Measures of central hyperexcitability in chronic whiplash associated disorder - A systematic review and meta-analysis

Objectives: To synthesise the evidence for central hyperexcitability in Chronic WAD (whiplash associated disorders) with meta-analysis, and review test protocols. Methods: Chronic WAD was compared to healthy controls. Studies were eligible if they used measures of central hyperexcitability with standardised procedure. Meta-analyses (where possible) were conducted. Results: The search yielded 27 trials of good quality and 13 were suitable for meta-analyses. Individuals with chronic WAD showed heightened sensitivity to the following tests (p < 0.05): Pressure Pain Thresholds at Head/Neck/Upper Thoracic area (H/N/UT) (SMD (Standardised mean differences) -1.36, 95% CI (confidence intervals) -1.89 to -0.82), Upper Limb (UL) (-1.33, 95% CI -2.50 to -0.16), Lower Limb (LL) (-1.01, 95% CI -1.70 to -0.33), flexor withdrawal (-0.73, 95% CI -1.11 to -0.35), Cold Pain Threshold at H/N/UT (0.91, 95% CI 0.66-1.17) and UL (0.66, 95% CI 0.37-0.94), Heat Pain Threshold at H/N/UT (-0.58, 95% CI -0.88 to -0.28), Electrocutaneous Stimulation at H/N/UT (-1.04, 95% CI -1.63 to -0.45) and LL (-0.85, 95% CI -1.67 to -0.03), and elbow extension with the Brachial Plexus Provocation Test (SMD -0.55, 95% CI -0.76 to -0.35). Discussion: There is compelling evidence for central hyperexcitability in chronic WAD. This should be considered in the management of chronic WAD. (C) 2012 Elsevier Ltd. All rights reserved.