[Clinical features in a Japanese patient with autosomal dominant lateral temporal epilepsy having LGI1 mutation].

We described a clinical feature of autosomal dominant lateral temporal epilepsy (ADLTE) in a Japanese patient having LGI1 mutation. The patient was a 27-year-old woman who had her first seizure at the age of 10 years, a nocturnal generalized seizure. She then had partial seizures manifesting auditory symptoms with or without anxiety, panic attack, déjà vu, sensory aphasia and visual symptoms. Repeated EEGs were normal. Brain MRI showed small left superior temporal gyrus. 18F-deoxyglucose positron emission tomography (PDG-PET) demonstrated glucose hypometabolism in the left lateral temporal lobe. Sequencing of the LGI1 revealed a single base substitution in exon 8 (1642C-->T) causing missense mutation at residue 473 of the LGI1 protein (S473 L). When one demonstrates ictal symptoms arising from the lateral temporal to occipital area with psychotic symptoms, ADLTE should be suspected and a detailed family history is warranted.