[Ischemic stroke and sleep apnea. Relationship between sleep breathing disorders and carotid stenosis]

To investigate the possible relation between the number of sleep breathing disorders (SBD) and significant extracranial carotid stenosis (ECS) in patients suffering ischemic stroke or transient ischemic attack (TIA).

Sixty-eight patients (72.2 years; 68 % males) surviving two months after ischemic stroke or TIA were studied, with the collection of general and anthropometric variables, the characteristics and repercussions of stroke, and the clinical manifestations related to sleep apnea-hypopnea syndrome (SAHS). Neurovascular status was evaluated by carotid continuous doppler flowmetry and transcraneal doppler, with cerebral MR-angio and/or arteriography when suspecting stenosis > 50 %, and respiratory polygraphy after the acute phase to assess the number and type of SBD.

Fifteen patients (22.1 %) presented ECS. Of these, 80 % had an apnea-hypopnea index (AHI) > 30. The patients with ECS presented increased drowsiness (p = 0.01), greater AHI (36.2 vs 21.9; p = 0.003), and increased nocturnal oxygen desaturation (p = 0.01). Arterial hypertension (AHT) was also significantly more prevalent in this group of patients (p = 0.003), as was diabetes mellitus (p = 0.01) and hypercholesterolemia (p = 0.02) though logistic regression analysis only showed AHT (odds ratio [OR]: 12,7) and AHI > 30 (OR: 13,6) to exhibit independent ECS predictive capacity.

The presence of numerous SBD is predictive of ECS, independently of the presence of AHT. Patients with ECS have more SAHS related clinical manifestations prior to stroke; as a result, SAHS could be anterior to the neurological event and act as a risk factor for the latter in this group of patients.