Correlating cognitive impairment with carotid atherosclerosis and carotid artery stenosis in patients with acute cerebral infarction

BACKGROUND: Studies have demonstrated that carotid atherosclerosis and carotid artery stenosis are closely associated with cognitive impairment in patients with and without clinically evident cerebrovascular disease.OBJECTIVE: To investigate the correlation between the degree of pathological changes in carotid atherosclerosis, carotid artery stenosis, and cognitive impairment in patients with acute cerebral infarction through the use of color Doppler imaging.DESIGN, TIME AND SETTING: The present concurrent, non-randomized, controlled experiment was performed at the Departments of Neurology and Ultrasound, Affiliated Hospital of North Sichuan Medical College between November 2006 and August 2007.PARTICIPANTS: Fifty-five patients with cerebral infarction, consisting of 35 males and 20 females, aged 50-82 years, were admitted to the hospital between November 2006 and August 2007 and recruited for this study, An additional 30 subjects consisting of 18 males and 12 females, aged 47-78 years, that concurrently received a health examination at the same hospital, were also included as normal controls.METHODS: Intima-media thickness (IMT), plaque shape, size, and echo intensity of all subjects were detected by color Doppler flow imaging. Assessment criteria: IMT > 1.0 mm was considered to be intimal thickening, and IMT > 1.2 mm was determined to be formed atherosclerotic plaques. In the position of the largest plaque, the degree of carotid artery stenosis was determined by the following formula:(1-cross-sectional area of residual vascular luminal area/vascular cross-sectional area) x 100%. Less than 30% exhibited mild stenosis, 30%-40% moderate stenosis, and > 50% severe stenosis.MAIN OUTCOME MEASURES: IMT and the degree of carotid artery stenosis were evaluated by color Doppler flow imaging. The Mini-Mental State Examination (MMSE), as well as the clinical memory scale,was compared between patients with cerebral infarction and normal controls.RESULTS: In the cerebral infarction group, IMT was increased, the degree of carotid artery stenosis was aggravated, and the MMSE and MQ scores of clinical memory scale were decreased. In particular,orientation of time and place, attention, calculation, and short-time memory were decreased. There were statistically significant differences in MMSE and MQ of clinical memory scale between patients with cerebral infarction and normal controls (P < 0.01). The scores from the two scales were significantly lower in patients with cerebral infarction with carotid plaque subgroup compared to the cerebral infarction with no carotid plaque subgroup (P < 0.01). The scores from the two scales were also significantly lower in patients with IMT > 1.0 mm, as well as moderate and severe carotid artery stenosis, compared to patients with IMT ≤1.0 mm, and normal and mild stenosis group (P < 0.05).CONCLUSION: More severe atherosclerotic and carotid artery stenosis leads to more obvious cognitive impairment.