Functional assessment of mild traumatic brain injury using SPECT and neuropsychological testing.

The aim of this study was to ascertain whether SPECT and neuropsychological testing provide converging evidence of normal and abnormal regional cerebral function in patients with mild traumatic brain injury (mTBI). Four patients with mTBI were evaluated with SPECT and selected neuropsychological tests with putative localizing capabilities to specific cortical regions. The performance of each patient on each test was graded as either normal or abnormal. Additionally, SPECT images were graded for normal and/or abnormal patterns of regional cerebral blood flow (rCBF) in eight regions of the cortex. These data were then used to predict outcomes from one modality to the other, i.e. rCBF patterns on SPECT were used to predict either normal or abnormal performance on specific tests and performance on specific tests was used to predict the presence or absence of rCBF abnormalities on SPECT. Statistical analysis of composite data from all four patients showed that test performance predicted SPECT findings, but SPECT findings did not predict test performance.