Frequency and case identification of dementia with Lewy bodies using the revised consensus criteria.

OBJECTIVE

To find the proportion of dementia with Lewy bodies (DLB) in a referral cohort of patients with a first-time diagnosis of mild dementia.

BACKGROUND

The proportion of DLB among the dementia sufferers is not known and the clinical consensus criteria have low sensitivity. We employed the revised DLB criteria to study the proportion with DLB in a community sample of patients with mild dementia.

METHODS

From March 2005 to March 2007, we included 196 patients from referrals to all geriatric medicine, old age psychiatry and neurology outpatient clinics in Rogaland and Hordaland counties in Western Norway. Standardized clinical instruments and diagnostic criteria were employed.

RESULTS

65% had Alzheimer dementia, 20% DLB (16% probable DLB), 5.6% vascular dementia, 5.6% Parkinson disease with dementia, 2.0% frontotemporal dementia and 1.5% alcoholic dementia. There were no significant differences in the proportion with DLB according to age bands and dementia severity groups. The revised criteria for a clinical diagnosis of DLB increased the proportion of probable DLB by 25% compared to the previous criteria.

CONCLUSION

DLB is common in patients with mild dementia, and is the second most common type of dementia. The introduction of new clinical criteria for DLB leads to an increase in the proportion diagnosed with probable DLB.