Faculty Bibliography

OBJECTIVE: To examine the relationship between gender and cognitive recovery 1 year following traumatic brain injury (TBI). METHODS: Patients with blunt TBI were identified from the TBI Model Systems of Care National Database, multi-centre cohort study. The included patients (n = 325) were 16-45 years at injury, admitted to an acute care facility within 24 hours, received inpatient rehabilitation, had documented admission Glasgow Coma Scale (GCS) scores, completed neuropsychological follow-up 1 year post-injury and did not report pre-morbid learning problems. Multivariate analyses of variance examined the unadjusted association between gender and six cognitive domains examining attention/working memory, verbal memory, language, visual analytic skills, problem-solving and motor functioning. Analyses of covariance models were constructed to determine if confounding factors biased the observed associations. RESULTS: Females performed significantly better than males on tests of attention/working memory and language. Males outperformed females in visual analytic skills. Gender remained significantly associated with performance in these areas when controlling for confounding variables. CONCLUSIONS: These results suggest a better cognitive recovery of females than males following TBI. However, future studies need to include non-TBI patients to control for possible pre-injury gender-related differences, as well as to conduct extended follow-ups to determine the stability of the observed differences

The present study used the National Institute on Disability Rehabilitation and Research (NIDRR) funded Traumatic Brain Injury Model Systems (TBIMS) database to examine the effect of gender on presentation of executive dysfunction following traumatic brain injury (TBI) and variables that might impact the course and degree of recovery. The Wisconsin Card Sort Test (WCST) was chosen as a measure of executive function which has good credentials without reports of gender effects. Female subjects performed significantly better on the WCST than male subjects as shown by analyses of variance on scores of 1,331 patients for Categories Achieved (means for females = 4.09, males = 3.67, p = .003) and Perseverative Responses (means for females = 32.17, males = 36.42, p = .003). Outperformance by females was also noted in additional ANOVAs examining the interaction of education and gender, and ethnicity and gender in relation to Categories Achieved (p < .01), and for ethnicity and gender in relation to Perseverative Responses (p < .01). A multiple logistic regression revealed that gender, minority status, education level, history of illicit drug use, cause of injury, and length of coma each contributed uniquely to predicting Categories Achieved on the WCST. Simple logistic regression analyses showed that, of these variables, gender and cause of injury (violent vs. non-violent) were the strongest predictors. In contrast, when examining Perseverative Responses, regression analyses found gender, minority status and length of coma predicted impairment. Simple logistic regression analyses showed that, of these three variables, gender and minority status were most robust in predicting impaired Perseverative Responses scores. Implications of these findings are discussed and recommendations for further research are offered

OBJECTIVE: Evaluate the association between neuroendocrine findings and fatigue after traumatic brain injury (TBI) Research design: Prospective, observational. METHODS AND PROCEDURES: Sixty-four individuals at least 1 year post-TBI underwent neuroendocrine testing including thyroid, adrenal, gonadal axes and growth hormone (GH) after glucagon stimulation with assessment of fatigue using the Global Fatigue Index (GFI) and the Fatigue Severity Scale (FSS). MAIN OUTCOMES AND RESULTS: GFI and FSS scores were significantly higher within this sample compared to published control data. At least one pituitary axis was abnormal in 90% of participants. Higher GH levels were significantly associated with higher FSS scores. There was a noted trend between lower basal cortisol and higher scores on both the FSS and GFI. CONCLUSIONS: The association between higher GH levels and greater fatigue contradicted the prevailing hypothesis that post-acute TBI fatigue is associated with GH deficiency. The association between lower basal cortisol and greater fatigue was in the expected direction. While no other trends were noted, the fatigue derived from neuroendocrine abnormalities alone may be masked by fatigue induced by other factors commonly experienced following TBI. Given the high prevalence of pituitary abnormalities, screening for hypopituitarism after TBI is a reasonable recommendation. The contribution of GH deficiency to diminished quality of life post-TBI remains unclear

OBJECTIVES: To investigate environmental barriers reported by people with spinal cord injury (SCI), and to determine the relative impact of environmental barriers compared with demographic and injury characteristics and activity limitations in predicting variation in participation and life satisfaction. DESIGN: Cross-sectional, follow-up survey. SETTING: Individuals rehabilitated at 16 federally designated Model Spinal Cord Injury Systems of care, now living in the community. PARTICIPANTS: People with SCI (N=2726) who completed routine follow-up research interviews between 2000 and 2002. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The Craig Hospital Inventory of Environmental Factors-Short Form (CHIEF-SF), the Craig Handicap Assessment and Reporting Technique-Short Form, and the Satisfaction With Life Scale. RESULTS: The top 5 environmental barriers reported by subjects with SCI, in descending order of importance, were the natural environment, transportation, need for help in the home, availability of health care, and governmental policies. The CHIEF-SF subscales accounted for only 4% or less of the variation in participation; they accounted for 10% of the variation in life satisfaction. CONCLUSIONS: The inclusion of environmental factors in models of disability was supported, but were found to be more strongly related to life satisfaction than to societal participation

BACKGROUND: The incidence of late posttraumatic seizures (LPTS) in individuals with traumatic brain injury (TBI) ranges anywhere from 5% to 18.9% in civilian populations up to 32% to 50% in military personnel. OBJECTIVE: This article reviews the current knowledge about the incidence and prevalence of LPTS following a TBI, the risk factors for developing LPTS, and the options available for preventing the development of LPTS. METHODS: The psychosocial ramifications of LPTS following a TBI have not been well explored. As a result, the psychosocial findings from the current literature on epilepsy will be reviewed with the hope that the need for future TBI outcomes research to investigate the impact of LPTS following a TBI or, at least, to include LPTS as a potential contributing factor will be recognized

OBJECTIVE: To study cognitive, communication, and social changes experienced by individuals between 1 and 5 years after traumatic brain injury (TBI). DESIGN: Prospective cohort. SETTING AND PARTICIPANTS: TBI Model System Database with 927 eligible subjects using a cohort with complete 1- and 5-year data (N = 292). MAIN OUTCOME MEASURES: Change in Functional Independence Measure trade mark -Cognitive (FIM-Cog) items from Year 1 to Year 5 postinjury. RESULTS: On the FIM-Cog Total score, 26% individuals improved, 61% stayed the same, and 14% worsened by more than 1 point from Year 1 to Year 5. On the 2 FIM Communication items, 19% individuals improved, 68% stayed the same, and 13% worsened by greater than 1 point. On the FIM Social Interaction item, 12% individuals improved, 76% stayed the same, and 11% worsened. On the FIM Memory and Problem Solving items, 34% individuals improved, 48% stayed the same, and 19% worsened. Several variables predicted this improvement and worsening, some of which were available at the time of injury and most were those available at 1 year postinjury. The Memory and Problem Solving items, taken together, showed fewer participants at ceiling at Year 1 and more change between Year 1 and Year 5 compared to the Communication and Social Interaction items. CONCLUSIONS: Many individuals did not demonstrate meaningful change on FIM-Cog and its component items from Year 1 to Year 5. In particular, a high proportion of improvement was observed in Memory/Problem Solving, and worsening in Social Interaction. Demographic and functional indicators present at 1 year postinjury may be predictive of subsequent change

OBJECTIVE: Study functional changes between one and five years after traumatic brain injury (TBI). DESIGN: Prospective cohort. SETTING AND PARTICIPANTS: TBI Model Systems National Database subjects using cohort with complete one and five year data (n = 301). MAIN OUTCOME MEASURES: Disability Rating Scale (DRS) Level of Functioning and Employability Items. RESULTS: On Level of Functioning, 53 (18%) individuals improved, 228 (76%) stayed the same, and 20 (7%) worsened by more than one point from Year 1 to Year 5. On Employability, 50 (17%) individuals improved, 237 (79%) stayed the same, and 14 (5%) worsened by greater than one point. Level of Functioning improvement was predicted by FIM-Motor, FIM-Cognitive, Rey Auditory Verbal Learning Test, Symbol Digit Modalities Test (written and oral), and Wechsler Adult Intelligence Scale-Revised Block Design, and worsening predicted by Symbol Digit Modalities Test (written and oral). Improvement in Employability was predicted by race, while Glasgow Coma Scale Eye Opening was predictive of worsening. CONCLUSIONS: Although the majority did not demonstrate meaningful change on the DRS items from year 1 to 5, some individuals made dramatic gains and a minority declined. There are demographic and functional indicators present at one-year post-injury that may be predictive of subsequent change

OBJECTIVES: To ascertain the natural history and to stratify risks for the development of late posttraumatic seizures in individuals with moderate to severe traumatic brain injury (TBI). DESIGN: Prospective, observational study of individuals with TBI admitted to 4 trauma centers within 24 hours of injury. SETTING: Four tertiary care trauma centers in urban areas. PARTICIPANTS: A total of 647 individuals (>/=16 y) with any of the following abnormal computed tomography (CT) scan findings: extent of midline shift and/or cisternal compression or presence of any focal pathology (eg, punctate, subarachnoid, or intraventricular hemorrhage; cortical or subcortical contusion; extra-axial lesions) during the first 7 days postinjury or best Glasgow Coma Scale (GCS) score of </=10 during the first 24 hours post-TBI. Subjects were enrolled from August 1993 through September 1997 and followed for up to 24 months, until death or their first late posttraumatic seizures. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Cumulative probability, relative risk, and survival analyses were used to stratify risks for development of late postttraumatic seizures on the basis of demographic factors, etiology of injury, initial GCS, early posttraumatic seizures, time post-TBI, types of intracerebral lesion by CT scan, and number and types of intracranial procedures. RESULTS: Sixty-six individuals had a late posttraumatic seizures; 337 had no late posttraumatic seizures during full 24-month follow-up; 167 had no late posttraumatic seizures during time followed (<24 mo); and 54 were placed on anticonvulsants without a late posttraumatic seizures, whereas 23 died before their first late posttraumatic seizures. The highest cumulative probability for late posttraumatic seizures included biparietal contusions (66%), dural penetration with bone and metal fragments (62.5%), multiple intracranial operations (36.5%), multiple subcortical contusions (33.4%), subdural hematoma with evacuation (27.8%), midline shift greater than 5mm (25.8%), or multiple or bilateral cortical contusions (25%). Initial GCS score was associated with the following cumulative probabilities for development of late posttraumatic seizures at 24 months: GCS score of 3 to 8, 16.8%; GCS score of 9 to 12, 24.3%; and GCS score of 13 to 15, 8.0%. CONCLUSIONS: Stratification by CT scan findings and neurosurgical procedures performed were the most useful findings in defining individuals at highest risk for late posttraumatic seizures

OBJECTIVE: To examine job stability moderating variables and develop a postinjury work stability prediction model. DESIGN: Multicenter analysis of individuals with traumatic brain injury (TBI) who returned for follow-up at 1, 2, and 3, or 4 years postinjury, were of working age (between 18 and 62 years of age at injury), and were working preinjury. SETTING: Six National Institute on Disability and Rehabilitation Research TBI Model System centers for coordinated acute and rehabilitation care. PARTICIPANTS: A total of 186 adults with TBI were included in the study. MAIN OUTCOME MEASURES: Job stability was categorized as stably employed (employed at all 3 follow-up intervals); unstably employed (employed at one or two of all three follow-up intervals); and unemployed (unemployed at all three follow-up intervals). RESULTS: After injury, 34% were stably employed, 27% were unstably employed, and 39% were unemployed at all three follow-up intervals. Minority group members, people who did not complete high school, and unmarried people were more likely to be unemployed. Driving independence was highly influential and significantly related to employment stability. A discriminant function analysis, which included age, length of unconsciousness and Disability Rating Scale scores at 1 year postinjury, accurately predicted job stability groupings. CONCLUSION: Data analysis provided evidence that employment stability is predictable with a combination of functional, demographic, and injury severity variables. Identification of people at risk for poor employment outcomes early on can facilitate rehabilitation planning and intervention

The Traumatic Brain Injury Model Systems of Care (TBIMS) is a program that has been funded by the National Institute on Disability and Rehabilitation Research (US Department of Education) since 1987. The program is a collaborative effort of rehabilitation centers across the United States to further knowledge about the natural history of recovery and outcomes over the life course of individuals with traumatic brain injury, as well as to provide comprehensive services across the continuum of care and to foster innovative research programs. This introduction describes the underlying principles of the TBIMS program and the research initiatives carried out in the 1997/1998-2002 funding cycle