Cold hyperesthesia and chronic pain after pediatric-onset spinal cord injury: an exploratory cross-sectional study.

OBJECTIVE

To characterize the sensory signs of nociceptive, neuropathic, and mixed pain (NP) subtypes, in a pediatric-onset spinal cord injury (SCI) cohort.

DESIGN

Exploratory cross-sectional observational study.

SETTING

Monographic SCI Rehabilitation Hospital.

SUBJECTS: Fifty-one individuals (12.8 ± 3.4 years; 52.9% females) with pediatric-onset SCI (8.1 ± 4.8 years).

METHODS

Standardized bedside and quantitative sensory testing (BST/QST), and a novel dynamic QST method to test cold hyperesthesia above, at, and below the SCI.

RESULTS

BST performed to evaluate differences in sensory function at or below the level of SCI revealed no differences with dynamic light touch (Brush), pinprick, cold, or heat thermoroller stimuli, except for hypoesthesia to dynamic light touch (Q-tip) in youth with nociceptive pain. Dynamic QST assessment detected a high level of perceived tonic cold intensity above the level of SCI that was characteristic of probable NP, whereas standardized QST identified elevated at- and below-level cold pain thresholds that were typical of nociceptive pain. In the nociceptive pain cohort, SCI evolution time correlated positively with both at-level and above-level tonic cold intensity. Finally, in youth with nociceptive pain, at-level tonic cold intensity correlated with below-level tonic cold intensity.

CONCLUSIONS

Assessment of change in cold sensory function, above, at, or below the SCI, highlights the presence of pathophysiological mechanisms throughout the neuroaxis after SCI in the pediatric cohort. Further understanding of cold hyperesthesia with chronic nociceptive and neuropathic pain subtypes, in a larger statistically powered confirmatory study, may lead to an improved prognosis of SCI pain in the pediatric population.