Amygdalohippocampectomy for epilepsy in a patient with prior ipsilateral deep brain stimulator lead placement

In light of failed medical therapy for movement disorders, the use of deep brain stimulation (DBS) has increased the last two decades. Many complications may transpire; however, to our knowledge, the literature does not mention the phenomena of brain shift from a second unrelated neurosurgical procedure and its theoretical effect on lead displacement and lead function. We present a patient with a left sided DBS for essential tremor and subsequent left amygdalohippocampectomy for temporal lobe epilepsy with minimal radiographic distortion of the DBS lead and without clinical or functional complications. A 47-year-old woman presented with bitemporal epilepsy secondary to a brain injury acquired in childhood in addition to a comorbid bilateral essential tremor, both refractory to medical intervention. A successful left-sided DBS placement was performed with satisfactory resolution of her essential tremor. The patient subsequently developed deterioration of seizure control, becoming refractory to anti-epileptic medications, requiring surgical intervention. A left-sided selective amygdalohippocampectomy and techniques to minimize brain shift were performed without complications. Postoperative imaging suggested minimal distortion of the DBS lead. This did not correspond with reemergence of her essential tremor, implying that the lead maintained functional utility. Brain shift secondary to a craniotomy may cause DBS lead displacement. This phenomenon should be considered when planning operative approaches and can be limited by selective resections. With the growing propensity for placement of DBS leads and the risk of lead displacement, it is important to consider operative approaches to minimize brain shift.