Polymicrogyria: Clinical and Brain Imaging Correlation

Abstract

olymicrogyria (PMG) is not uncommon developmental brain malformations. It is associated with epilepsy, intellectual disability, motor dysfunction and speech disturbance. It is considered a disorder of neuronal organization defect. PMG is heterogeneous condition, clinically as well as etiologically It has variable imaging patterns. PMG affects variable portions of the cerebral cortex: it may be focal, multifocal, or diffuse; it may be unilateral, bilateral, and asymmetrical; or bilateral and symmetrical. Several subtypes of PMG have been recognized based on differences in topography, such as frontal, perisylvian, mesial parieto-occipital, and multilobar forms. The aim of this study was to determine the types and relative frequencies of different PMG patterns and define clinical findings in correlation of imaging findings. We studied the clinical and imaging features of 15 patients referred from the outpatient clinic of the Clinical Genetics Department and Ain Shams Children's Hospital between 2009 -2012, including 12 males and 3 females. The age ranged from 0.25 yrs. to 10 years. Consanguinity was evident in 80% of the patients. All patients had bilateral PMG (15/15 100 %). They were grossly symmetric in fourteen patients (14/15; 93.3%) and asymmetric in one patient (1/15; 6.7 %). Generalized PMG was seen in nine patients (9/15; 60%), BPP detected in two patients (2/15 13.3%) bilateral parieto-occipital PMG in two patients (2/15, 13.3%), BFPP in one patient (1/15; 6.7%) and multifocal in one patient (1/15; 6.7%).The most common clinical sequelae were global developmental delay (100%), epileptic seizures (87.7%) and spasticity (80%). For the diagnosis of PMG, good brain MRI quality is recommended.