EEG Relationships to Neural Aging in the Elderly: Overview and Bibliography

EEG and ERP assessment of normal aging

EEG was recorded from 120 normal adult subjects who ranged in age from 20 to 80+ years in separate eyes open/closed conditions. The P3(00) event-related brain potential (ERP) was elicited with auditory and visual stimuli in separate conditions in the same subjects. Spectral analysis indicated that overall EEG power decreased as subject age increased. P3 amplitude decreased and peak latency increased for both the auditory and visual stimulus conditions as subject age increased. Few age-related differences were observed for the N1, P2, or N2 components. Spectral power from the delta, theta, and alpha bands correlated positively with P3 amplitude across subject age, but mean band frequency demonstrated only weak associations with P3 latency. No strong relationships were found between EEG and the other ERP component variables. The results suggest that age contributes to EEG power shifts, and that such changes significantly affect age-related variability of the P3 ERP component.

The effects of nimodipine on the EEG of substance abusers

Cocaine abusers have increased EEG beta and areas of reduced cortical blood flow. Since, nimodipine has neuroprotective effects and increases blood flow, we investigated the efficacy of single and multiple doses of the nimodipine in normalizing the EEG of substance abusers. Fourteen subjects received single (0, 30, 60 mg) and eleven received multiple daily (up to 150 mg in 12 hours) doses of nimodipine to determine whether this drug would increase EEG alpha and decrease beta in substance abusers. The EEG was recorded from eight scalp locations (F3, C3, P3, O1, F4, C4, P4 and O2) for three minutes during eyes closed, and eyes open conditions. Single and multiple doses of nimodipine produced significant increases in EEG alpha and decreases in EEG beta in the eyes open condition. Thus, nimodipine may have potential therapeutic implications in the treatment of cocaine dependence. Chronic nimodipine dosing in cocaine-dependent individuals is now needed to confirm its efficacy in the treatment of cocaine dependence.

Non-pharmacological treatment of sleep and wake disturbances in aging and Alzheimer's disease: chronobiological perspectives

Numerous studies indicate a deterioration of nighttime sleep and daytime cognitive performance in elderly people and Alzheimer patients. As a result of the increasing number of elderly people and Alzheimer patients in the western society, attention for these problems has grown. However, so far, the major research effort has been concentrating on the development of pharmacological therapies for an isolated age-related problem. In the present review it is argued that several age-related problems with sleep and wakefulness may reflect a dampening of circadian rhythm amplitudes. Non-pharmacological manipulation of circadian rhythms by means of various external stimuli appears to be effective in improving sleep and cognitive functioning in elderly people and Alzheimer patients.

Quantitative EEG analysis in early onset Alzheimer's disease: a controlled study

We report EEG findings in 15 presenile Alzheimer patients (probable Alzheimer's disease according to NINCDS-ADRDA criteria) and 15 age-matched controls. The quantitative EEG was analysed with respect to absolute power for each frequency band at each location accounting for EOG and EMG artifacts respectively. Compared to controls patients showed an increase of power in the slow frequency bands delta and theta which occurred quite uniformly over the different brain regions. In contrast, the decrease of the power of the fast frequency bands alpha 2, beta 1 and beta 2 was accentuated over temporo-parietal regions. In the fast bands patients had a rather flat topographic power profile. The alpha activity was on the average still of a rhythmic nature but the peak frequency was slowed. Differences in slow and fast frequency bands were more pronounced on the left hemisphere.