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Aicardi syndrome is a rare neurodevelopmental disorder defined by the triad of agenesis of the corpus callosum (total or partial), typical chorioretinal lacunae and infantile spasms that affect almost exclusively females. About 200 individuals with Aicardi syndrome in have been reported in North America and Europe, but the true prevalence is likely underestimated. Single cases in males with karyotype 47, XXY have been reported. The disease is most commonly identified before the age of five months. In addition to the main clinical signs, Aicardi syndrome presents with characteristic facial features (prominent premaxilla, upturned nasal tip, decreased angle of the nasal bridge, and sparse lateral eyebrows). Coloboma, in addition to the lacunae, is common. Microcephaly, periventricular heterotopias, microgyria, enlarged ventricles or porencephalic cysts, axial hypotonia, and appendicular hypertonia with spasticity may occur. Epilepsy that is refractory to medication develops over time, with a variety of seizure types (infantile spasms that can be asymmetric or unilateral, partial seizures) and "split" brain EEG. Moderate-to-severe developmental delay and intellectual deficit is found in almost all patients. Marked scoliosis is present in up to one third of affected individuals. Gastrointestinal disorders, vascular malformations, small hands, pigmentary skin lesions, and an increased incidence of tumors are rare. It is believed that Aicardi syndrome is a sporadic disorder caused by heterozygous mutations in an X-linked gene in females, with early embryonic lethality in hemizygous males. However, a candidate region on the X chromosome has not yet been defined. Diagnosis is based on clinical features, brain magnetic resonance imaging (MRI) and skeletal findings. Differential diagnosis includes oculocerebrocutaneous syndrome, neuronal migration disorders (see these terms) and numerous syndromes that present with one or more of the features characteristic for Aicardi syndrome. Long-term follow-up by a pediatric neurologist is necessary for management of seizures. Physical, occupational, speech and vision therapy should begin at diagnosis. Appropriate musculoskeletal support and treatment for prevention of scoliosis-related complications is indicated. Prognosis and survival are highly variable. |