Table 2

Neurological and neuropsychological data, and quality of life for the three groups at baseline and 3 mFU

			Group-neg (n=8)	Group-mix (n=8)	Group-pos (n=14)	F/χ²	p Value
Neurological data
UPDRS-III	Med on	Baseline	16.00±4.14	20.88±7.36	23.57±12.75	2.333^b	0.312
UPDRS-III	Med off	Baseline	39.88±7.97	40.00±11.89	46.79±16.09	0.985^a	0.386
	Stim on and med off	3 mFU	28.63±10.47**	28.13±9.13*	24.77±18.11***§	0.232^a	0.795
LEDD (mg)		Baseline	900.75±576.63	806.25±371.63	709.86±340.60	0.534^a	0.593
		3 mFU	479.58±299.94*	250.42±243.01**	326.36±116.41**	2.000^b	0.368
Neuropsychological data
Digit span forwards T-scores		Baseline	58.13±9.46	57.86±9.25§	53.86±11.26	0.581^a	0.566
		3 mFU	52.50±13.31	53.25±5.87	49.79±12.59	0.280^a	0.758
Digit span backward T-scores		Baseline	49.00±11.59	43.43±6.13§	47.14±9.35	0.677^a	0.517
		3 mFU	49.13±12.68	41.88±19.78	45.15±7.16	0.866^b	0.649
Verbal fluency (letters) T-scores		Baseline	54.58±8.75	47.67±9.06§	49.93±10.25	1.050^a	0.364
		3 mFU	47.87±6.88*	46.63±9.95	50.02±10.95	0.333^a	0.720
Brief test of attention raw scores		Baseline	11.88±4.12	9.86±3.53§	10.14±4.69	0.535^a	0.592
		3 mFU	9.00±4.14	11.25±3.06	10.07±4.83	0.560^a	0.578
Quality of life
PDQ-39		Baseline	47.09±19.46	34.71±16.05	33.58±13.55	2.001^a	0.155
		3 mFU	43.17±14.01†,‡,§	20.44±9.28†*	21.56±12.06‡**	9.143^a	0.001

Values represent means±SD. p Values by ^a ANOVA (F) or ^b Kruskall–Wallis H-test (χ²).
*Represent significant changes for paired samples t test for UPDRS-III (baseline med off vs 3 mFU stim on/med off), LEDD, PDQ-39 and verbal fluency data within a group, *<0.05, **<0.01, ***<0.001.
†Bonferroni posthoc test: significant difference between group-neg and group-mix.
‡Bonferroni posthoc test: significant difference between group-neg and group-pos.
§Missing data for one patient.
N, number of patients; group-neg, subjective outcome negative; group-mix, subjective outcome mixed; group-pos, subjective outcome positive; med off, medication off; stim on, stimulation on; 3 mFU, 3 months follow-up; UPDRS, Unified Parkinson's Disease Rating Scale-III; LEDD, l-dopa equivalent daily dose; PDQ-39, Parkinson's Disease Questionnaire-39.
Test score range: UPDRS-III, 0–108, higher scores equal more impairment; digit span forwards, 0–100, higher scores equal better performance; digit span backwards, 0–100, higher scores equal better performance; verbal fluency (letters), 0–100, higher scores equal better performance; brief test of attention, 0–20, higher scores equal better performance; PDQ-39, 0–100, higher scores equal more impaired quality of life.