Citation

Sterling M. Pain 2010; 150(3): 501-506.

Affiliation

Centre for National Research on Disability and Rehabilitation Medicine (CONROD) and CCRE: Spine, Division of Physiotherapy, School of Health and Rehabilitation Sciences, The University of Queensland, Australia.

Copyright

(Copyright © 2010, Lippincott, Williams and Wilkins)

DOI

10.1016/j.pain.2010.06.003

PMID

20594646

Abstract

Widespread sensory hypersensitivity is present in acute whiplash and is associated with poor recovery. Decreased nociceptive flexion reflex (NFR) thresholds (spinal cord hyperexcitability) are a feature of chronic whiplash but have not been investigated in the acute to chronic injury stage. This study compared the temporal development of sensory hypersensitivity and NFR responses from soon after injury to either recovery or to transition to chronicity. It also aimed to identify predictors of persistent spinal cord hyperexcitability. Pressure and cold pain thresholds, NFR responses (threshold and pain VAS) were prospectively measured in 62 participants at <3weeks, 3 and 6months post whiplash injury and in 22 healthy controls on two occasions a month apart. Pain levels and psychological distress (GHQ-28; IES) were measured at baseline. Whiplash participants were classified at 6months post-injury using the Neck Disability Index: recovered (8%), mild pain and disability (10-28%) or moderate/severe pain and disability (30%). All whiplash groups demonstrated spinal cord hyperexcitability (lowered NFR thresholds) at 3weeks post-injury. This hyperexcitability persisted in those with moderate/severe symptoms at 6months but resolved in those who recovered or reported lesser symptoms at 6months. In contrast generalized sensory hypersensitivity (pressure and cold) was only ever present in those with persistent moderate/severe symptoms and remained unchanged throughout the study period. This suggests different mechanisms underlie sensory hypersensitivity and NFR responses. In multivariate analyses only initial NDI scores (p=0.003) were a unique predictor of persistent spinal cord hyperexcitability indicating possible ongoing peripheral nociception following whiplash injury.

Language: en