Supplemental Table 1 PainDETECT score adjusted with respect to age at investigation and pain duration
Parameter ALBP
(N = 63)
CDRS (N = 23)
LSS
(N = 25) p1 Post-hoc
PainDETECT score (0-38 scale) 7.6 (± 4.7) 11.8 (± 6.9) 11.6 (± 6.0) < 0.001 a/b/b
≤ 12 negative 55 (87.3%) 11 (47.8%) 13 (52.0%)
< 0.001 a/b/b 13-18 unclear 6 (9.5%) 8 (34.8%) 11 (44.0%)
≥ 19 positive 2 (3.2%) 4 (17.4%) 1 (4.0%)
Data are presented as absolute and relative frequencies or mean (± SD)
1
The p-values are based on ANCOVA for continuous variables or Fisher’s exact test for other variables; same letters
denote homogeneous groups (post-hoc analysis with Bonferroni adjustment).
Supplemental Table 2 Quantitative sensory testing – results, QST parameters are adjusted with respect to pain duration
QST parameters Controls
(N = 74)
ALBP (N = 63)
CDRS (N = 23)
LSS
(N = 25) p1 Post-hoc affected root affected root
CDT Z-score -0.46 (± 0.94) -0.31 (± 1.12) -1.35 (± 0.98) -1.28 (± 1.09) < 0.001 a/a/b/b
Normal 71 (95.9%) 58 (92.1%) 18 (78.3%) 19 (76.0%)
0.007 a/ab/ab/b
Abnormal (loss) 3 (4.1%) 5 (7.9%) 5 (21.7%) 6 (24.0%)
WDT Z-score -0.71 (± 1.07) -0.61 (± 1.20) -1.57 (± 0.93) -1.26 (± 0.62) < 0.001 a/a/b/ab
Normal 64 (86.5%) 57 (90.5%) 17 (73.9%) 21 (84.0%)
0.255 Abnormal (loss) 10 (13.5%) 6 (9.5%) 6 (26.1%) 4 (16.0%)
TSL Z-score -0.65 (± 1.01) -0.51 (± 1.05) -1.45 (± 0.93) -1.28 (± 0.83) < 0.001 a/a/b/b
Normal 67 (90.5%) 59 (93.7%) 19 (82.6%) 22 (88.0%)
0.422
Abnormal (loss) 7 (9.5%) 4 (6.3%) 4 (17.4%) 3 (12.0%)
CPT Z-score -0.12 (± 1.13) -0.07 (± 1.04) -0.26 (± 1.06) -0.42 (± 0.85) 0.522
Normal 73 (98.6%) 62 (98.4%) 22 (95.7%) 25 (100.0%)
0.585
Abnormal (gain) 1 (1.4%) 1 (1.6%) 1 (4.3%) 0 (0.0%)
Abnormal (loss) 0 (0.0%) 0 (0.0%) 0 (0.0%) 0 (0.0%)
HPT Z-score -0.61 (± 1.14) -0.28 (± 1.43) -0.90 (± 0.89) -1.29 (± 0.62) 0.003 ab/a/ab/b
Normal 64 (86.5%) 58 (92.1%) 20 (87.0%) 25 (100.0%)
0.223
Abnormal (gain) 2 (2.7%) 3 (4.8%) 0 (0.0%) 0 (0.0%)
Abnormal (loss) 8 (10.8%) 2 (3.2%) 3 (13.0%) 0 (0.0%)
PHS Normal (absent) 72 (97.3%) 47 (74.6%) 13 (56.5%) 13 (52.0%)
< 0.001 a/b/b/b Abnormal (present) 2 (2.7%) 16 (25.4%) 10 (43.5%) 12 (48.0%)
VDT Z-score 0.14 (± 0.70) 0.11 (± 1.54) -0.91 (± 2.07) -0.57 (± 1.56) 0.002 a/a/b/ab
Normal 73 (98.6%) 58 (92.1%) 18 (78.3%) 19 (76.0%)
< 0.001 a/ab/b/b
Abnormal (loss) 1 (1.4%) 5 (7.9%) 5 (21.7%) 6 (24.0%)
QST summary*
No abnormalities 53 (71.6%) 38 (60.3%) 8 (34.8%) 8 (32.0%)
< 0.001 a/ab/b/b At least 1 abnormality 21 (28.4%) 25 (39.7%) 15 (65.2%) 17 (68.0%)
At least 2 abnormalities 9 (12.2%) 10 (15.9%) 10 (43.5%) 10 (40.0%) < 0.001 a/ab/b/b At least 3 abnormalities 4 (5.4%) 3 (4.8%) 5 (21.7%) 2 (8.0%) 0.073
Clusters Any thermal loss† 11 (14.9%) 9 (14.3%) 8 (34.8%) 8 (32.0%) 0.049 a/a/b/b Pure thermal loss†† 11 (14.9%) 6 (9.5%) 6 (26.1%) 7 (28.0%) 0.087
Pure VDT loss††† 1 (1.4%) 2 (3.2%) 3 (13.0%) 5 (20.0%) 0.003 a/ab/ab/b Any thermal loss and VDT loss 0 (0.0%) 3 (4.8%) 2 (8.7%) 1 (4.0%) 0.064
Any thermal loss and/or VDT loss 12 (16.2%) 11 (17.5%) 11 (47.8%) 13 (52.0%) < 0.001 a/ab/bc/c Any thermal loss
and/or PHS and/or VDT loss 14 (18.9%) 22 (34.9%) 15 (65.2%) 17 (68.0%) < 0.001 a/ab/bc/c
Any thermal gain# 2 (2.7%) 4 (6.3%) 1 (4.3%) 0 (0.0%) 0.565
Data are presented as absolute and relative frequencies or mean (± SD).
1
The p-values are based on ANCOVA for continuous variables or Fisher’s exact test for categorical variables comparing values in four groups (controls, ALBP, affected root in CDRS, affected root in LSS); same letters denote homogeneous groups (post-hoc analysis with Bonferroni adjustment).
* Hypoesthesia to thermal stimuli and/or vibration (i.e. loss of detection in CDT, WDT, TSL, VDT) and/or hyper- or hypoalgesia to thermal stimuli (i.e. either gain or loss of function in CPT, HPT) and/or gain in PHS were taken into account in the definition of abnormality.
†
Any thermal loss: Hypoesthesia to thermal stimuli (i.e. loss of detection in CDT, WDT, TSL).
††
Pure thermal loss: Hypoesthesia to thermal stimuli (i.e. loss of detection in CDT, WDT, TSL) in combination with normal VDT.
†††
Pure VDT loss: Loss of detection in VDT in combination with normal CDT, WDT, TSL.
#
Any thermal gain: gain in CPT and/or HPT.
Loss function: z-scores <-1.96, Gain function: z-scores >1.96
QST – quantitative sensory testing, CDT – cold detection threshold, WDT – warm detection threshold, TSL – thermal
sensory limen, CPT – cold pain threshold, HPT – heat pain threshold, PHS – paradoxical heat sensation, VDT –
vibration detection threshold
Supplemental Table 3 Quantitative sensory testing – results, QST parameters are adjusted with respect to pain duration
QST parameters Controls
(N = 74)
CDRS
(N = 23) p1 p2 LSS
(N = 25) p1 p2
contra-lateral root contra-lateral root
CDT Z-score -0.34 (± 0.94) -0.57 (± 0.97) < 0.001 0.324 -0.52 (± 1.12) 0.013 0.475
Normal 71 (95.9%) 22 (95.7%)
0.125 0.999 21 (84.0%)
0.687 0.066
Abnormal (loss) 3 (4.1%) 1 (4.3%) 4 (16.0%)
WDT Z-score -0.73 (± 1.07) -0.77 (± 0.92) < 0.001 0.840 -1.03 (± 0.77) 0.054 0.138
Normal 64 (86.5%) 22 (95.7%)
0.063 0.451 22 (88.0%)
0.999 0.999
Abnormal (loss) 10 (13.5%) 1 (4.3%) 3 (12.0%)
TSL Z-score -0.60 (± 1.01) -0.62 (± 0.79) < 0.001 0.910 -0.80 (± 0.85) 0.011 0.331
Normal 69 (93.2%) 23 (100.0%)
0.125 0.335 23 (92.0%)
0.999 0.999
Abnormal (loss) 5 (6.8%) 0 (0.0%) 2 (8.0%)
CPT Z-score -0.07 (± 1.13) -0.09 (± 1.05) 0.421 0.955 -0.12 (± 0.96) 0.131 0.856
Normal 72 (97.3%) 23 (100.0%)
0.999 0.999
25 (100.0%)
0.999 0.999
Abnormal (gain) 2 (2.7%) 0 (0.0%) 0 (0.0%)
Abnormal (loss) 0 (0.0%) 0 (0.0%) 0 (0.0%)
HPT Z-score -0.59 (± 1.14) -0.44 (± 1.09) 0.051 0.561 -1.08 (± 0.86) 0.119 0.030
Normal 64 (86.5%) 22 (95.7%)
0.625 0.304
25 (100.0%)
0.999 0.196
Abnormal (gain) 2 (2.7%) 1 (4.3%) 0 (0.0%)
Abnormal (loss) 8 (10.8%) 0 (0.0%) 0 (0.0%)
PHS Normal (absent) 72 (97.3%) 14 (60.9%)
0.999 < 0.001 19 (76.0%)
0.146 0.003
Abnormal (present) 2 (2.7%) 9 (39.1%) 6 (24.0%)
VDT Z-score 0.16 (± 0.70) -0.39 (± 1.29) 0.297 0.063 -0.28 (± 1.48) 0.136 0.161
Normal 73 (98.6%) 22 (95.7%)
0.219 0.420 21 (84.0%)
0.500 0.014
Abnormal (loss) 1 (1.4%) 1 (4.3%) 4 (16.0%)
QST summary*
No abnormalities 52 (70.3%) 14 (60.9%)
0.180 0.447 14 (56.0%)
0.109 0.224
At least 1 abnormality 22 (29.7%) 9 (39.1%) 11 (44.0%)
At least 2 abnormalities 8 (10.8%) 3 (13.0%) 0.039 0.719 6 (24.0%) 0.344 0.180
At least 3 abnormalities 3 (4.1%) 1 (4.3%) 0.125 0.999 2 (8.0%) 0.999 0.598
Clusters Any thermal loss† 11 (14.9%) 2 (8.7%) 0.031 0.727 5 (20.0%) 0.375 0.542
Pure thermal loss†† 11 (14.9%) 1 (4.3%) 0.063 0.283 5 (20.0%) 0.625 0.542
Pure VDT loss††† 1 (1.4%) 0 (0.0%) 0.250 0.999 4 (16.0%) 0.999 0.014
Any thermal loss and VDT loss 0 (0.0%) 1 (4.3%) 0.999 0.237 0 (0.0%) 0.999 0.999
Any thermal loss and/or VDT loss 12 (16.2%) 2 (8.7%) 0.004 0.508 9 (36.0%) 0.219 0.049 Any thermal loss and/or PHS and/or VDT loss 14 (18.9%) 9 (39.1%) 0.180 0.055 11 (44.0%) 0.109 0.018
Any thermal gain# 3 (4.1%) 1 (4.3%) 0.999 0.999 0 (0.0%) - 0.569
Data are presented as absolute and relative frequencies or mean (± SD).
1
The p-values are based on paired t-test for continuous variables or McNemar’s test for categorical variables comparing values of affected and contra-lateral roots in CDRS and LSS groups separately.
2
The p-values are based on two-sample t-test for continuous variables or Fisher’s exact test for categorical variables comparing values in controls and CDRS (contra-lateral roots), and in controls and LSS (contra-lateral roots).
* Hypoesthesia to thermal stimuli and/or vibration (i.e. loss of detection in CDT, WDT, TSL, VDT) and/or hyper- or hypoalgesia to thermal stimuli (i.e. either gain or loss of function in CPT, HPT) and/or gain in PHS were taken into account in the definition of abnormality.
†
Any thermal loss: Hypoesthesia to thermal stimuli (i.e. loss of detection in CDT, WDT, TSL).
††
Pure thermal loss: Hypoesthesia to thermal stimuli (i.e. loss of detection in CDT, WDT, TSL) in combination with normal VDT.
†††
Pure VDT loss: Loss of detection in VDT in combination with normal CDT, WDT, TSL.
#