title: Laughter is not always funny: breath-holding spells in familial dysautonomia.
abstract: 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.
authors.affiliation: Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: Channa
authors.initials: C
authors.lastname: Maayan
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Eliot
authors.initials: E
authors.lastname: Katz
authors.affiliation: Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: Michal
authors.initials: M
authors.lastname: Begin
authors.affiliation: Hebrew University-Hadassah Medical School, Jerusalem, Israel.
authors.forename: Ivelin
authors.initials: I
authors.lastname: Yuvchev
authors.affiliation: Boston Children's Hospital, Harvard Medical School, Boston, MA, USA virginia.kharasch@childrens.harvard.edu.
authors.forename: Virginia S
authors.initials: VS
authors.lastname: Kharasch
mesh_terms: D062485:Breath Holding; D002648:Child; D002675:Child, Preschool; D003448:Crying / Q000502:physiology*; D004402:Dysautonomia, Familial / Q000453:epidemiology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007557:Israel / Q000453:epidemiology; D007845:Laughter / Q000502:physiology*; D008297:Male; D012189:Retrospective Studies; D012720:Severity of Illness Index
keywords: breath-holding spells (BHS); crying; familial dysautonomia (FD); laughter; prolonged expiratory apnea