Temporal lobe dysfunction in late-onset epilepsy of unknown origin.

Area of Science:

• Neurology
• Neuroscience
• Geriatrics

Background:

• Late-onset epilepsy (LOE) is a growing concern in aging populations.
• Late-Onset Epilepsy of Unknown origin (LOEU) is diagnosed when underlying causes are excluded.
• Understanding LOEU's characteristics is crucial for effective management.

Purpose of the Study:

• To investigate the semiological, electroencephalographic, metabolic, and neuropsychological features of LOEU.
• To characterize the clinical presentation and prognosis of LOEU.
• To explore potential underlying pathophysiology in LOEU.

Main Methods:

• Retrospective analysis of 23 LOEU patients (≥55 years).
• Comprehensive evaluation including brain MRI, EEG, 18F-FDG-PET, and neuropsychological testing.
• Exclusion of known epilepsy causes through detailed clinical and instrumental assessment.

Main Results:

• Half of LOEU patients experienced focal-onset seizures (FOS), the other half focal to bilateral tonic-clonic seizures (FBTCS).
• Most patients showed a mild seizure phenotype with good response to single antiseizure medication.
• EEG and 18F-FDG-PET indicated temporal lobe dysfunction, with normal or nonspecific MRI findings in most cases.

Conclusions:

• LOEU, presenting as FOS or FBTCS, generally has a favorable prognosis.
• Metabolic imaging and neurophysiology highlight temporal structure involvement in LOEU.
• Further research is needed to elucidate the precise role of temporal lobe dysfunction in LOEU pathogenesis.