Diagnostic efficiency of an ability-focused battery.

An ability-focused battery (AFB) is a selected group of well-validated neuropsychological measures that assess the conventional range of cognitive domains. This study examined the diagnostic efficiency of an AFB for use in clinical decision making with a mixed sample composed of individuals with neurological brain dysfunction and individuals referred for cognitive assessment without evidence of neurological disorders. Using logistic regression analyses and ROC curve analysis, a five-domain model composed of attention, processing speed, visual-spatial reasoning, language/verbal reasoning, and memory domain scores was fitted that had an AUC of.89 (95% CI =.84-.95). A more parsimonious two-domain model using processing speed and memory was also fitted that had an AUC of.90 (95% confidence interval =.84-.95). A model composed of a global ability score calculated from the mean of the individual domain scores was also fitted with an AUC of.88 (95% CI =.82-.94).

Clinical utility of demographically corrected WAIS-III subtest scores after traumatic brain injury.

The present study explored the diagnostic accuracy of demographically corrected norms for the Wechsler Adult Intelligence Scale-Third Edition (WAIS-III) in a diverse sample of 57 patients with traumatic brain injury (TBI) and a matched group of 61 pseudoneurologic controls. The use of demographic corrections did not significantly improve the sensitivity or specificity of WAIS-III subtest scores to TBI relative to traditional age-corrected norms. Overall classification rates were quite good for both normative systems. Although the demographic corrections attenuate ethnicity differences on the subtest scores of TBI patients, the updated norms are no more or less beneficial than traditional age-corrected norms for neurodiagnostic purposes.

Brain injury severity, litigation status, and self-report of postconcussive symptoms.

The Postconcussive Symptom Questionnaire (PCSQ) was developed to assess the symptoms associated with the controversial diagnosis of postconcussion syndrome. We examined item endorsement on the PCSQ in two groups. The first group was made up of individuals diagnosed with moderate to severe traumatic brain injury. The second group was made up of individuals meeting criteria for mild traumatic brain injury who exhibited no evidence of neurological injury. In addition, they demonstrated poor effort during neuropsychological examination. Significant differences in item endorsement were found the majority of individual items as well as on the PCSQ indices. The poor effort mild traumatic brain injury group consistently reported more symptoms with greater severity. The results raise further questions about the validity of postconcussion symptoms.

The repeatable battery for the assessment of neuropsychological status (RBANS): clinical utility in a traumatic brain injury sample.

The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS; Randolph, 1998), a neuropsychological screening measure initially designed to assess the cognitive deficits associated with dementia, has since been clinically implemented with other neurological populations including traumatic brain injury (TBI). This study evaluated the clinical utility of the RBANS in a TBI population by comparing the profiles of 51 TBI cases and 34 non-head-injured controls. Across RBANS' Index Scores, the TBI group performed at a significantly lower level than the controls; sensitivity to TBI and likelihood ratios ranged from modest to strong; and specificity was high. Particularly efficacious was the clinical efficiency exhibited by the Total Scale Index (summary score) of the RBANS.

An effort index for the Repeatable Battery For The Assessment Of Neuropsychological Status (RBANS).

The present study aimed to develop an internal validity indicator for a brief general purpose screening battery, the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Two subtests of the RBANS were predicted to be relatively resilient to cognitive dysfunction on the basis of previous research. An Effort Index (EI) was created by combining them via a scaling system. The frequency of EI scores was first examined in a heterogenous clinical sample. A subsequent validation study showed good discriminability. In conclusion, the EI appears to be useful for detecting insufficient effort on a screening battery.

Reliability and validity of the RBANS in a traumatic brain injured sample.

The RBANS has become increasingly utilized in various populations since it reliably assesses individual neurocognitive domains in a rapid, efficient manner. The present study examined the convergent validity of the RBANS to frequently administered instruments in a moderate-severe traumatic brain injured (M-S TBI) sample. Fifty-seven individuals who sustained a M-S TBI were included in this study. The RBANS subtests showed moderate to strong internal reliability within the sample. Most of the subtests displayed moderate to strong correlations with the other neuropsychological tests, including the CVLT-II, COWAT, and WAIS-III subtests. The strongest correlations were within the RBANS Attention Index, with both the Digit Span and Coding subtests showing strong correlations with their WAIS-III counterparts. The RBANS measures distinct abilities that supplement other neuropsychological instruments that assess similar functions within a TBI sample. In addition to its administration advantages, the results of this study provide support for the use of the RBANS as a clinical valid and reliable tool in the brief screening of individuals with M-S TBI.

Detecting incomplete effort with Digit Span from the Wechsler Adult Intelligence Scale-Third Edition.

The current study evaluated the utility of the Digit Span subtest in discriminating patients with mild head trauma from individuals referred for independent neuropsychological evaluation with objective evidence of poor effort. Various indices from the Digit Span subtest were evaluated to determine the best discriminator of brain injury from poor motivation patient groups: Digit Span Forward, Digit Span Backwards, Reliable Digit Span, Digit Span Age-Corrected Scaled Score, and the difference score between the Vocabulary and Digit Span scaled scores. The Digit Span scaled score was found to be the best discriminating index. A cutoff score of less than or equal to 7 accurately classified 75% of persons in the incomplete effort group and 69% of persons in the TBI group. Application of this cutoff score to a non-litigating mild brain injury group yielded a 77% correct classification rate. However, Digit Span scaled score accounted for a modest amount of variation and it is not recommended as a stand-alone validity measure.

Replication of the Test of Memory Malingering (TOMM) in a traumatic brain injury and head trauma sample.

The purpose of the current study was to replicate the clinical validation study of the Test of Memory Malingering (Tombaugh, 19961997). Fifty cases were selected from two different participant pools: medically documented traumatic brain-injury patients and compensation-seeking, mild head trauma cases. Results replicated and expanded those found by Tombaugh and indicated that employing a Trial 2 cutting score of greater than 5 errors provided adequate sensitivity to suboptimal effort while demonstrating remarkable insensitivity to cognitively impaired traumatic brain-injury cases. Use of a lower cutting score (e.g., 2 to 5 errors) is also discussed.

Neuropsychological performance and sleep disturbance following traumatic brain injury.

OBJECTIVE: To examine the relation between sleep disturbance and neurocognitive ability among persons with traumatic brain injury (TBI). DESIGN: Correlational research evaluating demographic and neuropsychological predictors of sleep disturbance using multiple regression analysis and analysis of variance. PARTICIPANTS: Eighty-seven patients with mild to severe TBI admitted to a comprehensive outpatient neurorehabilitation program. MAIN OUTCOME MEASURES: Sleep disturbance assessed using the Pittsburgh Sleep Quality Index. RESULTS: Hierarchical regression analysis revealed that performance on selected measures of cognitive functioning significantly improved prediction of sleep disturbance, accounting for 14% of variance beyond that accounted for by injury severity and gender. The total model accounted for 31% of the variance in Pittsburgh Sleep Quality Index scores. Patients with mild TBI reported more sleep disturbance (P < .01) than did patients with severe TBI. CONCLUSIONS: Sleep disturbance among patients with TBI may be associated with a particular constellation of neuropsychological abilities. These issues are discussed in relation to prior findings that indicate the involvement of additional neuropsychiatric factors associated with sleep disturbance in mild TBI.

Detection of sub-optimal performance using a floor effect strategy in patients with traumatic brain injury.

This archival study examined the effectiveness of using a normative floor effect method to detect suboptimal performance in a clinical sample of 120 cases consecutively referred for a neuropsychological evaluation. These cases were divided into moderate-severe TBI, mild TBI, and poor effort litigants (demonstrating suboptimal effort). Percentiles, sensitivity, specificity, positive and negative predictive power, and overall correct classification rates were calculated using the moderate-severe TBI sample as the clinical reference group. Several levels of stringency for the floor effect using different base rates were also examined. Setting the floor at the 50th percentile consistently appeared to provide for the best overall hit rate when comparing cases with mild brain injury versus poor effort. At this level, a strong trend (greater than one third of total scores) toward the generation of positive scores offers compelling evidence that, in general, the neuropsychological data have been invalidated by poor motivation. Clinical implications are discussed.

Insomnia in a post-acute brain injury sample.

OBJECTIVE: The purpose was to establish the frequency of insomnia within the post-acute TBI population and compare it with insomnia rates among other rehabilitation outpatients. DESIGN: A prospective study was undertaken of 50 consecutive post-acute TBI admissions and a comparison group of 50 rehabilitation outpatients evenly divided between spinal cord injury (SCI) and musculoskeletal (MSK) cases. SETTING: Subjects were recruited at various outpatient clinics of a major rehabilitation hospital. PATIENTS: Among the TBI subjects, the predominant cause of injury was motor vehicle accident; both mild and severe injuries were well represented in the sample; and, on average, patients were almost 4 months post-injury. The comparison and TBI groups did not differ significantly with respect to education or marital status. However, the MSK group was older and a higher proportion of the SCI group was female. MEASURES: The Pittsburgh Sleep Quality Index (PSQI), Beck Depression Inventory (BDI), and sleep diaries were administered to the TBI group. Only the PSQI and BDI were completed by the comparison group. RESULTS: Thirty per cent of the patients were found to suffer from insomnia. Sleep initiation was a problem almost twice as often as sleep duration. An additional 12% did not meet the DSM-IV criteria for insomnia but, nevertheless, experienced a degradation of sleep quality, as measured by the PSQI. Conversely, only slightly more than half (58%) of the TBI sample reported sleep to be relatively normal and satisfactory. Insomnia was also commonly reported by the patients in the rehabilitation comparison groups. They generated significantly higher mean PSQI Global Scores relative to the TBI group and the frequency of poor sleep quality was elevated significantly above the TBI rate. Relative to the TBI cases, twice as many comparison group patients were classified by the PSQI as insomniacs. CONCLUSION: Poor sleep quality and insomnia were definitely problems for the TBI group, although the magnitude of these problems was much greater for the rehabilitation comparison group. Degraded and disordered sleep may represent widespread challenges within the rehabilitation population in general.

Index, summary, and subtest discrepancy scores on the WAIS-III in postacute traumatic brain injury patients.

WAIS-III profile interpretation typically involves the analysis of disparities between summary and subtest scores. Determination of clinically meaningful differences has been guided by published rates of discrepancies based upon the normative sample. However, noting that a particular profile discrepancy is uncommon among normals only represents one step in the interpretive process. Rates of such pairwise differences have yet to be published for clinical samples. In order to begin filling this void in the literature, we present frequencies of composite and subtest differences from a postacute traumatic brain injury sample. The practical utility of these tables, in conjunction with the normative tables, is demonstrated.