Influence of cerebellar stereotactic stimulation on left–right electrodermal information transference in a patient with cerebral palsy
A 13-year-old boy suffering from cerebral palsy developed spastic quadriparesis with a pronounced startle reaction that seriously disabled his voluntary activity (patient in wheelchair). The patient had two deep brain stimulation electrodes (Medtronic model 3389; Minneapolis, MN, USA) stereotactically implanted (September 6, 2011) in the anterior lobe of the cerebellum (culmen and central lobule–superior cerebellar peduncle) from lateral suboccipital regions ( and ). The electrodes were temporarily connected to a transcutaneous extension to allow further clinical tests and neurophysiological examination, and effects of the stimulation were assessed and verified.\nAfter verification of the effectiveness of stimulation, an internal pulse generator (Medtronic Activa PC) was implanted (September 12, 2011) and stimulation programs were set for therapeutic stimulation (frequency, 250 Hz; pulse width, 0.180 milliseconds; amplitude: right electrode, 1.1 V, and left electrode, 2.7 V; and cycling mode of stimulation, on for 15 minutes, off for 3 hours). Using these parameters of stimulation, the patient was relaxed and spasticity decreased. During a test at a slightly higher amplitude (plus 0.2–0.4 V), the patient experienced an immediate feeling of pleasure. However, an even higher stimulation voltage (3–4 V) evoked bilateral aggravation of the pathological posture of the patient and was accompanied with an intense feeling of fear. For therapeutic stimulation, the amplitude was adjusted to the level at which relaxation and decreased spasticity were achieved.\nDuring experimental EDA measurement, the application of monopolar stimulation was performed in the interval from 1 to 1.5 V with an increase of 0.1 V in each step. The stimulation lasted 120 seconds. Because of stimulation spasticity and pathological startle, reactions were remarkably reduced and there was improved fluency in speech, mood, and cooperation of the patient during physical therapy. The study was approved by the Slovak Medical University ethical committee (Banska Bystrica, Slovakia), and all participants gave written informed consent.