Polymicrogyria-associated epilepsy: a multicenter phenotypic study from the Epilepsy Phenome/Genome Project

Area of Science:

• Neuroscience
• Developmental Neurology
• Epileptology

Background:

• Polymicrogyria (PMG) is a malformation of cortical development associated with epilepsy.
• Understanding the clinical and imaging spectrum of PMG-related epilepsy is crucial for diagnosis and management.

Purpose of the Study:

• To describe the clinical epilepsy and neuroimaging features of a large cohort with polymicrogyria-related epilepsy.
• To investigate the relationship between PMG topography and epilepsy characteristics.

Main Methods:

• Retrospective review of phenotypic data from 87 participants with epilepsy and PMG.
• Data collected through the multicenter Epilepsy Phenome/Genome Project.

Main Results:

• Most participants (87.4%) presented with focal epilepsy; infantile spasms were most prevalent in generalized seizure types (45.2%).
• Perisylvian PMG was the most common topographic pattern (77.0%).
• Generalized PMG correlated with earlier seizure onset (median 8 months) and higher rates of pre-existing developmental delay (57.1%).

Conclusions:

• Polymicrogyria-related epilepsy encompasses both focal and generalized seizure onsets.
• More extensive PMG distributions are associated with earlier seizure onset and increased developmental delay.