21. Occipital sources of resting state alpha rhythms are related to local gray matter density in subjects with amnesic mild cognitive impairment and Alzheimer’s disease

Occipital sources of resting state alpha rhythms are abnormal in patients with amnesic mild cognitive impairment (MCI) and Alzheimer’s disease (AD). Here we hypnotized whether the activity of these sources is related to neurodegeneration in occipital lobe as measured by magnetic resonance imaging (MRI). Resting-state eyes-closed EEG rhythms were recorded in 30 healthy elderly (Nold), 37 MCI, and 40 AD subjects. Neurodegeneration of the occipital lobe was indexed by weighted averages of gray matter density (GMD). EEG rhythms of interest were alpha 1 (8–10.5 Hz) and alpha 2 (10.5–13 Hz). EEG cortical sources were estimated by LORETA. Results showed a positive correlation between GMD in the occipital lobe and the magnitude of occipital alpha sources in the MCI and AD subjects. Furthermore, there was a positive correlation between the magnitude of alpha sources and the cognitive status as revealed by Mini Mental State Evaluation score all subjects. These results suggest that in amnesic MCI and AD subjects, occipital sources of resting state alpha rhythms reflect AD neurodegeneration in the occipital lobe. Cortical sources of resting state EEG rhythms in AD patients are promising for preliminary screening of elderly subjects at risk for AD.