A large sample of chronic postconcussive patients with and without overt malingering signs was compared with objectively brain-injured patients on common episodic memory and malingered amnesia measures. Probable malingerers and traumatically brain-injured subjects were not differentiated on popular episodic recall tests. In contrast, probable malingerers performed poorly on the Rey 15-Item, Rey Word Recognition List, Reliable Digit Span, Portland Digit Recognition Test, and Rey Auditory Verbal Learning Test recognition trial. These findings validated both commonly cited malingering measures and newly introduced methods of classifying malingering in real-world clinical samples. The base rate for malingering in chronically complaining mild head injury patients may be much larger than previously assumed.

A known group methodology was used to compare the predictive accuracies of MMPI-2 validity scales and malingered amnesia measures in the detection of real versus feigned traumatic brain-injury. The domain specific compliance measures were consistently more accurate in the separation of factitious brain-injury patients (JT = 68) from severe brain-injury patients ( N = 56). Among MMPI-2 measures, only scale SL. improved on base-rate predictions of probable malingering. Anti-social traits, as measured by Pd, had no relationship to malingered amnesia. Factor analysis suggested independent psychiatric and neurological malingering factors. The implications for DSM-IV malingering criteria and models of feigned illness are discussed.

The correlational and diagnostic properties of Lees-Haley's MMPI-2 Fake Bad Scale (FBS) were examined in litigating atypical minor, litigating moderate-severe, and non-litigating moderate-severe head injury samples. Overall, the FBS was sensitive to both litigation status and nonconforming versus conforming symptom courses. The FBS appeared superior to the MMPI-2 F and F-K scales in differentiating atypical from real brain-injury outcomes. High FBS scorers also had higher scores on somatic complaining (Hs, Hy) and to a lesser degree with psychotic complaints (F, Pa, Sc). FBS showed significant associations with various neuropsychological symptom validity measures. FBS appears to capture a hybrid of infrequent symptom reporting styles with an emphasis on unauthentic physical complaints. However, FBS also correlated with documented abnormal neurological signs within a litigating moderate-severe brain-injury group. Its use as a symptom infrequency measure may have to be modified in more severe injury litigants, as some FBS items may reflect true long-term outcome in severe cerebral dysfunction.

Motor measures are sensitive to central lesions, but they are also affected by peripheral injury and motivation. The motor skills profiles of proven brain injury clients were compared with the profiles of healthy postconcussion patients. The chief result was a double dissociation: The traumatic brain injury (TBI) group produced a motor dysfunction gradient consistent with upper motor neuron disease, while the compensation-seeking postconcussion group produced a nonphysiologic pattern. Objective measures of behavioral pain and emotional distress did not correlate with the findings. Motor skill deficiencies in postconcussion syndrome (PCS) are probably functional in nature. (JINS, 1996, 2, 477-485.)

The present study explored the predictive value of interval change in neuropsychological performance at three time-points following moderate-to-severe TBI (inpatient rehabilitation, 1-year, and 2-year follow-up) on functional outcome measures collected at 2-year follow-up. Symmetrized percent change scores were calculated and used to predict scores on functional measures using linear regression while controlling for age and injury severity. Results showed that change in performance from inpatient to 1-year on total list learning (CVLT-II or RAVLT) and oral SDMT significantly predicted 2-year ratings of functional status. By comparison, most neuropsychological measures taken at 1-year follow-up also accounted for unique variance in 2-year functional outcomes. These results indicate that changes in learning and processing speed during the first year of recovery are sensitive indicators when predicting long-term disability and degree of functional independence, though absolute performance at 1 year is also highly associated with functional outcome at 2 years post-injury.