Single photon emission computed tomography evaluation in patients with mild to moderate head injury

Abstract

Head injury is a major cause of disability and death in adults. The commonest pathological substrate in patients dying with blunt head injury is ischemic brain damage. Evaluation of cerebral perfusion is currently not a standard practice. We reviewed the medical records of 40 patients with Mild & Moderate Head Injury (GCS 9–14) who had 43 SPECT brain perfusion studies (Tc99m-ECD). They were evaluated in relation to GCS, NCCT (TCDB) grading, timing of scan and other factors. It was found that some degree of hypoperfusion in SPECT was noted in most, with moderate head injury patients having more severe hypoperfusion than those with mild head injury. Also, hypoperfusion was more marked during the first 24 hours of injury. In univariate analysis of various factors on the outcome, severe hypoperfusion and moderate/severe hypoperfusion emerged as significant predictors of unfavourable outcome (P values 0.05 and < 0.001 respectively). With respect to the area of hypoperfusion, parietal involvement had more impact on neurological outcome than other areas (P = 0.07). Bilateral involvement and other factors had no significant relationship with outcome. In multivariate analysis using binary logistic regression, severe hypoperfusion was found to have significant effect on outcome independent of GCS, CT category and timing of SPECT (P=0.02).