Figure 1.
Sensory findings in healthy controls and neuropathic pain patients
Sensory findings (gain and/or loss of sensory function) in % for healthy controls (n = 208 with 418 test sides) and for patients at the affected and contralateral side (n = 81). Sensory abnormalities were defined as Z score <−1.96 or >1.96 corresponding with 95% of values obtained from healthy volunteers. “No sensory abnormalities”: none of the Quantitative Sensory Testing (QST) parameters were outside the 95% CI. “Only sensory gain”: at least one QST parameter indicating thermal or mechanical hyperesthesia or hyperalgesia without the presence of hypoesthesia or hypoalgesia. “Only sensory loss”: at least one QST parameter indicating thermal or mechanical hypoesthesia or hypoalgesia without the presence of hyperesthesia or hyperalgesia. “Sensory gain and loss”: at least one positive sign combined with one negative sign.
Table 1.
Patient characteristics.
Figure 2.
Z-score profiles at the affected side and contralateral side in neuropathic pain patients.
Sensory abnormalities (Z score <−1.96 or >1.96) for each Quantitative Sensory Testing (QST) parameter at the affected side (left) and contralateral side (right) in 81 neuropathic pain patients. Grey area indicates parameters within the normal range (−1.96<Z<1.96 corresponding with 95% of values obtained from healthy volunteers). QST parameters: Cold Pain Threshold (CPT), Heat Pain Threshold (HPT), Warm Detection Threshold (WDT), Wind Up Ratio (WUR), Cold Detection Threshold (CDT), Thermal Sensory Limen (TSL), Paradoxical Heat Sensation (PHS), Mechanical Pain Threshold (MPT), Mechanical Pain Sensitivity (MPS), Mechanical Detection Threshold (MDT), Vibration Disappearance Threshold (VDT), Pressure Pain Threshold (PPT).
Table 2.
Overview of sensory abnormalities in QST.
Figure 3.
Quantitative Sensory Testing (QST) abnormalities at the affected and contralateral side in neuropathic pain patients.
Quantitative Sensory Testing (QST) Z-score abnormalities in % at the affected (left) and contralateral side (right) in 81 neuropathic pain patients. Sensory abnormalities were defined as Z score < −1.96 or >1.96 corresponding with 95% of values obtained from healthy volunteers. QST parameter are ordered as sensory parameters: Cold Detection Threshold (CDT), Warm Detection Threshold (WDT), Thermal Sensory Limen (TSL), Mechanical Detection Threshold (MDT), Vibration Disappearance Threshold (VDT), Paradoxical Heat Sensation (PHS), Dynamic Mechanical Allodynia (DMA) and nociceptive parameters: Cold Pain Threshold (CPT), Heat Pain Threshold (HPT), Pressure Pain Threshold (PPT), Mechanical Pain Threshold (MPT), Mechanical Pain Sensitivity (MPS) and Wind Up Ratio (WUR). Z-scores with positive sensory signs (gain of sensory function) plotted rightwards and negative sensory signs (loss of sensory function) plotted leftwards. Absence of DMA is normal and therefore no negative sign possible.
Table 3.
Overview of sensory abnormalities at the contralateral side given an abnormality at the affected side.
Figure 4.
Incidence of QST abnormalities at the contralateral side in neuropathic pain patients.
Incidence of QST abnormalities at the contralateral side in 81 neuropathic pain patients. Sensory abnormality in percent (%) of either gain or loss of function for each Quantitative Sensory Testing (QST) parameter at the contralateral side once there was already an abnormality detected for the same parameter at the affected side. Sensory abnormalities were defined as Z score < −1.96 or >1.96 corresponding with 95% of values obtained from healthy volunteers. QST parameter in this radar diagram are ordered as mechanical stimuli consisting of Mechanical Pain Threshold (MPT), Dynamic Mechanical Allodynia (DMA), Pressure Pain Threshold (PPT), Vibration Disappearance Threshold (VDT), Mechanical Detection Threshold (MDT), Mechanical Pain Sensitivity (MPS) and Wind Up Ratio (WUR) (left side) and thermal stimuli consisting of Cold Pain Threshold (CPT), Heat Pain Threshold (HPT), Warm Detection Threshold (WDT), Cold Detection Threshold (CDT), Thermal Sensory Limen (TSL), Paradoxical Heat Sensation (PHS) (right side).
Table 4.
Diagnostic consequence of using either the contralateral side or normative data from healthy volunteers.