Kinematic Metrics from a Wireless Stylus Quantify Tremor and Bradykinesia in Parkinson’s Disease

Table 3

GEE estimates, mean values, and empirical standard errors, comparing on/on kinematic measures to off/off kinematic measures.

	DBS off LS mean (SE)	DBS on LS mean (SE)	Difference in estimate (SE)	Z
RMSrest Vel (%)	320.49 (0.62)	102.65 (0.26)	−217.83 (56.99)	−3.82	0.0001
RMSpostural Vel (%)	296.21 (0.52)	1.21 (0.32)	−174.79 (25.02)	−6.94	<0.0001
RMSSMT Acc (m/sec^2)	0.3875 (0.03)	0.5029 (0.05)	0.12 (0.04)	2.74	0.006
RMSSMT Vel (m/sec)	105.62 (13.2)	143.28 (14.52)	37.65 (12.71)	2.96	0.003
Peak Acc (m/sec^2)	0.2147 (0.11)	0.75 (0.23)	0.54 (0.24)	2.24	0.025
Peak Vel (m/sec)	346.66 (50.59)	433.73 (50.95)	87.07 (53.12)	1.64	0.101
Dwell time (sec)	0.45 (0.06)	0.33 (0.05)	−0.1231 (0.05)	−2.36	0.018
Frequency (Hz)	36.95 (2.46)	48.02 (3.92)	11.08 (3.70)	3.00	0.003
CV dwell time	0.98 (0.12)	0.84 (0.09)	−0.13 (0.089)	−1.45	0.146

Metric with a logarithmic relationship; significant metric (p < 0.05).