1043-3155 Pediatr Neurol Briefs pedneurbriefs Pediatr Neurol Briefs Pediatric Neurology Briefs Pediatr Neurol Briefs 2166-6482 1043-3155 2166-3155 Pediatric Neurology Briefs Publishers Chicago, IL, USA PNB-2013-27-5-6 10.15844/pedneurbriefs-27-5-6 Seizure Disorders Neurology Pediatrics Nervous System Diseases Child Development Brain Diseases Neurosurgery Child Infant Cortical Excitability Measures in Patients and Unaffected Siblings http://orcid.org/0000-0002-0173-7931 Millichap J. Gordon MD 1 2 * Division of Neurology, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, IL Departments of Pediatrics and Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL Correspondence: Dr. J. Gordon Millichap, E-mail: jgmillichap@northwestern.edu 05 2013 15 10 2015 27 5 37 37 Copyright: © 2013 The Author(s) 2013 This work is licensed under the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Capturing the epileptic trait: cortical excitability measures in patients and their unaffected siblings

Researchers at St Vincent's Hospital, Victoria, Australia, measured cortical excitability using transcranial magnetic stimulation in 157 patients with epilepsy (95 generalized and 62 focal) and their asymptomatic siblings and results were compared to those of 12 controls and 20 of their siblings.

 Cortical Excitability Unaffected Siblings Myoclonus Epilepsy

Researchers at St Vincent's Hospital, Victoria, Australia, measured cortical excitability using transcranial magnetic stimulation in 157 patients with epilepsy (95 generalized and 62 focal) and their asymptomatic siblings and results were compared to those of 12 controls and 20 of their siblings. No differences were observed in cortical excitability between healthy controls and their siblings. Compared to controls, cortical excitability was higher in siblings of patients with generalized or focal seizures. Motor threshold was lower in patients with juvenile myoclonic epilepsy compared with their siblings. The disturbance in cortical excitability appears to involve intracortical inhibitory circuits even in siblings of patients with a structural abnormality and acquired epilepsy. [1]

COMMENT. The authors conclude that certain genetic factors that predispose to epilepsy and a complex genetic/environmental interaction determine the clinical phenotype.

Gene mutations in progressive myoclonus epilepsies

A mutation in the potassium channel associated gene CNTN2 was the cause of a cortical myoclonic tremor and epilepsy in a consanguineous Egyptian family. [2]

A mutation in the GOSR2 gene was identified in 12 patients with “North Sea” progressive myoclonus epilepsy. Early onset ataxia at 2 years of age was followed by myoclonic seizures at average age 6.5 years, followed by multiple seizure types. All patients developed scoliosis by adolescence, an important diagnostic clue, some had pes cavus or syndactyly, and all had elevated serum creatine kinase (mean 734 IU) and normal muscle biopsies. EEG showed generalized S/W with posterior predominance and photosensitivity. With progressive decline, patients became wheelchair bound by mean age 13 years. The cases all came from countries bounding the North Sea. The relentless course distinguished “North Sea” progressive myoclonus epilepsy (PME) from other PMEs [3]. Other PMEs include Unverricht-Lundborg disease (gene CSTB mutation), Lafora's disease (EPM2A), Northern with mental retardation (CLN8), and teenage-onset PME (CLNB). [4]

 Badawy RAB Vogrin SJ Lai A Cook MJ Capturing the epileptic trait: cortical excitability measures in patients and their unaffected siblings Brain 2013 Apr 136 Pt 4 1177 91 10.1093/brain/awt047 23485850 Stogmann E Reinthaler E Eltawil S El Etribi MA Hemeda M El Nahhas N Autosomal recessive cortical myoclonic tremor and epilepsy: association with a mutation in the potassium channel associated gene CNTN2 Brain 2013 Apr 136 Pt 4 1155 60 10.1093/brain/awt068 23518707 Boissé Lomax L Bayly MA Hjalgrim H Møller RS Vlaar AM Aaberg KM 'North Sea' progressive myoclonus epilepsy: phenotype of subjects with GOSR2 mutation Brain 2013 Apr 136 Pt 4 1146 54 10.1093/brain/awt021 23449775 Andrade DM Paton T Turnbull J Marshall CR Scherer SW Minassian BA Mutation of the CLN6 gene in teenage-onset progressive myoclonus epilepsy Pediatr Neurol 2012 Sep 47 3 205 8 10.1016/j.pediatrneurol.2012.05.004 22883287