Another look at paradoxical severity effects in head injury with the Personality Assessment Inventory.

Previous investigations of psychiatric symptomatology after head injury using the MMPI-2 (Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) have consistently revealed greater Basic scale elevations in mild injuries versus more severe injuries. In this study, we tested this pattern of paradoxical severity effects using the Personality Assessment Inventory (PAI; Morey, 1991). We gathered PAI and MMPI-2 data from 34 patients with moderate-to-severe head injuries and from 52 patients with mild head injuries. MMPI-2 Basic scale profiles were consistent with the paradoxical severity effect; mild injury patients had significantly more elevated scores on four Basic scales (Scales 1, 2, 3, and 7). PAI Clinical scale profiles showed significantly more elevated scores among mild injury patients on 2 scales, Somatization and Depression, and more elevated scores among moderate-to-severe patients on 2 scales, Antisocial Features and Alcohol Problems. We consider unique contributions of the PAI for the psychological assessment of head injury.

Detecting insufficient effort using the Seashore Rhythm and Speech-Sounds Perception Tests in head injury.

This study examined the capacity of the Seashore Rhythm Test (SRT) and the Speech-Sounds Perception Test (SSPT) to detect insufficient effort in a clinical sample. Forty-six participants with financially compensable mild head injury who obtained scores indicative of insufficient effort on multiple measures were compared to 49 participants with brain injury who were not involved in litigation. Receiver operating characteristic (ROC) curve analysis indicated that both the SRT (AUC = .84) and SSPT (AUC = .80) were significant (p < .001) predictors of insufficient effort. Maximizing sensitivity and specificity, the optimal cutoff scores were 8 errors on the SRT and 10 errors on the SSPT. Combining both variables into a logistic regression function increased the diagnostic efficiency.

Patient-informant agreement on personality ratings and self-awareness after head injury.

To address concerns about self-awareness deficits and the validity of self-ratings by patients with head injury (HI), the current study examines mean differences and correlations between self-ratings from 52 patients with HI and ratings of the patient by informants using the revised NEO Personality Inventory (NEO-PI-R). Patient self-ratings were significantly lower than informant ratings on neuroticism and extraversion and significantly higher on conscientiousness. Patient-informant correlations ranged from .42 for conscientiousness to .67 for agreeableness, and these agreement correlations compare favorably with those obtained from normal adult samples. Hierarchical multiple regression equations for each of the five NEO-PI-R trait domains showed that more severe injuries were associated with higher agreement for extraversion. For all five traits, the strongest predictors of informant personality ratings were the patients' self-ratings. The implications of these findings for clinical assessment and improved research on self-awareness deficits after HI are discussed.

Psychological disturbance, incomplete effort, and compensation-seeking status as predictors of neuropsychological test performance in head injury.

Indices from the Minnesota Multiphasic Personality Inventory-2 (MMPI-2; Butcher, Dahlstrom, Graham, Tellegen, & Kaemmer, 1989) representing cognitive and emotional disturbance as well as incomplete effort on the Recognition Memory Test (RMT; Warrington, 1984) were examined as predictors of performance on the Halstead-Reitan Neuropsychological Test Battery (HRB; Reitan & Wolfson, 1993). In the current study, which included a large sample (N = 369) of patients referred for neuropsychological (NP) evaluation after presumptive head injury, MMPI-2 measures of psychological disturbance accounted for as much as 25% of the variance in HRB test scores, resulting in a moderate overall effect size (median Adj. R(2) = .16; R = .40). When demographic variables, head injury severity, and compensation-seeking status were entered in previous steps, incomplete effort as defined by chance performance on the RMT accounted for between 2% and 13% of the variance in HRB test scores, with modest overall effect size (median R(2) Delta = .07; R = .26) in multiple regression equations. Additionally, when MMPI-2 indices of psychological disturbance were included in the last step, they accounted for 2% to 11% of additional variance, retaining a modest overall effect (median R(2) Delta = .03; R = .17). Compensation-seeking status and injury severity as measured by duration of post-traumatic amnesia were, at best, modestly related to NP test performance. Findings confirm the reliable relationship between test performance and psychological disturbance as well as incomplete effort when assessing dysfunction following head injury. In contrast to previous studies, incomplete effort was unrelated to compensation-seeking status.

MMPI-2 indices of psychological disturbance and attention and memory test performance in head injury.

A number of studies have investigated the relationship between psychological disturbance and neuropsychological (NP) test performance. The current study is a replication and extension of who found that MMPI-2 indices of psychological disturbance are related to performance on NP tests of attention and memory in psychiatric and head-injured patients. In a large sample (N=381) referred for evaluation after sustaining presumed head injury, we examined the relationship between MMPI-2 indices of psychological disturbance and measures of attention and memory from the Wechsler Memory Scale-Revised (WMS-R), Wechsler Adult Intelligence Scale-Revised (WAIS-R), California Verbal Learning Test (CVLT), and the Memory Assessment Scales (MAS). Although related to other domains, MMPI-2 variables were most consistently related to measures of attention and List Learning. Even when demographic variables, injury severity, and litigation status were controlled, MMPI-2 indices significantly predicted performance on six out of eight tests. However, the correspondence between similar indices on the WMS-R and MAS were relatively low, especially for Verbal Memory and Visual Reproduction. Further, litigation was significant in predicting only 2 of 8 attention and memory indices.

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.