Clinical variability of polymicrogiria: report of 35 new cases and review of the literature

The study of polymicrogyria with magnetic resonance imaging (MRI) has made possible the report of several series of patients in which the main clinical manifestations differ considerably. The aims of the study were to review the literature and to know the clinical variability of the patients attended in a neuropediatric service. A retrospective study was conducted between 1989-2011 for the patients attended in our neuro-pediatric service and diagnosed of polymicrogyria by MRI. On the totality of 44 patients having polymicrogyria, 9 did not satisfy de inclusion criteria (Barkovich's radiological criteria). The polymicrogyria was bilateral in 22/35 patients (1 frontal, 22 perisylvian) and unilateral in 13/35 (2 frontal, the rest perisylvian). All patients with bilateral polymicrogyria had intellectual disability, 71% had global development delay, 75% had oromotor disorder and 40% had epilepsy. Patients with unilateral polymicrogyria had the following symptoms: 65% intellectual disability, 55% global development delay, 55% oromotor disorder, 55% epilepsy and 2 patients where free of symptoms (the oldest 2 year old). The initial symptoms were depending upon the age: the oromotor disorder was the most common in the newborn period, global development delay if the symptoms started before 2 years old and after 2 years epilepsy was the initial most common symptom. In our study the most common symptom was intellectual disability (independently of the type of poly-microgyria), followed by oromotor disorder and, with fewer proportion, epilepsy (in contrast with other series).