.3, p = 0.001), and 67.1% of the MS patients compared to 43.9% of the controls (p = 0.002) were poor sleepers. Pain (p = 0.02), fatigue (p = 0.001), depression (p = 0.01) and female gender (p = 0.04) were associated with sleep disturbance. Multivariate analyses showed that female gender (p = 0.02), use of immunotherapy (p = 005) and a high psychological burden of MS (p = 0.001) were associated with poor sleep among MS patients.

Conclusions

Poor sleep is common in patients with MS. Early identification and treatment of modifiable risk factors may improve sleep and quality of life in MS.

Pain in experimental autoimmune encephalitis: a comparative study between different mouse models

BACKGROUND

Pain can be one of the most severe symptoms associated with multiple sclerosis (MS) and develops with varying levels and time courses. MS-related pain is difficult to treat, since very little is known about the mechanisms underlying its development. Animal models of experimental autoimmune encephalomyelitis (EAE) mimic many aspects of MS and are well-suited to study underlying pathophysiological mechanisms. Yet, to date very little is known about the sensory abnormalities in different EAE models. We therefore aimed to thoroughly characterize pain behavior of the hindpaw in SJL and C57BL/6 mice immunized with PLP139-151 peptide or MOG35-55 peptide respectively. Moreover, we studied the activity of pain-related molecules and plasticity-related genes in the spinal cord and investigated functional changes in the peripheral nerves using electrophysiology.

METHODS

We analyzed thermal and mechanical sensitivity of the hindpaw in both EAE models during the whole disease course. Qualitative and quantitative immunohistochemical analysis of pain-related molecules and plasticity-related genes was performed on spinal cord sections at different timepoints during the disease course. Moreover, we investigated functional changes in the peripheral nerves using electrophysiology.

RESULTS

Mice in both EAE models developed thermal hyperalgesia during the chronic phase of the disease. However, whereas SJL mice developed marked mechanical allodynia over the chronic phase of the disease, C57BL/6 mice developed only minor mechanical allodynia over the onset and peak phase of the disease. Interestingly, the magnitude of glial changes in the spinal cord was stronger in SJL mice than in C57BL/6 mice and their time course matched the temporal profile of mechanical hypersensitivity.

CONCLUSIONS

Diverse EAE models bearing genetic, clinical and histopathological heterogeneity, show different profiles of sensory and pathological changes and thereby enable studying the mechanistic basis and the diversity of changes in pain perception that are associated with distinct types of MS.

Defining mild, moderate, and severe pain in persons with multiple sclerosis

OBJECTIVE

  To identify empirically derived cutoffs for mild, moderate, and severe pain in persons with multiple sclerosis (MS). Design.  Cross-sectional survey.

SETTING

.  Community-based survey.

PARTICIPANTS

  Convenience sample of 236 individuals with MS and pain. Intervention.  Not applicable.

MAIN OUTCOME MEASURES

  Zero to 10 Numeric Rating Scale for pain severity (both average and worst pain) and Brief Pain Inventory for pain interference.

RESULTS

  The optimal classification scheme for average pain was 0-2 = mild, 3-5 = moderate, and 6-10 = severe. Alternatively, the optimal classification scheme for worst pain was 0-4 = mild, 5-7 = moderate, and 8-10 = severe.

CONCLUSIONS

  The present study furthers our ability to use empirically based cutoffs to inform the use of clinical guidelines for pain treatment as well as our understanding of the factors that might impact the cutoffs that are most appropriate for specific pain populations. The results of the present study also add to the existing literature by drawing similarities to studies of other populations, but also by highlighting that clear, between-condition differences may exist that warrant using different cutoffs for patients with different medical conditions. Specifically, the present study highlights that cutoffs may be lower for persons with MS than other populations of persons with pain.

Change in disability profile and quality of life in multiple sclerosis patients: a five-year longitudinal study using the Multiple Sclerosis Impact Profile (MSIP)

Background: Evidence on the progress of disease severity in Multiple Sclerosis (MS) is generally limited in scope.

Objectives: To examine the course of a broad spectrum of MS-related disabilities and quality of life (QOL) in relation to disease severity, and responsiveness of the Multiple Sclerosis Impact Profile (MSIP).

Methods: The mortality rate was calculated after checking the national population register for vital status of the initial cohort. We performed a longitudinal study among 245 patients with MS attending the Groningen MS Center in the Netherlands. We assessed these patients in 2004 and 2009 using a postal survey including the MSIP to evaluate disabilities, the World Health Organization Quality of Life-Abbreviation version (WHOQOL-BREF) to evaluate QOL, and the ambulation question of the Expanded Disability Status Scale (EDSS) to evaluate disease severity. Responsiveness of the MSIP was estimated using standardized response mean (SRM).

Results: Increase of disability in the MSIP disability domains and loss of QOL were most prevalent and pronounced in patients with EDSS 0 to < 4.5 in 2004. MSIP and QOL scores were remarkably stable in the higher disease severity groups. Mortality rates were highest (24%) in patients with EDSS ≥ 7 to < 10 in 2004. SRM indices for the MSIP ranged between 0.26 and 0.56.

Conclusions: Prominent increases in multiple aspects of disability and loss of QOL occur especially in the early stages in MS. Health care interventions may lead to health and QOL gains, in particular when offered to patients in the first stage of the MS process. Responsiveness was sufficient for nine of the 11 MSIP domains.

Depression in multiple sclerosis: reactive or endogenous?

Multiple sclerosis is associated with high rates of depression. The extent to which this is related to living with chronic illness or part of the disease process remains unclear. This question was investigated by comparing rates of depression in MS with those in rheumatoid arthritis, which involves similar physical and psychosocial stressors but without central nervous system involvement. The study involved an on-line survey, which included measures of depression not confounded by somatic symptoms, medication use, self-reported physical functioning, pain, and other demographic variables. Results indicated that disease group (multiple sclerosis, rheumatoid arthritis) independently predicted depression above and beyond demographic and disease-related variables. Results support the hypothesis that depression in MS is partly determined by direct neurological consequences of the condition.

Central pain in multiple sclerosis - sensory abnormalities

Many patients with multiple sclerosis (MS) develop central neuropathic pain (CP). In the present study somatosensory abnormalities have been analysed in detail in 62 patients with MS and CP (42 women, 20 men; mean age 52 years) and in a control group of 10 women and 6 men (mean age 47 years) with MS and sensory symptoms, but without pain. Assessment included clinical testing and quantitative methods (QST) for the measurement of perception thresholds for touch, vibration, and temperatures. All CP patients except two (97%) had abnormal thresholds for innoxious and/or noxious temperatures, compared to 81% in the control group (p<0.05). There was a tendency towards the opposite regarding sensibility to touch, which was decreased in 66% vs. 87% (n.s.), vibration (55% vs. 81%; n.s.) and to joint movement (32% vs. 62%; p<0.04). Comparisons between painful and non-painful regions showed both the absolute threshold values and the index values to be significantly more abnormal, in the CP regions, for warmth (p<0.001), cold (p<0.05), difference limen (innoxious warmth and cold, p<0.01), cold pain (p<0.01) and heat pain/cold pain combined (p<0.001). Also the comparisons between regions with central pain and regions with sensory symptoms in the controls showed significantly more abnormal thresholds in the CP patients for warmth (p<0.05), cold (p<0.01), difference limen (innoxious warmth and cold, p<0.01) and heat pain/cold pain combined (p<0.001). The results support the general hypothesis that only patients who have lesions affecting the spinothalamo-cortical pathways run the risk of developing central pain.

A comparison of self-hypnosis versus progressive muscle relaxation in patients with multiple sclerosis and chronic pain

Twenty-two patients with multiple sclerosis (MS) and chronic pain we recruited into a quasi-experimental trial comparing the effects of self-hypnosis training (HYP) with progressive muscle relaxation (PMR) on pain intensity and pain interference; 8 received HYP and the remaining 14 participants were randomly assigned to receive either HYP or PMR. HYP-condition participants reported significantly greater pre- to postsession as well as pre- to posttreatment decreases in pain and pain interference than PMR-condition participants, and gains were maintained at 3-month follow-up. Most of the participants in both conditions reported that they continued to use the skills they learned in treatment and experienced pain relief when they did so. General hypnotizability was not significantly related to treatment outcome, but treatment-outcome expectancy assessed before and after the first session was. The results support the efficacy of self-hypnosis training for the management of chronic pain in persons with MS.

Illness and demographic correlates of chronic pain among a community-based sample of people with multiple sclerosis

OBJECTIVE

To investigate the prevalence, nature, and correlates of pain among a community-based sample with multiple sclerosis (MS).

DESIGN

A cross-sectional survey and structured pain interview.

SETTING

Community.

PARTICIPANTS

People with MS (N=219) recruited through systematic sampling from a randomly ordered MS society membership database.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURES

Pain presence or absence, pain intensity (numeric rating scales), pain quality (McGill Pain Questionnaire), pain location(s) and extent (pain drawing), pain duration and frequency, provoking and relieving pain factors, and pain management techniques.

RESULTS

Pain was common with some 67.1% of the sample reporting pain during the 2 weeks preceding the study. Comprehensive pain assessment revealed that a substantial subset of these subjects experience chronic pain conditions characterized by moderate-to-severe pain intensity. Among those with pain, 75% reported pain in 3 or more locations, with participants reporting an average of 4.0+/-1.8 distinct pain sites. Women and people with more severe MS-related disability were significantly more likely to report both the presence of pain and greater pain intensity. In contrast, being in a married or in a de facto relationship and longer time since MS diagnosis were significantly associated with lower pain intensity.

CONCLUSIONS

Given the high prevalence and nature of pain experienced by people with MS, health care providers need to approach pain with a priority similar to that given to other MS-related problems such as mobility and functional independence. Women and people with more severe MS-related disability appear to be at particular risk for significant pain problems and therefore these groups warrant particular attention, such that routine clinical assessment should trigger routine pain assessment.

Biopsychosocial correlates of adjustment to pain among people with multiple sclerosis

OBJECTIVES

The objective of this study was to examine the extent to which pain-related beliefs and coping strategies predicted measures of adjustment to pain among people with multiple sclerosis (MS), over and above that accomplished by demographic and clinical variables.

METHODS

Participants were a community-based sample of people with chronic MS-related pain (N=105) who completed postal surveys and standardized interviews that included measures of demographic and MS-related variables, typical pain intensity, psychologic functioning, pain interference, pain beliefs, and coping strategies.

RESULTS

Pain-specific beliefs and coping strategies were associated with and explained a significant proportion of the variance in adjustment to pain (24% to 34%) among people with MS, over and above that accomplished by demographic and disease-related variables and pain intensity. Compatible with previous studies, greater endorsement of pain constancy and catastrophizing were significant predictors of poorer adjustment, whereas perceived ability to decrease pain and increasing behavioral activities in response to pain were related to positive adaptation.

DISCUSSION

These findings provide support for the premise that psychosocial factors remain central in disability-related pain and suggest the possibility that interventions targeting these variables would reduce the negative impact of pain among people with MS.

Pain in multiple sclerosis: a clinical and instrumental approach

BACKGROUND

Pain is a frequent and disabling symptom in multiple sclerosis (MS) patients. In this study we assess the frequency and intensity of pain, as well as its impact on the quality of life and activities of daily living, in a sample of MS patients.

METHODS

One hundred and twenty eight MS patients underwent a neurological examination, a structured interview designed to assess pain, and a Medical Outcome 36-item Short Form Health Survey. Functional status was assessed by means of the Barthel Index (BI) and Rivermead Mobility Index. We also assessed the presence of depression, by means of the Montgomery and Asberg Depression Rating Scale, and fatigue, by means of the Fatigue Severity Scale. An algometer was used to measure thermal and discomfort thresholds in all of the patients and a group of 61 age- and sex-matched healthy subjects.

RESULTS

Pain was present in 61 patients. No differences were found between patients with and those without pain in disease duration, disease form or Expanded Disability Status Scale and its functional systems. Patients with pain had a lower vitality score (p = 0.008), mental health score (p = 0.03) and physical (p < 0.001) and mental composite scores (p = 0.01) than patients without pain. Furthermore, there was a significant difference between patients with and those without pain in the BI (p = 0.04). Both thermal and discomfort thresholds, as assessed by means of the algometer, were statistically lower in MS patients than in controls, whereas no difference was observed between patients with and those without pain. There was a statistically significant improvement in the thermal threshold in patients with pain who were treated pharmacologically when compared with those who were not treated (p = 0.049).

CONCLUSION

The results of this study provide further evidence of the negative impact that the presence of pain has on both the quality of life and activities of daily living in MS patients. The lower thermal and discomfort thresholds observed in our MS patients, compared with controls, may represent a predisposition to develop pain during the course of the disease.

Depression in multiple sclerosis: review and theoretical proposal

Because of its high prevalence and implications for quality of life and possibly even disease progression, depression has been intensively studied in multiple sclerosis (MS) over the past 25 years. Despite the publication of numerous excellent empirical research papers on this topic during that time, the publication of theoretical work that attempts to explain depression in a comprehensive way is scarce. In this study, we present a theoretical model that attempts to integrate existing work on depression in MS and provide testable hypotheses for future work. The model suggests that risk for depression begins with the onset of MS. MS results in disease-related changes such as increased lesion burden/brain atrophy and immunological anomalies that are associated with depression in MS, but explain only a relatively limited proportion of the variance. Common sequelae of MS including fatigue, physical disability, cognitive dysfunction, and pain, have all been shown to have an inconsistent or relatively weak relationship to depression in the literature. In the model, we propose that four variables--social support, coping, conceptions of the self and illness, and stress--may moderate the relationship between the above common MS sequelae with depression and help to explain inconsistencies in the literature.

Current management of pain associated with multiple sclerosis

While pain is a common problem in patients with multiple sclerosis (MS), it is not frequently mentioned by patients and a more direct approach is required in order to obtain information about pain from patients. Many patients with MS experience more than one pain syndrome; combinations of dysaesthesia, headaches and/or back or muscle and joint pain are frequent. For each pain syndrome a clear diagnosis and therapeutic concept needs to be established. Pain in MS can be classified into four diagnostically and therapeutically relevant categories: (i) neuropathic pain due to MS (pain directly related to MS); (ii) pain indirectly related to MS; (iii) MS treatment-related pain; and (iv) pain unrelated to MS. Painful paroxysmal symptoms such as trigeminal neuralgia (TN), or painful tonic spasms are treated with antiepileptics as first choice, e.g. carbamazepine, oxcarbazepine, lamotrigine, gabapentin, pregabalin, etc. Painful 'burning' dysaesthesias, the most frequent chronic pain syndrome, are treated with TCAs such as amitriptyline, or antiepileptics such as gabapentin, pregabalin, lamotrigine, etc. Combinations of drugs with different modes of action can be particularly useful for reducing adverse effects. While escalation therapy may require opioids, there are encouraging results from studies regarding cannabinoids, but their future role in the treatment of MS-related pain has still to be determined. Pain related to spasticity often improves with adequate physiotherapy. Drug treatment includes antispastic agents such as baclofen or tizanidine and in patients with phasic spasticity, gabapentin or levetiracetam are administered. In patients with severe spasticity, botulinum toxin injections or intrathecal baclofen merit consideration. While physiotherapy may ameliorate malposition-induced joint and muscle pain, additional drug treatment with paracetamol (acetaminophen) or NSAIDs may be useful. Moreover, painful pressure lesions should be avoided by using optimally adjusted aids. Treatment-related pain associated with MS can occur with subcutaneous injections of interferon-beta or glatiramer acetate, and may be reduced by optimizing the injection technique and by local cooling. Systemic (particularly 'flu-like') adverse effects of interferons, e.g. myalgias, can be reduced by administering paracetamol, ibuprofen or naproxen. A potential increase in the frequency of pre-existing headaches after starting treatment with interferons may require optimization of headache attack therapy or even prophylactic treatment. Pain unrelated to MS, such as back pain or headache, is common in patients with MS and may deteriorate as a result of the disease. In summary, a careful analysis of each pain syndrome will allow the design of the appropriate treatment plan using various medical and nonmedical options (multimodal therapy), and will thus help to improve the quality of life (QOL) of the patients.