Comparison of autonomic dysfunction in patients with Parkinson's Disease, progressive supranuclear palsy, and multiple system atrophy.

Aim of the study: To assess and compare autonomic nervous system (ANS) dysfunction, especially cardiovascular dysautonomia, in Parkinson's Disease (PD), multiple system atrophy (MSA), progressive supranuclear palsy (PSP), and healthy controls.

Clinical rationale for the study: Assessment of ANS can be useful in differential diagnosis. Dysautonomia affects quality of life and can lead to potentially life-threatening complications. There is very little literature data regarding dysautonomia in PSP in relation to other parkinsonian syndromes. This study expands the knowledge about ANS dysfunction in parkinsonisms, especially PSP.

Material and methods: Patients with PD, MSA and PSP were prospectively recruited to our study. Demographic data and information about clinical and neuropsychological assessment, medication and comorbidities was collected. SCOPA-AUT questionnaire, 5-minute tilt test, and 5-minute heart rate variability (HRV) analysis in time and frequency domains were used to assess ANS. Analysis was also performed in patients with PSP-RS and PSP-P phenotypes, and in a subgroup with eliminated confounding factors, including age and disease duration.

Results: 76 PD, 25 PSP, and 12 MSA patients, and 20 controls, were included. Symptoms of dysautonomia revealed by a SCOPA-AUT questionnaire were present in all groups of patients. Urinary dysfunction was more pronounced in atypical parkinsonisms, and cardiovascular symptoms in α-synucleinopathies. HRV was disrupted in all groups of patients. However, when PSP-P and PSP-RS phenotypes were considered, HRV was diminished in PSP-RS, but there were no differences in HRV parameters between PSP-P and controls. Neurogenic orthostatic hypotension was present in 25% of PD and 58% of MSA patients, but it was absent in PSP patients and the control group. 13 PD and nine PSP patients and 16 controls were included in subanalysis. This revealed that PSP, but not PD, patients had significantly more symptoms of dysautonomia and lower HRV indices compared to controls, and that orthostatic hypotension was even more common in PD than in controls.

Conclusions and clinical implications: Our study suggests that dysautonomia is common in PD, MSA and PSP, even though it has different profiles in the different diseases. NOH is present in PD and MSA, but not in PSP.