Abstract

Background: Prevalence of sleep apnea decreases post-stroke but the impact of thrombolysis on evolution of sleep apnea is unknown.

Aims and objectives: We studied the change in prevalence and severity of sleep apnea (AHI=5/h) among ischemic stroke patients with (THR) or without thrombolysis (NTHR) during 6 months post-stroke in Northern Finland.

Methods: We prospectively studied 204 ischemic stroke patients. At month six eligible were 177 patients (98 THR/79 NTHR).  A cardiorespiratory sleep study was done during the first 48 hours after symptom onset and at month six.

Results: Male’s comprised 67.3% THR vs. 58.2% NTHR. THR group was younger (age 65.0 yr vs. 69.1 p =0.039). ESS was lower in the THR group (3.0 vs.3.8, p=0.045). Sleep apnea was diagnosed in 92.7% of patients, its prevalence at baseline being 95.9% THR vs 82.3% NTHR (p=0.003). At month 6 the change in prevalence was non-significant. The decrease of arterial oxyhemoglobin dips of =4% per hour (ODI4) was higher in the THR (-6.1%, p?0.001 vs. -1.8%, p=0.327). Central apneas/h increased 2.2% (p=0.002) and there was no group difference. Obstructive apneas per hour declined 1.7% (p=0.014) but the groups did not differ. Hypopneas per hour declined more in the THR than in the NTHR group (-2.2% vs. +0.1%, p<0.001). The risk for new sleep apnea was 6.1 times higher (p=0.024) in the NTHR group at follow-up.

Conclusions: Sleep apnea is present in the vast majority of newly diagnosed ischemic stroke patients and the prevalence remained high after six months follow-up. Remarkable declining in ESS, ODI4 and hypopneas per hour was observed in the thrombolysis group. Thrombolysis seems to be an independent protective factor for developing sleep apnea post-stroke.