Blood Pressure and Risk of Dementia in Parkinson Disease and Multiple System Atrophy Should You Buy the Dip in Such a Volatile Market?

Efferent baroreflex failure, also known as autonomic failure, is a key nonmotor feature of the synucleinopathies-Parkinson disease (PD), dementia with Lewy bodies, and multiple system atrophy (MSA).(1) It causes unstable blood pressure (BP) often manifesting as a fall in BP on standing, that is, neurogenic orthostatic hypotension (OH), which occurs in approximately 40% of patients with PD and approximately 80% of patients with MSA. An underrecognized consequence of efferent baroreflex failure is the converse problem: supine hypertension (SH), which coexists with OH in approximately 50% of patients with synucleinopathies.(2) When looking at an ambulatory 24-hour BP monitor tracing of a patient with efferent baroreflex failure, a resemblance to a stock market chart characterized by extreme volatility is apparent (Figure). Managing both hypertension and hypotension is a challenge because treating one generally exacerbates the other. Disentangling the consequences of each one is also puzzling. Cognition is another nonmotor domain affected in the synucleinopathies, with dementia troubling many patients with PD, particularly in advanced disease stages. While frank dementia in MSA is remarkably rare, some cognitive domains are affected in a minority of patients.

Automated summary

Efferent baroreflex failure is a major symptom in synucleinopathies, causing unstable blood pressure and leading to orthostatic hypotension and supine hypertension. Managing both conditions is challenging due to their opposite effects and the cognitive domains are also affected in these diseases.