Scott R. Millis

American Academy of Clinical Neuropsychology Consensus Conference Statement on the Neuropsychological Assessment of Effort, Response Bias, and Malingering

During the past two decades clinical and research efforts have led to increasingly sophisticated and effective methods and instruments designed to detect exaggeration or fabrication of neuropsychological dysfunction, as well as somatic and psychological symptom complaints. A vast literature based on relevant research has emerged and substantial portions of professional meetings attended by clinical neuropsychologists have addressed topics related to malingering (Sweet, King, Malina, Bergman, & Simmons, 2002). Yet, despite these extensive activities, understanding the need for methods of detecting problematic effort and response bias and addressing the presence or absence of malingering has proven challenging for practitioners. A consensus conference, comprised of national and international experts in clinical neuropsychology, was held at the 2008 Annual Meeting of the American Academy of Clinical Neuropsychology (AACN) for the purposes of refinement of critical issues in this area. This consensus statement documents the current state of knowledge and recommendations of expert clinical neuropsychologists and is intended to assist clinicians and researchers with regard to the neuropsychological assessment of effort, response bias, and malingering.

Long-term Neuropsychological Outcome After Traumatic Brain Injury

Objective:To describe neuropsychological outcome 5 years after injury in persons with traumatic brain injury (TBI) who received inpatient medical rehabilitation. To determine the magnitude and pattern neuropsychological recovery from 1 year to 5 years after injury. Design:Longitudinal cohort study with inclusion based on the availability of neuropsychological data at 1 year and 5 years after injury. Setting:National Institute on Disability and Rehabilitation Research Traumatic Brain Injury Model Systems of Care. Participants:One hundred eighty-two persons with complicated mild to severe traumatic brain injury. Primary Outcome Measures:Digits Forward and Backward, Logical Memory I and II, Token Test, Controlled Oral Word Association Test, Symbol Digit Modalities Test, Trail Making Test, Rey Auditory Verbal Learning Test, Visual Form Discrimination, Block Design, Wisconsin Card Sorting Test, and Grooved Pegboard. Results:Significant variability in outcome was found 5 years after TBI, ranging from no measurable impairment to severe impairment on neuropsychological tests. Improvement from 1 year after injury to 5 years was also variable. Using the Reliable Change Index, 22.2% improved, 15.2% declined, and 62.6% were unchanged on test measures. Conclusions:Neuropsychological recovery after TBI is not uniform across individuals and neuropsychological domains. For a subset of persons with moderate to severe TBI, neuropsychological recovery may continue several years after injury with substantial recovery. For other persons, measurable impairment remains 5 years after injury. Improvement was most apparent on measures of cognitive speed, visuoconstruction, and verbal memory.

Neuropsychologic and Functional Outcome After Complicated Mild Traumatic Brain Injury

OBJECTIVE To investigate the extent to which neuropsychologic and functional outcome after complicated mild traumatic brain injury (TBI) parallels that of moderate TBI recovery. DESIGN A longitudinal study comparing neuropsychologic and functional status of persons with complicated mild TBI and moderate TBI at discharge from inpatient rehabilitation and at 1 year postinjury. SETTING Rehabilitation hospital with a Traumatic Brain Injury Model System. PARTICIPANTS Persons with complicated mild TBI (n=102), each with an intracranial brain lesion documented through neuroimaging and a highest Glasgow Coma Scale (GCS) score in the emergency department between 13 and 15, and 127 persons with moderate TBI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES FIM instrument, Disability Rating Scale, Community Integration Questionnaire, Wechsler Memory Scale logical memory I and II, Rey Auditory Verbal Learning Test, Trail-Making Test, Controlled Oral Word Association Test, Symbol Digit Modalities Test, Wisconsin Card Sorting Test, and block design. RESULTS Few differences in neuropsychologic performance existed between the TBI groups. Less severely impaired information processing speed and verbal learning were seen in the complicated mild TBI group at rehabilitation discharge and 1 year postinjury. Despite overall improvement across cognitive domains within the complicated mild TBI group, some degree of impairment remained at 1 year postinjury on those measures that had identified participants as impaired soon after injury. No differences on functional ability measures were found between the TBI groups at either time period postinjury, with both groups exhibiting incomplete recovery of functional status at the 1-year follow-up. CONCLUSIONS When classifying severity of TBI based on GCS scores, consideration of a moderate injury designation should be given to persons with an intracranial bleed and a GCS score between 13 and 15.

Measures of executive functioning as predictors of functional ability and social integration in a rehabilitation sample

OBJECTIVE To examine the utility of executive function tests in predicting rehabilitation outcome. DESIGN A prospective, descriptive study of the value of neuropsychologic and motor functioning measures in the prediction of functional outcome 6 months after acute rehabilitation. SETTING A Midwestern, urban, university-affiliated rehabilitation hospital. PATIENTS Ninety consecutive admissions to traumatic brain injury, orthopedic, and spinal cord injury units. Age of the participants ranged from 17 to 73. MAIN OUTCOME MEASURES Community Integration Questionnaire (CIQ), Disability Rating Scale (DRS), SF-36 Health Survey. RESULTS Canonical correlation analyses indicated that measures of executive functioning and verbal memory were strongly related to measures of functional outcome 6 months after rehabilitation, as measured by the DRS and the CIQ. In contrast, perceived health status as measured by the SF-36 was highly related to estimated premorbid IQ and modestly related to visuospatial impairment. CONCLUSIONS Executive functioning, verbal memory, and estimated premorbid intelligence predict functional dependence after discharge from rehabilitation beyond information regarding basic sensory and motor skills. Moreover, there is a dissociation between measures of functional outcome, such that objective and behaviorally oriented measures of disability (CIQ and DRS) are strongly related to each other; however, they are not related to perceptions of general health status (SF-36).

The California Verbal Learning Test in the detection of incomplete effort in neuropsychological evaluation

This study determined whether performance patterns on four California Verbal Learning Test variables (CVLT ; Trials 1-5 List A, discriminability, recognition hits, and long-delay cued recall) could differentiate participants with moderate and severe brain injuries from those with mild head injuries who were giving incomplete effort. Litigating mild head injury participants (n = 23) performing at chance level or worse on a forced-choice test obtained significantly lower scores on the four CVLT variables than participants with moderate and severe brain injuries (n = 23). The linear discriminant function accurately classified 91%, and the quadratic function, 96%. The discriminability cutoff score accurately classified 93% of the cases ; recognition hits, 89% ; long-delay cued recall, 87% ; and CVLT total, 83%.

The recognition memory test in the detection of malingered and exaggerated memory deficits

Abstract The capacity of the Recognition Memory Test (RMT) to detect exaggerated or malingered memory impairment was investigated in a study of 30 subjects. Subjects with reported mild head trauma (MT) who were seeking financial compensation obtained significantly lower scores on both subtests of the RMT than subjects who had documented moderate and severe traumatic brain injuries (ST) who were not seeking financial compensation. Of the MT subjects, 50% performed worse on the Words subtest of the RMT than any of the ST subjects. At a 90% specificity level, the sensitivity of the Words subtest to classify correctly the MT subjects was 70%. An unreplicated discriminant function using both RMT subtests resulted in an overall correct classification rate of 76%.

Executive functioning and predictors of falls in the rehabilitation setting.

OBJECTIVE To examine the incremental utility of executive function tests in the prediction of inpatient falls. DESIGN Evaluation of neuropsychologic and medical risk factors for fall was completed at admission. Inpatient falls were tabulated following discharge. SETTING A freestanding, urban rehabilitation hospital. PATIENTS Ninety consecutive admissions to traumatic brain injury, orthopedic, and spinal cord injury wards. Age of the participants ranged from 17 to 73 years old. MAIN OUTCOME MEASURE Incident reports of inpatient falls. RESULTS Standard multiple regression analyses indicated that measures of executive functioning sensitive to self-monitoring accounted for unique variance in falls beyond that explained by age and functional motor ability as assessed by the Functional Independence Measure. Visuospatial functioning, although not directly related to falls, was a significant predictor in combination with measures of executive functioning. Together, these variables accounted for 30.3% of the variance in inpatient falls (multiple r = .55; p < .001). CONCLUSION The findings suggest that the influence of motor and sensory impairments on falls are moderated, in part, by executive functioning. Patients with intact executive functioning are less likely to act in ways that could result in a fall; thus, aggressive fall prevention measures may be unnecessary. In contrast, executive dysfunction may signal the need for intervention, even among patients whose profiles are unremarkable with regard to traditional risk factors for fall.

Relationship between Glasgow coma scale and functional outcome.

The Glasgow Coma Scale (GCS) is routinely used in the acute care setting after traumatic brain injury (TBI) to guide decisions in triage, based on its ability to predict morbidity and mortality. Although the GCS has been previously demonstrated to predict mortality, efficacy in prediction of functional outcome has not been established. The purpose of this study was to assess the value of the acute GCS in predicting functional outcome in survivors of TBI. This study used the Multicenter National Institute on Disability and Rehabilitation Research TBI Model Systems database of 501 patients who had received acute medical care and inpatient rehabilitation within a coordinated neurotrauma program for treatment of TBI. Initial and lowest 24 hr GCS scores were correlated with the following outcome measures: the Disability Rating Scale (DRS), Rancho Los Amigos Levels of Cognitive Functioning Scale (LCFS), and cognitive and motor components of the Functional Independence Measure (FIM(SM)-COG and FIM(SM)-M). Outcome data were collected at admission to and discharge from the inpatient TBI rehabilitation unit. Correlation analysis revealed only modest, but statistically significant, relationships between initial and lowest GCS scores and outcome variables. Initial and lowest GCS score comparison with outcome demonstrated the following correlation coefficients: admission DRS, -0.25 and -0.28; discharge DRS, -0.24 and -0.24; admission LCFS, 0.31 and 0.33; discharge LCFS, 0.27 and 0.25; admission FIM-COG, 0.36 and 0.37; discharge FIM-COG, 0.23 and 0.23; admission FIM-M, 0.31 and 0.31; discharge FIM-M, 0.25 and 0.21. The GCS as a single variable may have limited value as a predictor of functional outcome.

Better object recognition and naming outcome with MRI-guided stereotactic laser amygdalohippocampotomy for temporal lobe epilepsy.

Patients with temporal lobe epilepsy (TLE) experience significant deficits in category‐related object recognition and naming following standard surgical approaches. These deficits may result from a decoupling of core processing modules (e.g., language, visual processing, and semantic memory), due to “collateral damage” to temporal regions outside the hippocampus following open surgical approaches. We predicted that stereotactic laser amygdalohippocampotomy (SLAH) would minimize such deficits because it preserves white matter pathways and neocortical regions that are critical for these cognitive processes.

Assessment of response bias in mild head injury: beyond malingering tests.

The evaluation of response bias and malingering in the cases of mild head injury should not rely on a single test. Initial injury severity, typical neuropsychological test performance patterns, preexisting emotional stress or chronic social difficulties, history of previous neurological or psychiatric disorder, other system injuries sustained in the accident, preinjury alcohol abuse, and a propensity to attribute benign cognitive and somatic symptoms to a brain injury must be considered along with performances on specific measures of response bias. This article reviews empirically-supported tests and indices. Use of the likelihood ratio and other statistical indicators of diagnostic efficiency are demonstrated. Bayesian model averaging as a statistical technique to derive optimal prediction models is performed with a clinical data set.