Repetitive transcranial magnetic stimulation-associated neurobehavioral gains during coma recovery

Background

Repetitive transcranial magnetic stimulation (rTMS) is a noninvasive method to induce changes in cortical neural excitability. This report presents findings from the first participant of a safety and efficacy study that examined a therapeutic rTMS protocol for persons with severe traumatic brain injury (TBI).

Objective

The primary hypothesis was that there will be no adverse events related to the provision of a 6-week rTMS protocol for persons with severe TBI who remain, at best, in a minimally conscious state for longer than 3 months. The secondary hypothesis was that the rTMS protocol would induce significant neurobehavioral gains during treatment and that these gains would persist at 6-week follow-up.

Methods

A 6-week rTMS protocol (30 sessions) was delivered to a 26-year-old man who remained in a vegetative state 287 days after severe TBI. Stimulation was directed over the right dorsolateral prefrontal cortex. Repeated safety measures, neurobehavioral assessments, clinical examinations, and evoked potentials (EP) were obtained at baseline, every fifth rTMS session (weekly), and at a 6-week follow-up.

Results

There were no adverse events related to the provision of rTMS treatment. A trend toward significant (P = .066) neurobehavioral gains was temporally related to provision of rTMS. Left-sided brain stem auditory EP wave V latencies and waves I to V interpeak latencies improved along with neurobehavioral gains during provision of rTMS, suggesting that improved neural conduction in the pathway mediated the neurobehavioral improvements.

Conclusions

Repetitive TMS merits further investigation as a safe therapeutic intervention to alter neural activity, to modulate neural activity, and/or to facilitate recovery in persons with disordered consciousness subsequent to severe TBI.

Keywords: neual stimulation, coma, treatment, intervention, traumatic brain injury