Adding RBD to DLB Diagnostic Criteria Improves Accuracy

[Guest guest]

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This is apropos of our discussion on RBD, fluctuating cognition, the diagnostic

criteria, and diagnostic accuracy.

Robin

This important article by DLB (dementia with Lewy bodies) experts at the Mayo

Clinic was published in " Neurology, " a top journal, last week. One reason this

article is important is that it includes autopsy-confirmed cases of DLB.

Unfortunately, the high volume of statistical terminology makes reading the

abstract and full article rather challenging.

The authors argue that it is " critical to properly diagnose DLB during life in

order to optimize symptom management, reduce...treatment complications, and

develop new therapies designed to prevent or interfere with disease

progression. "

In this study, Mayo researchers concluded that when they added RBD to the " core

features " list, diagnostic accuracy of autopsy-confirmed DLB improved.

These comparisons of clinical features between the autopsy-confirmed DLB group

and the non-DLB group are interesting:

" Compared to the non-DLB group, the DLB group had more males, a shorter duration

of illness, greater baseline daytime somnolence, and greater parkinsonism

severity. There were no group differences in baseline dementia severity.

Fluctuations were more frequent in the DLB compared to non-DLB autopsy group at

baseline and by end of life. VH and parkinsonism were more common in the DLB

autopsy group and occurred earlier in the disease compared to their non-DLB

counterparts. Males were more likely to have DLB, and were also more likely to

have RBD (males 82% vs females 54%, p < 0.01), but gender was equally

represented across the other core DLB features. "

And this info on RBD is interesting: " RBD was reported in 74/98 of the DLB

group compared to 5/136 in the non-DLB group, and preceded the estimated onset

of dementia by an average of 6 years. Moreover, the onset of RBD preceded VH by

8.4 ± 12 years, and parkinsonism by 7.6 ± 12 years. ... [RBD] may become less

frequent or less symptomatic as the dementia progresses. "

In the Discussion section, the authors seem to suggest adding RBD to the list of

core features of DLB and eliminating fluctuating cognition from the list of core

features. And, they indicate that further study should be done to determine if

there need to be cutoffs for the onset of visual hallucinations and parkinsonism

-- two of the core features -- since these symptoms can also occur in non-DLB

patients.

I've copied the abstract below. Probably Sue will post extensive excerpts

to the caringspouses Yahoo!Group.

Robin

Neurology. 2011 Aug 30;77(9):875-82. Epub 2011 Aug 17.

Inclusion of RBD improves the diagnostic classification of dementia with Lewy

bodies.

Ferman TJ, Boeve BF, GE, Lin SC, Silber MH, Pedraza O, Wszolek Z,

Graff-Radford NR, Uitti R, Van Gerpen J, Pao W, Knopman D, Pankratz VS, Kantarci

K, Boot B, Parisi JE, Dugger BN, Fujishiro H, sen RC, Dickson DW.

Department of Psychiatry and Psychology, Mayo Clinic, ville, FL

Abstract

OBJECTIVE:

To determine whether adding REM sleep behavior disorder (RBD) to the dementia

with Lewy bodies (DLB) diagnostic criteria improves classification accuracy of

autopsy-confirmed DLB.

METHODS:

We followed 234 consecutive patients with dementia until autopsy with a mean of

4 annual visits. Clinical diagnoses included DLB, Alzheimer disease (AD),

corticobasal syndrome, and frontotemporal dementia. Pathologic diagnoses used

the 2005 DLB consensus criteria and included no/low likelihood DLB (non-DLB; n =

136) and intermediate/high likelihood DLB (DLB; n = 98). Regression modeling and

sensitivity/specificity analyses were used to evaluate the diagnostic role of

RBD.

RESULTS:

Each of the 3 core features increased the odds of autopsy-confirmed DLB up to

2-fold, and RBD increased the odds by 6-fold. When clinically probable DLB

reflected dementia and 2 or more of the 3 core features, sensitivity was 85%,

and specificity was 73%. When RBD was added and clinically probable DLB

reflected 2 or more of 4 features, sensitivity improved to 88%. When dementia

and RBD were also designated as probable DLB, sensitivity increased to 90% while

specificity remained at 73%. The VH, parkinsonism, RBD model lowered sensitivity

to 83%, but improved specificity to 85%.

CONCLUSIONS:

Inclusion of RBD as a core clinical feature improves the diagnostic accuracy of

autopsy-confirmed DLB.

PubMed ID#: 21849645 (see pubmed.gov for this abstract only)