Authors: Edis Mustafa1,2, Marius Nicolae Popescu1,3, Matei Teodorescu1,3, Mihai Berteanu1,3
1 “Carol Davila” University of Medicine and Pharmacy, Bucharest, Romania
2 Medical Rehabilitation Department of the Sf. Ioan Clinical and Emergency Hospital, Bucharest, Romania
3 Medical Rehabilitation Department of the Elias Emergency University Hospital, Bucharest, Romania
Background. Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system and the main cause of disability in young people. Drug therapy cannot completely control many disabling symptoms in MS, such as cramps, pain, depression, and cognitive impairment. Non-invasive brain stimulation (NIBS) technology can be used as a tool to regulate changes in cortical excitability and plasticity in MS patients, thereby improving the disability symptoms that affect such patients.
Aims. Our objective was to explore the effectiveness and safety of non-invasive brain stimulation in the treatment of fatigue in patients with multiple sclerosis.
Methods. We performed a literature review in different databases: PubMed, Web of Science, Cochrane Library, Medline, Google Scholar. Full text articles that used NIBS for exercise performance improvement in athletes were included (only articles in English were found). We searched for articles available in each database until 30 October 2019. We used articles published in journals, randomized or pseudo-randomized, sham-controlled clinical trials to evaluate the effects of non-invasive brain stimulation (NIBS). The main result is the fatigue score before and after stimulation; the secondary result is the adverse event.
Results. The general inverse variance method was used to aggregate data from cross-group and parallel group studies. A total of 14 studies (tDCS 11, TMS 2 and tRNS 1) which recruited 186 patients were included in the study. No qualified tACS, transcranial electrical therapy stimulation or non-invasive cortical electrical stimulation study with reduced impedance was found. The short-term and long-term therapeutic effects are for tDCS, TMS is significant, and TMS and tRNS are not superior to sham stimulation. Existing evidence supports the effectiveness of the 1.5 mA subgroup and the bilateral S1 subgroup of tDCS. Adverse events are mild and transient, but are comparable between real and sham stimulation.
Conclusions. tDCS is a safe and effective way to treat fatigue in MS patients. However, there is further research needed to confirm our results in a large population and investigate the effectiveness of other NIBS subtypes.
Key words: transcranial direct current stimulation (tDCS or HD-tDCS), tACS (transcranial alternative current stimulation), TMS (transcranial magnetic stimulation), fatigue, MS (multiple sclerosis), non-invasive brain stimulation (NIBS).