Norman L. Fichtenberg

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.

Neuropsychological performance and sleep disturbance following traumatic brain injury.

ObjectiveTo examine the relation between sleep disturbance and neurocognitive ability among persons with traumatic brain injury (TBI). DesignCorrelational research evaluating demographic and neuropsychological predictors of sleep disturbance using multiple regression analysis and analysis of variance. ParticipantsEighty-seven patients with mild to severe TBI admitted to a comprehensive outpatient neurorehabilitation program. Main Outcome MeasuresSleep disturbance assessed using the Pittsburgh Sleep Quality Index. ResultsHierarchical 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. ConclusionsSleep 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.

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.

Effort Indicators within the California Verbal Learning Test-II (CVLT-II)

This study determined whether performance patterns on the California Verbal Learning Test-II (CVLT-II) could differentiate participants with traumatic brain injury (TBI) showing adequate effort from those with mild TBI exhibiting poor effort using a case-control design. The TBI group consisted of 124 persons with moderate to severe traumatic brain injury (TBI). The poor effort group consisted of 77 persons with mild head injury who were involved in litigation (LG) and failed at least one stand-alone symptom validity measure (SVT) and also either a second SVT or an effort indicator embedded within a standard clinical test. A total of 18 CVLT-II variables were investigated using Bayesian model averaging (BMA) for logistic regression to determine which variables best differentiated the groups. The CVLT-II variables having the most support were Long-Delay Free Recall, Total Recognition Discriminability (d′), and Total Recall Discriminability.

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.

Factors associated with insomnia among post-acute traumatic brain injury survivors

This study investigated the relationships between insomnia and select demographic, injury and psychosocial variables in post-acute, traumatic brain injury. Clinical assessment of sleep and mood was undertaken via objective measures and a diagnostic interview among 91 consecutive brain injury admissions to an outpatient neurorehabilitation clinic. No associations between insomnia and gender, education, age, and time since injury were found. A logistic regression model of insomnia prediction based upon the Beck Depression Inventory (BDI), self-reported pain disturbance, litigation and Glasgow Coma Score (GCS) correctly classified 87% of the sample with respect to the presence or absence of insomnia; however, depression and injury severity were the only variables that made a significant unique contribution to the prediction of insomnia. It is concluded that among post-acute traumatic brain injury patients, insomnia is linked with both the presence of depression and a history of milder brain injuries. This suggests that the determinants of insomnia may differ from the acute to the post-acute phase, with neurological factors playing a primary role early in the recovery process and psychosocial factors ascending later. Therefore, assessment and treatment of insomnia must give careful attention to the larger psychosocial context in which the sleep disorder emerges, particularly to role of emotional disturbance.This study investigated the relationships between insomnia and select demographic, injury and psychosocial variables in post-acute, traumatic brain injury. Clinical assessment of sleep and mood was undertaken via objective measures and a diagnostic interview among 91 consecutive brain injury admissions to an outpatient neurorehabilitation clinic. No associations between insomnia and gender, education, age, and time since injury were found. A logistic regression model of insomnia prediction based upon the Beck Depression Inventory (BDI), self-reported pain disturbance, litigation and Glasgow Coma Score (GCS) correctly classified 87% of the sample with respect to the presence or absence of insomnia; however, depression and injury severity were the only variables that made a significant unique contribution to the prediction of insomnia. It is concluded that among post-acute traumatic brain injury patients, insomnia is linked with both the presence of depression and a history of milder brain injuries. This suggests that the determinants of insomnia may differ from the acute to the post-acute phase, with neurological factors playing a primary role early in the recovery process and psychosocial factors ascending later. Therefore, assessment and treatment of insomnia must give careful attention to the larger psychosocial context in which the sleep disorder emerges, particularly to role of emotional disturbance.

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.

Performance Characteristics of Postacute Traumatic Brain Injury Patients on the WAIS-III and WMS-III

Publication of the third editions of the Wechsler intelligence and memory batteries in 1997 created a need for research identifying Wechsler Adult Intelligence Scale-Third Edition/Wechsler Memory Scale-Third Edition (WAIS-III/WMS-III) profile patterns associated with neuropathology. The WAIS-III/WMS-III Technical Manual offers data on various diagnostic groups, including traumatic brain injury (TBI). Hawkins (1998) employed Technical Manual data to propose certain diagnostic guidelines. In order to validate the conclusions put forth by Hawkins as they apply to brain injury, we examined WAIS-III and WMS-III profiles in an independent sample of 46 TBI cases. As expected, the WAIS-III Processing Speed Index (PSI) was more sensitive to brain injury than other WAIS-III composites; and specific WAIS-III scores were stronger than certain WMS-III scores. On the other hand, the predicted relationship for WMS-III auditory and visual indexes was not found. The lack of specificity for TBI of the proposed index comparisons confirms the need to validate such hypotheses in independent samples.

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, 1996 1997). 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.

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.