Sudden Unexpected Death During Sleep in Familial Dysautonomia: A Case-Control Study

Area of Science:

• Neurology
• Sleep Medicine
• Genetics

Background:

• Familial dysautonomia (FD) is an autosomal recessive disorder causing sensory and autonomic dysfunction.
• Sudden unexpected death during sleep (SUDS) is the primary cause of mortality in FD patients.
• The specific causes and risk factors for SUDS in FD remain largely unknown.

Purpose of the Study:

• To investigate the association between sleep-disordered breathing and SUDS in patients with familial dysautonomia.
• To identify specific risk factors contributing to SUDS in the FD population.

Main Methods:

• Retrospective analysis of FD patients who experienced SUDS and age-matched survivors.
• Polysomnography data collected within 18 months prior to death or study enrollment.
• Analysis of clinical data including EKG, blood pressure, blood gases, and metabolic panels.

Main Results:

• Patients experiencing SUDS were more likely to have untreated obstructive sleep apnea (OR 17.4).
• SUDS cases showed higher odds of receiving fludrocortisone (OR 29.7) and having low plasma potassium (<4 mEq/L) (OR 19.5).
• Noninvasive ventilation use at night was less common in SUDS cases (OR 0.19).

Conclusions:

• Untreated obstructive sleep apnea and low potassium levels are significant risk factors for SUDS in FD.
• Discontinuation of fludrocortisone and initiation of noninvasive ventilation may mitigate SUDS risk.
• Findings highlight the interplay of autonomic, cardiovascular, and respiratory factors in SUDS within the FD population.