Acidente vascular cerebral isquêmico e “wake-up stroke” : relações com a apneia obstrutiva do sono e com o estresse oxidativo

Abstract

Stroke is the main cause of disability in the world and one of the main causes of death. Among the subtypes of ischemic stroke, there is found the called “wake-up stroke” (WUS), defined as the ischemic stroke which is perceived by the patients upon waking and that occurs within 20 to 25% of strokes. Some studies show absence of differences between patients that wake up with deficits and patients that developed the deficit along the day. Patients from this subgroup tend to have an unfavorable evolution in relation to the other subtypes, being necessary depth on the study of the etiopathogenic mechanisms. Natural biological factors related to the circadian rhythm such as body temperature, hormonal levels and variability of the cardiac rhythm, among others, influences this process. The Obstructive Sleep Apnea syndrome (OSA) has appointed as an independent risk factor that worsens the prognostic. The study aims to evaluate the clinic-demographic characteristics from the cases with and without WUS e its relations with the OSA and the oxidative stress. Seventy patients, 57.1% being men with age between 32 and 80 years (58.5±13.3) had been studying. WUS has observed in 24.3% of the patients. Hypertension (67.1%), diabetes (27.1%) and disturb of the lipid metabolism (22.8%) were frequent. Diabetes and previous physical inactivity were more common with WUS (p<0.05). In the total sample, 62.3% of the cases showed mild to moderate stroke (NIHSS<5). Excessive daytime somnolence (SED, Epworth Scale>10) was identified in 20% of the patients. There has not been difference among the groups with and without WUS in relation to the severity of stroke and the somnolence. Patients with somnolence were younger and more physical inactive (p<0.05). The individuals with alcoholism had the highest rate of somnolence (p=0.03). In this study, 29.6% of the cases showed OSA of mild intensity (Apnea and Hypopnea Index – AHI: 530). The patients with OSA were older and showed large cervical perimeter and higher waist- hip index (p<0.05). It was observed a tendency for a greater severity of OSA on patients with WUS (p=0.05). The patients with WUS showed a tendency for higher levels of TBARS (p=0.05) and lower levels of nitrite (p=0.14). Shortly, approximately 50% of studied patients with ischemic stroke showed moderated/severe OSA. WUS was identified in 25% of the cases, and these patients were younger and diabetes more frequent. It has observed a tendency for a greater occurrence of OSA and high levels of TBARS on patients with WUS.