Electrical Brain Stimulation for Treatment of Secondary Symptoms in Multiple Sclerosis

• transcranial direct current stimulation (Device): Patients will receive 10 sessions of either 1.5 mA electrical stimulation for 20 minutes each day over 10 consecutive days.
• transcranial direct current stimulation combined with cognitive training (Device): Patients will receive 10 sessions of 20 minutes of 1.5 mA electrical stimulation on 10 consecutive days. Each session is followed by 30 minutes cognitive training in which patients conduct several computerized cognitive tests.
• transcranial direct current stimulation (Device): Patients will receive 10 sessions of sham (placebo) electrical stimulation for 20 minutes each day over 10 consecutive days.

Primary outcomes

• Multiple Sclerosis Impact Scale (MSIS-29) [up to 1 day after the intervention]: The MSIS-29 is a questionnaire that comprises of 29 questions. The initial 20 questions are related to the physical impact, whereas the last 9 questions focus on the psychological impact. Each question is rated on a scale of 1 to 5, where 1 indicates "not at all" and 5 indicates "extremely". There are five response options available for the respondents to choose from.
• and Depression Anxiety Stress Scale-21 (DASS-21) [up to 1 day after the intervention]: The DASS-21 is a tool used to assess the severity of symptoms related to depression, anxiety, and stress in individuals who have not been diagnosed before. The assessment has three scales, and responses to each are measured on a four-point Likert scale, ranging from 0 to 3.
• Mini sleep questionnaire (MSQ) [up to 1 day after the intervention]: The Mini Sleep Questionnaire (MSQ) is used to screen for sleep disturbances in clinical populations. It consists of 10 items, each scored on a seven-point Likert scale ranging from "never" to "always". The questionnaire measures insomnia and oversleeping, with a high score indicating excessive sleepiness and a low score indicating insomnia.

Secondary outcomes

• psychomotor speed task [up to 1 day after the intervention]: Performance in the psychomotor speed task (Reaction Time task)
• attention / vigilance task [up to 1 day after the intervention]: Performance in the attention / vigilance task (Rapid Visual Information Processing task)

Sex: All, ages: 18 Years to 60 Years

Inclusion Criteria:

1. diagnosis of MS according to the diagnostic criteria for multiple sclerosis: 2010 Revisions to the McDonald criteria (Polman et al., 2011), certified by a professional neurologist
2. being 25-55 years old
3. providing written informed consent
4. If female, a negative urine pregnancy test
5. stable medication regime especially the classical neuroleptics and all CNS-activating medications, if taken, 4-6 weeks before the experiment and during the experiment
6. right handed

Exclusion Criteria:

1. smoker
2. pregnancy
3. alcohol or substance dependence
4. history of seizure
5. history of other neurological disorders than MS
6. history of head injury
7. presence of ferromagnetic objects in the body that are contraindicated for brain stimulation of the head (pacemakers or other implanted electrical devices, brain stimulators, some types of dental implants, aneurysm clips, metallic prostheses, permanent eyeliner, implanted delivery pump, or shrapnel fragments) or fear of enclosed spaces.

• Results publication: Zakibakhsh N, Basharpoor S, Ghalyanchi Langroodi H, Narimani M, Nitsche MA, Salehinejad MA. Repeated prefrontal tDCS for improving mental health and cognitive deficits in multiple sclerosis: a randomized, double-blind, parallel-group study. J Transl Med. 2024 Sep 13;22(1):843. doi: 10.1186/s12967-024-05638-1. PMID 39272101