Clinical and imaging heterogeneity of polymicrogyria: A study of 328 patients

Richard J. Leventer, Anna Jansen, Daniela T. Pilz, Neil Stoodley, Carla Marini, Francois Dubeau, Jodie Malone, L. Anne Mitchell, Simone Mandelstam, Ingrid E. Scheffer, Samuel F. Berkovic, Frederick Andermann, Eva Andermann, Renzo Guerrini, William B. Dobyns

Research output: Contribution to journalArticle

Abstract

Polymicrogyria is one of the most common malformations of cortical development and is associated with a variety of clinical sequelae including epilepsy, intellectual disability, motor dysfunction and speech disturbance. It has heterogeneous clinical manifestations and imaging patterns, yet large cohort data defining the clinical and imaging spectrum and the relative frequencies of each subtype are lacking. The aims of this study were to determine the types and relative frequencies of different polymicrogyria patterns, define the spectrum of their clinical and imaging features and assess for clinical/imaging correlations. We studied the imaging features of 328 patients referred from six centres, with detailed clinical data available for 183 patients. The ascertainment base was wide, including referral from paediatricians, geneticists and neurologists. The main patterns of polymicrogyria were perisylvian (61), generalized (13), frontal (5) and parasagittal parieto-occipital (3), and in 11 there was associated periventricular grey matter heterotopia. Each of the above patterns was further divided into subtypes based on distinguishing imaging characteristics. The remaining 7 were comprised of a number of rare patterns, many not described previously. The most common clinical sequelae were epileptic seizures (78), global developmental delay (70), spasticity (51) and microcephaly (50). Many patients presented with neurological or developmental abnormalities prior to the onset of epilepsy. Patients with more extensive patterns of polymicrogyria presented at an earlier age and with more severe sequelae than those with restricted or unilateral forms. The median age at presentation for the entire cohort was 4 months with 38 presenting in either the antenatal or neonatal periods. There were no significant differences between the prevalence of epilepsy for each polymicrogyria pattern, however patients with generalized and bilateral forms had a lower age at seizure onset. There was significant skewing towards males with a ratio of 3:2. This study expands our understanding of the spectrum of clinical and imaging features of polymicrogyria. Progression from describing imaging patterns to defining anatomoclinical syndromes will improve the accuracy of prognostic counselling and will aid identification of the aetiologies of polymicrogyria, including genetic causes.

Original languageEnglish
Pages (from-to)1415-1427
Number of pages13
JournalBrain
Volume133
Issue number5
DOIs
Publication statusPublished - May 2010

Keywords

  • Cortical malformations
  • Epileptology
  • Magnetic resonance
  • Polymicrogyria

ASJC Scopus subject areas

  • Clinical Neurology

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    Leventer, R. J., Jansen, A., Pilz, D. T., Stoodley, N., Marini, C., Dubeau, F., Malone, J., Mitchell, L. A., Mandelstam, S., Scheffer, I. E., Berkovic, S. F., Andermann, F., Andermann, E., Guerrini, R., & Dobyns, W. B. (2010). Clinical and imaging heterogeneity of polymicrogyria: A study of 328 patients. Brain, 133(5), 1415-1427. https://doi.org/10.1093/brain/awq078