Long-Term Migration of a Deep Brain Stimulation (DBS) Lead in the Third Ventricle Caused by Cerebral Atrophy in a Patient with Anterior Thalamic Nucleus DBS.

The long-term (5-years) antiepileptic effect of deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) against refractory epilepsy has been reported. However, experience with ANT DBS for epilepsy is limited, and so hardware complications and technical problems related to ANT DBS are unclear. We report the case of a 57-year-old male who underwent re-implantation of a DBS lead in the left ANT because of lead migration into the third ventricle detected 8 years after the first DBS, and which was caused by the significant enlargement of the lateral and third ventricles. After re-implantation, the patient showed a mechanically-related antiepileptic effect and a prominent driving response of the electroencephalography was verified. We speculate that progressive dilatation of the ventricle and shallow, insufficient implantation of the lead during the initial ANT DBS may have caused migration of the DBS lead. Because dilatation of the ventricle could progress years after DBS in a patient with chronic epilepsy, regular follow-up imaging is warranted in ANT DBS patients with an injured, atrophied brain.