The Changes of Cortical Metabolism Associated With the Clinical Response to Donepezil Therapy in Traumatic Brain Injury

OBJECTIVES: To determine the effects of treatment with donepezil on cortical metabolism in patients with traumatic brain injury using F-fluorodeoxyglucose positron emission tomography. METHODS: Twenty-six patients with cognitive impairment after traumatic brain injury were enrolled and randomly assigned into the donepezil-treated group and the control group. There was no significant difference between 2 groups in age, sex, education, and postinjury duration. Donepezil 5 mg was administered daily for 3 weeks and then 10 mg/d for 3 weeks to patients in the experimental groups. For both groups, we evaluated cognitive function with Mini-Mental State Examination, Wechsler Memory Test, Boston Naming Test, Colored Progressive Matrices upon initial evaluation and at the 6-week follow-up. An 18F-fluorodeoxyglucose positron emission tomography of the brain was performed before and after 6 weeks of the donepezil-treated group. Effects of donepezil treatment on cortical metabolism were analyzed using Statistical Parametric Mapping software (Institute of Neurology, University College London, UK). RESULTS: There was no significance difference between the 2 groups in initial evaluation of cognitive functions. After 6 weeks, compared with the control group, donepezil-treated group showed enhanced cognitive functions (P < 0.05), and 18F-fluorodeoxyglucose positron emission tomography showed a statistically significant increase in the cerebral cortical metabolism for both of the frontal, parietal, occipital, and temporal cortices (P < 0.01) which are the key role of attention and object naming. CONCLUSIONS: Cholinergic augmentation by donepezil therapy in traumatic brain injury shows a cortical metabolic effect on the both of the frontal, parietal, occipital, and temporal cortices associated with clinical response to treatment.