Brain Injury Lawyer

I recently received some back issues of Brain Injury, the Official Research Journal of the International Brain Injury Association.  In both the March and April 2007 issues, there were three studies regarding the Word Memory Test and effort in mild traumatic brain injury patients.  The word memory test was developed by Dr. Paul Green, a neuropsychologist.  According to Dr. Green, the WMT has consistently been found to be close to or actually 100% accurate in classifying simulators versus good effort volunteers. 

One of the issues besides the validity of the WMT to properly classify malingerers is an explanation or the factors explaining a patient’s failure to “pass” the WMT.  In patients in litigation, Dr. Green asserts that failure of the WMT properly permits a classification of malingering.

However, a recent article by Donders and Boonstra presents excellent research seriously questioning Dr. Green’s classification of malingering.  Dr. Donders, a member of the Psychology Service at the Mary Free Bed Rehabilitation Hospital in Grand Rapids and Dr. Boonstra, a member of the Department of Psychology, Hope College, Holland, Michigan present interesting research in the March 2007 issue of Brain Injury in their article entitled “Correlates of Invalid Neuropsychological Test Performance after Traumatic Brain Injury”.  According to the abstract, their primary objective was to investigate the external correlates of invalid test performance after traumatic brain injury as assessed by the California Verbal Learning Test-Second Edition and the Word Memory Test.  The researchers viewed consecutive two-year series of rehabilitation referrals with a diagnosis of traumatic brain injury (N=87).  According to their research, 21 of the 87 participants (approximately 24%) performed in the invalid range.  The researchers found that “the combination of a premorbid psychiatric history with minimal or no coma was associated with an approximately four-fold increase in the likelihood of invalid performance.”  While the authors found that the WMT “appears to be a promising instrument for the purpose of identifying those cases where neuropsychological test results are compounded by factors not directly related to acquired cerebral impairment”, they caution that “care should be taken to not routinely assume that all persons with mild traumatic brain injury and premorbid psychiatric histories are simply malingering.”  The authors did, however, find that “the presence of disputed financial compensation seeking did not add further to the differentiation of those with versus without psychometric indicators of invalid neuropsychological test performance.”  The authors found that only eight of twenty-six persons (30.77%) with potential financial incentives for poor performance scored in the suspect range on any of the validity indicators in the study.

In that same issue, similar findings were reported out of the Netherlands in a study published by Maja Stulemeijer, et al, members of the Department of Medical Psychology and Department of Neurology at Radboud University Nijmegn Medical Center.  In their research entitled “Cognitive Performance After Mild Traumatic Brain Injury: The impact of poor effort on test results and its relation to distress, personality and litigation”, the researchers sought to compare consecutive mild traumatic brain injury patients with and without adequate effort on cognitive performance, litigation status, fatigue, distress and personality.  The authors evaluated 110 patients from a cohort of 618 consecutive mild traumatic brain injury patients (ages 18-60) who were seen at the emergency department of the hospitals level I trauma center.  Effort was tested with the Amsterdam Short Term Memory Test.  The study revealed that 27% of the patients failed the effort test.  “Poor effort was associated with lower educational levels and changes in work status, but not litigation.”

The authors cautioned

    “Although deliberate faking or cognitive deficits cannot be ruled out, the diagnosis of malingering should not rely on a single test.  Alternative explanations should also be considered as likely causes of poor effort.  For example, poor effort may serve as a “unconscious” strategy to protect oneself against exhaustion, or may reflect the need to get recognition for complaints in the face of medical skepticism.  Moreover, it may result from the poor physical and emotional state the patient is in at the time of the assessment, although in this case detrimental effects would be expected to be most prominent on demanding cognitive tests and not on a relatively easy test like the ASPM.”

In the April issue of Brain Injury, Dr. Green and colleagues utilized the Word Memory Test to compare effort in mild brain injury patients versus parents seeking custody.  Dr. Green found that patients with mild traumatic brain injury had 23 times higher failure rates than those parents seeking custody.  Not surprisingly, Dr. Green asserted that this finding was explained by differences in external incentives.  Dr. Green found that in cases of mild traumatic brain injury the pass rate on the WMT was only 60% while with parents seeking child custody the pass rate was 98.3%.  The WMT failure rate was also found to be twice as frequent in the mild TBI group then in those with more severe TBI.  Also, adults with mild TBI had a greater failure rate than children with significant impairment from various clinical conditions.

Dr. Green asserted that monetary incentive explains why almost twice as many cases of mild TBI failed the WMT compared with moderate to severe TBI.  It appears that Dr. Green, however, did not consider the other factors found important by the other researchers whose work is cited above.