Table 1.

HRV Time domain parameters evaluated in PD patients and controls

Variables	Description (unit)
SDNN 24	Standard deviation (SD) of all NN intervals (ms)
SDNN D
SDNN N
pnn50 24	Percentage of successive RR intervals that differ by more than 50 ms (%)
pnn50 D
pnn50 N
rMSS 24	Root mean square of successive RR interval differences (ms)
rMSS D
rMSS N
SDANN	Standard deviation of the average NN intervals for each 5 min segment of a 24 h HRV recording (ms)
ISDNN	Mean of the Standard deviation of all NN intervals for all 5 min segments of the entire recording (ms)

PD Parkinson’s disease, D day, N: night