Noninvasive brain stimulation as focal epilepsy treatment in the hospital, clinic, and home

Objective

Noninvasive brain stimulation (NIBS) provides a treatment option for patients not eligible for surgical intervention or who seek low-risk approaches and may be used in the hospital, clinic, and at home. Our objective is to summarize our single-center experience with multiple NIBS approaches for the treatment of focal epilepsy.

Methods

A retrospective chart review identified drug-resistant focal epilepsy patients who received NIBS as an epilepsy treatment at Mayo Clinic in Rochester, MN. Patients were typically treated as follows: (1) for TMS, 1 Hz stimulation was applied for five consecutive days in the neuromodulation clinic, (2) for outpatient tDCS, stimulation was applied for five consecutive days in the clinic, followed by optional treatment at home, and (3) for inpatient tDCS, stimulation was applied for three consecutive days. We analyzed continuous EEG data for the inpatient tDCS cohort and available HD-EEG data for outpatient cohorts to quantify changes in interictal epileptiform discharges (IEDs) as a result of stimulation. Outcomes were assessed at 1 month for TMS and outpatient tDCS and 1 week for inpatient tDCS.

Results

Twenty-four patients were treated with TMS (n = 10) and tDCS (n = 14, 9 as outpatients). The median age was 40 years (range 15–73). The median seizure reduction following stimulation was 50%. Fourteen patients (58%) were responders to treatment (TMS = 4/10, tDCS Outpatient = 7/9, tDCS Inpatient = 3/5). Five outpatient tDCS participants elected to continue treatment at home. Four TMS and four outpatient tDCS patients underwent high-density EEG before and after 5 days of therapy. Following stimulation, IED rate was reduced in 4/5 inpatient tDCS patients, 4/4 outpatient tDCS patients, and 4/4 TMS patients. Two patients experienced an increase in seizure frequency (1 following TMS and 1 following outpatient tDCS), which returned to baseline 4–6 weeks after stimulation treatments were discontinued.

Significance

TMS and tDCS are potential treatment approaches for drug-resistant focal epilepsy patients in the hospital, clinic, and home. They have a favorable safety profile and can lead to a reduction in IED rates and seizures. These results suggest further studies are needed to examine NIBS as a treatment for epilepsy.

Plain Language Summary

Noninvasive brain stimulation, such as transcranial magnetic stimulation and transcranial direct current stimulation, offers new treatment options for patients with focal seizures. This study reviewed the experience at Mayo Clinic using noninvasive brain stimulation in the hospital, clinic, and at-home settings to treat seizures. The results showed an overall 50% median seizure reduction, and 58% of patients had at least a 50% reduction in seizures. Noninvasive brain stimulation is a promising treatment approach with a favorable safety profile.