MRI and polysomnographic findings of patients affected by post-stroke sleep apnea

ABSTRACT Aim: The aim of our study was to to compare characteristics of stroke patients who presented Obstructive Sleep Apnea/Hypopnea (OSAH) to those of cases that presented Central Sleep Apnea/Hypopnea (CSAH) events at PSG, and to investigate relationships between the type of breathing disturb during sleep and the location of brain damage. Methods: Thirty four patients were submitted to clinical, neuroradiological and polisomnographyc study (PSG) after 4 months of stroke. A Sleep Disordered Breathing (SDB) was diagnosed in all cases with an AHI > 5. Patients were classified as affected by pre-dominantly OSAH (pOSAH), or predominantly CSAH (pCSAH). Comparisons were made among the groups and correlation analyses were done in each group. Significance was set at p < 0.005. Results: Twenty six patients with ischemic strokes had a SDB during sleep (56% embolic, 31% lacunar, 8% large artery, 8% with undeter-mined cause). The 61% of them showed pOSAH. Except for age, no statistical differences were found between the two groups as to clinical findings, risk factors for stroke, PSG data, or location of brain lesion. Correlation analysis outlined that in pOSAH cases the time interval from stroke to PSG (Δt), was inversely related to both TST (p = 0.017) and TSP (p = 0.039); in pCSAHs it was inversely related to SE Index (p = 0.021) and directly related to both ODI (p = 0.016) and with the n. of arrhythmias/h sleep (p = 0.033). In pCSAH, AHI did not correlate with ODI. Con-clusions: our data suggest that among cases with post stroke SDB are included 3 different subgroups of cases: OSAHs who terminate the obstruction by arousal, OSAHs who do not arise and alternate obstructive to central events, and CSAHs due to the direct effect of stroke on the breathing network; in a forth subgroup of cases the microstructure of sleep might be altered, with the consequent occurrence of sleep-related events. Further studies are needed to clarify these hypotheses as well as the role of post- stroke depression on the nature and occurrence of SDB after stroke.