Abnormal regional benzodiazepine receptor uptake in the prefrontal cortex in patients with mild traumatic brain injury.

OBJECTIVE The diagnosis and management of mild traumatic brain injury continues to be a subject of debate, with varying opinions regarding the extent to which organically based impairments vs the impact of other stressors cause ongoing disability. The aim of this study was to elucidate the possible abnormalities in benzodiazepine receptor uptake in the brains of patients with mild traumatic brain injury. Nine unmedicated patients with mild traumatic brain injury were investigated using 123I-iomazenil single photon emission computerized tomography (SPECT). DESIGN A descriptive study comparing patients after mild traumatic brain injury with matched control subjects. SUBJECTS Nine patients with mild traumatic brain injury and 5 controls. METHODS The SPECT scan was taken 180 min after injection of tracer. RESULTS AND CONCLUSION All 9 patients had a significant increase (> 2 standard deviations higher than the mean of controls) in benzodiazepine receptor uptake in the prefrontal cortex and significantly higher frontal association cortex-to-average global brain activity ratios than in controls. This SPECT study demonstrated focally altered benzodiazepine receptor uptake in the prefrontal cortices in patients with mild traumatic brain injury.