Effects of repeated anodal tDCS coupled with cognitive training for patients with severe traumatic brain injury: a pilot randomized controlled trial

Abstract

Objective: To determine whether cumulative anodal transcranial direct current stimulation (A-tDCS) of the left dorsolateral prefrontal cortex (DLPFC) could enhance rehabilitation of memory and attention in patients with traumatic brain injury (TBI).

Setting: Inpatient and outpatient neurorehabilitation unit.

Participants: Twenty-three adult patients, 4- to 92- months post severe TBI.

Design: Participants were randomly allocated to 2 groups. The experimental group received A-tDCS (10 minutes; 1 mA; in the DLPFC), followed by rehabilitative cognitive training, daily for 15 days. Controls received A-tDCS for 25 seconds (sham condition) with the same rehabilitation.

Main measures: Battery of memory and attention tests, which included visual and auditory modalities. Participants were tested twice before beginning rehabilitation (to control for spontaneous recovery), after rehabilitation completion, and 4 months later.

Results: Tests scores in both groups were similar at 3 weeks before and immediately before treatment. After treatment, the experimental group exhibited larger effect sizes in 6 of 8 cognitive outcome measures, but they were not significantly different from controls. At follow-up, differences remained insignificant.

Conclusion: In contrast to previous studies, our study did not provide sufficient evidence to support the efficacy of repeated A-tDCS for enhancing rehabilitation of memory and attention in patients after severe TBI.