Rivastigmine effects on EEG spectra and three-dimensional LORETA functional imaging in Alzheimer's disease

Psychopharmacology (Berl). 2008 Jun;198(3):323-32. doi: 10.1007/s00213-008-1111-1. Epub 2008 Apr 30.


Objective: The objective of the study is to investigate the electrocortical and the global cognitive effects of 3 months rivastigmine medication in a group of mild to moderate Alzheimer's disease patients.

Materials and methods: Multichannel EEG and cognitive performances measured with the Mini Mental State Examination in a group of 16 patients with mild to moderate Alzheimer's Disease were collected before and 3 months after the onset of rivastigmine medication.

Results: Spectral analysis of the EEG data showed a significant power decrease in the delta and theta frequency bands during rivastigmine medication, i.e., a shift of the power spectrum towards 'normalization'. Three-dimensional low resolution electromagnetic tomography (LORETA) functional imaging localized rivastigmine effects in a network that includes left fronto-parietal regions, posterior cingulate cortex, bilateral parahippocampal regions, and the hippocampus. Moreover, a correlation analysis between differences in the cognitive performances during the two recordings and LORETA-computed intracortical activity showed, in the alpha1 frequency band, better cognitive performance with increased cortical activity in the left insula.

Conclusion: The results point to a 'normalization' of the EEG power spectrum due to medication, and the intracortical localization of these effects showed an increase of cortical activity in frontal, parietal, and temporal regions that are well-known to be affected in Alzheimer's disease. The topographic convergence of the present results with the memory network proposed by Vincent et al. (J. Neurophysiol. 96:3517-3531, 2006) leads to the speculation that in our group of patients, rivastigmine specifically activates brain regions that are involved in memory functions, notably a key symptom in this degenerative disease.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Alzheimer Disease / drug therapy*
  • Alzheimer Disease / pathology
  • Alzheimer Disease / psychology
  • Cerebral Cortex / pathology
  • Cholinesterase Inhibitors / pharmacology*
  • Cholinesterase Inhibitors / therapeutic use
  • Cognition Disorders / psychology
  • Electroencephalography*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Male
  • Middle Aged
  • Neuroprotective Agents / pharmacology*
  • Neuroprotective Agents / therapeutic use
  • Phenylcarbamates / pharmacology*
  • Phenylcarbamates / therapeutic use
  • Psychomotor Performance / drug effects
  • Rivastigmine


  • Cholinesterase Inhibitors
  • Neuroprotective Agents
  • Phenylcarbamates
  • Rivastigmine