Idiopathic central sleep apnea: friend or foe of autonomic nervous system function in neurology?

Abstract

Background: Idiopathic central sleep apnea (ICSA) is a rare condition in which CSA occurs at night and in the absence of heart failure (HF). While it has been reported to occur in neurological patients in particular its impact on autonomic nervous system function at night has not yet been studied. Methods: 10 patients without HF and diagnosed ICSA (9 male, 5 with a history of stroke, 58 ± 13 years) were enrolled. Autonomic nervous system function (spectral analysis of heart rate –HRV-, blood pressure variability –BPV- and baroreceptor reflex sensitivity by sequence method) and hemodynamics were monitored noninvasively (TaskForce Monitor, CNSystems, Graz) and beyond 12 channel polysomnography (PSG) throughout an entire (attended) night in a sleep laboratory. Mean values were recorded at baseline and both during 10 miunutes of ICSA and normal breathing in stable Non REM II sleep. Results: Stable segments of an ICSA breathing pattern were consistently available during NonREM II sleep in all patients. Therein mean heart rate and low frequency component of diastolic BPV (considered to reflect sympathetic nerve activity -SNA-) revealed less SNA during ICSA compared to normal breathing (56 ± 5 vs. 58 ± 6 bpm, p Conclusions: ICSA leads to less SNA even if adjusted for sleep stage in neurological patients. ICSA might present a compensatory mechanism in neurological patients.