Thalamic Responsive Neurostimulation After Anatomic Hemispherectomy With Direct Targeting

Nearly one-third of patients with epilepsy are unable to achieve adequate seizure control with medication alone. Responsive neurostimulation (RNS) of thalamic nuclei is a relatively new option for the treatment of drug-resistant epilepsy (DRE). Here the authors present a complex case of a pediatric patient with DRE secondary to left hemimegencephaly after anatomic hemispherectomy and vagal nerve stimulation. One year after undergoing right centromedian (CM) and anterior nucleus (ANT) thalamic RNS, the patient achieved a greater than 50% seizure frequency reduction. The technical challenges of targeting of the CM and ANT nuclei due to the lack of contralateral hemisphere and thalamus are discussed. Ultimately, the use of direct targeting with advanced MRI sequences allowed for successful targeting despite the challenges posed by the patient's unique anatomy.