Factors for Computed Tomography Assessed Progression of Lesions in Patients with Traumatic Subarachnoid Hemorrhage

ABSTRACT

PURPOSE: Traumatic subarachnoid hemorrhage (TSAH) is frequently found after traumatic brain injury (TBI) and its presence is a powerful predictor for the computed tomography (CT) assessed progression of intracranial lesions. The initial CT findings of progressing intracranial lesions in patients with tSAH are poorly understood. The aim of this study was to identify the factors that may predict the progression of lesions on the initial CT scans of patients with tSAH. METHODS: We evaluated 224 patients with tSAH and who were consecutively admitted from January 1, 2004 to December 31, 2008. The CT progression, the amount of SAH, the site of SAH, the presence and volume of associated intracranial lesion and the bilaterality of lesions were examined to identify the factors to predict CT progression of lesion. The initial and "worst" CT scans were compared. The CT scan changes were classified as "any CT progression" or "significant CT progression" (changes in the Marshall score). RESULTS: Eighty-two patients with tSAH (36.6%) had some CT progression and thirty-seven patients with tSAH (16.5%) had significant CT progression among the patients with tSAH. The initial CT findings according to the Marshall classification, the amount of SAH, the site of SAH and the associated intracranial lesions were significantly related to CT progression (p<0.05). The prognostic model to predict CT evolution, which consisted of the four initial CT findings described above, had high sensitivity (96.6~100%) and a high negative predictive value (94.1~100%). The area under the receiver operating characteristic (ROC) curve for the predictive model to predict the CT assessed evolution of SAH lesions was 0.701 (95% CI, 0.633~0.770). CONCLUSION: The prognostic model to predict CT progression of SAH lesions can help emergency medicine physicians decide when to perform repeat head CT scans in patients with tSAH.