Spinal cord injury is not a feature of chronic whiplash-associated disorder: a magnetic resonance spectroscopy study

Purpose Injury to the cervical spinal cord has been suggested as a mechanism that may underpin chronic whiplash-associated disorder (WAD). This study aimed to assess metabolite concentrations indicative of neuronal injury or pathology in the cervical cord in people with chronic WAD. Methods Forty-one people with chronic WAD (mean [SD] age 39.6 [11.0] years, 25 females) and 14 healthy controls (39.2 [12.6] years, 9 females) underwent cervical spinal cord magnetic resonance spectroscopy to measure the metabolites N-acetylaspartate (NAA), creatine (Cr) and choline (Cho). Participants with WAD completed clinical questionnaires on pain intensity (Visual Analogue Scale), disability (Neck Disability Index) and psychological factors (Pain Catastrophising Scale, Post-traumatic Diagnostic Scale), and underwent cervical range of motion assessment and pain threshold testing to cold and pressure stimuli. Data were analysed using hypothesis testing and Spearman correlations (p < 0.05). Results There were no differences between the WAD and control groups for NAA/Cr (median [IQR] WAD 1.73 [1.38, 1.97], controls 2.09 [1.28, 2.89], p = 0.37), NAA/Cho (WAD 1.50 [1.18, 2.01], controls 1.57 [1.26, 1.93], p = 0.91) or Cr/Cho (WAD 0.84 [0.64, 1.17], controls 0.76 [0.60, 0.91], p = 0.33). There were no significant correlations between NAA/Cr, NAA/Cho or Cr/Cho and any clinical variable (p >= 0.06). Conclusions Findings are consistent with major metabolic changes not being present in chronic WAD.