Transcranial magnetic stimulation in Alzheimer disease: motor cortex excitability and cognitive severity

Neurosci Lett. 2001 Nov 13;314(1-2):57-60. doi: 10.1016/s0304-3940(01)02288-1.


To study the possible changes of cortical excitability in the Alzheimer disease (AD) by transcranial magnetic stimulation (TMS) and to evaluate their eventual correlation with its stage twenty-one AD patients and 18 normal controls underwent TMS. Motor threshold, amplitudes of motor evoked potentials (MEPs), central motor conduction time (CMCT) and silent period (SP) were considered. The motor threshold in AD patients was lower than in normal subjects with a significant correlation between the stage of cognitive severity. The amplitude of MEPs was increased and the SP duration was reduced in AD patients. No significant differences were obtained for CMCT. These findings could suggest a correlation between increased motor cortical excitability and cognitive severity. Moreover, the increased cortical excitability could represent a key to understand the mechanism of AD and may have implication for novel treatment strategies.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / diagnosis
  • Alzheimer Disease / physiopathology*
  • Cognition / physiology*
  • Cognition Disorders / pathology
  • Cognition Disorders / physiopathology*
  • Disease Progression
  • Electric Stimulation
  • Evoked Potentials, Motor / physiology*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Motor Cortex / physiopathology*
  • Muscle Contraction / physiology
  • Neural Conduction / physiology
  • Predictive Value of Tests
  • Reaction Time / physiology
  • Transcranial Magnetic Stimulation*