"Benign" temporal lobe epilepsy with hippocampal sclerosis: A forgotten entity?

Area of Science:

• Neurology
• Epileptology

Background:

• Mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) typically presents in childhood or early adolescence.
• Late-onset epilepsy requires careful characterization to understand its unique features and management.

Purpose of the Study:

• To describe a cohort of patients with late-onset MTLE-HS presenting with atypical features.
• To characterize their demographics, electroclinical features, imaging, autoantibody status, and response to antiseizure medication (ASM) therapy.

Main Methods:

• Retrospective case series of five patients with first seizure after age 50.
• Characterization included demographics, seizure history, electroencephalography (EEG), magnetic resonance imaging (MRI), autoantibody testing (serum and CSF), and treatment response to ASMs.

Main Results:

• All five patients experienced their first seizure after age 50, with no preceding precipitating events.
• None had positive serum or CSF autoantibodies and all remained seizure-free for over two years on ASMs alone.
• Two patients experienced motor vehicle accidents due to seizures; three had seizures during sleep.

Conclusions:

• Late-onset MTLE-HS is a distinct clinical entity that can present atypically in adulthood.
• These patients demonstrate a favorable response to ASMs, achieving sustained seizure freedom.
• Despite good treatment response, the potential for serious consequences like motor vehicle accidents underscores the importance of timely diagnosis and treatment.