Laughter Is Not Always Funny: Breath-Holding Spells in Familial Dysautonomia

Clin Pediatr (Phila). 2015 Feb;54(2):174-8. doi: 10.1177/0009922814563512. Epub 2014 Dec 23.


Familial dysautonomia (FD) is a genetic disease characterized by primary autonomic dysfunction including parasympathetic hypersensitivity. Breath-holding spells (BHS) are believed to be caused by autonomic dysregulation mediated via the vagus nerve and increased in patients with a family history of BHS. Details and understanding of its pathophysiology are lacking. In this retrospective study of patients with FD, the incidence of BHS was higher at 53.3%, compared with previous studies in normal children. Laughter as a precipitating factor for BHS has not been previously reported in FD and occurred in 10% of patients in this study. Lower lung volumes, chronic lung disease, chronic CO2 retention, and inadequate autonomic compensation occur in those with FD leading to a higher incidence and severity of BHS when crying or laughing. Thus, FD may be a good model for understanding manifestations of the autonomic nervous system dysfunction and contribute to our knowledge of BHS mechanisms.

Keywords: breath-holding spells (BHS); crying; familial dysautonomia (FD); laughter; prolonged expiratory apnea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Breath Holding*
  • Child
  • Child, Preschool
  • Crying / physiology*
  • Dysautonomia, Familial / epidemiology*
  • Dysautonomia, Familial / physiopathology*
  • Female
  • Humans
  • Incidence
  • Infant
  • Israel / epidemiology
  • Laughter / physiology*
  • Male
  • Retrospective Studies
  • Severity of Illness Index