Cerebral microbleeds: prevalence and relationship to clinical features in cognitive impairment with lewy body disease

The burden of cerebral microbleeds (CMBs) is greater in patients with dementia with Lewy bodies (DLB) than in those with Parkinson disease dementia (PDD), while few studies have been carried out in a large sample size, or focused on the prodromal stage. Thus, we investigated the clinical prevalence of CMBs and its relationship to clinical features in patients with DLB, PDD, mild cognitive impairment with Lewy bodies (MCI-LB) and Parkinson's disease with MCI (PD-MCI) in this study.

In this retrospective multicenter cohort study, the study population consisted of 486 patients with DLB, 262 cases with PDD, 74 cases with MCI-LB and 107 cases with PD-MCI from 22 memory clinics between January 2018 and June 2022 in China. Demographic and clinical information were collected by reviewing medical records. CMBs were classified as "present" or "absent" in the Gradient Recalled-Echo or Susceptibility Weighted Imaging.

The prevalence of CMBs was significantly greater in patients with DLB with 24.69% (95% CI [20.92%, 28.78%]) than patients with PDD with 20.23% (95% CI [5.54%, 25.61%]), patients with MCI-LB with 16.22% (95% CI [8.67%, 26.61%]), and patients with PD-MCI with 12.15% (95% CI [6.63%, 19.88%]). There were sex and age differences in this prevalence. In all patients, the presence of CMBs was significantly and independently associated with the presence of visual hallucination (OR = 1.597, 95% CI [1.014, 2.517], p = 0.044) and fluctuating cognition (OR = 1.707, 95% CI [1.140, 2.556], p = 0.009); and it was associated with the severity of hallucination (B = 0.775, SE = 0.368, p = 0.036) and disinhibition (B = 0.363, SE = 0.148, p = 0.014) reflected by NPI. Moreover, CMBs in DLB were associated with the presence of parkinsonism symptoms (OR = 1.821, 95% CI [1.001, 3.314], p = 0.05), and the scores of UPDRS-III (B = 4.711, SE = 1.939, p = 0.016) and Hoehn-Yahn stage (B = 0.452, SE = 0.165, p = 0.007).

Patients with DLB had a higher proportion of CMBs than PDD, MCI-LB and PD-MCI. CMBs in all DLB, PDD, MCI-LB and PD-MCI cases were associated with the presence of visual hallucination and fluctuating cognition; in DLB were associated with motor function.