REDUCTION IN VOICE TREMOR UNDER THALAMIC-STIMULATION

We studied the effect of deep brain stimulation (DBS) of the ventral i ntermediate thalamic nucleus on voice symptoms in seven patients with essential tremor. All had undergone DBS for management of hand tremor. Five of the patients had received unilateral implants; two were treat ed bilaterally. Each reported improvement in hand tremor with thalamic stimulation (a 1-to-3-point change on a 5-point severity scale). Voic e tremor was evaluated with and without stimulation using patient and clinician severity ratings, and acoustic measures (rate and amplitude) . Four of the seven patients showed reductions in voice symptoms in at least two of these measures, although degree of change differed (e.g. , from 1 to 3 points on the 5-point severity scale). Voice gains typic ally were restricted to those patients with the more severe symptoms a nd did not parallel improvements in the upper extremities. It appears that reduced voice tremor may be an additional benefit of DBS for some individuals.