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.