Posttraumatic basilar artery vasospasm

During the past decade, vasospasm following posttraumatic subarachnoid hemorrhage (tSAH) has drawn increasing attention. However, despite accumulating evidence linking this phenomenon with poorer outcome, the clinical significance of posttraumatic vasospasm is still debated and often disputed, so that no definite therapeutic attitude has yet been adopted. Recent attention has been drawn to basilar vasospasm, suggesting a negative influence on neurologic outcome. The aim of the present study was the evaluation of basilar vasospasm as an independent factor of secondary brain damage following posttraumatic hemorrhage.

Daily transcranial Doppler (TCD) evaluations were conducted in 93 consecutive patients with tSAH. Basilar artery (BA) vasospasm was defined by blood flow velocity (FV) higher than 85 cm/s for at least 2 consecutive days.

Thirty-two patients (34.4%) had BA FVs higher than 85 cm/s. In those patients, the ratio between BA FV and mean vertebral artery FV was higher than 2.5 and below 2 and those without TCD signs of vasospasm. Using multivariate logistic regression analysis, BA vasospasm proved to independently influence neurologic outcome.

BA vasospasm severe enough to compromise cerebral blood flow to the brainstem, although uncommon, may nevertheless have a potential deleterious effect on neural tissue sensitized by trauma. The present results suggest that specific imaging procedures and eventually therapeutic measures should be conducted in the presence of significant BA vasospasm.