Allen W. Brown

Natural History of Headache after Traumatic Brain Injury

Headache is one of the most common persisting symptoms after traumatic brain injury (TBI). Yet there is a paucity of prospective longitudinal studies of the incidence and prevalence of headache in a sample with a range of injury severity. We sought to describe the natural history of headache in the first year after TBI, and to determine the roles of prior history of headache, sex, and severity of TBI as risk factors for post-traumatic headache. A cohort of 452 acute, consecutive patients admitted to inpatient rehabilitation services with TBI were enrolled during their inpatient rehabilitation from February 2008 to June 2009. Subjects were enrolled across 7 acute rehabilitation centers designated as TBI Model Systems centers. They were prospectively assessed by structured interviews prior to inpatient rehabilitation discharge, and at 3, 6, and 12 months after injury. Results of this natural history study suggest that 71% of participants reported headache during the first year after injury. The prevalence of headache remained high over the first year, with more than 41% of participants reporting headache at 3, 6, and 12 months post-injury. Persons with a pre-injury history of headache (p<0.001) and females (p<0.01) were significantly more likely to report headache. The incidence of headache had no relation to TBI severity (p=0.67). Overall, headache is common in the first year after TBI, independent of the severity of injury range examined in this study. Use of the International Classification of Headache Disorders criteria requiring onset of headache within 1 week of injury underestimates rates of post-traumatic headache. Better understanding of the natural history of headache including timing, type, and risk factors should aid in the design of treatment studies to prevent or reduce the chronicity of headache and its disruptive effects on quality of life.

Incidence of traumatic brain injury across the full disease spectrum: A population-based medical record review study

Background: Extremely few objective estimates of traumatic brain injury incidence include all ages, both sexes, all injury mechanisms, and the full spectrum from very mild to fatal events. Methods: We used unique Rochester Epidemiology Project medical records-linkage resources, including highly sensitive and specific diagnostic coding, to identify all Olmsted County, MN, residents with diagnoses suggestive of traumatic brain injury regardless of age, setting, insurance, or injury mechanism. Provider-linked medical records for a 16% random sample were reviewed for confirmation as definite, probable, possible (symptomatic), or no traumatic brain injury. We estimated incidence per 100,000 person-years for 1987–2000 and compared these record-review rates with rates obtained using Centers for Disease Control and Prevention (CDC) data-systems approach. For the latter, we identified all Olmsted County residents with any CDC-specified diagnosis codes recorded on hospital/emergency department administrative claims or death certificates during 1987–2000. Results: Of sampled individuals, 1257 met record-review criteria for incident traumatic brain injury; 56% were ages 16–64 years, 56% were male, and 53% were symptomatic. Mechanism, sex, and diagnostic certainty differed by age. The incidence rate per 100,000 person-years was 558 (95% confidence interval = 528–590) versus 341 (331–350) using the CDC data-system approach. The CDC approach captured only 40% of record-review cases. Seventy-four percent of missing cases presented to the hospital/emergency department; none had CDC-specified codes assigned on hospital/emergency department administrative claims or death certificates; and 66% were symptomatic. Conclusions: Capture of symptomatic traumatic brain injuries requires a wider range of diagnosis codes, plus sampling strategies to avoid high rates of false-positive events.

Predicting family functioning after TBI: Impact of neurobehavioral factors

ObjectiveTo identify risk factors for poor family functioning and neurobehavioral problems after traumatic brain injury (TBI) or orthopedic injuries (OI). DesignLongitudinal analyses of data from an inception cohort. ParticipantsSeventy-five patients with moderate/severe TBI, 47 patients with mild TBI, and 44 patients with OI at discharge; and 49 patients with moderate/severe TBI, 24 patients with mild TBI, and 33 patients with OI at 1-year follow-up. Outcome measures: Measures of family functioning (Family Assessment Device) and Neurobehavioral Functioning Index at hospital discharge and 1-year follow-up. ResultsAt discharge, patients with moderate/severe TBI had more symptoms of depression, memory/attention problems, and motor impairments than patients with OI and greater communication difficulties than patients with OI or mild TBI. At follow-up, patients with moderate/severe TBI continued to have more problems in memory/attention, depression, and communication. Approximately one third of each group had unhealthy family functioning at each assessment period. Few patients reported both impaired family functioning and clinical depression. Distressed family functioning correlated strongly with increased rates of neurobehavioral symptoms. Family dysfunction at follow-up was best predicted by family dysfunction at discharge and depression or memory/attention deficits at follow-up. ConclusionsAfter TBI, patients at the greatest risk for distress at follow-up were those with family dysfunction at discharge and continued neurobehavioral problems. High-risk families need to be identified so that necessary referrals and/or treatment can be offered.

Age effect on motor recovery in a post-acute animal stroke model

Male Fischer 344 rats aged 3, 6, 12, 18 and 24 months were trained to walk on a narrow beam, then lesioned in the right hindlimb sensorimotor cortex by photothrombosis. Motor performance was measured daily for 60 days using a 7-point rating scale from which deficit scores were calculated. Tissue analysis included lesion volume measurement after Nissl staining. Animals aged 3 and 6 months fully recovered by day 10 and 31, respectively. Animals aged 18 months acquired significant neurological impairment that persisted greater than 60 days. Deficit scores were significantly greater than in groups aged 12, 6 and 3 months. Degenerative morbidity and mortality confounded behavioral study of animals aged 24 months. The duration of neurological impairment after photochemical sensorimotor cortex lesion increased with age. Animals aged 18 months at lesion acquired the greatest chronic impairment. This aged post-acute animal model is clinically relevant to stroke rehabilitation.

A Survey of Very-Long-Term Outcomes after Traumatic Brain Injury among Members of a Population-Based Incident Cohort

To assess quality of life and barriers to participation in vocational and community life for persons with traumatic brain injury (TBI) over the very-long term, a population-based cohort was identified in Olmsted County, Minnesota; 1623 individuals were identified as having experienced a confirmed TBI while a resident of Olmsted County, Minnesota, during the period from 1935-2000. A survey was sent to eligible individuals that included elements of standardized instruments addressing health status and disability, and questions that assessed issues important to successful social reintegration after TBI. Of 1623 eligible participants sent surveys, 605 responded (37% response rate). Thirty-nine percent of respondents were female and 79% had mild injuries. Mean age at injury was 30.8 years, and mean years since injury was 28.8. Overall, respondents reported living in the community; the majority were married and had achieved education beyond high school. Problems with memory, thinking, and physical and emotional health were most often reported. Respondents reported low levels of depression and anxiety, and high levels of satisfaction with life. Seventy-three percent of respondents reported no problems that they attributed to their TBI. Increasing injury severity was associated with a significant risk of reporting injury-related problems at survey completion. Respondents with a longer time since injury were less likely to report any TBI-related problems. These results indicate that self-reported outcomes and adaptation to impairment-related limitations improve as the time since injury increases. These findings highlight the importance of providing coordinated medical rehabilitation and community-based support services to promote positive outcomes over the life span after TBI.

A Preliminary Model for Posttraumatic Brain Injury Depression

OBJECTIVE To develop, based on previous research, and evaluate a model for depression after traumatic brain injury (TBI). DESIGN Cross-sectional structural equation modeling (SEM) of data from consecutively recruited patients. SETTING Acute hospital and inpatient rehabilitation units. PARTICIPANTS Adult patients (N=158) after hospital admission for moderate to severe TBI. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES External appraisal of ability in participants was measured by the Mayo-Portland Adaptability Inventory (MPAI-4) Ability Index completed by a TBI clinical nurse specialist. Patient self-appraisal of post-TBI ability and depression were measured by the Awareness Questionnaire and Beck Depression Inventory-II. Functional outcome 1 year after injury was assessed with the MPAI-4 Participation Index. RESULTS Successive SEM resulted in a parsimonious model with excellent fit. Consistent with prior research, a moderately strong association between self-appraisal of post-TBI ability and depression was found. Injury severity, as measured by the duration of posttraumatic amnesia (PTA), was not significantly associated with post-TBI depression. The 1-year functional outcome was associated with depression and TBI severity. CONCLUSIONS The strong association between self-appraisal of post-TBI ability and depression is consistent with the cognitive-behavioral model of depression and recommends consideration and further study of cognitive-behavioral therapy for post-TBI depression. The lack of association between TBI severity and depression may represent the indirect and proxy nature of current measures of TBI severity such as PTA. Emerging neuroimaging techniques (eg, diffusion tensor imaging, magnetic resonance imaging spectroscopy) may provide the more direct measures of disruption of brain function after TBI that are needed to advance this line of research.

Factors associated with balance deficits on admission to rehabilitation after traumatic brain injury: a multicenter analysis.

OBJECTIVE To evaluate how demographics, measures of injury severity, and acute care complications relate to sitting and standing balance in patients with traumatic brain injury (TBI). DESIGN Multicenter analysis of consecutive admissions to designated TBI Model Systems of Care (TBIMS). SETTING Ten National Institute for Disability and Rehabilitation Research TBI Model System centers for coordinated acute and rehabilitation care. PARTICIPANTS 908 adults with TBI were included in the study. MAIN OUTCOME MEASURES Sitting and standing balance were assessed within 72 hours of admission to inpatient rehabilitation. RESULTS Age less than 50 years had a significant association with normal sitting and standing balance (P =.001 and.05, respectively). Measures of severity of traumatic brain injury, including admission Glasgow Coma Score, length of posttraumatic amnesia (PTA), length of coma, and acute care length of stay were each significantly related to impaired sitting and standing balance ratings (P <.01). Initial abnormalities in pupillary response had a significant relationship with impairment of sitting (P =.009) but not standing balance. Incidence of respiratory failure, pneumonia, soft tissue infections, and urinary tract infections were all related to impaired sitting balance (P <.01). Presence of intracranial hemorrhages did not have a significant relationship with either sitting or standing balance. Intracranial compression had a significant relationship with standing (P =.05) but not sitting balance. A discriminant function analysis, which included neuroradiological findings, injury severity, and medical complications, could not accurately predict impaired balance ratings. CONCLUSIONS This study demonstrated that rehabilitation admission balance ratings have a significant relationship with age, multiple measures of severity, and acute care medical complications after TBI. Prospective studies are indicated to evaluate the role balance at rehabilitation admission plays in the functional prognosis of patients with TBI.

Medical care costs associated with traumatic brain injury over the full spectrum of disease: A controlled population-based study

Data on traumatic brain injury (TBI) economic outcomes are limited. We used Rochester Epidemiology Project (REP) resources to estimate long-term medical costs for clinically-confirmed incident TBI across the full range of severity after controlling for pre-existing conditions and co-occurring injuries. All Olmsted County, Minnesota, residents with diagnoses indicative of potential TBI from 1985-2000 (n=46,114) were identified, and a random sample (n=7175) was selected for medical record review to confirm case status, and to characterize as definite (moderate/severe), probable (mild), or possible (symptomatic) TBI. For each case, we identified one age- and sex-matched non-TBI control registered in REP in the same year (±1 year) as cases TBI. Cases with co-occurring non-head injuries were assessed for non-head-injury severity and assigned similar non-head-injury-severity controls. The 1145 case/control pairs for 1988-2000 were followed until earliest death/emigration of either member for medical costs 12 months before and up to 6 years after baseline (i.e., injury date for cases and comparable dates for controls). Differences between case and control costs were stratified by TBI severity, as defined by evidence of brain injury; comparisons used Wilcoxon signed-rank plus multivariate modeling (adjusted for pre-baseline characteristics). From baseline until 6 years, each TBI category exhibited significant incremental costs. For definite and probable TBI, most incremental costs occurred within the first 6 months; significant long-term incremental medical costs were not apparent among 1-year survivors. By contrast, cost differences between possible TBI cases and controls were not as great within the first 6 months, but were substantial among 1-year survivors. Although mean incremental costs were highest for definite cases, probable and possible cases accounted for>90% of all TBI events and 66% of total incremental costs. Preventing probable and possible events might facilitate substantial reductions in TBI-associated medical care costs.

A prospective trial of elective extubation in brain injured patients meeting extubation criteria for ventilatory support: A feasibility study

IntroductionTo assess the safety and feasibility of recruiting mechanically ventilated patients with brain injury who are solely intubated for airway protection and randomising them into early or delayed extubation, and to obtain estimates to refine sample-size calculations for a larger study. The design is a single-blinded block randomised controlled trial. A single large academic medical centre is the setting.MethodsSixteen neurologically stable but severely brain injured patients with a Glasgow Coma Score (GCS) of 8 or less were randomised to early or delayed extubation until their neurological examination improved. Eligible patients met standard respiratory criteria for extubation and passed a modified Airway Care Score (ACS) to ensure adequate control of respiratory secretions. The primary outcome measured between groups was the functional status of the patient at hospital discharge as measured by a Modified Rankin Score (MRS) and Functional Independence Measure (FIM). Secondary measurements included the number of nosocomial pneumonias and re-intubations, and intensive care unit (ICU) and hospital length of stay. Standard statistical assessments were employed for analysis.ResultsFive female and eleven male patients ranging in age from 30 to 93 years were enrolled. Aetiologies responsible for the neurological injury included six head traumas, three brain tumours, two intracerebral haemorrhages, two subarachnoid haemorrhages and three ischaemic strokes. There were no demographic differences between the groups. There were no unexpected deaths and no significant differences in secondary measures. The difference in means between the MRS and FIM were small (0.25 and 5.62, respectively). These results suggest that between 64 and 110 patients are needed in each treatment arm to detect a treatment effect with 80% power.ConclusionsRecruitment and randomisation of severely brain injured patients appears to be safe and feasible. A large multicentre trial will be needed to determine if stable, severely brain injured patients who meet respiratory and airway control criteria for extubation need to remain intubated.

Life expectancy following rehabilitation: a NIDRR Traumatic Brain Injury Model Systems study.

Objective:To characterize overall and cause-specific mortality and life expectancy among persons who have completed inpatient traumatic brain injury rehabilitation and to assess risk factors for mortality. Design:Prospective cohort study. Setting:The Traumatic Brain Injury Model Systems. Participants:A total of 8573 individuals injured between 1988 and 2009, with survival status per December 31, 2009, determined. Interventions:Not applicable. Main Outcome Measures:Standardized mortality ratio (SMR), life expectancy, cause of death. Results:SMR was 2.25 overall and was significantly elevated for all age groups, both sexes, all race/ethnic groups (except Native Americans), and all injury severity groups. SMR decreased as survival time increased but remained elevated even after 10 years postinjury. SMR was elevated for all cause-of-death categories but especially so for seizures, aspiration pneumonia, sepsis, accidental poisonings, and falls. Life expectancy was shortened an average of 6.7 years. Multivariate Cox regression showed age at injury, sex, race/ethnic group, marital status and employment status at the time of injury year of injury, preinjury drug use, days unconscious, functional independence and disability on rehabilitation discharge, and comorbid spinal cord injury to be independent risk factors for death. Conclusion:There is an increased risk of death after moderate or severe traumatic brain injury. Risk factors and causes of death have been identified that may be amenable to intervention.