Bilateral high-frequency electrical impulses to the thalamus reduce voice tremor: acoustic and electroglottographic analysis. A case report.

An 81-year-old female patient suffering from disabling Holmes' tremor affecting both upper extremities, the head and additionally the vocal apparatus underwent bilateral thalamic ventralis intermedius nucleus (v.i.m.) stimulation. With the stimulation ON, the patient experienced complete suppression of the limb and head tremor and thorough voice normalization. Acoustic and electroglottographic (EGG) analysis showed a tendency towards hyperfunctional phonation with the stimulation ON as well as OFF, but a less disturbed vocal cord vibration pattern with the stimulation ON in comparison with a group of normal female speakers. This example shows that long-term monitoring of the vocal apparatus under deep brain stimulation therapy (DBS) of movement disorders must be planned in order to modify the stimulation parameters, if necessary, or to initiate logopaedic treatment.