Use of Brain Oxygen Tension Level and Cleaved-tau Protein to Detect Vasospasm After SAH

Rupture of a cerebral aneurysm causes subarachnoid hemorrhage (SAH). Blood in the subarachnoid space of the brain can cause irritation of the cerebral blood vessels, leading to constriction of these vessels, a phenomenon known.as vasospasm. Cerebral vasospasm can cause stroke and possibly death. Of all the patients with SAH, approximately 20-40% will suffer from clinical vasospasm and more than 60% of those patients will never get back to their previous functional status. Tools to identify early vasospasm and thus early treatment could greatly decrease the morbidity and mortality following SAH. Cleaved tau protein is a neuronal marker that has been detected in blood and CSF of stroke patients early in its time course. Since vasospasm can lead to stroke, the purpose of this project is to determine whether increase in cleaved tau protein in blood and/or CSF can predict early stroke from vasospasm. Changes in brain oxygen tension measured by a brain tissue oxygen monitor and cerebral blood flow measured by CT perfusion will be correlated with cleaved tau protein levels and clinical status. Utilizing statistical analysis the levels of Cleaved tau protein, brain oxygen and blood flow during hospitalization will be correlated with patient outcome. Through this study we hope to identify increase in cleaved tau protein and decrease in cerebral blood flow and oxygenation as predictors of early vasospasm. Early detection and treatment of vasospasm could decrease the stroke rate in SAH patients and therefore be of great benefit to society.