·This study was a retrospective cohort study. The patients with LS-TIA who were hospitalized in the Department of Neurology, Shanghai Songjiang District Central Hospital from January 2018 to December 2019 were selected. By using the standard deviation of systolic blood pressure collected by ambulatory sphygmomanometer as the short-term systolic blood pressure variation (SSBPV) index, the LS-TIA patients were divided into 16 cases in high SSBPV group and 14 cases in normal SSBPV group, according to the level of SSBPV. During the same period, 15 patients who went to hospital because of headache or dizziness served as healthy control (HC) group. The patients' age, gender, smoking history, drinking history, body mass index, history of hypertension, history of coronary heart disease, history of hyperlipidemia and history of cerebral infarction were collected. All the patients were anesthetized with 1% lidocaine, and underwent cerebral angiography with a single curved catheter, including bilateral common carotid arteries, bilateral internal carotid arteries, bilateral subclavian arteries, and bilateral vertebral arteries. The number of intracranial arterial stenosis and the patency of collateral circulation were assessed by the surgeon. By single-photon emission computed tomography (SPECT) examination, the region of interest (ROI) was delineated, and the cerebellum was used as a control. The ratio less than 0.9 was used as the criterion for judging lobe hypoperfusion. SPSS 25.0 software was used for statistical analysis. The measurement data conforming to the normal distribution were compared by independent samples t test between the two groups, and the comparison among the three groups was performed by variance analysis. The rest data were qualitative data, the chi-square test was used for comparison between the groups, and P<0.05 was considered statistically significant.

·Compared with the HC group, the total number of intracranial artery stenosis and the number of internal carotid artery stenosis in the high SSBPV group and the normal SSBPV group increased, and the differences were statistically significant (all P=0.000). The number of lobes with hypoperfusion in the high SSBPV group and the normal SSBPV group were higher than that in the HC group (all P=0.000). The number of cases with severe hypoperfusion in the high SSBPV group was higher than that in the HC group (P=0.000). The total number of open collateral circulation in the high SSBPV group was higher than that in the HC group (P=0.001), and the number of secondary collateral circulation in the high SSBPV group was higher than that in the HC group (P=0.014). Compared with the normal SSBPV group, the high SSBPV group had more lobes with hypoperfusion (P=0.041), more severe hypoperfusion cases (P=0.024), and more collateral circulation openings (P=0.034).

·The increased short-term systolic blood pressure variability results in a wider range of cerebral hypoperfusion and a higher proportion of severe cerebral hypoperfusion in the patients with LS-TIA. This may contribute to the pathogenesis of LS-TIA. As a part of the compensatory mechanism, the proportion of openning collateral circulation in the patients is high.