A proposed scoring system to screen for vasospasm following aneurysmal subarachnoid hemorrhage

ABSTRACT

Vasospasm has been known to cause permanent morbidity in 40-70% of survivors who suffered from subarachnoid hemorrhage (SAH). Early recognition of vasospasm is the key to better outcome of SAH. Cerebral angiography is expensive and impractical as a monitoring tool. Transcranial Doppler is operator dependent, and not readily available. The objective of this study is to devise a non invasive tool to screen for cerebral vasospasm following SAH. The proposed vasospasm score was based on clinical and cranial CT scan features. The features are hypertension, admission World Federation of Neurosurgeons Score (WFNS), amount of blood in the cisterns and subarachnoid space, intraventricular hemorrhage and hydrocephalus. Thirty six patients with aneurismal SAH were assessed retrospectively and correlated with the angiogram for vasospasm. The patients’ vasospasm score and their corresponding sensitivity and specificity were 1 (100%, 0%), 2 (100%, 8%), 3 (100%, 8%), 4 (100%, 8%), 5 (91%, 46%), 6 (74%, 85%), 7 (48%, 85%), 8 (26%, 23%), 9 (3%, 100%), 10 (4%, 100%). A receiver operator characteristic curve was constructed that yielded a cut-off score of 6. The score of 6 was a good trade-off between sensitivity (74%) and specificity (85%). A clinical vasospasm score was proposed to screen for vasospasm after SAH. A score of 4 to 6 was found to correlate with angiographic vasospasm. Prospective study is required to validate the scoring system.