title: A case of Dravet syndrome with cortical myoclonus indicated by jerk-locked back-averaging of electroencephalogram data.
abstract: We report a female patient with Dravet syndrome (DS) with erratic segmental myoclonus, the origin of which was first identified in the cerebral cortex by the detection of myoclonus-associated cortical discharges. The discharges were disclosed through jerk-locked back-averaging of electroencephalogram (EEG) data using the muscle activity of myoclonus as triggers. The detected spikes on the contralateral parieto-central region preceded myoclonic muscle activity in the forearms by 28-46ms. The patient was six months old at the time of examination, and was developing normally before seizure onset at two months of age. She suffered from recurrent afebrile or febrile generalized tonic-clonic seizures that often developed into status epilepticus. Interictal EEG and brain magnetic resonance imaging (MRI) showed no significant findings. The amplitudes of the somatosensory-evoked potentials were not extremely large. She has a chromosomal microdeletion involving SCN1A and adjacent genes.
authors: Department of Pediatrics, Kobe City Medical Center General Hospital, Hyogo, Japan; Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
authors: Yoshinori
authors: Y
authors: Kobayashi
authors: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
authors: Yoshiyuki
authors: Y
authors: Hanaoka
authors: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
authors: Tomoyuki
authors: T
authors: Akiayma
authors: Department of Special Needs Education, Okayama University Graduate School of Education, Okayama, Japan.
authors: Iori
authors: I
authors: Ohmori
authors: Department of Molecular Oncology, Graduate School of Medicine, Dentistry, and Pharmaceutical Sciences, Okayama University, Okayama, Japan.
authors: Mamoru
authors: M
authors: Ouchida
authors: Tokyo Women's Medical University Institute for Integrated Medical Sciences, Tokyo, Japan.
authors: Toshiyuki
authors: T
authors: Yamamoto
authors: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
authors: Makio
authors: M
authors: Oka
authors: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan.
authors: Harumi
authors: H
authors: Yoshinaga
authors: Department of Child Neurology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences and Okayama University Hospital, Okayama, Japan. Electronic address: k_koba@md.okayama-u.ac.jp.
authors: Katsuhiro
authors: K
authors: Kobayashi
mesh_terms: D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology; D003937:Diagnosis, Differential; D004569:Electroencephalography / Q000379:methods*; D004831:Epilepsies, Myoclonic / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology; D005260:Female; D006801:Humans; D007223:Infant; D009207:Myoclonus / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology; D062550:NAV1.1 Voltage-Gated Sodium Channel / Q000235:genetics; D017384:Sequence Deletion; D013226:Status Epilepticus / Q000000981:diagnostic imaging / Q000188:drug therapy / Q000235:genetics / Q000503:physiopathology
chemical_list: D062550:NAV1.1 Voltage-Gated Sodium Channel; C568242:SCN1A protein, human
keywords: Cortical myoclonus; Dravet syndrome; EEG; Jerk-locked averaging