Introduction: Retention of the mesial structures is responsible for surgical failures in patients with drug-resistant mesial temporal lobe epilepsy (MTLE) due to mesial temporal sclerosis (MTS). Stereotactic laser ablation allows precise obliteration of the amygdalohippocampal complex (AHC). Utilization of real-time brain MRI permits immediate information about the region of ablation. We report clinical outcomes in a cohort of patient with MTS who received laser ablation of AHC as well as changes in the volume of AHC on pre- and post-operative MRI.
Methods: Eleven patients underwent pre-surgical evaluation for drug-resistant focal seizures. A 3-T brain MRI demonstrated abnormality in 10/11 patients. One patient with normal MRI had seizures coming from left mesial temporal lobe recorded by depth electrodes. Occipital-temporal laser ablation was performed in all patients as part of an IRB approved study protocol. Post-operative AHC ablation was compared with the pre-operative MRI.
Results: Eleven patients (5F: 20-68 years) with MTLE received laser ablation after multi-disciplinary evaluation. A 3-month post-operative MRI was obtained in 9 patients. More than 75% of the amygdala and 100% of the head-to-tail hippocampal region was ablated in 9/11 patients. One patient had < 25% of parahippocampal gyrus and the uncal recess ablated. One patient had 50% of the parahippocampal gyurs and the anterior-medial hippocampus ablated with a greater T2 signal in the remaining AH. Two patients experienced a single post-operative seizure (complete ablation) and 10/11 remains seizure free. One patient had the relapse of seizures after 4 months of seizure-free period. One patient experienced right quadrantanopia post-operatively.
Conclusions: Minimally invasive laser ablation allows for selective targeting of AHC with a near perfect anatomic amygdalohippocampectomy. Even in cases of incomplete ablation, early seizure freedom was obtainable due to the interruption of seizure network. Ongoing data collection is being performed to evaluate long-term efficacy of this novel technique.
Patient Care: Minimally invasive laser ablation of AHC for medically intractable epilepsy shows promising results. Long-term studies are needed to evaluate for sustained benefits from the procedure. This novel technique can potentially become the standard of care for patients with medically intractable mesial temporal epilepsy and for those who failed to control seizure after traditional temporal lobectomy.
Learning Objectives: By the conclusion of this session, participants should be to: 1) Describe the advantages of minimally invasive amygdalohippocampectomy in patients with medically intractable seizures, 2) Discuss in small groups about the anatomic considerations when performing laser ablation, 3) Identify an effective treatment for mesial temporal epilepsy