Treatment of Cognitive Deficits in Multiple Sclerosis With High-Definition Transcranial Direct Current Stimulation

The purpose of the study is to test whether low level electric stimulation, called transcranial Direct Current Stimulation (tDCS), on the part of the brain (i.e., presupplementary motor area) thought to aid in memory will improve verbal retrieval in multiple sclerosis patients. The primary outcome measures are neuropsychological assessments of verbal retrieval, and the secondary measures are neuropsychological assessments of other cognitive abilities and electroencephalography (EEG) measures. Additionally, the study will examine the degree to which baseline assessments of cognition and concussion history predict responses to treatment over time, both on assessments administered within the intervention period and at follow-up.

Using two treatment arms, the study will examine improvement of verbal retrieval and other cognitive deficits associated with multiple sclerosis by comparing (1) 1 milliamp transcranial direct current stimulation (tDCS) active treatment applied to presupplementary motor area for 20 minutes over 10 sessions to (2) sham tDCS following the same schedule. Additionally, after completing the initial active or sham treatment and immediate and 2-month follow-up testing sessions, selected participants will be invited back for newly assigned treatment conditions, 20 minutes over 10 sessions and will be re-evaluated at immediate and 2-month follow-up testing sessions.

Patients with multiple sclerosis and observed cognitive deficits will be randomly assigned to one of the two treatment arms (and re-assigned for the second round of intervention, as described above). Primary outcome verbal retrieval measures, secondary neuropsychological and electroencephalography (EEG) measures, and prescreening assessments for study concussion history and contraindications for treatment will be collected prior to being assigned to a treatment arm (i.e., baseline).

Primary outcome verbal retrieval measures and secondary neuropsychological and electroencephalography (EEG) measures will be at baseline and two times following treatment competition (i.e., immediate and 2-months). For participants selected for the second round of intervention, primary outcome verbal memory measures and secondary neuropsychological and electroencephalography (EEG) measures will be collected again two times immediately following completion of the last treatment and 2-months afterward.

Eligibility Criteria:
Inclusion Criteria:

º Diagnosed with relapsing-remitting multiple sclerosis (RRMS)

º Memory retrieval deficit based on neuropsychological testing done in our lab

º Must be fluent in speaking and reading English.

Exclusion Criteria:

º Relapse or acute MS exacerbation or a course of steroids in the two months preceding the testing

º Participants using benzodiazepines must have been on a stable dose for at least two months

º Potentially confounding psychological or neurological disorder, including:

* dementia of any type
* epilepsy or other seizure disorders
* severe traumatic brain injury
* brain tumor
* present drug abuse
* stroke
* blood vessel abnormalities in the brain
* Parkinson's disease
* Huntington's disease

º inability to give informed consent

º cranial implants

º skull defects that affect tDCS administration

º use of medications that interact with or potentially interact with tDCS effects, including:

* anti-convulsants
* L-dopa
* carbamazepine
* sulpiride
* pergolide
* lorazepam
* rivastigmine
* dextromethorphan
* D-cycloserine
* flunarizine
* ropinirole
* stimulants (dextroamphetamine/amphetamine/modafinil/armodafinil) must be stopped during enrollment