Lobar cerebral microbleeds may be associated with cognitive decline in Parkinson disease, according to a recent study published in the Journal of the Neurological Sciences.
Researchers in this retrospective study evaluated 124 patients diagnosed with Parkinson disease for cerebral microbleeds, blood pressure, orthostatic hypotension, and factors association with dementia.
Cerebral microbleeds were identified on an MRI scan and the Microbleed Anatomical Rating Scale was used to describe any lesions found. Ambulatory blood pressures were monitored for 24 hours, and nocturnal variations categorized patients. Orthostatic hypotension was defined as a 20 mmHg drop in systolic blood pressure and/or a 10 mmHg drop in diastolic blood pressure when moving from a supine reading to a standing reading. Dementia was defined as a score less than 26 on the Mini-Mental State Examination and impairment to daily life functions.
Results indicated that gender (P <.001), age (P <.001), Hoehn and Yahr stage (P <.001), stroke (P <.001), orthostatic hypotension (P <.001), supine hypertension (P <.001), cerebral microbleeds (P <.001), and anticoagulants (P =.02) were significantly associated with dementia in Parkinson disease.
Cerebral microbleeds, whether deep and infratentorial or strictly lobar, occur significantly more often in patients with dementia (P <.001). Male gender (OR 0.06, 95% CI 0.003-0.43; P =.004), orthostatic hypotension (OR 68.2, 95% CI 4.61–3528.1, P =.0006), and lobar cerebral microbleeds (OR 57.9, 95%CI 1.6–11,916.1, P =.03) were independent risks for dementia in Parkinson disease.
Future studies need to increase sample size to encompass a greater population, enroll recently diagnosed cases to assess the relationship between cerebral microbleeds and developing dementia, and use a more accurate measurement tool for dementia.
In conclusion, strictly lobar cerebral microbleeds are associated with dementia in Parkinson disease, possibly due to small vessel disease and cerebral amyloid angiopathy.
Daida K, Tanaka R, Yamashiro K, et al. The presence of cerebral microbleeds is associated with cognitive impairment in Parkinson’s disease. J Neurol Sci. 2018; 393: 39-44.