Core and suggestive symptoms of dementia with lewy bodies cluster in persons with mild dementia.

OBJECTIVES

To explore how the core and suggestive symptoms of dementia with Lewy bodies (DLB) cluster in persons with newly diagnosed mild dementia, and whether they are associated with a particular pattern of cognitive impairment.

METHOD: Persons with mild dementia (n = 139) were recruited from dementia clinics in western Norway. Symptoms were rated using standardized instruments. A 2-step cluster analysis was applied to classify persons into groups according to scores on scales for hallucinations, parkinsonism, fluctuations and REM sleep behaviour disorder (RBD).

RESULT: Four distinct clusters were revealed: a 'Lewy body dementia' (LBD) cluster with high scores for hallucinations, parkinsonism and fluctuation, and a 'non-LBD' cluster with low scores on all DLB symptom scales. In addition, 2 clusters with high scores on either RBD or cognitive fluctuation scales emerged. Persons in the LBD cluster had lower scores for visuospatial cognitive abilities as compared to the non-LBD group (p = 0.002).

CONCLUSION

Applying cluster analysis, we identified distinct subgroups in mild dementia based on symptoms such as hallucinations, parkinsonism and cognitive fluctuations. Our findings provide empirical support for diagnosing DLB. Visual hallucinations and motor parkinsonism might be the most distinguishing symptoms for DLB in mild dementia.