Abstracts

Rationale: In AES 2010, we reported tonic posturing seizures with prominent crying followed by epileptic spasms in a cluster as peculiar seizure types specific for CDKL5 (cyclin-dependent kinase-like 5) related epileptic encephalopathy in infancy. In 2011, we investigated useful clinical clues for early diagnosis of CDKL5 related epileptic encephalopathy. Methods: We investigated clinical characteristics in 9 patients (3 boys and 6 girls) with CDKL5 mutations/microdeletions. Six (3 boys and 3 girls) had mutations by direct DNA sequence and 3 (all girls) had microdeletions by array CGH. We compared them with 35 infantile onset epileptic patients without CDKL5 mutations/microdeletions. Results: None of 11 patients with cortical malformations had CDKL5 mutations/microdeletions. CDKL5 mutations were found in 3/17 boys (18%) and 3/18 girls (17%) without specific abnormal MRI findings. Among them, CDKL5 mutations were found in 3/15 boys (20%) and 3/10 girls (30%) with epileptic spasms, 3/9 boys (33%) and 3/14 girls (21%) with focal seizures, 3/6 boys (50%) and 3/9 girls (33%) with early onset (<3m) focal seizures, 3/8 boys (38%) and 3/7 girls (43 %) with both epileptic spasms and focal seizures, and 2/4 boys (50%) and 3/3 girls (100%) with compound seizures of epileptic spasms and focal seizures.Conclusions: No specific abnormal MRI findings, early onset (<3m) focal seizures (typically starting with crying and tonic posturing), epileptic spasms, and the presence of compound seizures of them highly suggest CDKL5 related epileptic encephalopathy in both boys and girls.