The Impact of Posttraumatic Stress Disorder on Physiological Arousal, Disability and Sensory Pain Thresholds in Patients with Chronic Whiplash

Objective: Whiplash-associated disorders (WAD) are common and incur substantial personal and economic costs. Research has shown that persistent posttraumatic stress reactions predict poorer functional recovery in WAD; however, the specific mechanism through which this occurs is unclear. The current study is the first to examine the direct impact of posttraumatic stress disorder (PTSD) symptoms in WAD using laboratory tested pain measures. Materials and Methods: A mixed experimental design was used to examine the impact of exposure to accident cues on chronic WAD individuals with (n=33) and without (n=39) PTSD. Groups were compared at baseline and postaccident cue on self-reported pain and negative effect and laboratory tested arousal and sensory pain threshold measures. Results: At baseline, WAD individuals with PTSD reported greater disability, negative effect, pain, arousal, and lower pain thresholds than those without PTSD. As expected, exposure to accident cues resulted in greater increases in arousal and negative effect for those with PTSD. Changes in sensory pain thresholds revealed a hyperalgesic effect in cold pain thresholds for the PTSD group compared with the No PTSD group and mixed findings for pressure pain thresholds. Discussion: Findings from the current study highlight the negative impact of PTSD on both physical and psychological outcomes in chronic WAD. From a clinical perspective, data suggest that patients exposed to accident cues may experience arousal that lowers their threshold to certain pain stimuli. Further investigation of effective multidisciplinary interventions and in particular the treatment of PTSD in WAD is identified as an important area of further investigation