Parkinson’s Disease

Research Article

Cognitive Training and Transcranial Direct Current Stimulation for Mild Cognitive Impairment in Parkinson’s Disease: A Randomized Controlled Trial

Table 2

Standard cognitive training and tailored cognitive training group cognitive performance at baseline, post-intervention, and follow-up.


	Standard cognitive training						Pairwise comparison statistics
	Baseline		Post-intervention		Follow-up		Baseline to post-intervention			Baseline to follow-up

Outcome	M	SD	M	SD	M	SD	t	p	^a	t	p	^a
COWAT	38.86	13.89	44.14	11.40	42.20	13.60	1.81	0.07	0.70	1.31	0.19	−0.16
SOC	8.17	0.64	6.43	2.52	7.69	2.33	−1.90	0.06	−1.19	−0.51	0.61	−0.70
LNS	18.73	2.54	19.02	4.77	17.14	3.97	0.24	0.81	−0.04	−1.26	0.21	−0.42
Stroop test	33.83	6.20	36.11	6.76	36.16	5.31	0.82	0.42	0.35	1.67	0.10	−0.31
HVLT	22.08	5.41	26.94	5.35	27.44	2.33	3	0.003^b	0.46	2.76	0.01^b	0.44
Paragraph Recall	5	2.20	6.36	2.28	7.09	2.71	1.36	0.18	0.62	3.16	0.002	0.93
BNT	14.14	1.72	13.86	0.98	13.60	1.17	−0.73	0.43	−0.55	−0.79	0.43	0.01
Similarities	22.14	3.05	23.71	3.31	21.89	1.17	1.51	0.25	0.28	−0.30	0.76	−0.70
JLO	25.61	3.39	24.90	4.35	20.61	3.42	−0.71	0.48	−0.08	−2.94	0.004	−1.19
HVOT	24.49	3.76	25.21	3.45	26.07	2.96	0.84	0.40	0.06	1.38	0.17	0.36
MMSE	26.95	2.09	26.80	1.78	28.19	2.24	−0.19	0.85	0.41	0.86	0.39	−0.09
PD-CRS	89.42	10.28	96.13	9.12	100.09	8.94	1.42	0.16	0.44	2.29	0.02^b	0.28
PDQ-39	24.20	10.07	20.68	10.76	25.60	9.95	−3.05	0.003	0.24	0.71	0.48	0.06
UPDRS-II	0.96	0.77	0.73	0.74	0.85	0.74	−4.60	0.001	0.33	−1.55	0.13	0.36

	Tailored cognitive training						Pairwise comparison statistics
	Baseline		Post-intervention		Follow-up		Baseline to post-intervention			Baseline to follow-up

Outcome	M	SD	M	SD	M	SD	t	p	^a	t	p	^a
COWAT	32.43	16.59	34.71	12.19	37.17	21.27	0.56	0.58	0.42	0.96	0.34	−0.07
SOC	6.43	2.33	6.55	2.07	5.26	2.84	0.14	0.89	−0.51	−0.98	0.33	−0.85
LNS	17.39	4.43	18.87	3.10	19.81	2.70	1.95	0.06	0.19	3.30	0.001	0.30
Stroop test	31.89	9.01	35.17	10.65	31.83	9.49	1.42	0.16	0.34	−0.03	0.98	−0.51
HVLT	22.15	5.35	24.58	6.15	26.52	6.36	2.41	0.02^b	0.05	2.93	0.004^b	0.27
Paragraph Recall	5.64	2.20	7.36	3.50	7.23	3.21	2.21	0.03^b	0.58	1.35	0.18	0.74
BNT	13.14	1.25	13.86	1.25	13.78	1.05	1.48	0.14	0.09	1.14	0.26	0.66
Similarities	22.11	2.47	23.71	3.31	22.72	1.52	−0.03	0.98	−0.36	0.51	0.61	−0.54
JLO	20.25	3.55	22.97	4.32	22.32	3.87	2.13	0.04^b	0.49	1.94	0.06	−0.06
HVOT	20.37	3.76	23.22	3.45	23.19	5.35	3.35	0.001^b	0.61	2.62	0.01^b	0.65
MMSE	25.49	2.44	26.92	2.54	25.85	1.20	−2.70	0.01^b	0.98	0.55	0.59	−0.45
PD-CRS	86.58	12.72	95.29	21.44	98.61	18.28	2.31	0.02^b	0.39	3.64	0.001^b	0.35
PDQ-39	21.41	7.39	18.09	5.19	18.21	8.65	−2.46	0.02	0.26	−2.44	0.02	0.30
UPDRS-II	0.68	0.32	0.80	0.40	0.71	0.27	0.88	0.38	−0.06	0.17	0.87	−0.24

M = mean; SD = standard deviation; t = t statistic; a = effect size computed using change scores with the control group, positive effect favours corresponding intervention group; b = not statistically significant due to nonsignificant main effect; = ; = ; tDCS = transcranial direct current stimulation; COWAT = Controlled Oral Word Association Test; SOC = Stockings of Cambridge; LNS = Letter-Number Sequencing; HVLT = Hopkin’s Verbal Learning Test; BNT = Boston Naming Test; JLO = Judgement of Line Orientation; HVOT = Hooper’s Visual Orientation Test; MMSE = Mini-Mental State Examination; PD-CRS = Parkinson’s Disease—Cognitive Rating Scale; UPDRS-II = Unified Parkinson’s Disease Rating Scale—Section II (ADL); PDQ-39 = Parkinson’s Disease Questionnaire-39.