To investigate the correlation between hemodynamic parameters in the middle cerebral artery region and cerebral infarction volume in patients with chronic middle cerebral artery occlusion (CMCAO).

From October 2015 to July 2018, 43 consecutive patients diagnosed with unilateral CMCAO by transcranial Doppler (TCD) at the neurology and neurosurgery department were enrolled retrospectively. The leptomeningeal anastomosis (LMA) grades were assessed by digital subtraction angiography (DSA) and all patients were divided into a good LMA group (n=26, grades 3~4) or a poor LMA group (n=17, grades 0~2). TCD and/or transcranial color-coded sonography (TCCS) were used to measure and record the mean velocity (MV) of the contralateral and ipsilateral MCA, and the ratios of bilateral MV of MCA were calculated (MV_cMCA/MV_iMCA). According to the results of magnetic resonance diffusion weighted imaging (DWI), the patients were divided into four groups, including no infarction, small volume, medium volume, and large volume of cerebral infarction. The differences in general data, laboratory tests, clinical symptoms, and MCA flow velocity between the good and poor LMA group were compared, and Spearman rank correlation analysis was used to analyze the correlation between MCA flow parameters and the cerebral infarction volume.

The difference in the clinical symptoms of the two groups was statistically significant (P=0.031). The proportion of stroke patients in the good LMA group was significantly lower than that in the poor LMA group [15(57.7%) vs 16(94.1%)], and the proportion of asymptomatic patients was significantly higher that in the poor LMA group [5 (19.2%) vs 0 (0%)]. The MV_iMCA in the good LMA group was significantly higher than that in the poor LMA group [(40.15±12.32) vs (20.82±6.73), t=-5.900, P<0.001], and the MV_cMCA/MV_iMCA ratio was lower than that of the poor LMA group [1.38 (1.12, 1.65) vs 2.60 (2.12, 3.05), Z=-4.434, P<0.001]. The proportion of patients with no cerebral infarction or small volume infarction was significantly higher in the good LMA group, while the proportion of patients with moderate and large volume cerebral infarction was significantly higher in the poor LMA group. There was a statistically significant difference in the distribution of cerebral infarction between the two groups (Z=-3.518, P<0.001). Cerebral infarction volume had a moderate negative correlation with MV_iMCA (r=-0.574, P<0.001), and a moderate positive correlation with MV_cMCA/MV_iMCA (r=0.615, P<0.001). The cerebral infarction volume in the poor LMA group was moderately negatively correlated with MV_iMCA (r=-0.621, P=0.008), and highly positively correlated with MV_cMCA/MV_iMCA (r=0.721, P=0.001).

The flow velocity in the MCA significantly correlates with the volume of cerebral infarction. Using TCD or TCCS to detect cerebral hemodynamic changes can directly evaluate reverse blood flow compensation like LMA and blood flow compensation in the MCA, and indirectly reflect the size of the brain infarction in patients, thus providing a reliable, real-time, dynamic assessment basis for the formulation of individualized treatment protocols and follow-up.