Evaluation of pulsing magnetic field effects on paresthesia in multiple sclerosis patients, a randomized, double-blind, parallel-group clinical trial

Effects of pulsed electromagnetic field therapy on fatigue, walking performance, depression, and quality of life in adults with multiple sclerosis: a randomized placebo-controlled trial

BACKGROUND

Multiple sclerosis has a great disability burden. Management of the disease is complex, and patients often seek new conservative approaches.

OBJECTIVE

To investigate the effect of low-frequency pulsed electromagnetic field (PEMF) therapy, compared to placebo, on the level of fatigue, walking performance, symptoms of depression, and quality of life (QOL) in patients with relapsing-remitting multiple sclerosis (RRMS).

METHODS

Forty-four adults with RRMS and minimal to significant disability were randomly assigned to a 4-week protocol using a PEMF or a placebo whole-body mat. The PEMF group were initially treated with 15Hz frequency, gradually increased to 30Hz (intensity between 25-35µT). The primary outcome was fatigue, assessed with the Fatigue Severity Scale (FSS) and the Modified Fatigue Impact Scale (MFIS). Secondary measures included walking function (GAITRite system and Timed 25-Foot Walk test), the Beck Depression Inventory-II, and the Multiple Sclerosis International Quality of Life Questionnaire. Data were collected at baseline, after intervention, and at 3-months post-intervention (follow-up).

RESULTS

There were no differences between groups for changes in fatigue symptoms from baseline to end of intervention (mean and 95% confidence interval FSS: -0.6, 95%CI: -1.3, 0.1; MFIS: -5.4, 95% CI: -15.1, 4.4) or at follow-up (FSS: -0.6, 95% CI: -1.4, 0.2; MFIS: -2.1, 95% CI: -10.9, 6.8). Similarly, both groups did not differ for any of the secondary outcomes at post-intervention or follow-up.

CONCLUSIONS

Low-frequency PEMF therapy is no more effective than placebo to produce changes in fatigue, gait performance, severity of depression, and QOL in people with RRMS and minimal to significant disability.

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.