Significance of white matter abnormalities in patients with closed head injury

Neuroimaging in patients with closed head injury (CHI) may frequently revea l abnormalities of white matter. Because white matter abnormalities may be seen in patients aged over 40 years even without CHI, the significance of t hese abnormalities in patients with CHI is questionable and needs to be ass essed in the context of relevance to clinical outcome. The aims of this stu dy were to determine the relative incidence of white matter abnormalities i n a group of patients with CHI, and to assess the impact (if any) of these abnormalities on clinical outcome. Sixty-three patients with CHI underwent neuroimaging with magnetic resonance imaging (MRI) and regional cerebral bl ood flow (rCBF) single photon emission tomography (SPET) approximately 6 mo nths after trauma. Seven patients had white matter abnormalities on MRI sca nning. There are no rCBF SPET criteria for defining abnormal perfusion to t he white matter. The SPET scans ranged from normal tone patient) and abnorm al perfusion to frontal, temporal or parietal lobes in these patients (n=6) . Patients were assessed for outcome after undergoing appropriate rehabilit ation programmes with indices of reintegration into the community, activiti es of daily living, disability, and their cognitive ability to perform task s. This assessment was conducted 2 years after initial trauma. Of these sev en patients with abnormal MRI of the white matter, one performed poorly and six had moderate to good clinical outcome. When individual lobar perfusion is considered, abnormal perfusion to the frontal or temporal lobes was sig nificantly associated with poorer outcome (P < 0.005). In conclusion, white matter abnormalities detected by MRI are frequently associated with cortic al perfusion defects identified by SPET (6/7 or 86%). However, when these w hite matter abnormalities were accompanied by perfusion defects in the fron tal and temporal lobes, these were statistically significant in predicting poorer outcome. ((C) 2000 Lippincott Williams & Wilkins).