Table 2 Mean, standard deviation (SD) and interquartile range (IQR) [25 ^th percentile; 75 ^th percentile] for the amplitude of contact heat evoked potentials of the volar forearm (2a) and the pooled cheek (right and left cheek, 2b) of migraine patients and healthy controls for trains without and with performing the calculation task for blocks 1 to 4 of train 1 and train 2

a

Volar forearm without performing the calculation task

Migraine patients

Healthy controls

Amplitude (μV)

Mean

SD

IQR

Mean

SD

IQR

Ampl_1_1

56.33

22.38

[48.80; 77.50]

66.09

24.93

[51.38; 79.28]

Ampl_1_2

48.57

25.73

[31.00; 76.70]

56.21

24.58

[40.93; 75.82]

Ampl_1_3

43.78

22.73

[29.20; 58.10]

51.11

27.48

[41.10; 55.10]

Ampl_1_4

43.32

22.27

[29.60; 61.10]

47.39

22.92

[35.08; 66.35]

Ampl_2_1

47.55

20.33

[33.30; 98.50]

57.36

26.81

[47.20; 80.05]

Ampl_2_2

42.30

18.59

[28.36; 59.80]

48.51

24.06

[40.58; 59.03]

Ampl_2_3

43.15

20.76

[24.75; 63.30]

47.32

23.96

[34.20; 65.10]

Ampl_2_4

36.50

18.02

[25.20; 48.60]

49.05

23.59

[28.88; 58.75]

p value of train 1 (power)

p = 0.006 (0.74)

chi-square = 9.579; df = 2

p < 0.001 (0.94)

chi-square = 20.667; df = 2

p value of train 2 (power)

p = 0.001 (0.73)

chi-square = 13.875; df = 2

p = 0.001 (0.32)

chi-square = 14.632; df = 2

Volar forearm with performing the calculation task

Migraine patients

Healthy controls

Amplitude (μV)

Mean

SD

IQR

Mean

SD

IQR

Ampl_1_1

35.80

13.60

[32.20; 57.45]

39.96

29.61

[21.04; 60.38]

Ampl_1_2

34.75

15.33

[32.42; 59.58]

39.69

29.23

[21.37; 55.70]

Ampl_1_3

29.56

13.21

[21.52; 47.58]

34.43

24.98

[20.99; 55.75]

Ampl_1_4

30.30

11.85

[26.63; 48.80]

30.95

25.74

[16.93; 50.00]

Ampl_2_1

36.80

13.41

[32.99; 47.63]

44.87

35.63

[23.51; 52.35]

Ampl_2_2

32.15

12.41

[23.38; 44.78]

39.04

25.35

[23.27; 56.53]

Ampl_2_3

32.40

11.27

[26.82; 44.25]

31.29

27.05

[20.11; 45.88]

Ampl_2_4

29.78

8.98

[22.26; 38.48]

42.24

26.86

[18.72; 66.38]

p value of train 1 (power)

p = 0.176 (0.49)

chi-square = 4.000; df = 2

p = 0.018 (0.31)

chi-square = 9.385; df = 2

p value of train 2 (power)

p = 0.199 (0.80)

chi-square = 4.500; df = 2

p = 0.662 (0.06)

chi-square = 1.500 ; df = 2

b

Pooled cheek without performing the calculation task

Migraine patients

Healthy controls

Amplitude (μV)

Mean

SD

IQR

Mean

SD

IQR

Ampl_1_1

53.07

20.41

[38.44; 68.10]

55.91

24.72

[41.77; 69.05]

Ampl_1_2

44.85

17.99

[31.56; 54.63]

43.74

16.83

[32.04; 50.83]

Ampl_1_3

41.76

18.05

[29.98; 49.60]

44.82

18.82

[34.23; 54.35]

Ampl_1_4

39.15

22.90

[27.27; 49.00]

40.24

14.69

[29.85; 51.39]

Ampl_2_1

40.20

15.53

[27.89; 55.10]

44.00

18.43

[30.20; 59.70]

Ampl_2_2

35.38

12.89

[27.64; 44.45]

38.84

13.15

[27.30; 47.70]

Ampl_2_3

36.61

16.55

[24.59; 46.40]

36.80

11.86

[30.60; 40.70]

Ampl_2_4

34.10

14.50

[21.94; 44.77]

36.47

14.57

[25.51; 48.70]

p value of train 1 (power)

p < 0.001 (0.99)

chi-square = 24.057; df = 2

p = 0.001 (0.999)

chi-square = 15.895; df = 2

p value of train 2 (power)

p = 0.007 (0.75)

chi-square = 9.235; df = 2

p = 0.038 (0.84)

chi-square = 6.359; df = 2

Pooled cheek with performing the calculation task

Migraine patients

Healthy controls

Amplitude (μV)

Mean

SD

IQR

Mean

SD

IQR

Ampl_1_1

31.72

11.30

[25.40; 44.25]

36.16

21.46

[20.74; 53.10]

Ampl_1_2

28.53

9.90

[25.49; 38.85]

31.83

14.08

[21.04; 42.55]

Ampl_1_3

25.83

9.29

[20.68; 37.10]

30.08

12.77

[19.44; 44.19]

Ampl_1_4

26.71

6.26

[22.39; 32.25]

26.76

8.37

[19.95; 34.27]

Ampl_2_1

34.73

12.22

[24.20; 46.40]

32.07

18.22

[18.80; 49.00]

Ampl_2_2

31.42

9.38

[27.28; 38.30]

27.17

11.60

[19.51; 69.91]

Ampl_2_3

27.87

8.27

[20.30; 34.00]

26.75

11.90

[18.88; 37.80]

Ampl_2_4

25.45

10.05

[16.33; 32.10]

25.66

10.29

[19.92; 34.87]

p value of train 1 (power)

p = 0.401 (0.96)

chi-square = 3.000; df = 2

p = 0.010 (1.00)

chi-square = 8.957; df = 2

p value of train 2 (power)

p < 0.001 (0.999)

chi-square = 16.300; df = 2

p = 0.287 (0.70)

chi-square = 3.111; df = 2