Cerebral hemisphere asymmetry in cerebrovascular regulation in ventilated traumatic brain injury.

Disturbances in cerebrovascular regulation in the form of diminished cerebral vasoreactivity (CVR) to carbon dioxide and an altered pressure autoregulatory response (PAR) are common after traumatic brain injury (TBI) and correlate with clinical outcome. Daily assessment of the state of cerebrovascular regulation may assist in the clinical management of TBI patients. This study examined 20 ventilated TBI patients. We employed blood flow velocity (BFV) measurement using transcranial Doppler ultrasonography to assess the impact of injury type (focal and diffuse) on cerebral hemisphere asymmetry in cerebrovascular regulation and to examine whether impairment in CVR and PAR correlate with clinical outcomes. Significant hemisphere asymmetries were found in BFV and PAR. Impairment in CVR was associated with unfavorable outcomes and bilateral CVR impairment predicted mortality.