. Author manuscript; available in PMC: 2013 Jul 31.

Published in final edited form as: J Neurol Neurosurg Psychiatry. 2010 Sep 22;82(10):1122–1124. doi: 10.1136/jnnp.2010.209783

Table 1.

Characteristics of dominant and non-dominant-side onset groups

Patients with asymmetrical onset (n=1015)	Side of onset		p Values
Patients with asymmetrical onset (n=1015)	Dominant (n=575)	Non-dominant (n=440)	p Values
Age (years) at symptom onset, mean (SD)	57.3 (11.1)	57.1 (11.2)	0.86
Disease duration (mo), mean (SD)	87.2(68.2)	82.5 (66.8)	0.27
Time (mo) to diagnosis, mean (SD)	21.5 (25.4)	18.4 (21.4)	0.038
Initial motor symptom, n (%)
Tremor	380 (66.1)	292 (66.4)	0.0001
Bradykinesia	101 (17.6)	40 (9.1)^*
Rigidity	53 (9.2)	54 (12.3)
Gait difficulty	23 (4.0)	40 (9.1)^*
Other	18 (3.1)	14 (3.2)

Patients with asymmetrical onset and complete UPDRS (Part I–III) scores (n=909)	Side of onset		p Values
	Dominant (n=508)	Non-dominant (n=401)	p Values
Corrected UPDRS Part I, mean	0.035	0.037	0.68
Corrected UPDRS Part II, mean	0.223	0.209	0.39
Dominant hand subscore, mean	0.095	0.075	0.004
Corrected UPDRS Part III, mean	0.591	0.664	0.21

In individual comparisons, the percentages of patients initially presenting with bradykinesia and gait difficulty were significantly different in the dominant and non-dominant-side onset groups (p<0.001).

Mo, months; UPDRS, Unified Parkinson Disease Rating Scale.