Transcranial direct current stimulation of the left prefrontal cortex improves attention in patients with traumatic brain injury: a pilot study

Abstract

Objective: To determine whether a single session of anodal transcranial direct current stimulation to the left dorsolateral prefrontal cortex improves attention in patients with traumatic brain injury.

Design: Double-blinded, cross-over design.

Patients: Nine patients with attention deficit after traumatic brain injury.

Methods: Patients underwent a computerized contrast reaction time task before and after the administration of real transcranial direct current stimulation (2 mA for 20 min) or sham transcranial direct current stimulation (2 mA for 1 min) to the left dorsolateral prefrontal cortex in a double-blind, crossover manner.

Results: Immediately post-stimulation, the transcranial direct current stimulation group showed a tendency of shortened reaction time relative to baseline (87.3 ± 7.8%), whereas the sham stimulation group (122.4 ± 715.5%) did not (p = 0.056). However, this difference was not significant 3 or 24 h after stimulation (p > 0.05). The numbers of correct responses were not changed at any time after stimulation.

Conclusion: Anodal transcranial direct current stimulation applied to the left dorsolateral prefrontal cortex improves attention compared with sham stimulation in patients with traumatic brain injury, which suggests a potential role for this intervention in improving attention during cognitive training after traumatic brain injury. A further prospective randomized trial is required to confirm the benefits conferred by transcranial direct current stimulation in this patient population.