Influence of Alzheimer pathology on clinical diagnostic accuracy in dementia with Lewy bodies.
OBJECTIVE
To determine whether AD neurofibrillary pathology influences clinical diagnostic accuracy in dementia with Lewy bodies (DLB).


BACKGROUND
Pathologic diagnosis of DLB mandates Lewy bodies but also allows for AD pathology in the form of plaques and tangles. Because clinical diagnostic accuracy of DLB remains low, the authors questioned whether the severity of AD pathology in the form of tangles might affect the clinician's ability to correctly diagnose DLB in life.


METHODS
Ninety-eight subjects with autopsy-proven DLB who had been evaluated annually at the University of California San Diego AD Research Center were identified. The clinical diagnosis used was the last diagnosis before death. Pathologic diagnosis of DLB was made according to Consensus guidelines, and Braak staging was used to assess the degree of neurofibrillary AD pathology. The clinical characteristics of subjects with DLB with low vs high Braak stages were compared and the clinical diagnostic accuracy for subjects stratified according to Braak stage was determined.


RESULTS
Only 27% of the subjects with DLB demonstrated both visual hallucinations and spontaneous extrapyramidal signs (EPS). The low Braak stage (0 to 2, n = 24) subjects had a higher frequency of visual hallucinations (65%) than did subjects with DLB with higher (3 to 6, n = 66) Braak stages (33%, p = 0.008), and showed a slightly greater but not significant degree of EPS. Although clinical diagnostic accuracy for DLB was relatively low (49%), it was higher for subjects with low (75%) compared to high (39%) Braak stages (p = 0.0039).


CONCLUSIONS
The degree of concomitant AD tangle pathology has an important influence on the clinical characteristics and, therefore, the clinical diagnostic accuracy of DLB.
Merdes
A R
AR
Department of Neurosciences, University of California, San Diego 92161, USA.
Hansen
L A
LA
Jeste
D V
DV
Galasko
D
D
Hofstetter
C R
CR
Ho
G J
GJ
Thal
L J
LJ
Corey-Bloom
J
J
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000473:pathology; D001480:Basal Ganglia Diseases / Q000209:etiology; D001921:Brain / Q000473:pathology; D015331:Cohort Studies; D003937:Diagnosis, Differential; D003951:Diagnostic Errors; D005260:Female; D006212:Hallucinations; D006801:Humans; D016631:Lewy Bodies / Q000737:chemistry; D020961:Lewy Body Disease / Q000150:complications / Q000175:diagnosis* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D016874:Neurofibrillary Tangles; D058225:Plaque, Amyloid; D011237:Predictive Value of Tests; D013194:Staining and Labeling / Q000379:methods