Transcranial Direct Current Stimulation in Mesial Temporal Lobe Epilepsy and Hippocampal Sclerosis

- Transcranial direct current stimulation (tDCS) has been evaluated in a limited number of pharmacoresistant epilepsy patients, but treatment parameters remain undefined.
- Safety and efficacy of two cathodal tDCS protocols were evaluated in patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS).
- Three and five sessions decreased seizure frequency and interictal epileptiform discharges in MTLE-HS patients, compared to placebo.

BackgroundTranscranial direct current stimulation (tDCS) has been evaluated in medication refractory epilepsy patients. The results have been inconclusive and protocols have varied between studies.ObjectiveTo evaluate the safety and efficacy of two protocols of tDCS in adult patients with mesial temporal lobe epilepsy and hippocampal sclerosis (MTLE-HS).MethodsThis is a randomized placebo-controlled, double-blinded clinical trial, with 3 arms, 3 sessions, 5 sessions and placebo stimulation. Frequency of seizures (SZs), interictal epileptiform discharges (IEDs) and adverse effects (AEs) were registered before and after treatment, and at 30 and 60 days follow-up. Descriptive statistics, k-related samples, Friedman's test, and relative risk (RR) estimation were used for analysis.ResultsWe included twenty-eight subjects (3d n = 12, 5d n = 8, placebo n = 8), 16/28 (57%) men, age 37.8(±10.9) years old. There was a significant reduction of the frequency of SZs at one (p = 0.001) and two (p = 0.0001) months following cathodal tDCS compared to baseline in the 3 arms (p = 0.0001). The mean reduction of SZ frequency at two months in both active groups was significantly higher than placebo (−48% vs. −6.25%, p < 0.008). At 3 days (−43.4% vs. −6.25%, p < 0.007) and 5 days (−54.6% vs. −6.25%, p < 0.010) individual groups showed a greater reduction of SZs. A significant IED reduction effect was found between baseline and immediately after interventions (p = 0.041) in all groups. Side effects were minor.ConclusionsCathodal tDCS technique of 3 and 5 sessions decreased the frequency of SZs and IEDs (between baseline and immediately post-tDCS) in adult patients with MTLE-HS compared to placebo tDCS.