Systematic assessment and characterization of chronic pain in multiple sclerosis patients

Pharmacological and Non-pharmacological Approaches for the Management of Neuropathic Pain in Multiple Sclerosis

Multiple sclerosis is a chronic inflammatory disease that affects the central nervous system and can cause various types of pain including ongoing extremity pain, Lhermitte's phenomenon, trigeminal neuralgia, and mixed pain. Neuropathic pain is a major concern for individuals with multiple sclerosis as it is directly linked to myelin damage in the central nervous system and the management of neuropathic pain in multiple sclerosis is challenging as the options available have limited efficacy and can cause unpleasant side effects. The literature search was conducted across two databases, PubMed, and Google Scholar. Eligible studies included clinical trials, observational studies, meta-analyses, systematic reviews, and narrative reviews. The objective of this article is to provide an overview of literature on pharmacological and non-pharmacological strategies employed in the management of neuropathic pain in multiple sclerosis. Pharmacological options include cannabinoids, muscle relaxants (tizanidine, baclofen, dantrolene), anticonvulsants (benzodiazepines, gabapentin, phenytoin, carbamazepine, lamotrigine), antidepressants (duloxetine, venlafaxine, tricyclic antidepressants), opioids (naltrexone), and botulinum toxin variants, which have evidence from various clinical trials. Non-pharmacological approaches for trigeminal neuralgia may include neurosurgical methods. Non-invasive methods, physical therapy, and psychotherapy (cognitive behavioral therapy, acceptance and commitment therapy and mindfulness-based stress reduction) may be recommended for patients with neuropathic pain in multiple sclerosis. The choice of treatment depends on the severity and type of pain as well as other factors, such as patient preferences and comorbidities. There is a pressing need for healthcare professionals and researchers to prioritize the development of better strategies for managing multiple sclerosis-induced neuropathic pain.

A systematic review and meta-analysis of neuropathic pain in multiple sclerosis: Prevalence, clinical types, sex dimorphism, and increased depression and anxiety symptoms

Chronic pain is the most disability symptom related to multiple sclerosis (MS) brain lesions and can also generate anxiety and depression. There are no updated reports of the general prevalence of neuropathic pain, MS clinical types, sex dimorphism, and its association with depression and anxiety. The protocol was listed in PROSPERO (CRD42022303571). The article selection resulted in 24 studies with a low risk of bias. The prevalence of neuropathic pain in MS patients was 26.8% with higher levels of depression and anxiety. We also observed that female patients (74.2%) have a higher prevalence of neuropathic pain than males (28.9%). We showed the enhanced prevalence of neuropathic pain using the female and male data (58.9%) compared to the total prevalence (26.8%). In addition, the SPMS (40.3%) presented an increased prevalence of neuropathic pain compared to PPMS (15.6%). Thus, we demonstrated the association between neuropathic pain, depression and anxiety symptoms and the influence of diagnosis, age, disease score, and disease duration in the increased prevalence of neuropathic pain in MS patients.

Interim guidelines for the assessment and treatment of pain in children with multiple sclerosis

Introduction

Pain in multiple sclerosis (MS) is common, but literature on pain in children with MS remains scarce. Pain has physical, psychological, and social implications in MS, and both comprehensive assessment and interdisciplinary management approaches are needed. We sought to develop an interdisciplinary interim guideline for the assessment and management of pain in children with MS.

Methods and materials

We convened a modified Delphi panel composed of 13 experts in pediatric and adult MS neurology, physiotherapy, pain, patient lived-experience, advanced practice nursing, psychology, physiatry, and MS research. A survey was sent to panelists for anonymous completion. The panel discussed survey themes extracted by the panel chair. The process was repeated twice.

Results

Thirteen assessment and treatment recommendations were produced regarding pain in children with MS.

Discussion

Future studies will assess implementation of these pain assessment and treatment guidelines in the clinical setting.

Research trends and hotspots of neuropathic pain in neurodegenerative diseases: a bibliometric analysis

Background

Neuropathic pain is caused by a neurological injury or disease and can have a significant impact on people's daily lives. Studies have shown that neuropathic pain is commonly associated with neurodegenerative diseases. In recent years, there has been a lot of literature on the relationship between neuropathic pain and neurodegenerative diseases. However, bibliometrics is rarely used in analyzing the general aspects of studies on neuropathic pain in neurodegenerative diseases.

Methods

The bibliometric analysis software CiteSpace and VOSviewer were used to analyze the knowledge graph of 387 studies in the Science Citation Index Expanded of the Web of Science Core Collection Database.

Results

We obtained 2,036 documents through the search, leaving 387 documents after culling. 387 documents were used for the data analysis. The data analysis showed that 330 papers related to neuropathic pain in neurodegenerative diseases were published from 2007-2022, accounting for 85.27% of all published literature. In terms of contributions to the scientific study of neuropathic pain, the United States is in the top tier, with the highest number of publications, citations, and H-indexes.

Conclusion

The findings in our study may provide researchers with useful information about research trends, frontiers, and cooperative institutions. Multiple sclerosis, Parkinson's disease, and Alzheimer's disease are the three most studied neurodegenerative diseases. Among the pathological basis of neurodegenerative diseases, microglia-regulated neuroinflammation is a hot research topic. Deep brain stimulation and gamma knife radiosurgery are two popular treatments.

Pain and participation in social activities in people with relapsing remitting and progressive multiple sclerosis

Background

Differences in pain between subtypes of multiple sclerosis are understudied.

Objective

To compare the prevalence of pain, and the association between pain and: (a) pain interference and (b) social participation in people with relapsing-remitting multiple sclerosis and progressive multiple sclerosis.

Methods

Participants completed the McGill Pain Questionnaire Short-Form-2, Pain Effects Scale and Ability to Participate in Social Roles and Activities-V2.0 questionnaires. We tested the association between multiple sclerosis subtype, pain severity, and pain interference/social participation using quantile regression.

Results

Of 231 participants (relapsing-remitting multiple sclerosis: 161, progressive multiple sclerosis: 70), 82.3% were women. The prevalence of pain was 95.2%, of more than mild pain was 38.1%, and of pain-related limitations was 87%; there were no differences between multiple sclerosis subtypes. Compared to participants with relapsing-remitting multiple sclerosis, those with progressive multiple sclerosis reported higher pain interference (mean (standard deviation) Pain Effects Scale; progressive multiple sclerosis: 15[6.0] vs relapsing-remitting multiple sclerosis: 13[5], p = 0.039) and lower social participation (Ability to Participate in Social Roles and Activities T-scores 45[9.0] vs 48.3[8.9], p = 0.011). However, on multivariable analysis accounting for age, physical disability, mood/anxiety and fatigue, multiple sclerosis subtype was not associated with differences in pain interference or social participation.

Conclusions

Pain was nearly ubiquitous. Over one-third of individuals with relapsing-remitting multiple sclerosis and progressive multiple sclerosis reported pronounced pain, although this did not differ by multiple sclerosis subtype.

Pain in patients with multiple sclerosis

Objectives

This study aims to identify the factors associated with pain and neuropathic pain (NP) in patients with multiple sclerosis (MS) and to determine the relationship between pain and NP with disability, functionality, activities of daily living, fatigue, mood, and quality of life (QoL).

Patients and methods

Between July 2017 and October 2017, a total of 100 adult patients with MS (18 males, 82 females; mean age: 35.3±9.9 years; range, 19 to 71 years) were included. All patients were evaluated in terms of pain and NP. Patients with and without pain, and patients with and without NP were compared in terms of sociodemographic characteristics, disease data, disability, functionality, daily living activities, fatigue severity, mood, and QoL using various scales.

Results

A total of 62% of the patients had pain. Pain was found to be associated with low education level (p=0.014), increased fatigue (p<0.001), depressive mood (p<0.001) and lower QoL (p<0.001). A total of 29.03% of patients with pain had NP. Patients with NP had a greater pain intensity (p<0.001) and fatigue (p=0.002) and lower QoL (p=0.011). The number of patients who received the correct treatment for their symptoms was low.

Conclusion

Pain and NP should be better investigated and treated by physicians, as these symptoms are common in MS and adversely affect the QoL and social relations of affected patients and reduce their productivity.

Neuropathic pain, cognitive fusion, and alexithymia in patients with multiple sclerosis: Cross-sectional evidence for an explanatory model of anxiety symptoms

Multiple sclerosis (MS) presents a high prevalence, a marked increase worldwide, and a relevant impact on patients, public health, and society. Anxiety often cooccurs with MS and can contribute to the worsening of MS symptoms. However, knowledge about predictors of anxiety in Patients with MS (PwMS) is scarce.

OBJECTIVE

This preliminary study explored a novel model for anxiety symptoms in PwMS, including neuropathic pain (NeP), cognitive fusion (CF), experiential avoidance (EA), and alexithymia as explanatory factors.

METHOD

This cross-sectional study integrated two independent convenience samples: 107 PwMS recruited from the Portuguese Society for Multiple Sclerosis and 97 age- and gender-matched participants without the MS diagnosis (no-MS sample) recruited from the Portuguese general population. Self-report questionnaires that measured the constructs included in the model were administered to both groups.

RESULTS

PwMS showed significantly higher values regarding anxiety symptoms and their explanatory variables (NeP, CF, EA, alexithymia) in comparison to non-MS participants. In the MS sample, no correlations were found between anxiety symptoms and sociodemographic and clinical characteristics. NeP, CF, and alexithymia showed significant correlations with anxiety symptoms and significantly explained this symptomatology in simple linear regression models. Thus, these variables were retained in the multiple linear regression model and emerged as significant regressors that together explained 38% of the variance in anxious symptomatology in PwMS.

CONCLUSIONS

This preliminary study provides novel evidence on NeP and some maladaptive emotion regulation strategies related to EA/psychological inflexibility, as vulnerability to anxiety in PwMS can be considerably increased by CF and alexithymia. Clinical implications were discussed.

Lower corticospinal excitability and greater fatigue among people with multiple sclerosis experiencing pain

Introduction

Persons with multiple sclerosis (MS) frequently report pain that negatively affects their quality of life. Evidence linking pain and corticospinal excitability in MS is sparse. We aimed to (1) examine differences in corticospinal excitability in MS participants with and without pain and (2) explore predictors of pain.

Methods

Sixty-four participants rated their pain severity on a visual analog scale (VAS). Transcranial magnetic stimulation (TMS) and validated clinical instruments characterized corticospinal excitability and subjective disease features like mood and fatigue. We retrieved information on participants' prescriptions and disability status from their clinical records.

Results

Fifty-five percent of participants reported pain that affected their daily functioning. Persons with pain had significantly greater fatigue and lower area under the excitatory motor evoked potential (MEP) recruitment curve (eREC AUC), a measure of total corticospinal excitability. After controlling for age, disability status, and pain medications, increased fatigue and decreased eREC AUC together explained 40% of the variance in pain.

Discussion

Pain in MS is multifactorial and relates to both greater fatigue and lesser corticospinal excitability. Future work should better characterize relationships between these outcomes to develop targeted pain interventions such as neuromodulation.

Summary

We examined pain in MS. Individuals with pain had higher fatigue and lower corticospinal excitability than those without pain. These outcomes significantly predicted self-reported pain.

Sex Differences in the Behavioural Aspects of the Cuprizone-Induced Demyelination Model in Mice

Multiple sclerosis is an autoimmune disease characterised by demyelination in the central nervous system. The cuprizone-induced demyelination model is often used in mice to test novel treatments for multiple sclerosis. However, despite significant demyelination, behavioural deficits may be subtle or have mixed results depending on the paradigm used. Furthermore, the sex differences within the model are not well understood. In the current study, we have sought to understand the behavioural deficits associated with the cuprizone-induced demyelination model in both male and female C57BL/6J mice. Using Black gold II stain, we found that cuprizone administration over 6 weeks caused significant demyelination in the corpus callosum that was consistent across both sexes. Cuprizone administration caused increased mechanical sensitivity when measured using an electronic von Frey aesthesiometer, with no sex differences observed. However, cuprizone administration decreased motor coordination, with more severe deficits seen in males in the horizontal bar and passive wire hang tests. In contrast, female mice showed more severe deficits in the motor skill sequence test. Cuprizone administration caused more anxiety-like behaviours in males compared to females in the elevated zero maze. Therefore, this study provides a better understanding of the sex differences involved in the behavioural aspects of cuprizone-induced demyelination, which could allow for a better translation of results from the laboratory to the clinic.

Keeping it together: The role of social integration on health and psychological well-being among individuals with multiple sclerosis

Research indicates that people with multiple sclerosis (MS) are more likely to report poorer health and well-being than their peers without MS. Fortunately, it is also known that an individual's social and lifestyle factors play a great role on maintaining and promoting one's health and overall well-being. The present study aimed to examine the role that social integration and social support, in particular have on health and psychological well-being (PWB) among individuals with MS. One hundred and eighty three individuals with MS completed measures of social and lifestyle factors, personality, physical and mental health, MS disease symptomatology and PWB. Cross sectional, regression analyses were conducted to determine the role of social and other lifestyle factors (e.g., diet/exercise) on health and PWB. A subset of this sample (108) completed a follow-up assessment. Longitudinal analyses of this sample were also conducted. Consistent with previous findings, the presence of social integration and social support were significant predictors of health and PWB even when taking into account other lifestyle factors (i.e., diet/exercise, substance use, smoking), cardiovascular risk, demographics (i.e., gender, age, education, relationship status) and personality. The role of social integration and support on health and PWB is well established. Present findings confirmed these associations among individuals with MS. These findings suggest that social integration and social support should be a crucial part of MS management and that further interventional studies aimed at improving social integration and reducing social isolation are warranted in an effort to promote and maintain overall health and well-being.

Interferon-Beta Injection in Multiple Sclerosis Patients Related to the Induction of Headache and Flu-Like Pain Symptoms: A Systematic Review and Meta-Analysis of Randomised Controlled Trials

Multiple sclerosis (MS) is a chronic neurodegenerative, inflammatory, and autoimmune disease characterised by the demyelination of the central nervous system. One of the main approaches for treating MS is the use of disease-modifying therapies (DMTs). Among the DMTs are interferons (IFNs), which are cytokines responsible for controlling the activity of the immune system while exerting immunomodulatory, antiviral, and antiproliferative activities. IFN-beta (IFN-β) is the first-choice drug used to treat relapsing-remitting MS. However, the administration of IFN-β causes numerous painful adverse effects, resulting in lower adherence to the treatment. Therefore, this study aimed to investigate the headache and flu-like pain symptoms observed after IFNβ injection in MS patients using a systematic review and meta-analysis of randomised controlled trials. A total of 2370 articles were identified through research databases. Nine articles were included (three involving IFNβ-1b and six involving IFNβ-1a). All studies included in the meta-analysis had a low risk of bias. The odds ratio of headache and flu-like pain symptoms increased in MS patients treated with IFN-β. Thus, the adverse effects of headache and flu-like pain symptoms appear to be linked to IFN-β treatment in MS. The protocol of the study was registered in the Prospective International Registry of Systematic Reviews (registration number CRD42021227593).

Unique features of central neuropathic pain in multiple sclerosis: Results of a cluster analysis

Background

Central neuropathic pain (CNP) is an excruciating condition, prevalent in up to a third of patients with multiple sclerosis (MS). Identifying CNP among MS patients is particularly challenging considering the ample comorbid chronic pain conditions and sensory disturbances entailed by the disease. The aim was to identify sensory features unique to CNP beyond those of chronic pain and MS.

Methods

Participants were 112 MS patients: 44 with a diagnosis of CNP, 28 with a diagnosis of chronic musculoskeletal pain (MSP), and 40 pain free. Participants underwent testing of thermal and mechanical thresholds, thermal grill illusion (TGI), pain adaptation (PA), and offset analgesia (OA), and chronic pain was characterized. A two‐step cluster analysis was performed, and the association between the cluster membership and the clinical group membership (CNP, MSP, pain free) was evaluated.

Results

The CNP and MSP groups were similar in most of the chronic pain variables (e.g., severity, location and quality) and MS‐related variables (e.g., type, severity and medication intake). The three created clusters had unique sensory features: (1) ‘Hyposensitivity’ (increased thermal and touch thresholds) characterized the CNP group; (2) ‘Poor inhibition and hyperalgesia’ (worst PA and OA and decreased TGI threshold) characterized the MSP group; and (3) ‘Efficient inhibition’ (best PA and OA, smallest sensory loss) characterized the pain‐free group.

Conclusions

The unique sensory features of CNP and MSP provide insight into their pathophysiology, and evaluating them may increase the ability to provide individually based interventions. Efficient inhibition may protect MS patients from chronic pain.

Significance

Cluster analysis among patients with multiple sclerosis (MS) revealed that while central neuropathic pain is associated with thermal and mechanical hypoesthesia, musculoskeletal pain is involved with reduced pain inhibition and hyperalgesia; sensory profiles that provide insights into the mechanisms of these conditions and may promote an individually based pain management.

Pain Prevalence in Multiple Sclerosis in a Lisbon Tertiary Hospital: A Cross-Sectional Study

Background: Multiple sclerosis is a chronic neurological disease with increasing incidence and prevalence worldwide being the main cause of non-traumatic disability in young adults. Both acute and chronic pain have been mentioned as the most common symptoms among those patients.

Objective: This study was designed to evaluate the pain experience among patients with multiple sclerosis by describing its prevalence, characteristics, analgesic treatment and its efficacy, and also the impact of pain on quality of life.

Methods: A cross-sectional observation survey was carried out on patients with multiple sclerosis followed in a tertiary hospital. Data were collected between December 2019 and March 2021 from a structured telephone inquiry, applying two questionnaires, the Brief Pain Inventory and the McGill Pain Questionnaire (MPQ), to evaluate the prevalence of pain and its impact on quality of life (QoL). Clinical records were also consulted to obtain data on disease duration, year of diagnosis, MS type, Expanded Disability Status Scale (EDSS) score.

Results: Our sample included 305 patients in a universe of 1500, mainly women, with mean age of 44.27 years, and most of them presented with an outbreak-remission subtype of disease. One hundred twenty-four patients experienced pain which corresponds to 41% of the patients. Considering the patients who experienced pain, 67.7% were under treatment and of these, 64.3% with only one painkiller. Pain significantly interfered with general activity, mood, and regular work.

Conclusion: Pain was an important symptom in this group of patients with MS and significantly interfered with mood, general activity, and regular work. The maximum intensity of pain felt by patients was significant and only 67.7% of patients were under analgesic treatment with mean pain relief of 54. NSAIDs were the most used drugs followed by gabapentinoids and acetaminophen for the management of pain. Medical community must continue to study this population in order to improve the approach to pain in these patients and improve quality of life.

Pain, cognition and disability in advanced multiple sclerosis

OBJECTIVES

In patients with multiple sclerosis (MS), a relationship between physical disability and pain has been observed. In addition a relationship between physical disability and cognition in MS has been suggested. However, cognitive functions and pain appear not to be correlated in MS patients. Therefore, we examined whether a possible relationship between pain and cognitive functioning may exist, and if so, if such a relationship is mediated by physical disability.

METHODS

Forty-five MS patients with chronic pain, and in an advanced stage of the disease were included. Physical disabilities were assessed by the Expanded Disability Status Scale (EDSS). Episodic memory was assessed by means of the Eight Words test, and Face and Picture Recognition. Executive functions (EF) were examined by Digit Span Backward for working memory, and the Rule Shift Cards and Category Fluency test for cognitive flexibility. Pain Intensity and Pain Affect were assessed by means of visual analogue scales and one verbal pain scale and mood (depression, anxiety) by the Beck Depression Inventory and the Symptom Check List (SCL-90). The research questions were analyzed by means of regression analyses and the Sobel test for mediation.

RESULTS

A significant relationship was found between Pain Affect and EF, but that relationship was not mediated by physical disabilities (EDSS). In addition, Pain Intensity and EF showed a significant relationship but only in combination with physical disabilities (EDSS). Finally, mood was related to pain affect.

DISCUSSION

The findings suggest that the lower the EF, exclusively or in combination with more physical disabilities, the more the patient may suffer from pain.

IMPLICATIONS

The more one is cognitively and physically impaired, the more one might suffer from pain, and, the less one is able to communicate pain. The latter could put MS patients at risk for underdiagnosing and undertreatment of pain.

Strain and sex differences in somatosensation and sociability during experimental autoimmune encephalomyelitis

Multiple Sclerosis (MS) is an immune-mediated disease that results in major locomotor deficits. However, recent studies have revealed that fatigue, slow processing speed, and memory impairment are the top variables impacting employment status for MS patients. These suggest that cognitive effects may have a greater impact on productivity, lifestyle, and quality of life than do disease-related motor deficits. However, these debilitating non-locomotive effects have been largely overlooked in rodent models of the disease, such as experimental autoimmune encephalomyelitis (EAE). We hypothesized that murine EAE can also be used to assess non-locomotive dysfunctions (mood, sociability, muscle strength, and balance), as well as potential biases in these dysfunctions due to sex and/or strain. We actively immunized male and female C57BL/6 (B6) and SJL mice for EAE and evaluated their performance on the Deacon's weight grip test, Kondziela's inverted screen test, Hall's rope grip test, manual von Frey test for somatic nociception, and a three-chamber social preference paradigm. We hypothesized that EAE progression is associated with changes in muscle strength, balance, pain, and sociability and that these variations are linked to sex and/or strain. Our results indicate that strain but not sex influenced differences in muscle strength and balance during EAE, and both sex and strain have an impact on mechanical nociception, regardless of EAE disease status. Furthermore, both sex and strain had complex effects on differences in sociability. In conclusion, testing these additional modalities during EAE helps to unveil other signs and symptoms that could be used to determine the efficacy of a drug or treatment in the modulation of a MS-like behavior.

[Pain in multiple sclerosis and neuromyelitis optica spectrum disorders]

Multiple sclerosis and neuromyelitis optica spectrum disorders are autoimmune inflammatory diseases of the central nervous system, which can lead to a multitude of neurological complaints and pain syndromes. Pain may be an acute symptom during disease exacerbation as well as a chronic symptom, whereby the latter sometimes substantially reduces the quality of life. The etiology of pain is very heterogeneous but the rapid differential diagnostic classification is decisive in order to be able to initiate a differentiated treatment strategy. Chronic pain must be differentiated from pain as a possible (early) symptom of an acute disease exacerbation, classified in more detail and individually treated. These include central neuropathic pain, pain associated with spasticity, musculoskeletal pain due to excess loading and pain as a side effect of immunotherapy and in the context of comorbidities. The treatment strategies are often insufficiently evidence-based due to the lack of data.

Characterizing chronic pain phenotypes in multiple sclerosis: a nationwide survey study

ABSTRACT

Chronic pain is highly prevalent in multiple sclerosis (MS). Pain heterogeneity may contribute to poor treatment outcomes. The aim of this study was to characterize pain phenotypes distributions in persons with MS and compare pain phenotypes in terms of pain intensity, frequency of chronic overlapping pain conditions, and use and analgesic effects of different classes of pain medications. Data were collected through a national web-based survey with measures of neuropathic (painDETECT) and nociplastic pain (Fibromyalgia Survey Criteria), chronic overlapping pain conditions, and pain medication use and pain relief. In a sample of N = 842 adults with chronic pain and MS, the largest proportion (41%) showed evidence of nociceptive pain, 27% had mixed neuropathic/nociplastic pain, 23% had nociplastic pain, and 9% had neuropathic pain. Nociplastic pain was associated with significantly higher pain intensity and frequency of chronic overlapping pain conditions. Across all pain types, high frequency of pain medication use along with poor-modest pain relief was reported. Cannabis use for pain was more common, and pain relief ratings were higher among those with nociplastic pain, relative to nociceptive pain. Although NSAID use was highest among those with nociplastic pain (80%), pain relief ratings for NSAIDs were highest among those with nociceptive pain. These findings underscore the need for multidimensional assessment of pain in MS with greater emphasis on the identification of pain phenotype. An improved characterization of pain as a multifaceted condition in MS could inform therapeutic approaches.

Effectiveness of Dry Needling versus Placebo on Gait Performance, Spasticity, Electromyographic Activity, Pain, Range-of-Movement and Quality of Life in Patients with Multiple Sclerosis: A Randomized Controlled Trial Protocol

Dry needling (DN) is an emerging technique commonly used in neurological and musculoskeletal pain conditions, but there have been no previous studies in patients with multiple sclerosis (pwMS). This trial aims to assess the efficacy of deep DN, compared with sham placebo DN, on gait performance, spasticity level, pain, electromyographic activity, range-of-movement (ROM) and quality of life in pwMS. Forty adults with MS were randomly assigned to one study group. The DN group will undergo 2 sessions (once per week) using DN over the rectus femoris (RF) and gastrocnemius medialis (GM) muscles at the lower extremity with higher spasticity. The placebo group will receive the same protocol using a sham placebo needle (Dong Bang needle). Outcome measures will include gait performance, using the GaitRite^® system, spasticity level with the Modified Ashworth Scale, superficial electromyographic activity of RF and GM, pain (pressure algometer), ROM (goniometer), and quality of life (Musiqol). This study is the first investigating the short-term effect of DN, compared with placebo, in pwMS, and taking into account the possible changes in the electromyographic activity of the lower limb. Therefore, the results may help to understand the suitability of using this technique in the clinical setting for this population. Trial registration: ACTRN12619000880145.

Sensory and pain modulation profiles of ongoing central neuropathic extremity pain in multiple sclerosis

BACKGROUND

Central neuropathic extremity pain (CNEP) is the most frequent type of pain in multiple sclerosis (MS). The aim of the present study was to evaluate sensory and pain modulation profiles in MS patients with CNEP.

METHODS

In a single-centre observational study, a group of 56 CNEP MS patients was compared with 63 pain-free MS patients and with a sex- and age-adjusted control group. Standardized quantitative sensory testing (QST) and dynamic QST (dQST) protocols comprising temporal summation and conditioned pain modulation tests were used to compare sensory profiles.

RESULTS

Loss-type QST abnormalities in both thermal and mechanical QST modalities prevailed in both MS subgroups and correlated significantly with higher degree of disability expressed as Expanded Disability Status Scale (EDSS). Comparison of sensory phenotypes disclosed a higher frequency of the 'sensory loss' prototypic sensory phenotype in the CNEP subgroup (30%) compared with pain-free MS patients (6%; p = .003).

CONCLUSION

The role of aging process and higher lesion load in the spinothalamocortical pathway might be possible explanation for pain development in this particular 'deafferentation' subtype of central neuropathic pain in MS. We were unable to support the role of central sensitization or endogenous facilitatory and inhibitory mechanisms in the development of CNEP in MS.

SIGNIFICANCE

This article presents higher prevalence of the 'sensory loss' prototypic sensory phenotype in multiple sclerosis patients with central extremity neuropathic pain compared to pain-free patients. Higher degree of disability underlines the possible role of higher lesion load in the somatosensory pathways in this particular 'deafferentation' type of central neuropathic pain.

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.

Cannabinoids in multiple sclerosis: A neurophysiological analysis

OBJECTIVES

To investigate the action of cannabinoids on spasticity and pain in secondary progressive multiple sclerosis, by means of neurophysiological indexes.

MATERIAL AND METHODS

We assessed 15 patients with progressive MS (11 females) using clinical scales for spasticity and pain, as well as neurophysiological variables (H/M ratio, cutaneous silent period or CSP). Testing occurred before (T0) and during (T1) a standard treatment with an oral spray containing delta-9-tetrahydrocannabinol (THC) and cannabidiol (CBD). Neurophysiological measures at T0 were compared with those of 14 healthy controls of similar age and sex (HC). We then compared the patient results at the two time points (T1 vs T0).

RESULTS

At T0, neurophysiological variables did not differ significantly between patients and controls. At T1, spasticity and pain scores improved, as detected by the Modified Ashworth Scale or MAS (P = .001), 9-Hole Peg Test or 9HPT (P = .018), numeric rating scale for spasticity or NRS (P = .001), and visual analogue scale for pain or VAS (P = .005). At the same time, the CSP was significantly prolonged (P = .001).

CONCLUSIONS

The THC-CBD spray improved spasticity and pain in secondary progressive MS patients. The spray prolonged CSP duration, which appears a promising tool for assessing and monitoring the analgesic effects of THC-CBD in MS.

Effects of hypnosis, cognitive therapy, hypnotic cognitive therapy, and pain education in adults with chronic pain: a randomized clinical trial

Chronic pain is a significant health problem worldwide with limited pharmacological treatment options. This study evaluated the relative efficacy of 4 treatment sessions each of 4 nonpharmacological treatments: (1) hypnotic cognitive therapy (using hypnosis to alter the meaning of pain); (2) standard cognitive therapy; (3) hypnosis focused on pain reduction, and (4) pain education. One hundred seventy-three individuals with chronic pain were randomly assigned to receive 4 sessions of 1 of the 4 treatments. Primary (pain intensity) and secondary outcome measures were administered by assessors unaware of treatment allocation at pretreatment, posttreatment, and 3-, 6-, and 12-month follow-up. Treatment effects were evaluated using analysis of variance, a generalized estimating equation approach, or a Fisher exact test, depending on the outcome domain examined. All 4 treatments were associated with medium to large effect size improvements in pain intensity that maintained up to 12 months posttreatment. Pretreatment to posttreatment improvements were observed across the 4 treatment conditions on the secondary outcomes of pain interference and depressive symptoms, with some return towards pretreatment levels at 12-month follow-up. No significant between-group differences emerged in omnibus analyses, and few statistically significant between-group differences emerged in the planned pairwise analyses, although the 2 significant effects that did emerge favored hypnotic cognitive therapy. Future research is needed to determine whether the significant differences that emerged are reliable.

A voxel-based lesion symptom mapping analysis of chronic pain in multiple sclerosis

BACKGROUND

Pain is one of the most disabling symptoms in multiple sclerosis. Chronic pain in multiple sclerosis is often neuropathic in nature, although a clear-cut distinction with nociceptive pain is not easy.

OBJECTIVE

The aim of our study was to analyze the MRIs of multiple sclerosis patients with chronic pain in order to explore possible associations with lesion sites, on a voxel-by-voxel basis.

MATERIALS AND METHODS

We enrolled patients aged > 18 years with multiple sclerosis in accordance with the 2010 McDonald criteria. Patients meeting criteria for persistent pain (frequent or constant pain lasting > 3 months) were included in the "pain group". The other patients were included in the "no pain group". We outlined lesions on FLAIR MRI scans using a semi-automated edge finding tool. To detect the association between lesion localization and persistent pain, images were analysed with the voxel-based lesion symptom mapping methods implemented in the (nonparametric mapping software included into the MRIcron.

RESULTS

We enrolled 208 MS patients (140 F, mean age 55.2 ± 9.4 years; 176 RR, 28 progressive MS; mean EDSS 2.0 + 2.0). Pain group included 96 patients and no pain group 112 patients. Lesions of the right dorsolateral prefrontal area were significantly more prevalent in patients without pain, whereas periventricular posterior lesions were significantly more prevalent in patients with persistent pain.

CONCLUSION

Our data suggest a role of the right dorsolateral prefrontal cortex in the modulation of pain perception and in the occurrence of chronic pain in MS patients. Our data also support a hemispheric asymmetry in pain perception and modulation.

Italian version of the Starkstein Apathy Scale (SAS-I) and a shortened version (SAS-6) to assess "pure apathy" symptoms: normative study on 392 individuals

OBJECTIVES

The present normative study aimed to (1) develop the Italian version of the Starkstein Apathy Scale (SAS-I) and (2) construct a shortened version including only the most sensitive items to "pure apathy" experiences.

METHODS

The normative sample included 392 healthy subjects. A regression-based procedure was used to explore the effects of sex, age, and education on the raw SAS-I score. A correction grid was designed for adjusting raw scores by adding or subtracting the contribution of any significant variable and net of sociodemographic interindividual differences. Cutoff scores were also calculated and fixed at the external tolerance limit on the ninety-fifth centile. To obtain the shortened version, each SAS-I item was correlated with the Beck's Depression Inventory (BDI) score. The only items showing no correlation with BDI were implemented to bypass the well-known overlap between apathetic and depressive symptoms.

RESULTS

The mean raw SAS-I score was 11.27 (SD = 4.42). A significant education effect was observed, with highly educated subjects obtaining lower scores than lowly educated ones. The proposed general cutoff score was 20.68. The SAS-I had fair internal consistency and discriminant validity. Internal consistency increased by removing item 3. The new SAS-6 included items 1, 2, 4, 10, 11, and 13 of the original scale.

CONCLUSION

The SAS-I is a reliable assessment tool to support the diagnosis of apathy. The SAS-6, instead, is a brief questionnaire useful for quickly screening apathetic symptoms in outpatient practice, addressing or not the clinician to further investigations.

Characteristics and treatment of Multiple Sclerosis-related trigeminal neuralgia: An Italian multi-centre study

BACKGROUND

The prevalence of trigeminal neuralgia (TN) in Multiple Sclerosis (MS) patients is higher than in the general population and its management can be particularly challenging. Our aim is to describe the characteristics, treatment and prognostic factors of MS-related TN in a retrospective multicentre study.

METHODS

Neurologists members of the RIREMS group (Rising Researchers in MS) enrolled MS patients with a TN diagnosis and filled out a spreadsheet comprising their clinical data.

RESULTS

Population consisted of 298 patients. First-choice preventive treatments were carbamazepine and oxcarbazepine. A surgical procedure was performed in 81 (30%) patients, most commonly gamma knife stereotactic radiosurgery (37%), followed by microvascular decompression (22%) and radiofrequency thermocoagulation (21%); one third of patients underwent at least two procedures. Surgery was associated with higher disability, male sex and longer interval between MS and TN onset. Patients (77%) who stayed on at least one preventive medication at most recent follow-up, after a mean period of 8 years, had a higher disability compared to the untreated group. Furthermore, patients with higher disability at TN onset were less likely to discontinue their first preventive medication due to pain remission, had bilateral TN more frequently and underwent surgical interventions earlier.

CONCLUSION

MS patients with a higher disability at TN onset and with a longer interval between MS and TN onset had differing clinical features and outcomes: pain was more frequently bilateral, surgery was more frequent and anticipated, and preventive medication discontinuation due to pain remission was less common.

Combined upper limb and breathing exercise programme for pain management in ambulatory and non-ambulatory multiple sclerosis individuals: part II analyses from feasibility study

PURPOSE

The present small semi-controlled feasibility study investigated a possible efficacy of a combined upper limb and breathing exercise programme in managing pain in ambulatory and non-ambulatory patients with EDSS from 0.0-8.0.

METHOD

People with MS (N = 19) were enrolled in this single-blind randomized controlled study and divided into 2 groups: exercise group (5 ambulatory, 5 non-ambulatory; Expanded Disability Status Scale (EDSS), 1.0-8.0) and related control group that performed no exercise (4 ambulatory, 5 non-ambulatory; EDSS, 1.0-7.5). The exercise group performed combined upper limb and breathing exercises in a group led by a physiotherapist (2 days/week, 60 min/session) accompanied by independent home exercises (3 days/week, ≥ 20 min/session). Participants underwent measures of pain level (visual analogue scale) for physical pain, functional independence of daily activities (Barthel index) and handgrip strength (HGS) for dominant (D) and non-dominant (ND) hand evaluated by a dynamometer before and after the 4-week period by the blinded assessor.

RESULTS

The VAS for pain showed statistically significant group-by-time interaction only in non-ambulatory (p = .049) individuals, but with large intervention effects on both subgroups (ambulatory, p = .159; non-ambulatory, d = 0.97). Functional independence in daily activities (Barthel index) showed statistically non-significant group-by-time interaction in ambulatory (p = .195, d = 0.89) and non-ambulatory (p = .102, d = 1.64) individuals, but despite the absence of statistical significance, there were large intervention effects. Handgrip strength was significantly improved for both hands in ambulatory (D, p = .012; d = 2.07; ND, p = .025, d = 1.77) and only non-dominant hand in non-ambulatory individuals (D, p = .288, d = 0.83; ND, p = .012, d = 2.21).

CONCLUSION

This small pilot study provides preliminary proof-of-concept data supporting low-intensity upper limb and breathing exercise programme for potential reduction of pain and improvement of functional independence in both ambulatory and non-ambulatory individuals with MS in a larger sample and that strengthening the upper limbs might be an additional pain relief mechanism.

TRIAL REGISTRATION

NTC03222596.

Advances in the Understanding and Management of Chronic Pain in Multiple Sclerosis: a Comprehensive Review

PURPOSE OF REVIEW

Multiple sclerosis (MS) is an autoimmune disorder of the central nervous system that can lead to severe physical, cognitive, and neurological deficits that often manifest in young adults. Central neuropathic pain is a common presenting symptom, often prompting patients to seek treatment with opioids, NSAIDS, antiepileptics, and antidepressants despite minimal effectiveness and alarming side-effect profiles. Additionally, spasticity occurs in more than 80% of MS patients and is an important consideration for further study in treatment.

RECENT FINDINGS

Related to inconsistencies in pain presentation and clinical reporting, current studies continue to investigate clinical patient presentation to define chronic pain characteristics to optimize treatment plans. Although often neuropathic in origin, the complex nature of such pain necessitates a multimodal approach for adequate treatment. While psychiatric comorbidities typically remain unchanged in their severity over time, physical conditions may lead to worsening chronic pain long-term, often due to decreased quality of life. The prevalence of neuropathic pain is ~ 86% in patients with multiple sclerosis and most commonly presents as extremity pain, trigeminal neuralgia, back pain, or headaches. As MS symptoms are frequently unremitting and poorly responsive to conventional medical management, recent attention has been given to novel interventions for management of pain. Among these, medicinal cannabis therapy, targeted physical therapy, and neuromodulation offer promising results. In this review, we provide a comprehensive update of the current perspective of MS pathophysiology, symptomatology, and treatment.

Exploring the feasibility of a mild and short 4-week combined upper limb and breathing exercise program as a possible home base program to decrease fatigue and improve quality of life in ambulatory and non-ambulatory multiple sclerosis individuals

PURPOSE

To evaluate the feasibility of a combined upper limb and breathing exercise for a home-based program and to explore its effect on primary fatigue and quality of life in ambulatory and non-ambulatory individuals with multiple sclerosis (MS) in a short time.

METHOD

Nineteen individuals with MS were assigned into semi-controlled pre-post feasibility study based on Expanded Disability Status Scale (EDSS) status and divided into two groups: exercise (five ambulatory, five non-ambulatory; EDSS 1.0-8.0) and related control with no exercise (four ambulatory, five non-ambulatory; EDSS 1.0-7.5). Exercise group performed combined upper limb and breathing exercise in a controlled group (2 days/week, 60 min/session) accompanied by independent home exercise (3 days/week, ≥ 20 min/session). Participants underwent measures of fatigue impact (Modified Fatigue Impact Scale (MFIS) and quality of life (RAND Medical outcomes study 36-item short-form health survey (SF-36)) before and after a 4-week period.

RESULTS

The MFIS (physical, psychosocial, total) showed statistically significant group-by-time interaction in ambulatory (p = 0.033, d = 1.60; p = 0.039, d = 1.59; p = 0.033, d = 1.62) and non-ambulatory individuals (p = 0.009, d = 2.42; p = 0.018, d = 1.96; p = 0.0008, d = 3.92). Physical functioning (SF-36) showed statistically significant group-by-time interaction in ambulatory (p = 0.014, d = 2.14) but no significance in non-ambulatory (p = 0.368, d = 0.68) individuals. Despite the absent statistical significance, there were large intervention effects on MFIS cognitive scores for ambulatory (d = 1.28) and non-ambulatory (d = 1.47), and on other SF-36 scores for ambulatory (general health: d = 1.76 and pain: d = 1.02) and non-ambulatory (physical limitation: d = 1.03 and emotional well-being: d = 0.94) individuals.

CONCLUSION

Our 4-week program reduced some aspects of fatigue and improved some aspects of quality of life in a small group of ambulatory and non-ambulatory individuals with MS. Good feasibility and significant positive changes from baseline warrant further exploratory work.

TRIAL REGISTRATION

Name of the registry: The Impact of Exercise Training on Living Quality in Multiple Sclerosis. Registration: The study was registered at www.clinicaltrial.gov on July 14, 2017. First participant enrollment: August 28, 2017. URL: 602-01/17-01-147; Trial registration ID: NTC03222596.