Posttraumatic cerebral infarction: incidence, outcome, and risk factors.

BACKGROUND: Outcome in patients with traumatic brain injury (TBI) is often affected by secondary insults including posttraumatic cerebral infarction (PTCI). The incidence of PTCI after TBI was previously reported to be 2% with no mortality impact. We suspected that recent advances in imaging modalities and treatment might affect incidence and outcome. We sought to define the incidence and mortality impact of PTCI. We also identified risk factors associated with PTCI.

METHODS: We retrospectively reviewed all patients admitted between 2004 and 2006 with severe TBI (brain Abbreviated Injury Scale [AIS] score >2, Glasgow Coma Scale score [GCS] <9). Demographics, injury specifics, and clinical data were abstracted. All brain imaging studies were reviewed with an attending trauma radiologist. Statistical analysis of outcome data were performed using chi and Student's t test and multivariate analysis was performed using logistic regression to identify independent risk factors.

RESULTS: Of the 384 patients identified with severe TBI; 93% sustained a blunt injury, 75% were men. Mortality was 21%, and 48% had a brain AIS score of 5. Mean age was 36 years (11-90 years), admission GCS score was 5 (3-8), and Injury Severity Score was 32 (9-75). Thirty-one (8%) had a confirmed PTCI. The PTCI group had a significantly increased mortality (45% vs. 19%, p < 0.002), hospital length of stay (LOS) (25 days vs. 18 days, p < 0.02), and intensive care unit LOS (21 days vs. 15 days, p < 0.03). In multivariate analysis, sex, age, Injury Severity Score, Revised Trauma Score, admission GCS, and brain AIS were not associated with PTCI; whereas the presence of blunt cerebral vascular injury [odds ratio (OR) 4.0, 95% confidence interval (CI) 1.9-8.7], the need for craniotomy (OR 3.0, 95% CI 1.2-6.9), or treatment with recombinant factor VIIa (OR 3.1, 95% CI 1.1-8.0) were each independently associated with an increased risk of PTCI.

CONCLUSIONS: The incidence of PTCI in patients with severe TBI is higher after severe brain injury than previously thought. PTCI has a significant impact on mortality and LOS. The presence of a blunt cerebral vascular injury, the need for craniotomy, or treatment with factor VIIa are risk factors for PTCI. Recognition of this secondary brain insult and the associated risk factors may help identify the group at risk and tailor management of patients with severe TBI.