Parallel improvement of cognitive functions and P300 latency following donepezil treatment in patients with Alzheimer's disease: a case-control study.
OBJECTIVE
To evaluate the effect of donepezil, one of the cholinesterase inhibitors, on P300 measurements in patients with Alzheimer's disease (AD) and investigate the relationship between the subfactors of cognitive performance and P300 components.


METHODS
One hundred outpatients with AD were evaluated for cognitive function (cognitive ability screening instrument) and event-related potentials before and after 22 to 23 weeks of treatment with donepezil (5 mg/day). Twenty age-matched normal control subjects were recruited.


RESULTS
The patients with AD showed prolonged P300 and N200 latency, no significant differences in N100 and P200 components, and poor performance in neuropsychological assessments compared with control subjects at baseline. After donepezil treatment, the patients with AD had reduction in P300 latency at Pz lead, which was associated with a parallel improvement in cognitive function in terms of remote memory, recent memory, visual instruction, and orientation. The pre-post treatment difference of P300 latency significantly correlated with the cognitive ability screening instrument score difference and recent memory score difference, respectively.


CONCLUSIONS
The patients with AD still had intact early sensory processing but impaired higher-level cognitive processes that could influence behavior deviation. The donepezil treatment, which enhances higher-level cognitive processing time, revealed that P300 latency decreases as cognitive capability increases, especially improved in recent memory.
*Department of Neuropsychiatry, Kaohsiung Municipal Kai-Syuan Psychiatric Hospital, Kaohsiung, Taiwan; Faculty of Nursing Department, Meiho University, Pingtung, Taiwan; †Kaohsiung Municipal Kai-Syuan Psychiatric Hospital, Kaohsiung, Taiwan; and ††Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan, China.
Yu-San
YS
Chang
Hsiang-Lan
HL
Chen
Chung-Yao
CY
Hsu
Shu-Hui
SH
Tang
Ching-Kuan
CK
Liu
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000188:drug therapy* / Q000503:physiopathology; D016022:Case-Control Studies; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use*; D003071:Cognition / Q000187:drug effects* / Q000502:physiology; D000077265:Donepezil; D018913:Event-Related Potentials, P300 / Q000187:drug effects* / Q000502:physiology; D005071:Evoked Potentials / Q000187:drug effects / Q000502:physiology; D005260:Female; D006801:Humans; D007189:Indans / Q000627:therapeutic use*; D008297:Male; D010880:Piperidines / Q000627:therapeutic use*
D002800:Cholinesterase Inhibitors; D007189:Indans; D010880:Piperidines; D000077265:Donepezil