This important article by Mayo Clinic DLB (dementia with Lewy bodies) experts was published in "Neurology," an important journal, last week. One reason this article is important is that it includes autopsy-confirmed cases of DLB.

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."

To have a clinical diagnosis of probable DLB, a patient MUST have progressive dementia, and MUST have two of three core features -- parkinsonism, fluctuating cognition, and visual hallucinations. Alternatively, the latest diagnostic criteria also allow for a probable DLB diagnosis if the patient has progressive dementia, one core feature, and one or more suggestive features. There are three possible suggestive features -- RBD (REM sleep behavior disorder), severe sensitivity to neuroleptics (or antipsychotics), and reduced dopamine transporter uptake (in a brain area called the basal ganglia) seen in functional imaging.

In this study, Mayo researchers concluded that when they added RBD to the "core features" list, diagnostic accuracy of autopsy-confirmed DLB improved.

How was RBD diagnosed? "Clinically probable RBD was diagnosed using the Mayo Sleep Questionnaire, and via clinical interview using the following query: 'Have you ever seen the patient appear to act out his or her dreams while sleeping?' with additional inquiry about the nature of the movements and whether the movements matched dream content. A minimum of 3 events during the patient's lifetime was needed to be considered clinically probable RBD."

The abstract is below.

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, Smith 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, Petersen RC, Dickson DW.
Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, 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)

when I repeatively asked Dr. Boeve about the confidence in my diagnosis…especially with the improved PET scan this visit….

he repeatively said…the clincher for the confidence is my RBD...

When I asked Dr. Boeve about his confidence in Coy's diagnosis, he said he is 95% confident and that the Mayo study very seldom misdiagnoses DLB when RBD is present.

I'm impressed with the number of autopsy-confirmed cases included.

Thanks for sharing, Robin.

Jeanne,
I thought of you when I posted this research as this is certainly in line with what you've been hearing from Dr. Boeve. It's interesting that polysomnography is so important to properly diagnosing RBD.
Robin

Robin- Thanks for posting this very informative article. I appreciate so much that you take the time to read and post all of the articles that you do. I would be much less well informed about this disease if not for you and your efforts.
Ellen

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