Faculty Bibliography

OBJECTIVE: To determine concordance between patient and family report of neurobehavioral symptoms and problems across 6 domains of function and 3 levels of injury severity at 1 year after traumatic brain injury (TBI). DESIGN: Prospective longitudinal design with follow-up between 10 and 14 months postinjury. SETTING: Seventeen Traumatic Brain Injury Model Systems centers. PARTICIPANTS: A total of 267 adults with primarily moderate and severe TBI who had completed self-ratings and whose neurobehavioral symptoms had also been rated by their significant others. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Neurobehavioral Functioning Inventory-Revised, a 70-item scale with subscales assessing frequency of symptoms in motor, somatic, memory and attention, depression, communication, and aggression domains. RESULTS: Twenty-three items showed significant differences or trends between the self- and other ratings; 18 of these were in the direction of the injured individual reporting less frequent problems. Differences were most pronounced on the depression, aggression, and memory and attention subscales. On the latter 2 subscales, patient-family concordance was higher for those with less severe injuries. However, severity effects were not clear cut. Analyses of selected rating patterns indicating clinically significant 'underreporting' of symptoms revealed that these affected the depression, aggression, and memory and attention subscales more than the motor or somatic subscales. CONCLUSIONS: At 1 year post-TBI, concordance between self- and other report of neurobehavioral symptoms was moderately high overall, but varied by symptom domain. For persons with moderate and severe TBI, reports from significant others may be needed for a full picture of the range, severity, and clinical importance of the patient's emotional, behavioral, and cognitive difficulties

OBJECTIVES: To examine the occurrence of and characteristics associated with violent traumatic brain injury (TBI) in the Traumatic Brain Injury Model Systems (TBIMS) project for 4 of the 5 original Model Systems centers and to determine the patient characteristics of this group, as well as the risk factors for sustaining such an injury. DESIGN: Prospective evaluation of individuals with violent TBI over a 10-year period. SETTING: Four TBIMS centers. PARTICIPANTS: A total of 1,229 individuals who received acute hospitalization and inpatient rehabilitation care for TBI. INTERVENTIONS: Not applicable. Main Outcome Measure: The occurrence of a violent TBI. RESULTS: Twenty-six percent of the participants in the TBIMS project sustained a violent TBI. This type of injury was more common in African-American men who were single and slightly older than the average TBI patient, were unemployed before injury, and had had a previous TBI. A higher injury rate was noted in the earlier part of the evaluation period. Those who sustained a violent TBI had higher levels of caregiver burden and disability, as well as decreased productivity and community reintegration at rehabilitation discharge and at 1 and 2 years postinjury. CONCLUSIONS: The occurrence of violent TBI in the TBIMS project is consistent with national trends of decreasing incidence of violent injuries in the 1990s. These results present a profile of those who have been injured through violence. The relative risks for sustaining such an injury appear to be well defined when considering demographic and temporal factors

OBJECTIVE: To characterize outcomes after traumatic brain injury (TBI) resulting from vehicular crashes, violence, falls, or other causes. DESIGN: Prospective, multicenter, longitudinal. SETTING: Seventeen Traumatic Brain Injury Model Systems. PARTICIPANTS: A total of 1,170 individuals with moderate to severe TBI with data from initial medical and rehabilitation stays and 1-year follow-up. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: At rehabilitation discharge, FIM instrument, Disability Rating Scale (DRS), and Rancho Los Amigo Levels of Cognitive Functioning Scale. At 1 year postinjury, FIM, DRS, Community Integration Questionnaire (CIQ), employment, residence, marital status, and seizure occurrence. RESULTS: The 4 etiology groups could be distinguished based on premorbid characteristics. Severity of injury indices indicated that individuals in vehicular crashes showed a trend toward incurring more severe injuries than the other 3 groups. At rehabilitation discharge, there were no functional differences between groups. At 1 year postinjury, the groups could be differentiated: individuals in violence-related TBI had higher unemployment rates and lower CIQ scores; persons in vehicular crashes reported the best functional and psychosocial outcomes; and individuals in the falls and other groups had outcomes lying between the vehicular and violence groups. CONCLUSION: This study elucidated important differences between persons with violence-related TBI and those with non-violence-related TBI. Further research is needed to find effective interventions to address these differences

OBJECTIVE: To compare demographics, injury characteristics, therapy service and intensity, and outcome in minority versus nonminority patients with traumatic brain injury (TBI). DESIGN: Retrospective analysis. SETTING: Twenty medical centers. PARTICIPANTS: Two thousand twenty patients (men, n=1,518; women, n=502; nonminority, n=1,168; minority, n=852) with TBI enrolled in the Traumatic Brain Injury Model Systems database. INTERVENTIONS: Not applicable. MAIN OUTCOMES MEASURES: Age, gender, marital status, education, employment status, injury severity (based on Glasgow Coma Scale [GCS] admission score, length of posttraumatic amnesia, duration of unconsciousness), intensity (hours) of therapy rendered, rehabilitation length of stay (LOS), rehabilitation charges, discharge disposition, postinjury employment status, FIM instrument change scores, and FIM efficiency scores. Independent sample t tests were used to analyze continuous variables; chi-square analyses were used to evaluate categorical data. RESULTS: Demographics: overall, minorities were found to be mostly young men who were single, unemployed, and less well educated, with a longer work week if employed when injured. Etiology: motor vehicle crashes (MVCs) predominated as the cause of injury for both groups; however, minorities were more likely to sustain injury from acts of violence and auto-versus-pedestrian crashes. Minorities also had higher GCS scores on admission and shorter LOS. Rehabilitation services: significant differences were found in the types and intensity of rehabilitation services provided; these included physical therapy, occupational therapy, and speech-language pathology, but not psychology. CONCLUSION: Minority patients who sustain TBI generally tend to be young men with less social responsibility. Although MVCs predominate as the primary etiology, acts of violence and auto-versus-pedestrian incidents are more common in the minority population. Minorities tend to have higher GCS scores at admission. Also, the type and intensity of rehabilitation services provided differed significantly for the various interdisciplinary subspecialties. Rehabilitation charges, discharge disposition, and postinjury employment status were similar for the 2 groups, even though LOS is typically 3 to 4 days shorter for the minority group. A more detailed investigation is warranted to explain these findings

This investigation evaluated yearly trends in charges and lengths of stay for patients with brain injury in acute care and rehabilitation settings over a 7 year period. Data was collected from 800 consecutive patients enrolled in four NIDRR Model Systems Traumatic Brain Injury programmes. Acute care daily charges showed almost routine increases, averaging nearly $550 per year. Conversely, lengths of stay generally showed a downward trend, with annual reductions averaging 2.25 days. Admission lengths of stay averaged 22-29 days between 1990-1994. Admissions averaged less than 20 days beginning in 1995, with the 1996 average of 16 days, nearly half that of the 1993 average. Between 1990-1996, average daily rehabilitation charges increased each year, with the rise averaging $83 or 7%. The rise in daily rehabilitation charges was offset by corresponding decreases in lengths of stay averaging 3.65 days or 8% annually. Increases in daily charges for brain injury rehabilitation care were roughly comparable to those for general medical care prices. However, the rate of change in acute care charges was substantially greater, with annual increases averaging 10% more than national medical care prices. The steady downward trend in lengths of stay raises serious concerns about the future availability of health care services to persons with brain injury

OBJECTIVES: To study group changes over time after traumatic brain injury (TBI). DESIGN: Prospective cohort. SETTING AND PARTICIPANTS: TBI Model System Database with 1160 subjects using cohort with complete data. MAIN OUTCOME MEASURES: Functional Independence Measure (FIM) and Disability Rating Scale (DRS) at rehabilitation discharge and annually after injury. RESULTS: Statistically significant differences existed between FIM-total, FIM-Motor, FIM-Cognitive subscales, and DRS at rehabilitation discharge and year 1. Comparisons of year-to-year intervals, years 1 and 3, 1 and 5, and 3 and 5, revealed no statistically significant differences except between years 1 and 3 and 1 and 5 with DRS, and years 1 and 5 with FIM. Including only those more dependent at year 1 revealed statistically significant differences between years 1 and 2 and 1 and 5 on FIM-Cognitive and DRS, but not the FIM-Motor. The proportion of change for FIM and DRS items from year 1 to years 2 and 5 revealed DRS Level of Functioning and Employability items accounted for most DRS change, whereas FIM change was more spread across its components. CONCLUSIONS: DRS is more sensitive to changes during a shorter time period than FIM and seems to be more appropriate for detecting long-term deficits. However, research studies aimed at detecting meaningful changes year to year after TBI may need to use other tools or consider changes among individuals instead of group changes. DRS Level of Function and Employability Items represent complex functions expected to recover later than the more basic DRS items. Sole use of these two DRS items might provide an efficient means of measuring long-term recovery when resources are limited, whereas expansion of these two items might allow greater sensitivity and detail

OBJECTIVES: To determine which outcome measures are best and least suited for assessing long-term functional outcome of individuals with traumatic brain injury (TBI) in the community. DESIGN: Survey of participants in the community an average of 5 years after TBI. A battery of outcome measures was given. SETTING: Community in northern California after inpatient rehabilitation. PARTICIPANTS: Forty-eight adult individuals with prior moderate to severe TBI. All subjects had received inpatient rehabilitation 2 to 9 years previously and could be reached for telephone interview. MAIN OUTCOME MEASURES: The Community Integration Questionnaire, Neurobehavioral Functioning Inventory (NFI), Patient Competency Rating Scale (PCRS), Level of Cognitive Functioning Scale (LCFS), FIM instrument, Functional Assessment Measure (FIM+FAM), Supervision Rating Scale (SRS), Disability Rating Scale (DRS), Revised Craig Handicap Assessment and Reporting Technique (R-CHART), and Glasgow Outcome Scale (GOS). The number of maximal scores on each of the surveys was studied to determine which instruments continued to reveal deficits years after TBI. RESULTS: Most individuals obtained maximum scores, ie, functional independence, on these scales: LCFS, FIM motor subscale and total score, R-CHART physical independence subscale, FIM+FAM, GOS, and the SRS. Measures with the fewest maximum scores (<36%, measuring deficits still extant in the group) were the R-CHART cognition subscale and the NFI memory/attention and communication subscales, and employment subscales. Items, subscales, and total scores that showed good variability and correlated most highly and frequently with other scales also demonstrating good variability were the PCRS, the DRS and FIM+FAM employment items, the R-CHART cognition subscale, and the NFI motor, memory/attention, communication, and depression subscales (the R-CHART cognition subscale and NFI memory/attention subscale were highly correlated with the PCRS;.84,.83). CONCLUSIONS: Measures that appeared to contribute little to assessing functional status of a TBI sample years postinjury were the FIM, FIM+FAM, SRS, GOS, and LCFS. Measures that showed a range of deficits across participants were DRS employability, the NFI, PCRS, and the R-CHART cognition subscale

This experiment investigated the existence of a direct anatomical connection between lateral preoptic and ventral tegmental areas that mediate brain stimulation reward using the behavioral adaptation of the collision test. This test is a double-pulse, two-electrode technique based on the axonal conduction failure that occurs when two separate sites in the same axon bundle are concurrently stimulated. This anatomical arrangement is inferred from the shape of the function relating the effectiveness of double-pulse stimulation to the interval between pulses. In this study, nine rats with a total of 44 pairs of sites were examined. In two pairs only was there a profile suggestive of an axonal collision effect, while the double-pulse effectiveness curve consistent with the properties of transynaptic collision was apparent for a single pair of sites; the remaining 93% were associated with relatively flat effectiveness curves. While electrode misalignment could be responsible for these results, there was adequate sampling to suggest that the preponderance of first stage signals that give rise to the rewarding effects mediated by the lateral preoptic and ventral tegmental areas do not travel along the same fiber bundle. However, stimulation applied to both sites concurrently produces a summation that is roughly 40% greater than stimulation at either site alone, suggesting reasonable integration of the reward signals generated by lateral preoptic and ventral tegmental area stimulation

Given the putative role of the lateral preoptic area as a primary contributor of the cell bodies of origin of the descending pathway linking a subset of lateral hypothalamic and ventral tegmental area reward neurons, the distribution of self-stimulation sites in this structure was mapped in 22 animals using moveable electrodes and threshold procedures. Ninety-seven electrode sites were evaluated with placements ranging from just rostral to the midline convergence of the anterior commissure back to the transition zone between the lateral preoptic and lateral hypothalamic areas; of these, roughly 2/3 supported self-stimulation which was widely observed throughout the lateral preoptic area and medial forebrain bundle. In general, self-stimulation thresholds obtained from lateral sites were most stable, and progressively so approaching more caudal regions. Examination of the slopes of the period/current trade-off functions revealed a tendency for higher values in lateral and caudal sites; in contrast, dorsoventral excursions did not influence these estimates. Taken together, these data provide support for the notion that the substrate for brain-stimulation reward in the lateral preoptic area has a relatively homogeneous distribution that is more diffusely organized than that found in reward sites activated further caudally in the medial forebrain bundle

The purpose of this study was to investigate the effect of a relatively novel technology, functional magnetic stimulation (FMS), on gastrointestinal transit of liquids in rats. Orogastric gavage with technetium-99 solution was used to assess gastric emptying and gastrointestinal transit time in 92 rats. FMS was performed over the anterior cervical and/or dorsal thoracolumbar regions using a figure-8 coil. Stimulation protocols were 1, 2, or 4 h in length. FMS accelerated gastric emptying and decreased gastrointestinal transit time. The acceleration was dependent on the stimulation parameters used as well as on the duration of the protocol; high levels of FMS produced a quicker effect, whereas lower levels were effective at later times. This study provides evidence that FMS could be an alternative or adjunct therapy to treat disorders in gastrointestinal motility