Aicardi syndrome: presentation at onset in Swedish children born in 1975-2002.

In a nation-wide survey of Aicardi syndrome, defined as the onset of epilepsy in the first six months of life, agenesis of the corpus callosum (partial or total) and lacunar chorioretinopathy, 18 patients, all girls, born between 1975 and 2002 were identified in Sweden. Fifteen were definite cases and three were regarded as probable, since they only fulfilled two of three inclusion criteria in addition to other cerebral malformations and/or chorioretinal changes. Calculations based on this survey and population-based studies on epilepsy in retarded children yielded a prevalence rate in the range of 2 - 15 : 100 000 girls. All but one had an ordinary birth weight, length and head circumference for gestational age. One was born preterm, one post term. The age at diagnosis varied from three days to 12 years and decreased during the period reflecting the increased awareness of the syndrome. Eleven came to medical attention because of seizures. Six had myoclonic, four generalized tonic-clonic and eight tonic, clonic or complex partial seizures. One had hypsarrhythmia, five multifocal epileptiform activity, three bilateral independent bursts, two burst-suppression pattern, six other types of spikes and one slowing of background activity. Asymmetrical EEG abnormalities indicating independent hemispheric dysfunction were detected in 13/18 (72 %). Complete absence of the corpus callosum was found in 13/18 (72 %), although not identical with the previous group, a partial defect in 3/18 (17 %), and a thinning in 2/18 (11 %). Of 15 children with definite Aicardi syndrome, 13 had binocular and two monocular lacunae. In one of the latter two, subtle monocular lacunae were found on fundus photographs, but had been missed on repeated clinical examinations. Of three children with probable Aicardi syndrome typical lacunae were reported in one and other kinds of depigmentation in the other two. Most of the children had anomalous optic discs. Neuroimaging in infancy or early childhood combined with ophthalmological examination and ocular fundus photography will facilitate an early diagnosis of Aicardi syndrome. Seizure type and EEG abnormalities may be non-specific at onset.