Authors :
Presenting Author: Adam Muncan, DO – Zucker School of Medicine at Hofstra/Northwell
Sean Hwang, MD – Zucker School of Medicine at Hofstra/Northwell
Fred Lado, MD – Zucker School of Medicine at Hofstra/Northwell
Erica Meltzer, PhD – Northwell
Ashesh Mehta, MD PhD – Northwell Health
Rationale:
Surgical interventions for drug resistant temporal epilepsy including hippocampal sparing surgical resections pose a significant challenge as far as memory and cognitive decline. In particular, language dominant resective surgery has been troublesome for patient's long term memory and post-surgical outcomes. Several means have been employed to avoid this outcome, including stereotactive laser amygdalohippocampectomy (SLAH) or hippocampal sparing anterior temporal lobectomy (HSATL). Many studies have reported significant decline in memory with various surgical interventions, even those that spare the mesial temporal structures, including HSATL and SLAH. Several drug resistant temporal epilepsy cases have been reviewed here that have underwent hippocampal sparing temporal lobe surgical interventions and have been tracked over time for neuropsychological evaluation, memory and cognition testing to determine the optimal surgical approach in these patients.Methods:
Surgical outcomes of a series of patients with drug resistant temporal epilepsy were tracked over time to include pre-operative and post-operative neuropsychological testing, memory and cognitive testing. These patients have been followed for at least 12 months. An analysis was performed comparing these patient’s memory and cognitive assessments to determine whether the hippocampus should be spared initially as had been done previously, or that recurrent seizures and cognitive issues are inevitable in any event.
Results:
A 30 year old male with intractable structural focal epilepsy due to a left cavernoma and resection had memory testing showing impaired verbal memory scores. Repeat memory and cognitive testing revealed verbal memory impaired has declined since surgery, with nonverbal memory mildly weak but is stronger than verbal memory. Word retrieval was thought to be subtly slower/weaker in conversational speech and working memory has declined including in visuospatial domains. Another patient, a 24 year old male with prior head injury at age 5, concussion and intractable epilepsy with prior left temporal pole resection and left temporal lobectomy. He had deficits in memory in the left hemisphere compared to the right. He had left temporal lobe resection and repair of encephalocele. His recent evaluation showered weaknesses in word retrieval and verbal memory, as well as working memory which has subtly declined over the years as well as processing speed. Lastly, a 33 year old male with left mesial temporal lobe lesion consistent with DNET with resection in November 2022. Since surgery, his memory scores showed deficits in the right hemisphere. Repeat neuropsychological testing showed a post surgical decline in memory and word retrieval, estimating functioning at 60-70% pre surgical baseline.Conclusions:
From these patients undergoing hippocampal sparing surgeries for seizures arising from the temporal lobe, it is clear that memory testing did not preclude them from undergoing intervention and that memory and cognitive issues occurred regardless of sparing mesial temporal structures. This could change the surgical approach for these patients with drug resistant temporal lobe epilepsies.Funding: Not applicable