[Spectral analysis of EEG signals in Alzheimer's disease].
Alzheimer's disease (AD) represents the most frequent cause of senile dementia in Western countries. The disease has a slow onset and gradual progress. Over the past few years considerable importance has been attributed to the diagnostic techniques of brain imaging able to highlight morphological and functional images. EEG mapping is one of the most widely used methods.


METHODS
The authors evaluated the characteristics of EEG mapping in relation to frequency and amplitude in a group of elderly patients with AD and in a group of healthy elderly control subjects. The former group consisted of 10 patients with AD aged between 65 and 83 years old. The control group included 10 healthy subjects who were matched for age and sex.


RESULTS
The spectral analysis of EEG signals relating to frequency and amplitude showed a slowing down of underlying activity in AD patients, with a frequency between 1 and 4 c/sec, amplitudes below 5 microW and no arrest reaction. In healthy subjects spectral analysis showed a signal percentage colocated at a frequency of between 8 and 13 c/sec in relation to frequency.


CONCLUSIONS
In view of these results, the authors recommend the use of EEG mapping to complete the diagnosis of Alzheimer's disease in the aged.
Terranova
R
R
Cattedra di Geriatria e Gerontologia, Università degli Studi, Catania.
Luca
S
S
Marletta
F
F
Marletta
C
C
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000503:physiopathology*; D001931:Brain Mapping; D004569:Electroencephalography; D005260:Female; D006801:Humans; D008297:Male; D012815:Signal Processing, Computer-Assisted