Brain activity patterns in stable and progressive mild cognitive impairment during working memory as evidenced by magnetoencephalography

J Clin Neurophysiol. 2011 Apr;28(2):202-9. doi: 10.1097/WNP.0b013e3182121743.


It has been reported that mild cognitive impairment (MCI) patients, when compared with controls, show increased activity in different brain regions within the ventral pathway during memory tasks. A key question is whether this profile of increased activity could be useful to predict which patients will develop dementia. Herein, we present profiles of brain magnetic activity during a memory task recorded with magnetoencephalography from MCI patients (N = 10), Alzheimer's disease (AD) patients (N = 10), and healthy volunteers (N = 17). After 2½ years of follow-up, five of the MCI patients developed AD. Patients who progressed to AD (PMCI) showed higher activity than those who remained stable (SMCI), AD patients and controls. This increased activity in PMCI patients involves regions within the ventral and dorsal pathways. In contrast, SMCI patients showed higher activation than controls only along the ventral pathway. This increase in both the ventral and dorsal pathways in PMCI patients may reflect a compensatory mechanism for the loss in efficiency in memory networks, which would be absent in AD patients as they showed lower activity levels than the rest of the groups.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Alzheimer Disease / diagnosis*
  • Alzheimer Disease / physiopathology
  • Alzheimer Disease / psychology
  • Brain / physiopathology*
  • Brain Mapping / methods*
  • Brain Waves*
  • Case-Control Studies
  • Cognition Disorders / diagnosis*
  • Cognition Disorders / physiopathology
  • Cognition Disorders / psychology
  • Cognition*
  • Disease Progression
  • Humans
  • Magnetoencephalography*
  • Memory, Short-Term*
  • Neuropsychological Tests
  • Predictive Value of Tests
  • Reaction Time
  • Severity of Illness Index
  • Spain
  • Time Factors