Effects of repetitive transcranial magnetic stimulation on electroencephalogram and memory function in patients with mild cognitive impairment

Table 1 Comparison of general characteristics

	Control group (n = 82)	Research group (n = 98)	t/χ² value	P value
Gender (male/female)	46/36	49/49	0.666	0.414
Age (years)	63.57 ± 3.59	64.17 ± 4.33	1.001	0.318
Body mass index (kg/m2)	23.03 ± 1.21	23.33 ± 1.31	1.583	0.115
Disease duration (years)	2.38 ± 1.01	2.32 ± 0.96	0.408	0.684
Duration of education (years)	9.93 ± 1.49	9.81 ± 1.77	0.486	0.627
Marital status			0.030	0.862
Married	50	61
Unmarried/divorced	32	37
Hypertension	31	40	0.170	0.681
Diabetes	28	35	0.0482	0.826
Hyperlipidemia	35	37	0.452	0.502

Measurement data were conducted using the t-test; counting data were conducted using χ² test.

Table 2 Changes in memory quotient and memory scores in both groups

		Memory quotient	Long-term memory	Short-term memory	Immediate memory
Before treatment	Control group (n = 82)	75.41 ± 11.83	19.74 ± 6.92	26.95 ± 10.52	4.59 ± 1.78
	Research group (n = 98)	75.66 ± 10.01	19.51 ± 6.79	27.63 ± 8.32	4.60 ± 2.38
	t value	0.154	0.224	0.484	0.031
	P value	0.878	0.822	0.629	0.975
After treatment	Control group (n = 82)	75.51 ± 10.00	20.73 ± 6.13	28.27 ± 8.19	4.67 ± 2.09
	Research group (n = 98)	86.53 ± 9.34a	23.62 ± 5.52a	33.93 ± 9.06a	5.12 ± 1.85
	t value	7.633	3.326	4.359	1.596
	P value	< 0.0001	0.001	< 0.0001	0.112
Net increase	Control group (n = 82)	0.13 ± 11.96	0.99 ± 9.27	0.63 ± 9.25	0.09 ± 2.84
	Research group (n = 98)	10.87 ± 7.53	4.11 ± 8.03	5.09 ± 11.77	0.52 ± 2.68
	t value	7.324	2.419	2.786	1.043
	P value	< 0.0001	0.017	0.005	0.298

^aP < 0.05 vs research group before treatment using t-test.

Table 3 Comparison of changes in Wechsler Memory Scale-Revised Chinese version subscale scores

	Control group (n = 82)			Research group (n = 98)
	Before treatment	After treatment	Net increase	Before treatment	After treatment	Net increase
Forward digit span (1–100)	7.05 ± 1.02	7.13 ± 1.92	0.09 ± 2.18	7.20 ± 2.58	7.93 ± 2.35a,b	0.72 ± 3.30
Backward digit span (100–1)	5.22 ± 1.86	5.49 ± 1.73	0.27 ± 2.46	5.43 ± 2.13	6.55 ± 1.76a,b	1.12 ± 2.05b
Cumulative calculations	7.03 ± 1.65	7.38 ± 2.11	0.35 ± 2.62	7.09 ± 2.32	8.00 ± 1.75a,b	0.91 ± 2.67
Visual recognition	6.09 ± 1.74	6.50 ± 1.95	0.41 ± 2.41	6.14 ± 2.17	7.09 ± 2.10a,b	0.95 ± 3.04
Visual reproduction	3.65 ± 1.50	3.74 ± 2.00	0.10 ± 2.57	3.59 ± 1.64	4.54 ± 2.06a,b	0.95 ± 2.58b
Associative learning	4.35 ± 1.96	4.78 ± 1.85	0.43 ± 2.66	4.43 ± 1.98	5.42 ± 1.77a,b	1.00 ± 2.66
Comprehension memory	5.50 ± 1.23	5.46 ± 1.37	-0.04 ± 1.97	5.46 ± 1.66	6.18 ± 1.47a,b	0.72 ± 2.12b
Digit span	4.78 ± 1.75	4.91 ± 1.81	0.13 ± 2.25	5.01 ± 1.82	5.82 ± 1.95a,b	0.81 ± 2.52

^aP < 0.05 vs research group before treatment.

^bP < 0.05 vs control group, t-test were used for comparison.

Table 4 Comparison of event-related potential-P300 latency and amplitude between the two groups

	Latency (ms)		t value	P value	Amplitude (uv)		t value	P value
	Before treatment	After treatment			Before treatment	After treatment
Control group (n = 82)	338.31 ± 18.79	341.34 ± 16.42	1.100	0.273	3.45 ± 0.99	3.63 ± 1.27	1.101	0.313
Research group (n = 98)	341.21 ± 16.47	312.18 ± 14.07	13.267	< 0.0001	3.48 ± 1.00	5.66 ± 1.20	13.816	< 0.0001
t value	1.103	12.831			0.201	11.006
P value	0.271	< 0.0001			0.841	< 0.0001

Measurement data were conducted using the t-test.

Table 5 Comparison of electroencephalogram improvement

		I	II	III	IV	V
Before treatment	Control group (n = 82)	13	57	12	0	0
	Research group (n = 98)	17	65	16	0	0
	χ² value	0.209
	P value	0.901
After treatment	Control group (n = 82)	15	37	30	0	0
	Research group (n = 98)	28	63	7	0	0
	χ² value	23.752
	P value	< 0.0001

Counting data were conducted using the χ² test.

Table 6 Comparison of adverse reactions, n (%)

	Diarrhea	Nausea and vomiting	Mild dizziness	Total incidence
Control group (n = 82)	3	6	7	16 (19.5)
Research group (n = 98)	1	4	3	8 (8.2)
χ² value				4.976
P value				0.026

Counting data were conducted using the χ² test.