Neurosurgical treatment of tremor in mitochondrial encephalopathy.

A 53-year-old woman underwent several ischemic stroke-like episodes and later developed incomplete, bilateral ophthalmoplegia, left vision deterioration, and bilateral tremor. The clinical course, laboratory data, and muscle histology led to a diagnosis of mitochondrial encephalomyopathy. No other etiology could be identified in the background of her disabling bilateral postural-kinetic tremor. As this tremor did not respond to pharmacological therapy, left thalamotomy and subsequently right thalamic deep brain stimulator (DBS) implantation were performed, which resulted in an excellent clinical outcome. The Fahn-Tolosa-Marin Tremor Rating Scale improved from 110 to 11 points. This case suggests that the rare tremor caused by mitochondrial encephalopathy may be treated long-term with either thalamotomy or thalamic DBS implantation.