Influence of internal carotid artery stenosis, blood pressure, glycated hemoglobin, and hemoglobin level on fMRI signals of stroke patients.

OBJECTIVES: To identify the effect of internal carotid artery (ICA) stenosis, blood pressure (BP), glycated hemoglobin (HbA1c), and hemoglobin level on blood oxygenation level-dependent (BOLD) functional magnetic resonance imaging (fMRI) signals in stroke patients.
METHODS: A total of 18 stroke patients with acute cerebral infarction (13 males and 5 females) and 13 age-matched healthy controls (5 males and 8 females) were recruited. Among 18 stroke patients, 8 had significant ICA stenosis (> 50%) and 10 had nonsignificant ICA stenosis (< 50%). During handgrip task, stroke patients and normal controls were allowed to use their hands coincided with infarction and right hands, respectively.
RESULTS: The mean BOLD signals in patients with significant ICA stenosis were significantly less than that in patients with nonsignificant ICA stenosis. Mean arterial pressure (MAP) was significantly correlated with activated voxels of Brodmann area 4 (P < 0.01) and total activated voxels (P  =  0.007), whereas hemoglobin and HbA1c showed no significant correlation with activated voxels of Brodmann area 4 or total activated voxels (P > 0.05).
CONCLUSION: It is suggested that both ICA stenosis and arterial BP could influence BOLD signal, while HbA1c and hemoglobin level had no effect on BOLD signal.