[Reversible hypogeusia during bilateral thalamic stimulation for essential tremor]

Deep brain stimulation of ventral intermediate nucleus (VIM-DBS) has become an established therapy for severe essential tremor (ET). The technique is however limited in some ET patients by relevant side effects such as paresthesia, dysarthria, and gait disturbances. To our knowledge, this is the first report of VIM-DBS-induced reversible hypogeusia along with retroinsular cortical deactivation under effective VIM stimulation measured with 18-fluorodexoglucose positron emission tomography. This case demonstrates that gustatory dysfunction should be considered in the pre- and postsurgical management of patients with VIM-DBS. Moreover it provides direct evidence that the thalamus acts as an important relay station in the human cerebral gustatory pathway.