Multilobar polymicrogyria, intractable drop attack seizures, and sleep-related electrical status epilepticus

Area of Science:

• Neurology
• Epileptology
• Pediatric Neurology

Background:

• Cortical malformations are often linked to intractable epilepsy, making patients candidates for surgery.
• Multilobar polymicrogyria is a specific cortical malformation typically associated with poor seizure prognosis.
• Electrical status epilepticus during sleep (ESES) usually predicts a good long-term seizure outcome.

Purpose of the Study:

• To investigate the seizure outcome of ESES in patients with multilobar polymicrogyria, a condition usually associated with difficult-to-treat epilepsy.
• To evaluate the long-term prognosis of ESES in a cohort of children with this specific structural brain lesion.

Main Methods:

• A longitudinal study of nine patients with multilobar polymicrogyria diagnosed with ESES.
• Data collection included brain MRI, serial sleep EEG recordings, and cognitive assessments over 4 to 19 years.
• Seizure status and cognitive function were evaluated during and after the ESES period.

Main Results:

• ESES and associated drop seizures occurred between ages 2-5 years and resolved by ages 5-12 years.
• At follow-up (mean age 14.5 years), patients were seizure-free or had infrequent focal motor seizures during sleep.
• Three patients discontinued antiepileptic drugs, and no significant cognitive deterioration was observed post-ESES.

Conclusions:

• Multilobar polymicrogyria may facilitate age-related secondary bilateral synchrony underlying ESES.
• The favorable seizure outcome in this cohort contrasts with the typical prognosis for cortical malformations.
• Epilepsy surgery should be approached cautiously in children with polymicrogyria and drop seizures; systematic sleep EEG is recommended.