Cognitive Training and Transcranial Direct Current Stimulation for Mild Cognitive Impairment in Parkinson’s Disease: A Randomized Controlled Trial
Table 4
Tailored cognitive training + tDCS and control group cognitive performance at baseline, post-intervention, and follow-up.
Tailored cognitive training + tDCS
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
32.14
9.22
36.29
8.45
35.86
11.50
1.74
0.08
0.70
1.77
0.08
−0.12
SOC
5.29
1.03
7
2.07
8.57
2.20
2.29
0.02
0.19
3.86
0.001
0.92
LNS
17.63
2.54
18.25
1.99
19.24
1.96
0.72
0.47
0.02
2.21
0.03
0.22
Stroop test
29.95
11.50
30.66
6.97
32.38
7.10
0.18
0.86
0.14
0.87
0.39
−0.17
HVLT
21.04
2.70
24.90
2.28
25.19
5.30
5.21
0.001b
0.37
2.78
0.01b
0.22
Paragraph Recall
3.21
1.43
5.71
1.64
6.43
2.23
4.60
0.001
1.36
3.25
0.002
1.75
BNT
14
1.43
14.29
1.03
14.57
0.50
0.86
0.39
−0.18
−0.42
0.68
0.73
Similarities
22.89
3.18
26.03
2.25
20.75
2.20
3.73
0.001
1.06
−2.15
0.03
−1.58
JLO
22.33
7.71
22.47
6.31
22.04
7.13
0.12
0.91
0.06
−0.55
0.59
−0.28
HVOT
21.51
3.79
24.08
3.71
24.37
3.29
3.02
0.003b
0.54
2.76
0.01b
0.62
MMSE
26.37
1.99
26.51
1.38
26.37
1.54
0.21
0.84
0.61
0.00
1
0.19
PD-CRS
85.56
12.91
93.84
11.69
90.99
8.98
2.41
0.02b
0.51
2.66
0.01b
−0.02
PDQ-39
25.62
14.63
27.25
10.52
20.44
11.32
0.53
0.60
−0.14
−1.64
0.11
0.27
UPDRS-II
1.17
0.56
0.97
0.48
1.16
0.48
−1.47
0.14
0.34
−0.01
0.99
0.22
Control
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
30.14
15.45
27.43
9.94
36
19.16
−0.87
0.39
—
1.81
0.07
—
SOC
6
2.84
7.28
2.27
7.21
1.84
1.89
0.06
—
1.75
0.08
—
LNS
14.30
6.07
14.82
5.78
14.97
5.02
0.77
0.44
—
1.04
0.30
—
Stroop test
19.03
10.07
18.60
9.38
24.24
20.56
−0.34
0.74
—
0.86
0.39
—
HVLT
21.26
5.51
23.40
5.75
24.04
5.71
1.49
0.14
—
2.84
0.01b
—
Paragraph Recall
4.07
2.41
4.07
1.80
3.81
1.30
0.00
1
—
−0.36
0.72
—
BNT
12.43
1.99
13
1.76
11.87
1.84
3.06
0.003b
—
−0.87
0.39
—
Similarities
18.80
1.99
19.55
1.96
20.70
2.43
1.06
0.29
—
1.85
0.07
—
JLO
21.10
6.92
20.82
7.55
23.56
8.18
−0.37
0.71
—
1.38
0.17
—
HVOT
23.60
4.06
24.10
3.71
23.66
3.38
0.54
0.59
—
0.05
0.96
—
MMSE
24.38
2.07
24.38
2.16
25.82
2.31
−1.37
0.17
—
0.71
0.48
—
PD-CRS
76.50
19.35
77.50
14.81
82.22
20.21
0.33
0.74
—
3.21
0.002b
—
PDQ-39
24.02
14.52
23.76
14.92
24.59
11.81
−0.35
0.73
—
0.39
0.70
—
UPDRS-II
1.18
0.69
1.25
0.94
1.35
0.93
0.71
0.48
—
1.04
0.30
—
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.
