Clinical And Molecular Genetic Study Of Idiopathic Nocturnal Frontal Lobe Epilepsy

Part one Clinical study of idiopathic nocturnal frontal lobe epilepsy ObjectiveTo make a comprehensive understanding of idiopathic nocturnal frontal lobe epilepsy, the clinical, electroencephalogram (EEG), neuroimaging, therapeutic efficacy and prognosis of 114 cases were analyzed. Methods114 cases of idiopathic nocturnal frontal lobe epilepsy from overall 2320 cases of epilepsy admitted in the epilepsy outpatient from June 1999 to January 2007 were collected, with detailed case history queried and neurological examination performed. Their ictal and interictal EEG and neuroimaging were carefully analyzed and their therapeutic efficacy and prognosis were evaluated. ResultsIdiopathic nocturnal frontal lobe epilepsy has distinctive clinical seizure characteristics. The onset age is younger than 20 and the ratio of male cases to female cases is 2 to 1. The most notable clinical characteristics are nocturnal clustered postural or dystonic seizures and complex motor activities, with 14% of the patients have epileptic family history. The interictal routine EEG of 22.9% and active EEG of 28% cases in wakeness and 38% cases in sleep showed frontal lobe epileptiform discharge while the ictal EEG of 66.7% cases showed frontal lobe epileptiform discharge. Drug therapy is effective in 80% cases with 30% completely controlled. ConclusionsIdiopathic nocturnal frontal lobe epilepsy has distinctive clinical semeiology. The ictal and interictal EEG abonrmalty is low and it should becarefully discriminated clinically. Frontal lobe epilepsy is prone to attack insleep, so sleep EEG is important in the evaluation of nocturnal epilepsy,especially in idiopathic nocturnal frontal lobe epilepsy.Part two Molecular genetic study of idiopathic nocturnal frontal lobeepilepsyObjectiveWe selected two definitive autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) genes CHRNA4, CHRNB2 as candidate genes and DNA sequencing was performed on the 5^th exons. MethodsBased on the progress reported in this field, we selected two definitive ADNFLE genes CHRNA4, CHRNB2 as candidate genes and DNA sequencing was performed on the 5^th exons in 13 families of 18 idiopathic nocturnal frontal lobe epilepsy cases, 23 sporadic idiopathic nocturnal frontal lobe epilepsy cases and 26 first degree relatives. ResultsWe carried out PCR amplification and DNA mutation screening of the 5^th exons of the CHRNA4 and CHRNB2 genes. We do not find any mutations in these regions in 13 families of 18 idiopathic nocturnal frontal lobe epilepsy cases, 23 sporadic idiopathic nocturnal frontal lobe epilepsy cases and 26 first degree relatives. ConclusionsThere were many case reports of ADNFLE and some of the pathogenic genes were determined. Few case reports were found in China and clinical doctors should enforce their knowledge to it. This report performed DNA screening mainly in sporadic idiopathic nocturnal frontal lobe epilepsy and part of the familial nocturnal frontal lobe epilepsy cases in China. No gene mutation in known regions of neuronal nicotinic acetylcholine receptor (nAChR) was found. A possible reasons may be insufficient cases, small andatypical family, too short gene screening field; becase heterogeneity exists in idiopathic nocturnal frontal lobe epilepsy, there may be gene mutation in other regions except the 5^th exons of the CHRNA4 and CHRNB2 genes in nAChR. There may also be other unknown responsible genes except nAChR.