Emergence of lingual dystonia and strabismus in early-onset SCN8A self-limiting familial infantile epilepsy

© 2024 The Authors. Epileptic Disorders published by Wiley Periodicals LLC on behalf of International League Against Epilepsy..

Pathogenic variants in SCN8A are associated with a broad phenotypic spectrum, including Self-Limiting Familial Infantile Epilepsy (SeLFIE), characterized by infancy-onset age-related seizures with normal development and cognition. Movement disorders, particularly paroxysmal kinesigenic dyskinesia typically arising after puberty, may represent another core symptom. We present the case of a 1-year-old girl with a familial disposition to self-limiting focal seizures from the maternal side and early-onset orofacial movement disorders associated with SCN8A-SeLFIE. Brain MRI was normal. Genetic testing revealed a maternally inherited SCN8A variant [c.4447G > A; p.(Glu1483Lys)]. After the introduction of valproic acid, she promptly achieved seizure control as well as complete remission of strabismus and a significant decrease in episodes of tongue deviation. Family history, genetic findings, and epilepsy phenotype are consistent with SCN8A-SeLFIE. Movement disorders are an important part of the SCN8A phenotypic spectrum, and this case highlights the novel early-onset orofacial movement disorders associated with this condition. The episodes of tongue deviation and protrusion suggest focal oromandibular (lingual) dystonia. Additionally, while infantile strabismus or esophoria is a common finding in healthy individuals, our case raises the possibility of an ictal origin of the strabismus. This study underscores the importance of recognizing and addressing movement disorders in SCN8A-SeLFIE patients, particularly the rare early-onset orofacial manifestations. It adds to the growing body of knowledge regarding the diverse clinical presentations of SCN8A-associated disorders and suggests potential avenues for clinical management and further research.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:26

Enthalten in:

Epileptic disorders : international epilepsy journal with videotape - 26(2024), 2 vom: 04. Apr., Seite 219-224

Sprache:

Englisch

Beteiligte Personen:

Ancora, Caterina [VerfasserIn]
Ortigoza-Escobar, Juan Dario [VerfasserIn]
Valletti, Margherita Aluffi [VerfasserIn]
Furia, Francesca [VerfasserIn]
Nielsen, Jens Erik Klint [VerfasserIn]
Møller, Rikke S [VerfasserIn]
Gardella, Elena [VerfasserIn]

Links:

Volltext

Themen:

Case Reports
Intermittent esotropia
Journal Article
Lingual dyskinesia
Movement disorders
NAV1.6 Voltage-Gated Sodium Channel
Paroxysmal strabismus
SCN8A
SCN8A protein, human
Self‐limiting familial infantile epilepsy

Anmerkungen:

Date Completed 15.04.2024

Date Revised 25.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1002/epd2.20203

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM369263766