Aicardi syndrome: an epidemiologic and clinical study in Norway.

BACKGROUND: Aicardi syndrome is a rare neurodevelopmental disorder. The main diagnostic features are agenesis of corpus callosum, chorioretinal lacunae, and infantile spasms. The outcome is in general severe, with poor cognitive development and difficult-to-treat epilepsy. The aim of this study was to perform a nationwide epidemiologic survey of patients with Aicardi syndrome and describe their clinical features. Norway is a small country with a well-developed health system, making epidemiologic studies of rare diseases feasible and reliable.

METHODS: We aimed at identifying all patients diagnosed with Aicardi syndrome in Norway. Prevalence of Aicardi syndrome was calculated for January 1, 2011. All available patients were examined, and their medical records were scrutinized.

RESULTS: Six females aged 7 to 27 years with the diagnosis of Aicardi syndrome were identified. With a female population of 949,578 in ages 0 to 29 years, we found an age-adjusted prevalence of 0.63 per 100,000 females. One patient never had epileptic seizures. The other five had all experienced infantile spasms, all had at some point hypsarrhythmia in electroencephalography, two had a clear picture of suppression burst, whereas three had periods of suppression. Four of the five patients with seizure disorders experienced a marked improvement with time.

CONCLUSION: We found an age-adjusted prevalence of 0.63 per 100,000 females with Aicardi syndrome and that their seizure disorder appeared to improve with age.