Cognitive decline similar in LBD and AD

This is an interesting study of 58 DLB (Dementia with Lewy Bodies) subjects and 100 AD (Alzheimer’s Disease) subjects, followed over a one-year period at 40 European centers. All patients had mild-moderate dementia. The diagnosis required a 123I-FP-CIT (dopamine transporter) SPECT. (There was no autopsy confirmation of the diagnoses.)

The authors state that DLB is associated with “earlier institutionalisation and a higher level of carer distress than are seen in Alzheimer’s disease.”

The authors believe prognosis info is important information for caregivers:

“Awareness of the rate of cognitive decline and also of non-cognitive symptoms can help carers and patients to adjust and plan appropriate lifestyle changes and to make arrangements for the future. This frequently involves making difficult decisions regarding treatment of psychiatric and motor symptoms and utilisation of limited resources available for patients with dementia.”

The authors want to investigate why the prognosis in DLB is worse than in AD. They thought perhaps it was due to a faster cognitive decline in DLB as compared to AD. In fact, they found that there were no significant differences when comparing the rates of decline of cognitive and neuropsychiatric symptoms in DLB and AD. One of the key messages of the article is: “the worse prognosis of DLB is likely to be mediated by neuropsychiatric or other symptoms and not only by cognitive decline.”

I’ve copied the abstract below.

Robin

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BMJ Open. 2012 Feb 8.

Comparison of cognitive decline between dementia with Lewy bodies and Alzheimer’s disease: a cohort study.

Walker Z, McKeith I, Rodda J, Qassem T, Tatsch K, Booij J, Darcourt J, O’Brien J.
Research Department of Mental Health Sciences, University College London, Bloomsbury Campus, London, UK.

Abstract

OBJECTIVES:
Dementia with Lewy bodies (DLB) accounts for 10%-15% of dementia cases at autopsy and has distinct clinical features associated with earlier institutionalisation and a higher level of carer distress than are seen in Alzheimer’s disease (AD). At present, there is on-going debate as to whether DLB is associated with a more rapid cognitive decline than AD. An understanding of the rate of decline of cognitive and non-cognitive symptoms in DLB may help patients and carers to plan for the future.

DESIGN:
In this cohort study, the authors compared 100 AD and 58 DLB subjects at baseline and at 12-month follow-up on cognitive and neuropsychiatric measures.

SETTING:
Patients were recruited from 40 European centres.

PARTICIPANTS:
Subjects with mild-moderate dementia. Diagnosis of DLB or AD required agreement between consensus panel clinical diagnosis and visual rating of 123I-FP-CIT (dopamine transporter) single photon emission computed tomography neuroimaging.

OUTCOME MEASURES:
The Cambridge Cognitive Examination including Mini-Mental State Examination and Neuropsychiatric Inventory (NPI).

RESULTS:
The AD and DLB groups did not differ at baseline in terms of age, gender, Clinical Dementia Rating score and use of cholinesterase inhibitors or memantine. NPI and NPI carer distress scores were statistically significantly higher for DLB subjects at baseline and at follow-up, and there were no differences between AD and DLB in cognitive scores at baseline or at follow-up. There was no significant difference in rate of progression of any of the variables analysed.

CONCLUSIONS:
DLB subjects had more neuropsychiatric features at baseline and at follow-up than AD, but the authors did not find any statistically significant difference in rate of progression between the mild-moderate AD and DLB groups on cognitive or neuropsychiatric measures over a 12-month follow-up period.

PubMed ID#: 22318660 (www.pubmed.gov/ID#22318660)