| Background and Purpose: Obstructive Sleep Apnea-hypopnea Syndrome (OSAHS) is a highly prevalent sleep respiratory disorder, characterized by repetitive episodes of complete or partial obstruction of the upper airway during sleep, resulting in oxygen desaturation. Its clinical manifestations include nocturnal sleep disorder, daytime somnolence and neuropsychological cognitive hypofunction. Recent years, studies show that OSAHS may be a main cause of adult dementia with the prolongation of the course. OSAHS has been suggested to be a independent risk factor for stroke. It can affect the rehabilitation and prognosis of stroke. Sixty-four percent patients suffer from cognitive disfunction of different degree after stroke, 1/3 of whom would develop into obvious dementia. Vascular Cognitive Impairment (VCI)could be the most common pattern of elders'chronical progressive cognitive impairment. But till now, there has been no final conclusion in the influence of OSAHS on cognition of patients with ischemic stroke. It is well-known that OSAHS can be interventionable by respiratory machine or surgery, therefore, studies in this field will contribute to preventing and curing for stroke and VCI. This research adopted prospective study methods to investigate the influence of OSAHS on cognition of patients with acute ischemic stroke and to provide evidence for earlier prevention of VCI.Methods: Totally 41 consecutive first-ever stroke patients and fifteen healthy volunteers were included in this research from January 2008 to November 2008. All patients were administered Polysomnogram (PSG), Mini-Mental State Examination (MMSE), Clock Drawing Task (CDT), Verbal Fluency Test (VFT) and P300 test. Fifteen age-matched healthy volunteers participated in the P300 test study as a normal control group.These stroke patients were divided into OSAHS group and non-OSAHS group by Apnea Hyponea Index(AHI).The scores of MMSE,CDT and VFT between two groups were analyzed. Latencies and amplitudes from FZ, CZ, PZ electrode positions were compared between patients and controls. Results: Forty-one patients with first stroke were divided into the OSAHS group (n=21) and the non-OSAHS group (n=21) by the results of PSG,Eight of whom were found cognitive impairment (19.51%) depending on MMSE: five in the OSAHS group(23.81%), three in the non-OSAHS group(15%). The scores of MMSE and CDT in the OSAHS group were less than those in non-OSAHS group. No significant differences were observed in the scores of MMSE, CDT and VFT between the two groups (p>0.05). The scores of MMSE and CDT in moderate- severe degree OSAHS group were 23.67±5.12,2.67±1.53 respectively, differing from those in non-OSAHS groups(p<0.05), which were 24.85±3.15,3.1±1.2 respectively. P300 latencies from FZ, CZ and PZ electrode positions in the OSAHS group were 393.05±60.82ms, 379.50±56.67ms, 384.40±52.61ms, respectively;in the non-OSAHS group were 359.85±26.81ms, 346.00±37.06ms, 356.90±38.36ms respectively; in the normal control group were 352.27±34.64ms, 349.47±29.01ms, 328.33±18.78ms respectively. P300 latency in the OSAHS group was significantly longer than that in the other two group (p<0.05). P300 latency in moderate-severe degree OSAHS group was longer than that of non-OSAHS group (p<0.05). P300 amplitude in every group showed no significant difference.Conclusion: OSAHS can aggravate cognitive impairment of patients with acute ischemic stroke . No doubt that cognitive impairment in the patients can get worse with the degree of OSAHS. P300 test may be more sensitive than MMSE and CDT to detection of cognitive impairment. |
