Damage to the Contralateral Thalamus after Magnetic Resonance Imaging-guided, Focused Ultrasound Surgery for Essential Tremor: A Case Report.

This study involved a 73-year-old man who underwent thalamotomy via magnetic resonance imaging (MRI)-guided, focused ultrasound surgery, in which the left thalamic ventral intermediate nucleus is targeted, as a treatment for action tremor of the right-hand fingers caused by essential tremor. Following treatment, the action tremor of the right-hand fingers mostly disappeared, but new symptoms of paresis and sensory impairment were evident in the left upper and lower limbs. Head MRI exhibited a hyperintense lesion on diffusion-weighted imaging and a decreased apparent diffusion coefficient in a region of the right thalamus following the anterior choroidal artery, medial posterior choroidal artery, and thalamogeniculate artery territory. Through an extensive literature search, only two reports of cavitation were found as a contributory cause of irreversible brain damage during focused ultrasound surgery, and both cases involved damage to the thalamus on the treated side. Along with a review of the literature on the mechanism of onset, a case of irreversible brain damage to the thalamus contralateral to the treated side is reported.