Exaggerated Functional Impairment due to Malingered Neurocognitive Dysfunction Following Mild Traumatic Brain Injury.

OBJECTIVE

Functional impairment associated with Neurocognitive Disorder is often claimed in medico-legal settings after mild Traumatic Brain Injury (mTBI). This case-control study examined self-reported functional impairment and the plausibility of chronic disability claims following uncomplicated mTBI.

METHOD

Independent Medical Evaluations included a battery of performance and symptom validity tests, along with self-reports of physical or emotional complaints and functional impairment. Slick and colleagues' (Slick, D. J., Sherman, E. M., & Iverson, G. L. (1999). Diagnostic criteria for malingered neurocognitive dysfunction: Proposed standards for clinical practice and research. The Clinical Neuropsychologist, 13, 545-561.) criteria ruled out probable malingering in 21 mTBI cases without psychiatric comorbidity and their self-reports were compared to those of seven non-malingering cases with a psychiatric comorbidity, 17 who were probable malingerers, and 31 orthopedic pain sufferers. Coherence Analysis of medical documentation corroborated assignment of mTBI cases to non-malingering versus probable malingering groups.

RESULTS

Probable malingerers reported more postconcussion symptoms than non-malingerers (d = 0.79) but they did not differ significantly on tests of neurocognitive performance. Probable malingerers and orthopedic pain patients gave significantly higher ratings of functional impairment (d = 1.28 and 1.26) than non-malingerers. Orthopedic pain patients reported more disability due to pain than non-malingerers (d = 1.03), but pain catastrophizing was rated more highly by the probable malingerers (d = 1.21) as well as by the orthopedic pain patients (d = 0.98). The non-malingerers reported lower emotional distress than the other three groups, but only the probable malingerers reported elevated depression symptoms compared to the non-malingerers (d = 1.01).

CONCLUSIONS

The combined evaluation of performance validity, function, and coherence analysis would appear to enhance the difficult clinical evaluation of postconcussion symptoms in the medical-legal setting.