Safety of repeated sessions of galvanic vestibular stimulation following stroke: A single-case study

Primary objective: Galvanic vestibular stimulation (GVS) involves the delivery of small electrical current to the part of the scalp that overlies the vestibular nerves. A single, brief session transiently reduces certain types of stroke impairment with no reported side-effects. It is anticipated that further reductions will occur if the duration and frequency of stimulation is increased. The aim of the present study was to assess whether this increased exposure is well-tolerated and consistent with patient well-being. Methods and procedures: GVS was administered to a stroke sufferer on 5 consecutive days, each for 30 minutes at an intensity of 1 milliamp. Tolerability was monitored via a range of behavioural scales sensitive to side-effects experienced during and after stimulation. Results: No unpleasant sensations were reported during stimulation and no deterioration in global function was observed over the 5-day period. Conclusion: The results imply that repeated applications of GVS are tolerable at the parameter settings applied and provide the basis for larger-scale investigations of safety and efficacy.