title: Stridor as a neonatal presentation of skeletal muscle sodium channelopathy.
abstract: OBJECTIVE
  To describe stridor as the presenting feature in a neonate with the skeletal muscle sodium channelopathy paramyotonia congenita.
  
  
  METHODS
  Case report.
  
  
  METHODS
  Outpatient neuromuscular clinics at Great Ormond Street Hospital for Children and the Medical Research Council Centre for Neuromuscular Disease at the National Hospital for Neurology and Neurosurgery, London, England.
  
  
  METHODS
  A child carrying the Thr1313Met SCN4A mutation associated with paramyotonia congenita.
  
  
  METHODS
  Supportive care in the neonatal period and administration of mexiletine hydrochloride at age 4 years.
  
  
  METHODS
  The association of stridor and paramyotonia congenita was made retrospectively following the diagnosis in the infant's mother; the child is now regularly reviewed at the pediatric outpatient clinic.
  
  
  RESULTS
  Persistent stridor was present for the first 6 months of life, and episodic stridor can still be exacerbated by intercurrent respiratory tract infection, cold, laughter, or crying. Common symptoms of paramyotonia congenita have been apparent from age 1 year and are beginning to respond to a recent trial of mexiletine.
  
  
  CONCLUSIONS
  To our knowledge, neonatal stridor has not previously been reported in skeletal muscle sodium channelopathies. The recognition that infants inheriting mutations known to cause paramyotonia congenita are inherently at risk for developing neonatal complications following an uneventful labor is important for all training neurologists so they can advise expectant mothers and pediatric and obstetric colleagues appropriately.
authors.affiliation: Institute of Neurology and Medical Research Council Centre for Neuromuscular Disease, National Hospital for Neurology and Neurosurgery, University College London, London, England.
authors.forename: Emma
authors.initials: E
authors.lastname: Matthews
authors.forename: Adnan Y
authors.initials: AY
authors.lastname: Manzur
authors.forename: Richa
authors.initials: R
authors.lastname: Sud
authors.forename: Francesco
authors.initials: F
authors.lastname: Muntoni
authors.forename: Michael G
authors.initials: MG
authors.lastname: Hanna
mesh_terms: D002675:Child, Preschool; D003937:Diagnosis, Differential; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018908:Muscle Weakness / Q000175:diagnosis* / Q000235:genetics; D018482:Muscle, Skeletal / Q000378:metabolism* / Q000473:pathology*; D020967:Myotonic Disorders / Q000175:diagnosis* / Q000235:genetics; D062553:NAV1.4 Voltage-Gated Sodium Channel; D012135:Respiratory Sounds / Q000175:diagnosis* / Q000235:genetics; D015222:Sodium Channels / Q000235:genetics*
chemical_list: D062553:NAV1.4 Voltage-Gated Sodium Channel; C106251:SCN4A protein, human; D015222:Sodium Channels