OBJECTIVE: Galvanic vestibular stimulation (GVS) activates the vestibular afferents, and these changes in vestibular input exert a strong influence on the subject's posture or standing balance. In patients with Parkinson's disease (PD), vestibular dysfunction might contribute to postural instability and gait disorders. METHODS: Current intensity was increased to 0.7 mA, and the current was applied to the patients for 20 minutes. To perform a sham stimulation, the current intensity was increased as described and then decreased to 0 mA over the course of 10 seconds. The patient's status was recorded continuously for 20 minutes with the patient in the supine position. RESULTS: Three out of 5 patients diagnosed with PD with postural instability and/or abnormal axial posture showed a reduction in postural instability after GVS. The score for item 12 of the revised Unified Parkinson's Disease Rating Scale part 3 was decreased in these patients. CONCLUSIONS: The mechanism of postural instability is complex and not completely understood. In 2 out of the 5 patients, postural instability was not changed in response to GVS. Nonetheless, the GVS-induced change in postural instability for 3 patients in our study suggests that GVS might be a therapeutic option for postural instability.
Gait ; Humans ; Parkinson Disease* ; Posture ; Supine Position

We present a 47-year-old right-handed woman with a 15-year history of writer's cramp who was provided with six sessions of cathodal transcranial direct current stimulation (tDCS) combined with observation of writing actions performed by a healthy subject and electromyographic (EMG) biofeedback training to decrease EMG activities in her right forehand muscles while writing for 30 min for 4 weeks. She showed improvement in dystonic posture and writing speed after the intervention. The writing movement and writing speed scores on a writer's cramp rating scale decreased, along with writing time. Our findings demonstrated that cathodal tDCS combined with action observation and EMG biofeedback training might improve dystonic writing movements in a patient with writer's cramp.
Biofeedback, Psychology ; Dystonic Disorders ; Female ; Healthy Volunteers ; Humans ; Middle Aged ; Muscles ; Posture ; Transcranial Direct Current Stimulation ; Writing