The influence of warm versus cold climate on the effect of physiotherapy in multiple sclerosis

Impacts of Climate Change and Air Pollution on Neurologic Health, Disease, and Practice: A Scoping Review

BACKGROUND AND OBJECTIVES

Although the international community collectively seeks to reduce global temperature rise to less than 1.5°C before 2100, irreversible environmental changes have already occurred, and as the planet warms, these changes will continue to occur. As we witness the effects of a warming planet on human health, it is imperative that neurologists anticipate how the epidemiology and incidence of neurologic disease may change. In this review, we organized our analysis around 3 key themes related to climate change and neurologic health: extreme weather events and temperature fluctuations, emerging neuroinfectious diseases, and pollutant impacts. Across each of these themes, we appraised and reviewed recent literature relevant to neurologic disease and practice.

METHODS

Studies were identified using search terms relating to climate change, pollutants, and neurologic disease in PubMed, OVID MEDLINE, EMBASE, PsycInfo, and gray literature. Studies published between 1990 and 2022 were included if they pertained to human incidence or prevalence of disease, were in English, and were relevant to neurologic disease.

RESULTS

We identified a total of 364 articles, grouped into the 3 key themes of our study: extreme weather events and temperature fluctuations (38 studies), emerging neuroinfectious diseases (37 studies), and pollutant impacts (289 studies). The included studies highlighted the relationships between neurologic symptom exacerbation and temperature variability, tick-borne infections and warming climates, and airborne pollutants and cerebrovascular disease incidence and severity.

DISCUSSION

Temperature extremes and variability both associated with stroke incidence and severity, migraine headaches, hospitalization in patients with dementia, and multiple sclerosis exacerbations. Exposure to airborne pollutants, especially PM2.5 and nitrates, associated with stroke incidence and severity, headaches, dementia risk, Parkinson disease, and MS exacerbation. Climate change has demonstrably expanded favorable conditions for zoonotic diseases beyond traditional borders and poses the risk of disease in new, susceptible populations. Articles were biased toward resource-rich regions, suggesting a discordance between where research occurs and where changes are most acute. As such, 3 key priorities emerged for further study: neuroinfectious disease risk mitigation, understanding the pathophysiology of airborne pollutants on the nervous system, and methods to improve delivery of neurologic care in the face of climate-related disruptions.

Long-term effects of latitude, ambient temperature, and ultraviolet radiation on the incidence of multiple sclerosis in two cohorts of US women

BACKGROUND

Differences in multiple sclerosis (MS) risk by latitude have been observed worldwide; however, the exposures driving these associations are unknown. Ultraviolet radiation (UV) has been explored as a risk factor, and ambient temperature has been correlated with disease progression. However, no study has examined the impact of all three exposures. We examined the association between these exposures and incidence of MS within two nationwide prospective cohorts of women, the Nurses' Health Study (NHS) and Nurses' Health Study II (NHSII).

METHODS

Both cohorts were followed with biennial questionnaires to ascertain new diagnoses and risk factors. Time-varying exposures to latitude, cumulative average July temperature (°C), and cumulative average July erythemal UV (mW/m2) were predicted at each participant's biennially updated residential addresses. Using Cox proportional hazards models adjusted for MS risk factors, we calculated hazard ratios (HR) and 95% confidence intervals (CIs) within each cohort and pooled via meta-analyses.

RESULTS

In multivariable models, there were suggestions that decreasing latitude (meta-analysis multivariable-adjusted HR = 0.72; 95% CI 0.55, 0.94 for women living <35.73° compared with those ≥42.15°, P-for-trend = 0.007) and increasing cumulative average July temperature (meta-analysis multivariable-adjusted HR = 0.81; 95% CI 0.72, 0.91 for each interquartile range increase [3.91°]) were associated with decreasing risk of MS. There was no evidence of heterogeneity between cohorts. We did not observe consistent associations with cumulative average UV.

CONCLUSION

Our results suggest that adult exposures to decreasing latitude and increasing temperature, but not UV, were associated with reduced MS risk in these two cohorts of women. Studies of MS incidence may want to consider temperature as a risk factor.

Non-pharmacological interventions for chronic pain in multiple sclerosis

BACKGROUND

Chronic pain is common and significantly impacts on the lives of persons with multiple sclerosis (pwMS). Various types of non-pharmacological interventions are widely used, both in hospital and ambulatory/mobility settings to improve pain control in pwMS, but the effectiveness and safety of many non-pharmacological modalities is still unknown.

OBJECTIVES

This review aimed to investigate the effectiveness and safety of non-pharmacological therapies for the management of chronic pain in pwMS. Specific questions to be addressed by this review include the following.Are non-pharmacological interventions (unidisciplinary and/or multidisciplinary rehabilitation) effective in reducing chronic pain in pwMS?What type of non-pharmacological interventions (unidisciplinary and/or multidisciplinary rehabilitation) are effective (least and most effective) and in what setting, in reducing chronic pain in pwMS?

SEARCH METHODS

A literature search was performed using the specialised register of the Cochrane MS and Rare Diseases of the Central Nervous System Review Group, using the Cochrane MS Group Trials Register which contains CENTRAL, MEDLINE, Embase, CINAHL, LILACUS, Clinical trials.gov and the World Health Organization International Clinical Trials Registry Platform on 10 December 2017. Handsearching of relevant journals and screening of reference lists of relevant studies was carried out.

SELECTION CRITERIA

All published randomised controlled trials (RCTs)and cross-over studies that compared non-pharmacological therapies with a control intervention for managing chronic pain in pwMS were included. Clinical controlled trials (CCTs) were eligible for inclusion.

DATA COLLECTION AND ANALYSIS

All three review authors independently selected studies, extracted data and assessed the methodological quality of the studies using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) tool for best-evidence synthesis. Pooling data for meta-analysis was not possible due to methodological, clinical and statistically heterogeneity of the included studies.

MAIN RESULTS

Overall, 10 RCTs with 565 participants which investigated different non-pharmacological interventions for the management of chronic pain in MS fulfilled the review inclusion criteria. The non-pharmacological interventions evaluated included: transcutaneous electrical nerve stimulation (TENS), psychotherapy (telephone self-management, hypnosis and electroencephalogram (EEG) biofeedback), transcranial random noise stimulation (tRNS), transcranial direct stimulation (tDCS), hydrotherapy (Ai Chi) and reflexology.There is very low-level evidence for the use of non-pharmacological interventions for chronic pain such as TENS, Ai Chi, tDCS, tRNS, telephone-delivered self-management program, EEG biofeedback and reflexology in pain intensity in pwMS. Although there were improved changes in pain scores and secondary outcomes (such as fatigue, psychological symptoms, spasm in some interventions), these were limited by methodological biases within the studies.

AUTHORS' CONCLUSIONS

Despite the use of a wide range of non-pharmacological interventions for the treatment of chronic pain in pwMS, the evidence for these interventions is still limited or insufficient, or both. More studies with robust methodology and greater numbers of participants are needed to justify the effect of these interventions for the management of chronic pain in pwMS.

Effectiveness of Exercise Interventions for Pain Reduction in People With Multiple Sclerosis: A Systematic Review and Meta-analysis of Randomized Controlled Trials

OBJECTIVE

To systematically review the evidence of the effect of exercise compared with passive control on pain in people with multiple sclerosis.

DATA SOURCE AND STUDY SELECTION

Five electronic databases were searched for randomized controlled trials published up to March 2017 that recruited people with multiple sclerosis where exercise was the intervention and pain was an outcome (PROSPERO registration number CRD42017060489).

STATISTICAL ANALYSIS

A random-effects meta-analysis was conducted to estimate the standardized mean difference of the effect of exercise on pain between treatment and control groups. We assessed risk of bias, fitted meta-regression models to explore heterogeneity between studies, and assessed small study effects.

DATA SYNTHESIS

Ten studies met the inclusion criteria (total sample size=389), and all studies were at high risk of bias. We found that exercise interventions were associated with less pain compared with passive control groups (standardized mean difference=-.46; 95% CI, -.92 to .00). There was high between-study heterogeneity (I²=77.0%), which was not explained by the prespecified study characteristics. There was also some evidence of small study effects.

CONCLUSION

This is the first systematic review of the effect of exercise interventions on pain in people with multiple sclerosis, a chronic neurological disorder that affects 2.5 million people. We found some evidence that exercise compared with passive control alleviates pain in this population, but there were limitations in reporting and study quality with high risk of bias of individual studies and heterogeneity between studies.

Exercise therapy for fatigue in multiple sclerosis

BACKGROUND

Multiple sclerosis (MS) is an immune-mediated disease of the central nervous system affecting an estimated 1.3 million people worldwide. It is characterised by a variety of disabling symptoms of which excessive fatigue is the most frequent. Fatigue is often reported as the most invalidating symptom in people with MS. Various mechanisms directly and indirectly related to the disease and physical inactivity have been proposed to contribute to the degree of fatigue. Exercise therapy can induce physiological and psychological changes that may counter these mechanisms and reduce fatigue in MS.

OBJECTIVES

To determine the effectiveness and safety of exercise therapy compared to a no-exercise control condition or another intervention on fatigue, measured with self-reported questionnaires, of people with MS.

SEARCH METHODS

We searched the Cochrane Multiple Sclerosis and Rare Diseases of the Central Nervous System Group Trials Specialised Register, which, among other sources, contains trials from: the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 10), MEDLINE (from 1966 to October 2014), EMBASE (from 1974 to October 2014), CINAHL (from 1981 to October 2014), LILACS (from 1982 to October 2014), PEDro (from 1999 to October 2014), and Clinical trials registries (October 2014). Two review authors independently screened the reference lists of identified trials and related reviews.

SELECTION CRITERIA

We included randomized controlled trials (RCTs) evaluating the efficacy of exercise therapy compared to no exercise therapy or other interventions for adults with MS that included subjective fatigue as an outcome. In these trials, fatigue should have been measured using questionnaires that primarily assessed fatigue or sub-scales of questionnaires that measured fatigue or sub-scales of questionnaires not primarily designed for the assessment of fatigue but explicitly used as such.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected the articles, extracted data, and determined methodological quality of the included trials. Methodological quality was determined by means of the Cochrane 'risk of bias' tool and the PEDro scale. The combined body of evidence was summarised using the GRADE approach. The results were aggregated using meta-analysis for those trials that provided sufficient data to do so.

MAIN RESULTS

Forty-five trials, studying 69 exercise interventions, were eligible for this review, including 2250 people with MS. The prescribed exercise interventions were categorised as endurance training (23 interventions), muscle power training (nine interventions), task-oriented training (five interventions), mixed training (15 interventions), or 'other' (e.g. yoga; 17 interventions). Thirty-six included trials (1603 participants) provided sufficient data on the outcome of fatigue for meta-analysis. In general, exercise interventions were studied in mostly participants with the relapsing-remitting MS phenotype, and with an Expanded Disability Status Scale less than 6.0. Based on 26 trials that used a non-exercise control, we found a significant effect on fatigue in favour of exercise therapy (standardized mean difference (SMD) -0.53, 95% confidence interval (CI) -0.73 to -0.33; P value < 0.01). However, there was significant heterogeneity between trials (I(2) > 58%). The mean methodological quality, as well as the combined body of evidence, was moderate. When considering the different types of exercise therapy, we found a significant effect on fatigue in favour of exercise therapy compared to no exercise for endurance training (SMDfixed effect -0.43, 95% CI -0.69 to -0.17; P value < 0.01), mixed training (SMDrandom effect -0.73, 95% CI -1.23 to -0.23; P value < 0.01), and 'other' training (SMDfixed effect -0.54, 95% CI -0.79 to -0.29; P value < 0.01). Across all studies, one fall was reported. Given the number of MS relapses reported for the exercise condition (N = 25) and non-exercise control condition (N = 26), exercise does not seem to be associated with a significant risk of a MS relapse. However, in general, MS relapses were defined and reported poorly.

AUTHORS' CONCLUSIONS

Exercise therapy can be prescribed in people with MS without harm. Exercise therapy, and particularly endurance, mixed, or 'other' training, may reduce self reported fatigue. However, there are still some important methodological issues to overcome. Unfortunately, most trials did not explicitly include people who experienced fatigue, did not target the therapy on fatigue specifically, and did not use a validated measure of fatigue as the primary measurement of outcome.

Responsiveness and clinically meaningful improvement, according to disability level, of five walking measures after rehabilitation in multiple sclerosis: a European multicenter study

BACKGROUND

Evaluation of treatment effects on walking requires appropriate and responsive outcome measures.

OBJECTIVES

To determine responsiveness of 5 walking measures and provide reference values for clinically meaningful improvements, according to disability level, in persons with multiple sclerosis (pwMS).

METHODS

Walking tests were measured pre- and postrehabilitation in 290 pwMS from 17 European centers. Combined anchor- and distribution-based methods determined responsiveness of objective short and long walking capacity tests (Timed 25-Foot Walk [T25FW] and 2- and 6-Minute Walk Tests [2MWT and 6MWT] and of the patient-reported Multiple Sclerosis Walking Scale-12 [MSWS-12]). A global rating of change scale, from patients' and therapists' perspective, was used as external criteria to determine the area under the receiver operating characteristic curve (AUC), minimally important change (MIC), and smallest real change (SRC). Patients were stratified into disability subgroups (Expanded Disability Status Scale score ≤4 [n = 98], >4 [n = 186]).

RESULTS

MSWS-12, 2MWT, and 6MWT were more responsive (AUC 0.64-0.73) than T25FW (0.50-0.63), especially in moderate to severely disabled pwMS. Clinically meaningful changes (MICs) from patient and therapist perspective were -10.4 and -11.4 for MSWS-12 (P < .01), 9.6 m and 6.8 m for 2MWT (P < .05), and 21.6 m (P < .05) and 9.1 m (P = .3) for 6MWT. In subgroups, MIC was significant from patient perspective for 2MWT (10.8 m) and from therapist perspective for MSWS-12 (-10.7) in mildly disabled pwMS. In moderate to severely disabled pwMS, MIC was significant for MSWS-12 (-14.1 and -11.9).

CONCLUSIONS

Long walking tests and patient-reported MSWS-12 were more appropriate than short walking tests in detecting clinically meaningful improvement after physical rehabilitation, particularly the MSWS-12 for moderate to severely disabled pwMS.

A need for national registries and international collaborative research in multiple sclerosis

OBJECTIVE

There is a growing need to identify biomarkers for early diagnosis and treatment in multiple sclerosis (MS). Such markers may also be involved in the cause and pathogenesis of the disease.

METHODS

Established national MS registries have through several decades allowed data collection to facilitate MS research. The European MS Registry (EUReMS) is a recent international collaborative effort to ultimately promote MS research and quality in health care across European countries. International collaborations based on such initiatives can facilitate studies on new biomarkers in MS.

RESULTS

Important studies on data from MS registries, as well as national- and international collaboration networks have been conducted.

CONCLUSION

The symposium "National MS Registries--to improve health care and research in Multiple Sclerosis" held in Bergen, Norway, earlier this year aimed to highlight the need and benefit from national MS registries and promote international collaborative research in MS.

Constraint-induced movement therapy for the lower extremities in multiple sclerosis: case series with 4-year follow-up

OBJECTIVE

To evaluate in a preliminary manner the feasibility, safety, and efficacy of Constraint-Induced Movement therapy (CIMT) of persons with impaired lower extremity use from multiple sclerosis (MS).

DESIGN

Clinical trial with periodic follow-up for up to 4 years.

SETTING

University-based rehabilitation research laboratory.

PARTICIPANTS

A referred sample of ambulatory adults with chronic MS (N=4) with at least moderate loss of lower extremity use (average item score ≤6.5/10 on the functional performance measure of the Lower Extremity Motor Activity Log [LE-MAL]).

INTERVENTIONS

CIMT was administered for 52.5 hours over 3 consecutive weeks (15 consecutive weekdays) to each patient.

MAIN OUTCOME MEASURES

The primary outcome was the LE-MAL score at posttreatment. Secondary outcomes were posttreatment scores on laboratory assessments of maximal lower extremity movement ability.

RESULTS

All the patients improved substantially at posttreatment on the LE-MAL, with smaller improvements on the laboratory motor measures. Scores on the LE-MAL continued to improve for 6 months afterward. By 1 year, patients remained on average at posttreatment levels. At 4 years, half of the patients remained above pretreatment levels. There were no adverse events, and fatigue ratings were not significantly changed by the end of treatment.

CONCLUSIONS

This initial trial of lower extremity CIMT for MS indicates that the treatment can be safely administered, is well tolerated, and produces substantially improved real-world lower extremity use for as long as 4 years afterward. Further trials are needed to determine the consistency of these findings.