Motor cortex disinhibition in Alzheimer's disease

Clin Neurophysiol. 2001 Aug;112(8):1436-41. doi: 10.1016/s1388-2457(01)00554-5.


Objectives: 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.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / complications
  • Alzheimer Disease / physiopathology*
  • Electric Stimulation
  • Female
  • Humans
  • Male
  • Motor Cortex / pathology*
  • Motor Cortex / physiology
  • Neural Inhibition / physiology*
  • Severity of Illness Index