Abstract
Background: Magnetic resonance-guided focused ultrasound thalamotomy (MR-FUS) is a promising, noninvasive treatment for medically refractory essential tremor (ET). It is well tolerated, with the most common side effects being sensory and gait disturbances.
Case Report: A 69-year-old man presented with orofacial dyskinesias, left hemichorea, and motor impersistence 1 week after MR-FUS of the right ventralis intermedius nucleus for ET. MRI brain demonstrated right ventral thalamus T2 hyperintensity with inferolateral extension abutting the subthalamic nucleus (STN).
Discussion: Chorea is a rare side effect of MR-FUS, but may be present with inferolateral lesions extension to the STN, disrupting the indirect pathway.