Clinical factors associated with cerebral autoregulation in ischemic stroke related to small artery occlusion

Existing data suggest that cerebral autoregulation (CA) varies among different subtypes of ischaemic stroke. CA is globally impaired in patients with small artery occlusion (SAO). However, the factors influencing CA impairment in patients remains to be elucidated.

Stroke patients with SAO who underwent brain magnetic resonance imaging (MRI) were prospectively studied. Within 7 days after stroke onset, CA was recorded from the middle cerebral artery blood flow velocity and arterial blood pressure was simultaneously measured. Transfer function analysis was used to derive CA parameters, including gain and phase. Clinical characteristics, mean arterial pressure (MAP), biochemical findings, and cerebral small vessel disease (CSVD) markers on MRI were assessed in each patient. Factors associated with CA parameters were investigated. Univariate and multivariate linear regression analyses were conducted to determine the relationship between clinical factors and CA parameters.

Sixty-three SAO patients (age, 56.3 ± 9.9 years; 55 men) were enrolled in the study. In the multiple linear regression analysis, after controlling for relevant clinical factors, MAP on admission (ipsilateral OR = 0.99 and contralateral OR = 0.99, both P < 0.005) was a significant independent predictor of bilateral gain. MAP > 105 mmHg on admission (OR = 0.77, P = 0.019) was significantly associated with ipsilateral gain. Diabetes mellitus was a significant predictive factor for bilateral gain (ipsilateral OR = 1.32 and contralateral OR = 1.22, both P < 0.005). No correlations were found between CA parameters and CSVD characteristics.

In SAO-related ischaemic stroke, patients with MAP > 105 mmHg on admission tended to have better ipsilateral CA. Diabetes mellitus appears to be an independent risk factor for CA impairment in patients with SAO-related stroke. CSVD may not be the main factor affecting bilateral CA in patients with SAO.