Re: EEG

[Guest guest]

dad had 3 eegs done over a year of 2 years and each time his frontal lobe being

more and more destroyed. and he had a faster rate of 'brain shrinkage' than a

normal man of 67 to 69

althoughthey did nothing to treeat it besides exelon and eventually namenda,

just wanted to share thishugs,sharon

wrote: EEG comparisons in early

Alzheimer's disease, dementia with Lewy

bodies and Parkinson's disease with dementia patients with a 2-year

follow-up

January 17, 2008

EEG abnormalities have been reported for both dementia with Lewy

bodies (DLB) and Alzheimer's disease (AD). Although it has been

suggested that variations in mean EEG frequency are greater in the

former, the existence of meaningful differences remains

controversial. No evidence is as yet available for Parkinson's

disease with dementia (PDD). The aim of this study was to evaluate

whether EEG abnormalities can discriminate between DLB, AD and PDD in

the earliest stages of dementia and to do this 50 DLB, 50 AD and 40

PDD patients with slight cognitive impairment at first visit (MMSE

20) were studied. To improve clinical diagnostic accuracy, special

emphasis was placed on identifying cognitive fluctuations and REM-

sleep behaviour disorder. EEG variability was assessed by mean

frequency analysis and compressed spectral arrays (CSA) in order to

detect changes over time from different scalp derivations. Patients'

initial diagnoses were revised at a 2-year follow-up visit with

neuroimaging evaluation. Initial diagnoses were confirmed in 36 DLB,

40 AD and 35 PDD patients. The most relevant group differences were

observed between the AD and DLB patients in EEGs from posterior

derivations (P<0.001). Dominant frequencies were 8.3 ± 0.6 Hz for the

AD group and 7.4 ± 1.6 Hz for the DLB group, in which most of the

patients (88%) exhibited a frequency band of 5.6–7.9 Hz. Dominant

frequency variability also differed between the AD (1.1 ± 0.4 Hz) and

DLB groups (1.8 ± 1.2 Hz, P<0.001). Of note, less than a half (46%)

of the patients with PDD exhibited the EEG abnormalities seen in

those with DLB. Graded according to the presence of alpha activity,

five different patterns were identified on EEG CSA from posterior

derivations. A pattern with dominant alpha bands was observed in

patients with AD alone while, in those with DLB and PDD, the degree

to which residual alpha and 5.6–7.9 bands appeared was related to the

presence and severity of cognitive fluctuations. At follow-up, EEG

abnormalities from posterior leads were seen in all subjects with DLB

and in three-quarters of those with PDD. Of interest, in four

patients initially labelled as having AD, in whom the occurrence of

fluctuations and/or REM-sleep behaviour disorder during the 2-year

follow-up had made the diagnosis of AD questionable, the initial EEG

was characterized by the features observed in the DLB group. If

revised consensus criteria for DLB diagnosis are properly applied

(i.e. emphasizing the diagnostic weight of fluctuations and REM sleep

behaviour disorder), EEG recording may act to support discrimination

between AD and DLB at the earliest stages of dementia, since

characteristic abnormalities may even precede the appearance of

distinctive clinical features.

Source:

http://brain.oxfordjournals.org/cgi/content/short/131/3/690?rss=1

---------------------------------

Never miss a thing. Make Yahoo your homepage.