[Show abstract][Hide abstract] ABSTRACT: Our aim was to develop a screening test to predict Dravet syndrome before the first birthday based on the clinical characteristics of infants and the SCN1A mutation analysis.
Ninety-six patients who experienced febrile seizures before the age of one were enrolled. The patients were divided into two groups-the Dravet syndrome group (n = 46) and the non-Dravet syndrome group (n = 50). We compared the clinical characteristics before one year of age of the two groups. We analyzed all coding exons of the SCN1A gene by the direct sequencing method. Scores from 0 to 3 were assigned to each risk factor based on the odds ratio and p-value.
An age of onset of febrile seizure <or= 7 months, a total number of seizures >or= 5, and prolonged seizures lasting more than 10 min. were regarded as significant risk factors for Dravet syndrome. Other factors highly predictive of this syndrome were hemiconvulsions, partial seizures, myoclonic seizures, and hot water-induced seizures. A total clinical score of six or above was the cutoff value indicating a high risk of Dravet syndrome. SCN1A missense and truncated mutations were detected significantly more often in the Dravet syndrome group than in the non-Dravet syndrome group.
This simple screening test was designed to be used by general pediatricians. It could help to predict Dravet syndrome before one year of age. If the sum of the clinical risk score is >or= 6, then the performance of an SCN1A mutation analysis is recommended.
[Show abstract][Hide abstract] ABSTRACT: We classified 28 patients with severe myoclonic epilepsy in infancy (SME) according to the presence or absence of myoclonic seizures and/or atypical absences. Eleven of the patients had myoclonic seizures and/or atypical absences, and we refer to this condition as 'typical SME (TSME)'. Seventeen of the patients had only segmental myoclonias, and we refer to this condition as 'borderline SME (BSME)'. We then analyzed the electroclinical and genetic characteristics of these two groups. Ten of the 11 TSME patients had a photoparoxysmal response at some time during their clinical course, while none of the BSME patients showed this response. TSME and BSME showed a significant difference in regard to gender ratio: female dominance in TSME and male dominance in BSME (P=0.008). The detection rate of the voltage-gated sodium channel alpha1-subunit (SCN1A) gene mutations was 72.7 and 88.2% in TSME and BSME, respectively. There was no difference in the type or rate of mutation between TSME and BSME. We conclude that TSME and BSME show distinct differences in photoparoxysmal response and gender, which might be caused by some genetic mechanism(s) other than the SCN1A gene mutation.
Brain and Development 11/2003; 25(7):488-93. · 1.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Three hundred eight patients with childhood and adolescent epilepsy were examined to clarify the incidence of epileptic discharges on initial and follow-up electroencephalograms. Epileptic discharges were found in 75.6% patients on the initial electroencephalogram, which is higher than figures previously reported for adults. The cumulative incidence of epileptic discharges was 92.3% by the third electroencephalogram recording. However, in 17.1% patients with nonspecific idiopathic generalized epilepsy, no epileptic discharges were found even after three electroencephalogram recordings. The incidence of epileptic discharges in patients with generalized epilepsy (84.3%) was significantly higher than in patients with localization-related epilepsy (71.6%). The incidence of epileptic discharges in patients with partial seizures was lower than those in patients with generalized seizures. The incidence of epileptic discharges was low in the 0- to 3-year-old and 15- to 20-year-old groups, and high in the 3- to 12-year-old groups. In the positive epileptic discharge patients, 38.8% of electroencephalograms were abnormal only during the waking or sleeping portion of the recordings. Knowing the incidence of epileptic discharges for each type of epilepsy will be useful in planning further electroencephalogram research and performing electroencephalograms in the clinical setting.