Motor cortex disinhibition in Alzheimer's disease.
OBJECTIVE
To explore subclinical disturbances in the motor cortex of patients with Alzheimer's disease (AD).


METHODS
We used transcranial magnetic stimulation in a paired pulse technique to test intracortical inhibition (ICI) and intracortical facilitation in mildly to moderately demented AD patients with a normal neurological examination. Patients were studied before and during treatment with the cholinesterase inhibitor donepezil.


RESULTS
AD patients had a reduced ICI compared to an age-matched control group. The amount of disinhibition correlated with the severity of dementia. Treatment with 10 mg donepezil daily was associated with an increase of ICI.


CONCLUSIONS
The subclinical motor cortex disinhibition in AD patients indicates a functional disturbance, and is probably associated with a cholinergic deficit.
Liepert
J
J
Department of Neurology, Friedrich Schiller University, Jena, Germany. liepert@uke.uni-hamburg.de
Bär
K J
KJ
Meske
U
U
Weiller
C
C
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000503:physiopathology*; D004558:Electric Stimulation; D005260:Female; D006801:Humans; D008297:Male; D009044:Motor Cortex / Q000473:pathology* / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology*; D012720:Severity of Illness Index