Obstructive and Central Sleep Apnea in First Ever Ischemic Stroke are Associated with Different Time Course and Autonomic Activation

Alessia Riglietti,1,* Francesco Fanfulla,2,* Massimo Pagani,3 Daniela Lucini,3,4 Mara Malacarne,3,4 Mauro Manconi,5– 7 Guido Ferretti,8,9 Fabio Esposito,10,11 Carlo W Cereda,12 Marco Pons1 1Department of Pulmonology, Regional Hospital of Lugano (EOC), Lugano, 6900, Switzerland; 2Respiratory Function and Sleep Unit – Istituti Clinici Scientifici Maugeri IRCCS, Pavia, Italy; 3Exercise Medicine Unit, Istituto Auxologico Italiano, MIlan, 20133, Italy; 4University of Milan, BIOMETRA Department, Milan, Italy; 5Sleep and Epilepsy Center, Neurocenter of the Southern Switzerland, Regional Hospital (EOC) of Lugano, Lugano, Switzerland; 6Faculty of Biomedical Sciences, Università della Svizzera Italiana, Lugano, Switzerland; 7Department of Neurology, University Hospital, Inselspital, Bern, Switzerland; 8Department APSI, University of Geneva, Geneva, Switzerland; 9Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy; 10Department of Biomedical Sciences for Health, Università degli Studi di Milano, Milan, Italy; 11IRCCS Istituto Ortopedico Galeazzi, Milan, Italy; 12Stroke Center EOC, Department of Neurology, Neurocenter of Southern Switzerland Regional Hospital (EOC) of Lugano, Lugano, Switzerland*These authors contributed equally to this workCorrespondence: Mauro ManconiRegional Hospital of Lugano, Via Tesserete, 46, Lugano, 6903, SwitzerlandTel +41-91-8116825Email mauro.manconi@eoc.chIntroduction: Sleep-related breathing disorders are highly prevalent in patients with ischemic stroke. Among sleep-disordered breathing disorders, obstructive sleep apnea is the most represented one, but central sleep apnea, isolated or in the context of a periodic breathing/Cheyne–Stokes respiration, is frequently reported in these patients. Altered baroreflex responses have been reported in the acute phases of a cerebral event.Methods: We conducted, in a group of patients with ischemic stroke (n=60), a prospective 3-month follow-up physiological study to describe the breathing pattern during sleep and baroreflex sensitivity in the acute phase and in the recovery phase.Results: In the acute phase, within 10 days from the onset of symptoms, 22.4% of patients had a normal breathing pattern, 40.3% had an obstructive pattern, 16.4% had a central pattern, and 29.9% showed a mixed pattern. Smaller variations in the Apnea–Hypopnea Index were found in normal breathing and obstructive groups (ΔAHI 2.1± 4.1 and − 2.8± 11.6, respectively) in comparison with central and mixed patterns (ΔAHI − 6.9± 15.1 and − 12.5± 13.1, respectively; ANOVA p=0.01). The obstructive pattern became the most frequent pattern, in 38.3% of patients at baseline and 61.7% of patients at follow-up. Modification of baroreflex sensitivity over time was influenced by the site of the lesion and by the sleep disorder pattern in the acute phase (MANOVA p=0.005).Conclusion: We suggest that a down-regulation of autonomic activity, possibly related to reduced vagal modulation, may help the recovery after stroke, or a transitory disconnection from the cortical node that participates in the regulation of sympathetic outflow.Keywords: sleep-disordered breathing, baroreflex, chemoreflex, brain lesion