Objectives-Cardiovascular reflex tests have shown both sympathetic and parasympathetic failure in Parkinson's disease. These tests, however, describe the autonomic responses during a restricted time period and have great individual variability, providing a limited view of the autonomic cardiac control mechanisms. Thus, they do not reflect tonic autonomic regulation. The aim was to examine tonic autonomic cardiovascular regulation in untreated patients with Parkinson's disease. Methods-24 Hour ambulatory ECG was recorded in 54 untreated patients with Parkinson's disease and 47 age matched healthy subjects. In addition to the traditional spectral (very low frequency, VLF; low frequency, LF; high frequency, HF) and non-spectral components of heart rate variability, instantaneous beat to beat variability (SD1) and long term continuous variability (SD2) derived from Poincaré plots, and the slope of the power law relation were analysed. Results-All spectral components (p<0.01) and the slope of the power-law relation (p<0.01) were lower in the patients with Parkinson's disease than in the control subjects. The Unified Parkinson's disease rating scale total and motor scores had a negative correlation with VLF and LF power spectrum values and the power law relation slopes. Patients with mild hypokinesia had higher HF values than patients with more severe hypokinesia. Tremor and rigidity were not associated with the HR variability parameters. Conclusions-Parkinson's disease causes dysfunction of the diurnal autonomic cardiovascular regulation as demonstrated by the spectral measures of heart rate variability and the slope of the power law relation. This dysfunction seems to be more profound in patients with more severe Parkinson's disease. (J Neurol Neurosurg Psychiatry 2001;70:305-310)

Parkinson's disease is known to affect the reflex cardiovascular control systems, resulting in a suppressed heart rate variability, but present knowledge concerning the long-term characteristics of heart rate and heart rate variability, e. g. circadian regulation, is limited. We investigated the circadian fluctuation of the time domain, frequency domain and some non-linear measures of heart rate variability in 44 untreated patients with Parkinson's disease and 43 age- and sex-matched control subjects.In the parkinsonian patients, the measured power spectral components of heart rate variability (low-frequency power and high-frequency power) and the SD(1) value of the Poincaré two dimensional vector analysis, that quantifies the short term beat-to-beat variability, were suppressed at night. During the daytime only the SD1 of the Poincaré was suppressed. The night-to-day-ratios of the heart rate variability measures did not differ significantly between the patients and the controls. The results indicate that the long-term parasympathetic cardiovascular regulation is impaired in untreated patients with Parkinson's disease. The dysfunction is more pronounced at night.

Disorders of the autonomic nervous system are common in Parkinson's disease (PD). Earlier studies suggest that some nonmotor symptoms may fluctuate with the motor symptoms, but the possible interrelationship between motor phenomena and sweating has not been studied. The authors measured sweating by using an evaporimeter on three different areas of the body (right hand, left hand, chest) immediately before the morning PD medication (baseline), and thereafter hourly up to 4 hour, in 16 PD patients with wearing-off type of motor fluctuations and in 15 patients without clinical motor fluctuations. The clinical state of the patients was evaluated using the Unified Parkinson's Disease Rating Scale motor score every hour. Sweating increased during the 4-hour follow-up, and reached its maximum level at the time of the highest Unified Parkinson's Disease Rating Scale motor score phase (off-stage) in patients with wearing-off (initially affected hand, P = 0.007; left hand, P = 0.004; right hand, P = 0.034), but in the patients without wearing-off no changes in sweating were observed during the follow-up. Sweating of the left hand (P < 0.001), right hand (P < 0.001), and initially affected hand (P = 0.008) during the whole observation period was significantly higher in patients with motor fluctuations than in those without. The present study shows that sweating fluctuates in conjunction with wearing-off phenomenon.

Selegiline withdrawal decreased systolic BP significantly during the on-stage in a supine position as well as during the orthostatic test. The initial drop of BP in the orthostatic test was significantly smaller after selegiline withdrawal. The heart rate remained unaffected.