Postmortem study of deep brain stimulation of the anterior thalamus: Case report

OBJECTIVE: As new clinical applications for deep brain stimulation (DBS) emerge and the number of patients with DBS systems continues to grow, lead technology will also advance. To direct improvement of these leads, improved understanding of the effects of the DBS electrodes and stimulation parameters on the surrounding brain parenchyma is necessary. We present a postmortem evaluation of a patient who had previously undergone bilateral DBS of the anterior thalamic nucleus. CLINICAL PRESENTATION: A 21-year-old, right-handed man with a 2-year history of epilepsy secondary to encephalitis underwent bilateral DBS of the anterior nucleus of the thalamus. He died 8 months after surgery, and his death was classified as a sudden, unexpected, unexplained death as a result of epilepsy. INTERVENTION: Microscopic examination and immunohistochemical analysis using glial fibrillary acidic protein, CD11b, CD45, and CD 68 were performed. The thalami of this patient were then compared with brain tissue obtained from a 45-year-old patient who died as a result of a myocardial infarction and had no history of neurological disease and no surgical intervention. There were no differences in the microscopic and histochemical evaluation of the thalami between patients, other than immediately around the electrode tract. Minimal tissue damage, mild astrocytosis, and mild inflammation surrounding the electrode termination site were observed. CONCLUSION: We report the first postmortem examination after bilateral DBS of the anterior nucleus of the thalamus for epilepsy. A comparison with control tissue showed no significant difference other than mild inflammation along the lead track.