Persistent neuropsychological deficits following whiplash: evidence for chronic mild traumatic brain injury?

OBJECTIVE: To investigate claims of neuropsychological evidence for acquired brain damage (axonal degeneration) in chronic whiplash.
DESIGN: Fifteen whiplash patients (Whiplash) were compared with 10 patients who had documented moderate-to-severe head injury (Mod-Sev), and with 24 patients who had chronic pain syndrome (CPS) and no history of head injury on two tests of mental efficiency considered highly sensitive to and specific for the subtle effects of brain trauma. All 3 groups, assessed 4 years after onset in a teaching hospital setting were matched for age, education, and IQ. Exclusion criteria included narcotics/benzo-diazepines or (suspected) malingering. Subjective ratings of depression and pain were collected as well as objective indices of outcome (return to work/school). MEASURES: Neuropsychological test scores were subjected to ANOVA followed by regression analysis regarding the possible effects of age, IQ, pain, and mood ratings.
RESULTS: No differences between the Whiplash, Mod-Sev, or CPS groups on the neuropsychological tests emerged. IQ was strongly related to mental efficiency. Counterintuitively, Mod-Sev patients complained of less depression and pain than did Whiplash or CPS patients (where no differences were seen) and displayed a better outcome. Finally, although results from 3 of the original 18 patients in the Whiplash group were later discarded for malingering, no malingering was detected in the 2 other groups.
CONCLUSIONS: The theory of neuronal degeneration in the etiology of whiplash-related cognitive complaints was not supported, nor was the specificity of neuropsychological tests in detecting the subtle effects of brain trauma.