SLEEP-DISORDERED BREATHING AND POOR FUNCTIONAL OUTCOME AFTER STROKE

Background and Purpose We objectively evaluated patients with recent s troke to determine the prevalence of sleep-disordered breathing (SDB) and whether SDB was associated with unfavorable clinical outcomes. Met hods Forty-seven patients with recent ischemic stroke (median, 13 days ) were studied with computerized overnight oximetry for evidence of ar terial oxyhemoglobin desaturation (SaO(2)). Polysomnography was also p erformed on 19 patients. Medical history, sleep history, location of s troke, and severity of neurological deficit were recorded, and patient s were observed by staff for evidence of snoring and excessive daytime sleepiness. Functional abilities were measured with the use of the Ba rthel Index (BI). Outcome variables included ability to return home at discharge, continued residence at home at 3 and 12 months, BI at disc harge, BI at 3 and 12 months, and death from any cause at 12 months. R esults Mean SaO(2) during oximetry was 94.0+/-1.7%, and percentage of recording time spent at <90% SaO(2) was 4.3+/-5.7%. The number of desa turation events per hour of recording time (desaturation index [DI]) w as 9.5+/-9.67, with 15 of 47 (32%) having DI >10 and 6 of 47 (13%) hav ing DI >20. Oximetry measures of SDB correlated with lower BI scores a t discharge and lower BI at 3- and 12-month follow-ups (P less than or equal to.05, Pearson coefficients). Oximetry measures correlated with return home after discharge, but the association between oximetry mea sures and living at home was lost at 12 months. Two oximetry variables correlated with death at 1 year. Brain stem location correlated with higher DI and time at <90% SaO(2) but patients with hemispheric stroke and oximetry abnormalities also had worse functional outcome. No corr elation was found between oximetry values and sex, age, preexisting me dical conditions (except previous stroke), or severity of neurological deficit. Oximetry abnormalities were associated with a history of sno ring. Polysomnography on 19 patients confirmed oximetry evidence of se vere SDB. Eighteen of 19 patients (95%) had an apnea-hypopnea index (A HI) of >10 events per hour of recording, 13 of 19 (68%) had an AMI >20 , and 10 of 19 (53%) had an AHI >30. Desaturation events were largely due to obstructive apneas. Conclusions SDB accompanied by arterial oxy hemoglobin desaturation is common in patients undergoing rehabilitatio n after stroke and is associated with higher mortality at 1 year and l ower Fl scores at discharge and at 3 anti 12 months after stroke. SDB may be an independent predictor of worse functional outcome. Obstructi ve sleep apnea appeared to be the most common form of SDB, and the fre quent history of snoring suggests that SDB preceded the stroke in most patients.