Carbon dioxide induced cerebral vasomotor reactivity in moderate-to-severe cerebral venous thrombosis patients and its impact on prognosis: A transcranial doppler-based prospective exploratory study

Abstract

Hyperventilation-induced intracranial pressure reduction might be impaired in cerebral venous thrombosis (CVT) patients. Using transcranial Doppler, we assessed carbon dioxide-vasomotor reactivity (CO2-VMR) within 24 hours of admission in CVT patients and studied its correlation with patient outcomes. Adult moderate-severe CVT patients (participants of another large observational study) were included. CO2-VMR was calculated as the percentage change in peak flow velocities during maximal hypercapnia and hypocapnia. Outcome was assessed with the modified Rankin scale (mRS) at one − month post-discharge, dichotomized into favourable (mRS≤2) and unfavourable (mRS>2). Twenty patients’ data was analysed. Impaired CO2-VMR (<70 %) was observed in 13 patients in the affected hemisphere; among them, 10 had impairments in both hemispheres. CO2-VMR correlated negatively with mRS (Rho = -0.688, p = 0.001). Odds for unfavourable outcomes were reduced by 92 % in patients with intact VMR on the ipsilateral hemisphere (Odds ratio (OR) 0.08, Confidence interval (CI) 0.006–––0.636, p = 0.027) and by 94 % with VMR intact on the contralateral hemisphere (OR 0.063, CI 0.003–––0.569, p = 0.03). Thus, impaired CO2-VMR in moderate to severe CVT patients is associated with unfavourable outcomes, and has the potential to prognosticate CVT patients objectively.