Demography, diagnostics, and medication in dementia with Lewy bodies and Parkinson's disease with dementia: data from the Swedish Dementia Quality Registry (SveDem)

Introduction: Whether dementia with Lewy bodies (DLB) and Parkinson's disease with dementia (PDD) should be considered as one entity or two distinct conditions is a matter of controversy. The aim of this study was to compare the characteristics of DLB and PDD patients using data from the Swedish Dementia Quality Registry (SveDem).

Methods: SveDem is a national Web-based quality registry initiated to improve the quality of diagnostic workup, treatment, and care of patients with dementia across Sweden. Patients with newly diagnosed dementia of various types were registered in SveDem during the years 2007-2011. The current cross-sectional report is based on DLB (n = 487) and PDD (n = 297) patients. Demographic characteristics, diagnostic workup, Mini-Mental State Examination (MMSE) score, and medications were compared between DLB and PDD groups.

Results: No gender differences were observed between the two study groups (P = 0.706). PDD patients were significantly younger than DLB patients at the time of diagnosis (74.8 versus 76.8 years, respectively; P < 0.001). A significantly higher prevalence of patients with MMSE score ≤24 were found in the PDD group (75.2% versus 67.6%; P = 0.030). The mean number of performed diagnostic modalities was significantly higher in the DLB group (4.9 ± 1.7) than in the PDD group (4.1 ± 1.6; P < 0.001). DLB patients were more likely than PDD patients to be treated with cholinesterase inhibitors (odds ratio = 2.5, 95% confidence interval = 1.8-3.5), whereas the use of memantine, antidepressants, and antipsychotics did not differ between the groups.

Conclusion: This study demonstrates several differences in the dementia work-up between DLB and PDD. The onset of dementia was significantly earlier in PDD, while treatment with cholinesterase inhibitors was more common in DLB patients. Severe cognitive impairment (MMSE score ≤24) was more frequent in the PDD group, whereas more diagnostic tests were used to confirm a DLB diagnosis. Some similarities also were found, such as gender distribution and use of memantine, antidepressants, and antipsychotics drugs. Further follow-up cost-effectiveness studies are needed to provide more evidence for workup and treatment guidelines of DLB and PDD.