Epileptic Disorders - Editor's Choice Archive
The following are past Editor's Choice articles. Free access may not be available.
Comments by Associate Editor Yushi Inoue MD PhD
Generalised electrographic seizures presenting as perioral myoclonia
Jennifer Deraborn and Peter Kaplan
A 41-year-old man had several episodes of rhythmic and intermittent, sometimes lateralized chin twitching lasting over a week for a seven years period. He reported understanding what was said but had difficulty replying due to the chin movement. The EEG during the episode showed paroxysms of polyspike and slow wave activity, maximal over the fronto-central regions, correlating with the chin movements. Brain imaging was normal. On one occasion, the episode was followed by a generalized tonic-clonic seizure. Levetiracetam added to valproate resolved the episode.
The authors along with video presentation guide the reader to the interesting differential diagnosis of this peculiar case with late onset long-lasting repetitive myoclonia localized to the perioral area with preserved consciousness. Published with videosequences
Extreme startle and photomyoclonic response in severe hypocalcaemia
Marcello Moccia, Roberto Erro, Elvira Nicolella, Pasquale Striano, Salvatore Striano
Moccia and colleagues report a case with episodes of sudden generalised muscle contractions resulting in violent falls with injuries and urinary incontinence. The fits appeared to relate to sudden auditory stimuli. During the examination, a sudden and unexpected noise triggered a violent startle with a forceful closure of eyes, cranial muscle contraction, and raising of arms over the head, immediately followed by generalised stiffness for several seconds. Flashing light triggered an excessive startle followed by myogenic potentials. There was no epileptic activity on the EEG. Blood tests revealed severe hypocalcaemia and the symptoms disappeared after calcium supplementation.
This report teaches us that electrolyte disturbances can be associated with abnormal startle responses. Published with videosequences
Confirming an expanded spectrum of SCN2A mutations: a case series
Dena Matalon, Ethan Goldberg, Livija Medne, Eric D. Marsh
Comments by Associate Editor Aristea S. Galanopoulou MD PhD
Mutations in voltage-sensitive sodium channels (SCN) have been increasingly identified in human epilepsy syndromes. These syndromes include both “benign” forms (e.g., benign familial neonatal-infantile epilepsy) and more severe types (e.g., Dravet syndrome, infantile epileptic encephalopathies). Matalon and colleagues here describe the clinical features of 3 girls with 3 different de novo SCN2A mutations that presented with early onset epilepsies, poor developmental outcomes and axial hypotonia. Thinning of the corpus callosum was eventually identified in two of the patients. Two of the girls manifested infantile spasms whereas the third had neonatal tonic seizures. In one of the patients with infantile spasms choreiform movements were also observed.
Of interest, a subsequent independent study by Hackenberg et al (Neuropediatrics, 2014) describes an identical mutation (c.4025T>C) of the SCN2A gene in a different girl who also presented with infantile spasms, choreiform movements, hypersomnia and progressive brain atrophy. These observations lend support to the pathogenicity of this specific mutation but also to its functional impact on both cortical and subcortical structures. Matalon et al nicely review the literature on genotype-phenotype correlations of the known human SCN2A mutations, discussing the inherent heterogeneity but also increasing evidence for a possible involvement of these mutations as modifiers of human epilepsies. Further studies are certainly needed to confirm the functional consequences of these mutations in the developing brain. The need for creation of comprehensive public access genotype-phenotype databases and animal models of the known and emerging epilepsy-related mutations is however becoming increasingly evident, so as to best study their clinical and pathogenic relevance.