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Updated: May 27, 2026
Anteromesial Temporal Lobectomy for Medically Intractable Temporal Lobe Epilepsy: An Operative Study
Published on: August 15, 2025
Subtypes of medial temporal lobe epilepsy: influence on temporal lobectomy outcomes?
Leonardo Bonilha1, Gabriel U Martz, Steven S Glazier
1Comprehensive Epilepsy Center, Medical University of South Carolina, Charleston, South Carolina, USA. bonilha@musc.edu
Abstract:
Surgical resection of the hippocampus is the most successful treatment for medication-refractory medial temporal lobe epilepsy (MTLE) due to hippocampal sclerosis. Unfortunately, at least one of four operated patients continue to have disabling seizures after surgery, and there is no existing method to predict individual surgical outcome. Prior to surgery, patients who become seizure free appear identical to those who continue to have seizures after surgery. Interestingly, newly converging presurgical data from magnetic resonance imaging (MRI) and intracranial electroencephalography (EEG) suggest that the entorhinal and perirhinal cortices may play an important role in seizure generation. These areas are not consistently resected with surgery and it is possible that they continue to generate seizures after surgery in some patients. Therefore, subtypes of MTLE patients can be considered according to the degree of extrahippocampal damage and epileptogenicity of the medial temporal cortex. The identification of these subtypes has the potential to drastically improve surgical results via optimized presurgical planning. In this review, we discuss the current data that suggests neural network damage in MTLE, focusing on the medial temporal cortex. We explore how this evidence may be applied to presurgical planning and suggest approaches for future investigation.
Insights
Predicting epilepsy surgery success is challenging. New research suggests focusing on medial temporal cortex damage may help identify patient subtypes for better surgical planning and outcomes.
Area of Science:
- Neurology
- Neurosurgery
- Epileptology
Background:
- Medication-refractory medial temporal lobe epilepsy (MTLE) is often treated with hippocampal resection.
- A significant portion of patients experience persistent disabling seizures post-surgery.
- Current methods cannot predict individual surgical outcomes effectively.
Purpose of the Study:
- To review evidence on neural network damage in MTLE, particularly in the medial temporal cortex.
- To explore the application of this evidence in presurgical planning for MTLE.
- To suggest future research directions for improving surgical outcomes.
Main Methods:
- Review of current magnetic resonance imaging (MRI) and intracranial electroencephalography (EEG) data.
- Analysis of presurgical data to identify patterns related to seizure generation.
- Focus on the role of entorhinal and perirhinal cortices in MTLE.
Main Results:
- Converging evidence suggests the entorhinal and perirhinal cortices are implicated in seizure generation in MTLE.
- These areas may remain epileptogenic post-surgery if not fully resected.
- Subtypes of MTLE may exist based on extrahippocampal damage and medial temporal cortex epileptogenicity.
Conclusions:
- Identifying MTLE subtypes based on medial temporal cortex involvement could improve presurgical planning.
- Optimized planning has the potential to significantly enhance surgical success rates.
- Further investigation into neural network damage is crucial for personalized epilepsy treatment.
