Facing the hidden wall in mesial extratemporal lobe epilepsy

Area of Science:

• Neurology
• Neurosurgery
• Epileptology

Background:

• Refractory extratemporal lobe epilepsy (ETLE) often has poorer surgical outcomes than temporal lobe epilepsy.
• Mesial ETLE presents unique diagnostic and therapeutic difficulties, especially with midline seizure origins.
• Interhemispheric functional diversity and connectivity lead to heterogeneous seizure semiology in ETLE.

Purpose of the Study:

• To review diagnostic challenges in mesial ETLE.
• To discuss therapeutic strategies for mesial ETLE.
• To highlight the role of advanced diagnostics and surgical interventions.

Main Methods:

• Review of literature on diagnostic and therapeutic approaches for mesial ETLE.
• Analysis of challenges in scalp EEG interpretation due to hidden mesial cortex.
• Emphasis on advanced imaging and intracranial studies for seizure localization.

Main Results:

• Mesial ETLE seizure semiology can be diverse, with signs like ictal body turning suggesting mesial onset.
• Scalp EEG has limited localizing value for mesial ETLE.
• Advanced imaging and intracranial recordings are crucial for identifying the seizure onset zone.
• Surgical access to the interhemispheric space poses challenges for electrode placement and resection.

Conclusions:

• Targeted intracranial recordings and tailored surgical interventions can yield satisfactory outcomes in carefully selected mesial ETLE patients.
• Overcoming diagnostic and surgical hurdles is key to improving outcomes for refractory ETLE.