Abstracts

Rationale: Mesial temporal lobe epilepsy (MTLE) with hippocampal sclerosis is a surgically remediable focal epilepsy. While selective amgydohippocampectomy (SAH) has been used previously to minimize brain resection, it still represents an open surgical procedure. Recently, laser ablation has been used to further minimize damage to surrounding tissue in an attempt to reduce the potential cognitive side effects of traditional neurosurgical resection. Unidirectional laser ablation (NeuroBlate™; Monteris, Inc.) provides the neurosurgeon with increased precision compared to standard laser surgery techniques via a side-firing laser that ablates tissue while cooling the environment on the opposite side. We present a case of medically refractory MTLE that was treated via directional laser ablation.Methods: A 21 year old woman with a 15-year history of refractory temporal lobe epilepsy. The patient presented with multiple complex partial seizures per week characterized by a strange feeling that progressed to loss of awareness, oral automatisms, right upper extremity dystonic posturing, right-sided head version and subsequent secondary generalization. Video EEG monitoring revealed left temporal lobe epilepsy. MRI of the brain showed left mesial temporal sclerosis. Subsequent neuropsychological testing was unremarkable without clear lateralizing signs. Wada testing showed right hemisphere language dominance with worse memory performance using the left hemisphere. Given her history, MRI-guided unidirectional laser ablation of the mesial temporal lobe was considered an optimal, minimally invasive, approach.Results: Using MRI guidance, unidirectional thermoablation of the left hippocampus was performed through a minimally invasive occipital approach. After an unremarkable hospital course, she was discharged home on post-operative day two. While too early to assign Engel class outcome, she has remained seizure free to this point. From a neuropsychological standpoint, the patient reports no decrease in memory or language abilities. Formal neuropsychological testing is pending at this time.Conclusions: MRI-guided unidirectional laser ablation is a novel, minimally invasive tool that allows increased surgical precision compared to standard laser ablation techniques, while conceivably providing similar seizure freedom outcomes and fewer postoperative neurocognitive deficits.