Event-related delta oscillatory responses of Alzheimer patients.
OBJECTIVE
Alzheimer type of dementia (AD) is the most common neuropsychiatric morbidity in elderly individuals. Event-related oscillations (ERO) provide an useful tool for detecting subtle abnormalities of cognitive processes with high temporal resolution.


METHODS
In the present report, event-related oscillations of patients with AD were analyzed by using a visual oddball paradigm. A total of 22 mild probable AD subjects according to NINCDS-ADRDA criteria and 20 age-, gender-, and education-matched healthy control subjects were compared. AD group consisted from 11 untreated patients and 11 patients treated with cholinesterase inhibitor. Oscillatory responses were recorded from 13 scalp electrodes.


RESULTS
Significant differences in delta frequency range were seen between the groups by using repeated measures of anova analysis [F(9.120) = 2.228; P = 0.022]. Post-hoc analyses using Wilcoxon test showed that at mid- and left central regions, (Cz, C3) peak amplitudes of delta responses of healthy subjects were significantly higher than either group. Also cholinesterase inhibitors did not have effect on delta oscillatory responses.


CONCLUSIONS
Our findings imply that the delta oscillatory responses at central locations are highly instable in mild probable AD patients regardless of treatment when compared to the healthy aged controls. This study supports the importance of oscillatory event-related potentials for investigating AD brain dynamics.
Yener
G
G
Department of Neurology, Brain Dynamics and Multidisciplinary Research Center, Dokuz Eylul University, Izmir, Turkey. gorsev.yener@deu.edu.tr
Güntekin
B
B
Başar
E
E
D000368:Aged; D000544:Alzheimer Disease / Q000188:drug therapy / Q000503:physiopathology*; D001921:Brain / Q000187:drug effects / Q000502:physiology*; D002800:Cholinesterase Inhibitors / Q000627:therapeutic use; D003071:Cognition / Q000502:physiology; D018913:Event-Related Potentials, P300 / Q000187:drug effects / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D010775:Photic Stimulation
D002800:Cholinesterase Inhibitors