A multi-disciplinary clinic for SCN8A-related epilepsy

John M Schreiber; Laura Tochen; Mackenzie Brown; Sarah Evans; Laura J Ball; Adrian Bumbut; Rapeepat Thewamit; Matthew T Whitehead; Chelsea Black; Emanuel Boutzoukas; Eleanor Fanto; William Suslovic; Madison Berl; Michael Hammer; William D Gaillard

doi:10.1016/j.eplepsyres.2019.106261

A multi-disciplinary clinic for SCN8A-related epilepsy

Epilepsy Res. 2020 Jan:159:106261. doi: 10.1016/j.eplepsyres.2019.106261. Epub 2019 Dec 23.

Authors

Affiliations

¹ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: jschreib@childrensnational.org.
² Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: ltochen@childrensnational.org.
³ Children's National Medical Center, Department of Physical Medicine and Rehabilitation, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: mbrown4@childrensnational.org.
⁴ Children's National Medical Center, Department of Physical Medicine and Rehabilitation, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: evanss3@email.chop.edu.
⁵ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA; The George Washington University Hospital, 900 23rd St NW, Washington, DC, 20037, USA. Electronic address: ljball@muw.edu.
⁶ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: abumbut@childrensnational.org.
⁷ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA; Department of Pediatrics, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand. Electronic address: RTHEWAMIT@childrensnational.org.
⁸ Children's National Medical Center, Department of Neuroradiology, 111 Michigan Ave NW, Washington, DC, 20010, USA; Neuroradiology, The George Washington University Hospital, 900 23rd St NW, Washington, DC, 20037, USA. Electronic address: mwhitehe@childrensnational.org.
⁹ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: BlackC1@email.chop.edu.
¹⁰ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: eboutzoukas94@ufl.edu.
¹¹ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: efanto@childrensnational.org.
¹² Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: wsuslovic2@childrensnational.org.
¹³ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: mberl@childrensnational.org.
¹⁴ University of Arizona, Keating Building 111, Department of Anthropology, PO Box 210030, Tucson, AZ, 85721, USA. Electronic address: mfh@email.arizona.edu.
¹⁵ Children's National Medical Center, Department of Neurology, 111 Michigan Ave NW, Washington, DC, 20010, USA. Electronic address: wgaillar@childrensnational.org.

PMID: 31887642
DOI: 10.1016/j.eplepsyres.2019.106261

Abstract

Objective: We endeavored to evaluate a cohort of patients diagnosed with SCN8A-related epilepsy in a multi-disciplinary clinic and to create a bio-repository.

Methods: We recruited patients with epilepsy due to SCN8A variants at Children's National Medical Center, through family organizations, or SCN8A.net. Study procedures included medical record review, review of EEG and MRI data, clinical evaluation, the Vineland Adaptive Behavior Scales, Third Edition (VABS-3), DNA extraction, and preparation of peripheral blood mononuclear cells.

Results: Seventeen patients (9 months - 19 years) completed the study. Age at seizure onset was 1 day to 4 years old (median age 4 months). Epilepsy phenotype ranged from mild epilepsy to severe developmental and epileptic encephalopathy. Medications targeting the voltage-gated sodium channel were most often effective, while levetiracetam resulted in worsening seizures and/or developmental regression in 7/16 (p < 0.05). VABS-3 scores were below age expectations for most children; older children had lower scores. Neurological examination revealed hypotonia (13), spastic quadriparesis (1), ataxia (9), dyskinesia (2)/ dystonia (7), and four non-ambulatory.

Conclusions: This is the first report of a large series of patients with epilepsy due to SCN8A variants evaluated in a single multi-disciplinary clinic. By utilizing a more comprehensive and consistent evaluation, we clarify specific seizure and epilepsy types, describe a distinct epilepsy phenotype in a patient with a nonsense variant, delineate patterns of developmental delay, language, and swallow function (specifically anomic aphasia and flaccid dysarthria), identify and characterize movement disorders, report common findings on physical exam, and demonstrate clinical worsening with levetiracetam.

Keywords: Epileptic encephalopathy; Ion channel gene defects; Levetiracetam; Neuropsychological assessment; SCN8A.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Anticonvulsants / therapeutic use
Child
Child, Preschool
Cross-Sectional Studies
Electroencephalography
Epilepsy / drug therapy
Epilepsy / genetics*
Female
Humans
Infant
Male
Mutation*
NAV1.6 Voltage-Gated Sodium Channel / genetics*
Seizures / drug therapy
Seizures / genetics*
Young Adult

Substances

Anticonvulsants
NAV1.6 Voltage-Gated Sodium Channel
SCN8A protein, human