Objectives: Recent research has identified the coexistence of generalized sensory hypersensitivity and hypoesthetic changes suggestive of a neuropathic component to chronic whiplash associated disorders (WAD). This study aimed to compare chronic whiplash with a cervical neuropathic condition-cervical radiculopathy, using Quantitative Sensory Testing.
Methods: Fifty participants with chronic grade II WAD (>3 mo), 38 participants with radiculopathy, and 31 controls who were age and sex matched to participants with WAD participated in the study. Quantitative Sensory Testing including detection thresholds (electrical, thermal, and vibration) and pain thresholds (pressure, cold) were measured from bilateral hand sites corresponding to innervation areas of the lower cervical nerve roots and a remote site in the lower limb.
Results: The whiplash and cervical radiculopathy groups demonstrated lower pain thresholds to both pressure and cold stimuli at all sites compared with the controls (P<0.01). The symptomatic limbs of the radiculopathy group showed the greatest elevation in detection thresholds for all stimuli compared with the asymptomatic limbs of this group, the whiplash and control groups (P<0.01). There was no difference in detection thresholds between the asymptomatic limbs of the radiculopathy group and the whiplash group (P>0.05) but both these groups showed higher detection thresholds than the controls (P<0.05).
Discussion: Generalized sensory hypersensitivity and hypoesthesia occur in both chronic whiplash and cervical radiculopathy. This may represent disordered central pain processing but could indicate peripheral nerve dysfunction.