Hypotensive Episodes Precede Cognitive Fluctuations in Parkinson's Disease Dementia

Cognitive fluctuations (CFs) are a disabling feature in Parkinson's disease dementia (PDD) and contribute to caregiver burden. The relationship between CFs and neurogenic orthostatic hypotension (nOH), a common autonomic complication in PDD, has not been adequately examined.

We describe four patients with PDD and nOH with caregiver-reported CFs manifesting as impaired attention, comprehension, language, and visuospatial skills. Each patient underwent bedside assessment for orthostatic vital signs and 24-hour ambulatory blood pressure monitoring (ABPM). CFs were consistently time-locked to periods of hypotension, independent of carbidopa/levodopa dosing.

Hypotensive episodes may be under-recognized contributors to CFs in PDD. Interventions targeting hypotension warrant further investigation as potential strategies to mitigate CFs. Incorporation of ABPM into routine clinical evaluation may help guide their management.