Supplementary Table 1: Demographic characteristics of patients with chronic post-surgical sciatica Sex,
age (years)
Pain aetiology Duration of pain/sensory disturbances (years)
Pain distribution Surgery Distribution of sensory disturbances
Meets CRPS clinical criteria a
CRPS-like features in the symptomatic limb b
Medication
F, 63 ankle fracture, immobilisation
9 / 1 Lower back, R hip, lateral leg, lateral foot
L4-5 discectomy Post-surgery: paraesthesia and hypoaesthesia R lateral foot
No Hot skin Gabapentin,
tapentadol
F, 38 disc rupture, surgery
8 / 6 L buttock, posterior leg, plantar foot
L5S1 discectomy;
L5S1 laminectomy
Post-surgery: paraesthesia and hypoaesthesia L heel, toes, thigh
No Tremor, muscle jerks, muscle weakness, cold skin
Tapentadol, duloxetine
M, 58 disc
degeneration
6 / 5 R lower back, lateral calf, first toe
L1-2 laminectomy; L2-3
laminectomy
Post-surgery: hypoaesthesia R toes 2, 3, 4
No Hot skin, swollen foot, muscle weakness, sweating
-
M, 54 disc rupture, surgery
3 / 2 R lateral leg, lateral foot
L4-5 discectomy Post-surgery: paraesthesia and hypoaesthesia R lateral leg, lateral foot
No Hot skin Tapentadol,
NSAID
F, 39 disc rupture 5 / 4.5 R posterior leg, plantar foot
Multiple laminectomies, discectomies
Before surgery: paraesthesia and hypoaesthesia R foot, calf
No Hot skin, tremor, muscle weakness, heat hyperalgesia
NSAID
F, 52 disc protrusion, surgery
11 / 5 R buttock, lateral leg, lateral foot
L4-5 L5S1 discectomy and spinal fusion;
laminectomy and
decompression L5S1 nerve roots
Before surgery: paraesthesia in R foot. Post-surgery:
hypoaesthesia R toes 3, 4, 5
No Cold hyperalgesia, dysaesthesia
NSAID
F, 62 disc protrusion, surgery
12 / .5 L ventral thigh and ankle
Multiple discectomies, foraminectomy, L4-5 L5S1
spacers inserted
Post-surgery: paraesthesia and hypoaesthesia L buttock, posterior thigh to ankle
No Pressure
hyperalgesia, cold skin
Tramadol
F, 51 disc rupture, surgery
16 / 12 Lower back, R dorsal thigh, calf
microdiscectomy;
insertion of spacers at L4-5
L5S1;revision of spacers
Post-surgery: hypoaesthesia R calf to ankle
No Cold skin, pressure hyperalgesia
-
M, 72 disc
degeneration, surgery
12 / 8 Lower back, R lateral thigh, medial calf, foot
L5S1 spinal fusion; pedicle screw fixation; S1
decompression
Post-surgery: hypoaesthesia R toes 3, 4, 5
No Hot skin NSAID,
oxycodone with naloxone F, 53 disc
degeneration, surgery
31 / 1 Lower back, L lateral thigh and foot, plantar foot
L5S1 anterior interbody fusion
Post-surgery: increase in paraesthesia and
hypoaesthesia L lateral leg and lateral foot
No Hot or cold skin, muscle weakness, dysaesthesia
Tapentadol, NSAID, oxycodone with naloxone M, 74 disc
degeneration, surgery
50 / 10 L buttock, calf decompressions; L2-4
pedicle screw fusion;
revision surgery
Post-surgery: hypoaesthesia plantar surface and great toe L foot
No Cold skin, decreased toe movement
Gabapentin
F, 53 disc
degeneration
24 / 3 L buttock and medial thigh
L4-5 laminectomy; L5S1
spinal fusion
Before surgery: paraesthesia L leg, foot. Post-surgery:
weakness and altered sensation L foot
No Muscle weakness, hot skin
Gabapentin, pregabalin, tramadol
M, 62 disc rupture 30 / 5 Lower back, L posterior thigh, calf
Multiple laminectomies, discectomies
Before surgery: paraesthesia L calf, dorsum foot, weak dorsiflexion great toe intensified gradually
No Muscle weakness, cold skin
NSAID, gabapentin, prednisolone
M, 53 disc rupture, spinal fusion
22 / 12 L posterior leg, medial dorsum foot
L4S1 spinal fusion; pedicle screws removed
Post-surgery: paraesthesia and hypoaesthesia L medial dorsum foot
No Cold skin, dynamic allodynia, muscle weakness, heat hyperalgesia
Oxycodone, NSAID
M, 51 disc rupture, surgery
4 / 2 Lower back, L thigh, toes 2, 3, 4
L2-3 microdiscectomy Post-surgery: hypoaesthesia in L thigh
No dynamic allodynia, hot skin
Tramadol, duloxetine, lignocaine patch M, 61 disc
protrusion
18 / 18 R buttock, posterior thigh, lateral calf, foot
2009: discectomy Before surgery:
hypoaesthesia R lateral calf.
Post-surgery: paraesthesia
No - -
F, 46 spinal fusion for sciatica
19 / 19 L anterior thigh L4-5 fusion Post-surgery: altered sensation L posterior thigh,
No dynamic allodynia, cyanotic, muscle
-
F, 66 disc rupture, surgery
32 / 29 R lateral leg, medial foot
L4-5 L5S1 laminectomies;
L4-5 decompression
Post-surgery: hypoaesthesia R lateral thigh, calf, foot
Yes Muscle weakness, dynamic allodynia, cold skin, cyanotic, heat hyperalgesia, dysaesthesia, trophic changes
Gabapentin, oxycodone
F, 60 disc rupture, surgery
29 / 11 Lower back, L leg, foot
Multiple lumbar spine surgeries, artificial disc insertion L5S1
Post-surgery: hypoaesthesia L leg, foot
Yes Dynamic allodynia, swollen foot, cold skin, pallid or flushed, muscle weakness, spontaneous toe movements, hot skin, trophic changes
Gabapentin, oxycodone, NSAID
F, 64 spinal fusion for sciatica
23 / 23 R buttock, lateral leg, lateral foot
L4-5 fusion Post-surgery: hypoaesthesia R foot and toes
Yes Hot or cold skin, dynamic allodynia, muscle weakness, dystonia, cold skin, dysaesthesia
NSAID
M, 47 disc protrusion, surgery
15 / 1 Lower back, R medial foot
L4-5 microdiscectomy; L4-5
fusion, pedicle screw fixation
Before surgery: paraesthesia R calf, foot, hypoaesthesia R thigh. Post-surgery:
paraesthesia R anterior shin, R large toe, R foot drop
Yes Dynamic allodynia, cold skin, flushed, reduced toe dorsiflexion, trophic changes,
dysaesthesia
Gabapentin, oxycodone
M, 35 disc protrusion
4 / 2 Lower back, L lateral calf, ankle, foot, first toe
L5S1 anterior fusion; L4-5
disc arthroplasty
Before surgery: paraesthesia L lateral thigh, calf. Post- surgery: hypoaesthesia ankle and lateral foot
Yes Tremor, moving toes, hot skin, flushed, swollen foot, pressure hyperalgesia, pinprick hyperalgesia
Gabapentin, duloxetine, tramadol
F, 53 disc
degeneration, spinal fusion
30 / 12 R buttock, lateral and posterior thigh, calf, lateral and medial foot
L3-4 fusion; L5S1 fusion;
T9-10 fusion
Before surgery: paraesthesia and hypoaesthesia R dorsum foot
Yes Dynamic allodynia, swollen foot, cyanotic, spontaneous toe movements, cold skin, cold hyperalgesia, dysaesthesia
Oxycodone with naloxone, NSAID
F, 60 disc rupture, surgery
24 / 14 L posterior thigh, calf
L5S1 laminectomy Post-surgery: paraesthesia and hypoaesthesia L lateral dorsum foot
Yes Dynamic allodynia, swollen foot, sweating, hot skin, muscle weakness, pinprick
hyperalgesia, cold skin
Gabapentin, oxycodone with naloxone, duloxetine
F, 38 disc rupture, surgery
6 / 4 L buttock, L posterior thigh, lateral calf, foot
L5S1 discectomy, facetectomy;
microdiscetomy
Post-surgery: paraesthesia and hypoaesthesia L buttock, L posterior thigh intensified gradually
Yes Dynamic allodynia, hot skin, tremor, muscle jerks, muscle weakness, cold skin, cold hyperalgesia, pinprick
hyperalgesia, pressure hyperalgesia
Gabapentin, amitriptyline, NSAID
a Apart from Budapest criterion 4 (“there is no other diagnosis that better explains the signs and symptoms”), meets Budapest clinical criteria for
symptoms and signs of CRPS (continuing pain which is disproportionate to any inciting event and which is associated with symptoms in three or four of the sensory, vasomotor, sudomotor/oedema and motor trophic categories, and signs in two or more of these categories) [17].
b Symptoms are shown in normal print and signs are shown in bold print. Pinprick hyperalgesia, cold hyperalgesia and heat hyperalgesia were defined as a rating at least two steps higher on the 0-10 verbal pain rating scale for the symptomatic than contralateral foot. Pressure hyperalgesia was defined as a pressure-pain threshold at least 1 kg lower for the symptomatic than contralateral foot. Dysaesthesia refers to abnormal sensations evoked by brushing the symptomatic foot (e.g., sharp, tingling or unpleasant sensations but not outright pain). In patients with verified cold skin, the toes or dorsum of the symptomatic foot were at least 1oC cooler than the contralateral foot. In patients with verified hot skin, the toes or dorsum of the symptomatic foot were
Post-surgical sciatica patients with many additional CRPS-like features versus post-surgical sciatica patients with few or no CRPS-like features
QST findings were compared in 9 women and 8 men aged between 38 and 74 years (mean age ± standard deviation 55.4 ± 9.8 years) with chronic post- surgical sciatica associated with few or no CRPS-like features and 6 women and 2 men aged between 35 and 66 years (mean age 52.9 ± 11.8 years) with chronic post-surgical sciatica and many additional CRPS-like features (supplementary Table 2). Sex and age distributions were similar in both groups.
Supplementary Table 2: Sensitivity to mechanical and thermal stimulation in patients with chronic post-surgical sciatica with many versus few additional CRPS-like features
Mean ± Standard Deviation
Many CRPS-like features (N = 8) Few CRPS-like features (N = 17) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Pressure-pain threshold (kg)
Foot 1.4 ± .9 1.4 ± .4 2.3 ± 1.1 2.3 ± .9 6.66 * .00 .12
Hand 1.6 ± .6 1.6 ± .9 1.9 ± .7 2.0 ± 1.0 1.36 .34 .00
Forehead .7 ± .3 .9 ± .4 1.1 ± .5 1.2 ± .5 4.73 * 8.11 ** .01
Sharpness rating to pin (0-10)
Foot 3.6 ± 2.8 3.0 ± 1.3 2.9 ± 2.4 3.6 ± 2.3 .01 .03 2.01
Hand 3.8 ± 1.7 2.3 ± 1.7 2.0 ± 1.8 2.1 ± 2.4 2.08 1.62 1.91
Forehead 5.3 ± 2.6 4.6 ± 2.4 4.1 ± 2.1 3.1 ± 2.5 1.96 5.20 * .07
Sharpness rating to hair x 1 (0-10)
Foot .4 ± .9 1.1 ± .9 1.4 ± 1.7 2.2 ± 2.2 3.66 1.86 .03
Hand 1.7 ± 2.2 1.2 ± 1.6 1.1 ± 1.3 1.2 ± 1.6 .18 .43 1.46
Forehead 2.4 ± 1.5 2.1 ± 1.7 2.2 ± 2.2 2.2 ± 2.2 .01 .54 .74
Windup to hair x 5 (0-10)
Foot 1.4 ± 1.7 1.2 ± 1.3 .2 ± .8 -.1 ± .8 15.23 *** .71 .01
Hand 1.3 ± 1.2 .9 ± 1.1 .3 ± 1.5 .6 ± .8 3.62 .01 .96
Forehead 1.5 ± 1.2 1.0 ± .9 .3 ± 1.3 .1 ± .6 8.58 ** 1.69 .39
Touch threshold (arbitrary units)
Foot 11.3 ± 3.3 10.4 ± 2.5 10.9 ± 1.7 10.1 ± 1.7 .14 16.85 *** .25
Supplementary Table 2 continued Mean ± Standard Deviation
Many CRPS-like features (N = 8) Few CRPS-like features (N = 17) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Warmth threshold (Δ from 32oC)
Foot 5.5 ± 3.2 5.0 ± 3.7 6.3 ± 2.4 5.0 ± 3.2 .09 2.38 .48
Hand 1.5 ± .9 1.8 ± 1.1 5.0 ± 3.6 4.2 ± 3.6 4.71 * .42 1.80
Forehead 1.9 ± 1.7 2.3 ± 1.9 2.9 ± 2.5 3.2 ± 2.7 .82 1.14 .18
Cold threshold (Δ from 32oC)
Foot -6.5 ± 3.5 -6.1 ± 4.2 -6.8 ± 3.9 -6.2 ± 3.9 .02 .66 .03
Hand -2.0 ± 1.7 -1.5 ± 1.0 -3.9 ± 3.7 -3.6 ± 2.7 2.52 .74 .03
Forehead -.9 ± 1.1 -2.0 ± 2.9 -1.4 ± 1.3 -1.5 ± 1.9 .00 2.80 1.67
Heat-pain threshold (Δ from 32oC)
Foot 8.6 ± 3.2 8.5 ± 4.1 9.3 ± 2.3 8.1 ± 2.7 .02 1.32 .79
Hand 6.7 ± 3.8 7.4 ± 3.7 9.3 ± 2.7 8.9 ± 3.1 2.26 .09 1.05
Forehead 7.1 ± 3.3 a 8.6 ± 2.9 9.2 ± 2.1 8.8 ± 1.6 1.44 3.21 9.89 **
Cold-pain threshold (Δ from 32oC)
Foot -20.4 ± 12.3 -18.7 ± 11.0 -25.0 ± 11.3 -25.1 ± 11.4 1.22 .38 .47
Hand -13.3 ± 10.8 -19.4 ± 12.0 -21.6 ± 11.0 -20.0 ± 10.2 .91 1.79 5.50 *
Forehead -13.8 ± 8.0 -14.8 ± 11.3 -17.2 ± 8.3 -16.7 ± 8.5 .50 .04 .33
Supplementary Table 2 continued Mean ± Standard Deviation
Many CRPS-like features (N = 8) Few CRPS-like features (N = 17) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Heat rating to 40oC (0-10)
Foot 3.2 ± 3.2 3.0 ± 2.6 2.8 ± 2.6 a 5.0 ± 2.5 .62 3.40 4.75 *
Hand 5.6 ± 2.5 5.0 ± 1.6 3.7 ± 2.3 4.0 ± 2.7 2.17 .09 1.64
Forehead 4.9 ± 3.7 5.2 ± 2.6 3.6 ± 2.0 3.6 ± 1.9 2.20 .18 .18
Cold rating to 4oC (0-10)
Foot 1.9 ± 1.6 3.4 ± 2.0 3.6 ± 2.2 3.6 ± 2.3 1.58 2.88 2.66
Hand 3.2 ± 1.6 3.4 ± 1.1 3.4 ± 1.6 3.7 ± 2.2 .10 1.94 .09
Forehead 4.2 ± 1.4 4.2 ± 1.8 5.0 ± 2.3 4.7 ± 2.4 .57 .18 .18
Heat-pain rating to 40oC (0-10)
Foot 1.3 ± 1.9 .6 ± 1.4 .2 ± .4 .4 ± 1.0 2.57 1.07 3.31
Hand .4 ± 1.1 .6 ± 1.2 .1 ± .3 .4 ± 1.2 .49 1.25 .02
Forehead .0 ± .0 .3 ± .7 .2 ± .7 .0 ± .0 .00 .00 2.67
Cold-pain rating to 4oC (0-10)
Foot 1.4 ± 2.4 .0 ± .0 .6 ± 1.5 .1 ± .6 .50 8.43 ** 1.97
Hand .5 ± 1.4 .0 ± .0 .3 ± .9 .3 ± 1.2 .02 1.45 1.14
Forehead 1.3 ± 1.8 .1 ± .4 .3 ± .9 .1 ± .2 2.70 8.07 ** 3.09
* p < .05; ** p < .01; *** p < .001. Significant Group x Side interactions were investigated within and between groups in tests of simple main effects: a significantly different from contralateral side (p < .05).
Post-surgical sciatica patients versus patients with chronic lower-limb CRPS
QST findings were compared in 15 women and 10 men aged between 35 and 74 years (mean age ± standard deviation 54.6 ± 10.3 years) with chronic post- surgical sciatica and 12 women and 3 men aged between 32 and 60 years (mean age 47.4 ± 9.2 years) with chronic CRPS affecting a lower limb
(supplementary Table 3). Pain had persisted for at least three years in all cases. Sex distribution was similar in both groups but patients with chronic post- surgical sciatica were older than patients with CRPS (p< .05). Each participant provided written informed consent for the procedures, which were approved by the Human Research Ethics Committee at Murdoch University. The same investigator (PDD) administered tests to all patients.
Supplementary Table 3: Sensitivity to mechanical and thermal stimulation in patients with chronic post-surgical sciatica versus patients with chronic CRPS affecting a lower limb
Mean ± Standard Deviation
CRPS (N = 15) Post-surgical sciatica (N = 25) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Pressure-pain threshold (kg)
Foot .5 ± .3 a,b 1.4 ± .8 b 2.0 ± 1.1 2.0 ± .9 17.4 *** 10.5 ** 11.8 ***
Hand 1.0 ± .6 1.2 ± .5 1.8 ± .7 1.9 ± .9 11.4 ** .99 .01
Forehead .7 ± .5 .9 ± .4 1.0 ± .4 1.1 ± .5 2.51 19.7 *** 2.09
Sharpness rating to pin (0-10)
Foot 7.0 ± 2.6 a,b 4.2 ± 2.8 3.1 ± 2.5 3.4 ± 2.0 12.6 *** 8.07 ** 13.0 ***
Hand 4.0 ± 2.8 3.1 ± 2.4 2.6 ± 1.9 2.2 ± 2.2 3.34 3.48 .54
Forehead 4.6 ± 3.2 3.8 ± 2.6 4.5 ± 2.3 3.6 ± 2.5 .06 7.34 ** .02
Sharpness rating to hair x 1 (0-10)
Foot 3.5 ± 2.5 2.6 ± 2.4 1.1 ± 1.6 1.8 ± 2.0 9.80 ** .04 3.70
Hand 2.8 ± 2.5 2.4 ± 2.2 1.3 ± 1.6 1.2 ± 1.6 5.08 * 1.01 .51
Forehead 2.5 ± 2.2 2.0 ± 2.0 2.3 ± 2.0 2.2 ± 2.0 .00 3.69 1.81
Windup to hair x 5 (0-10)
Foot 1.9 ± 2.3 a,b .5 ± 1.1 .6 ± 1.3 .3 ± 1.1 3.28 9.84 ** 4.38 *
Hand 1.2 ± 1.3 .4 ± .9 .6 ± 1.5 .7 ± .9 .16 1.87 3.05
Forehead 1.3 ± 1.1 .7 ± .7 .7 ± 1.4 .4 ± .8 2.34 5.01 * .57
Touch threshold (arbitrary units)
Foot 9.5 ± 1.2 9.0 ± 1.4 11.0 ± 2.2 10.2 ± 1.9 4.21 * 10.3 ** .78
Supplementary Table 3 continued Mean ± Standard Deviation
CRPS (N = 15) Post-surgical sciatica (N = 25) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Warmth threshold (Δ from 32oC)
Foot 3.8 ± 2.6 3.1 ± 1.1 6.1 ± 2.6 5.0 ± 3.3 5.00 * 3.61 .16
Hand 1.7 ± .9 1.7 ± .8 3.9 ± 3.4 3.4 ± 3.2 2.99 4.60 * 1.68
Forehead 1.3 ± .5 2.5 ± 2.5 2.6 ± 2.3 2.9 ± 2.5 .98 1.14 .18
Cold threshold (Δ from 32oC)
Foot -7.2 ± 4.0 -5.4 ± 2.7 -6.7 ± 3.7 -6.1 ± 3.9 .02 3.88 1.09
Hand -2.3 ± 2.0 -5.0 ± 6.2 -3.3 ± 3.3 -2.9 ± 2.5 .14 4.20 * 7.00 *
Forehead -1.5 ± 1.1 -1.7 ± 1.3 -1.2 ± 1.2 -1.6 ± 2.2 .06 .84 .05
Heat-pain threshold (Δ from 32oC)
Foot 5.1 ± 3.0 a,b 7.7 ± 2.1 9.1 ± 2.5 8.2 ± 3.1 5.87 * 2.99 11.2 **
Hand 7.2 ± 2.4 8.6 ± 1.5 8.5 ± 3.2 8.4 ± 3.3 .26 2.81 3.26
Forehead 6.2 ± 4.3 7.0 ± 3.4 8.6 ± 2.7 8.7 ± 2.0 3.49 1.86 .76
Cold-pain threshold (Δ from 32oC)
Foot -18.1 ± 10.9 a -25.3 ± 9.8 -23.7 ± 11.5 -23.2 ± 11.5 .17 6.93 * 8.88 **
Hand -9.9 ± 7.3 -17.2 ± 11.7 -19.1 ± 11.4 -19.8 ± 10.5 2.11 5.45 * 3.72
Forehead -8.4 ± 5.6 -11.6 ± 7.0 -16.2 ± 8.2 -16.1 ± 9.2 3.67 2.11 2.22
Supplementary Table 3 continued Mean ± Standard Deviation
CRPS (N = 15) Post-surgical sciatica (N = 25) F Ratio
Ipsilateral Contralateral Ipsilateral Contralateral Group Side Group x Side Heat rating to 40oC (0-10)
Foot 5.9 ± 3.2 5.1 ± 2.2 2.9 ± 2.7 a,b 4.4 ± 2.7 5.90 * .34 4.81 *
Hand 4.8 ± 2.5 4.2 ± 1.7 4.3 ± 2.5 4.3 ± 2.4 .04 .73 1.08
Forehead 6.3 ± 2.5 a,b 4.3 ± 1.6 4.0 ± 2.7 4.1 ± 2.2 2.81 12.7 *** 15.0 ***
Cold rating to 4oC (0-10)
Foot 4.3 ± 2.5 a 3.0 ± 1.7 3.1 ± 2.2 3.6 ± 2.2 .24 1.39 7.02 *
Hand 4.3 ± 1.8 a 3.4 ± 1.6 3.3 ± 1.6 3.6 ± 1.9 .41 1.95 10.4 **
Forehead 5.7 ± 1.9 4.7 ± 2.5 4.7 ± 2.1 4.6 ± 2.2 .68 5.89 * 3.16
Heat-pain rating to 40oC (0-10)
Foot 3.3 ± 12.8 a,b .3 ± .9 .5 ± 1.2 .4 ± 1.1 11.7 ** 20.3 *** 17.7 ***
Hand .7 ± 1.5 .1 ± .3 .2 ± .6 .5 ± 1.2 .04 .40 5.22 *
Forehead 1.2 ± 2.2 .3 ± 1.1 .2 ± .6 .1 ± .4 4.65 * 4.67 * 3.25
Cold-pain rating to 4oC (0-10)
Foot 1.8 ± 3.2 .0 ± .0 .9 ± 1.8 .1 ± .5 .93 11.6 ** 1.77
Hand .9 ± 1.7 .1 ± .3 .4 ± 1.1 .2 ± 1.0 .57 5.67 * 2.49
Forehead 1.4 ± 2.1 .4 ± 1.6 .6 ± 1.3 .1 ± .3 2.00 10.7 ** .75
* p < .05; ** p < .01; *** p < .001. Significant Group x Side interactions were investigated within and between groups in tests of simple main effects: a significantly different from contralateral side (p < .05); b significant difference between groups (p < .05).
