The electroencephalogram in dementia with Lewy bodies.
OBJECTIVE
Dementia with Lewy bodies (DLB) is the second commonest neurodegenerative cause of dementia. While there is consensus on the clinical diagnostic criteria for DLB, the use of EEG to increase the diagnostic sensitivity has not been substantiated.


METHODS
We studied the resting EEG findings in 18 consecutive patients with DLB and compared them with a control group of 20 patients with "probable" Alzheimer's disease (AD). We aimed to evaluate the use of EEG in a representative sample of patients with DLB.


RESULTS
All patients with DLB fulfilled accepted clinical criteria for DLB. The DLB group had a more severe dementia than the AD group, as measured by the Mini-Mental State Examination (MMSE) test (DLB mean MMSE 9.4 and AD mean MMSE 17.2) despite a similar duration of overall severity of illness. The EEG was slow in both groups, predominantly in the 4-7 Hz range. Although there was no statistically significant difference in the EEG findings between the DLB and AD groups, there was a correlation between the EEG score and MMSE score (Spearman Rank correlation rs = -0.61, P < 0.001).


CONCLUSIONS
These findings suggest that although patients with DLB have a more aggressive course than AD, EEG abnormalities do not differ in the 2 groups. However, we believe the EEG provides important supporting diagnostic information in DLB.
Barber
P A
PA
Cerebral Function Unit, Manchester Royal Infirmary, United Kingdom.
Varma
A R
AR
Lloyd
J J
JJ
Haworth
B
B
Snowden
J S
JS
Neary
D
D
D000368:Aged; D000544:Alzheimer Disease / Q000175:diagnosis / Q000503:physiopathology; D002540:Cerebral Cortex / Q000503:physiopathology; D003937:Diagnosis, Differential; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000175:diagnosis* / Q000503:physiopathology; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted