Transcranial Direct Current Stimulation for Treatment of Childhood Pharmacoresistant Lennox-Gastaut Syndrome: A Pilot Study

Abstract

Background: Lennox-Gastaut syndrome (LGS) is a severe childhood epileptic syndrome with high pharmacoresistance. The treatment outcomes are still unsatisfied. Our previous study of cathodal transcranial direct current stimulation (tDCS) in children with focal epilepsy showed significant reduction in epileptiform discharges. We hypothesized that cathodal tDCS when applied over the primary motor cortex (M1) combined with pharmacologic treatment will be more effective for reducing seizure frequency in patients with LGS than pharmacologic treatment alone.

Materials and methods: Study participants were randomized to receive either (1) pharmacologic treatment with five consecutive days of 2 mA cathodal tDCS over M1 for 20 min or (2) pharmacologic treatment plus sham tDCS. Measures of seizure frequency and epileptic discharges were performed before treatment and again immediately post-treatment and 1-, 2-, 3-, and 4-week follow-up.

Result: Twenty-two patients with LGS were enrolled. Participants assigned to the active tDCS condition reported significantly more pre- to post-treatment reductions in seizure frequency and epileptic discharges that were sustained for 3 weeks after treatment.

Conclusion: Five consecutive days of cathodal tDCS over M1 combined with pharmacologic treatment appears to reduce seizure frequency and epileptic discharges. Further studies of the potential mechanisms of tDCS in the LGS are warranted.

Trial registration: ClinicalTrials.gov, NCT02731300 (https://register.clinicaltrials.gov).

Keywords: Lennox–Gastaut syndrome; cathodal stimulation; childhood pharmacoresistant epilepsy; transcranial direct current stimulation.

Figure 1

Image of a single adverse event. Three points of superficial skin burn under the reference electrode in active tDCS group, which resolved within 2 days.

Figure 2

Effect of tDCS on seizure frequency. Data are presented as mean ± SD of number seizure frequency/day at baseline, treatment period (day 1–day 5), and various time points after treatment: 1, 2, 3, and 4 weeks. *p = 0.004, **p = 0.002, and ***p < 0.001 as compared to sham tDCS condition.

Figure 3

Effect of tDCS on epileptiform discharges. Data are presented as mean ± SD of number epileptiform discharges per 30 min of EEG recording at baseline, and various time points after treatment: 1, 2, 3, and 4 weeks. **p = 0.005 and ***p < 0.001 as compared to sham tDCS condition.