Faculty Bibliography

As healthcare continues to evolve, there are changes in the delivery of care for patients with severe neurologic injuries. Although the acute hospital stay is shortening, physiatrists can play a key role in preparing patients for rehabilitation, minimizing longer-term complications and helping to determine the most appropriate paths for further treatment. Inpatient rehabilitation facilities (IRFs) continue to be an important part of the care continuum for patients with severe injuries, but the role of IRFs has also evolved as patients have been admitted with increasing medical and neurologic complexity and length of stay continues to be reduced. Skilled nursing facilities and subacute facilities continue to evolve, in part to fill the gaps that have developed for patients who are "not yet ready for rehabilitation" and for those whose recovery trajectory has been deemed too slow for IRF. Outpatient care is also changing, in part due to the availability of new rehabilitation interventions as highlighted in other sections of the supplement. Furthermore, telemedicine will provide additional options for expanding specialized care beyond prior geographical limitations. Physiatrists need to be aware of these ongoing changes and the roles that they can play outside of the traditional IRF model of care. This article will focus on the innovations in healthcare delivery and opportunities to maximize outcomes in the current and future models of care.

OBJECTIVE:After traumatic brain injury (TBI), there may be persistent central-autonomic-network (CAN) dysfunction causing cardiovascular-autonomic dysregulation. Eyeball-pressure-stimulation (EPS) normally induces cardiovagal activation. In patients with a history of moderate or severe TBI (post-moderate-severe-TBI), we determined whether EPS unveils cardiovascular-autonomic dysregulation. METHODS:In 51 post-moderate-severe-TBI patients (32.7 ± 10.5 years old, 43.1 ± 33.4 months post-injury), and 30 controls (29.1 ± 9.8 years), we recorded respiration, RR-intervals (RRI), systolic and diastolic blood-pressure (BPsys, BPdia), before and during EPS (120 sec; 30 mmHg), using an ocular-pressure-device (Okulopressor®). We calculated spectral-powers of mainly sympathetic low (LF: 0.04-0.15 Hz) and parasympathetic high (HF: 0.15-0.5 Hz) frequency RRI-fluctuations, sympathetically mediated LF-powers of BPsys, and calculated normalized (nu) LF- and HF-powers of RRI. We compared parameters between groups before and during EPS by repeated-measurement-analysis-of-variance with post-hoc analysis (significance: p < 0.05). RESULTS:At rest, sympathetically mediated LF-BPsys-powers were significantly lower in the patients than the controls. During EPS, only controls significantly increased RRIs and parasympathetically mediated HFnu-RRI-powers, but decreased LF-RRI-powers, LFnu-RRI-powers, and LF-BPsys-powers; in contrast, the patients slightly though significantly increased BPsys upon EPS, without changing any other parameter. CONCLUSIONS:In post-moderate-severe-TBI patients, autonomic BP-modulation was already compromised at rest. During EPS, our patients failed to activate cardiovagal modulation but slightly increased BPsys, indicating persistent CAN dysregulation. SIGNIFICANCE/CONCLUSIONS:Our findings unveil persistence of subtle cardiovascular-autonomic dysregulation even years after TBI.

We seek to elucidate the underlying pathophysiology of injury sustained after mild traumatic brain injury (MTBI) using multi-shell diffusion MRI, deriving compartment-specific WM tract integrity (WMTI) metrics. WMTI allows a more biophysical interpretation of WM changes by describing microstructural characteristics in both intra- and extra-axonal environments. Thirty-two patients with MTBI within 30 days of injury and twenty-one age- and sex-matched controls were imaged on a 3T MR scanner. Multi-shell diffusion acquisition was performed with 5 b-values (250 - 2500 s/mm²) along 6 - 60 diffusion encoding directions. Tract-based spatial statistics (TBSS) was used with family-wise error (FWE) correction for multiple comparisons. TBSS results demonstrate focally lower intra-axonal diffusivity (D_axon) in MTBI patients in the splenium of the corpus callosum (sCC) (p < 0.05, FWE-corrected). The Area Under the Curve (AUC)-value for was 0.76 with low sensitivity of 46.9%, but 100% specificity. These results indicate that D_axon may be a useful imaging biomarker highly specific for MTBI-related WM injury. The observed decrease in D_axon suggests restriction of the diffusion along the axons occurring shortly after injury.

Introduction/Rational Despite the outcomes achieved by the diagnostic, treatment, preventative and other services provided to adults with TBI in inpatient acute and subacute rehabilitation facilities, nursing homes, residential and outpatient programs, of late access to comprehensive rehabilitation has been increasingly limited by third-party payers, not uncommonly with the justification that there is no 'Class I' evidence to support the provision of these needed services. The outcome of this discriminatory process is that individuals with TBI are unable to receive care from which they could benefit, thereby limiting their recovery and increasing the burden of care on their families and society. Method/Approach BIAA is funding the development of guidelines as to what diagnostic, treatment, preventative and other services, whether medical, social, psychological or educational, should be provided and in what settings and/or phases after injury onset. The project utilizes GRADE methodology and incorporates evidence from studies that are less than Class I. Where evidence is lacking, consensus recommendations developed by expert panels are included. The guidelines will be disseminated widely to patients, families, service providers, insurers and policymakers. Guidelines development started with the development of PICOT (Population, Intervention, Comparator, Outcome, Time point) questions to direct the identification of evidence. Results/Effects Five panels of about 11 stakeholders each (persons with TBI, family members, clinicians, researchers) have developed 54 PICOT questions, in five areas: behavioral issues; cognitive rehabilitation; functional issues; chronic medical issues; vocational-community. Many of these questions contain subsidiary questions focused on the subgroups or time points for which treatments are most effective. The chronic medical issues panel will formulate additional questions once the incidence/prevalence of chronic comorbidities has been determined. Screening of over 16,000 abstracts (using the Covidence website) has been completed for most questions, and extracting of data (using the Systematic Review Data Repository) has started. Conclusions/Limitations Conclusion: This presentation will highlight the PICOT questions, and some of the methodological challenges created by the large number of questions and the extensive literature at least potentially relevant to them

After traumatic brain injury (TBI), central autonomic dysfunction might contribute to long-term increased mortality rates. Central autonomic dysfunction might depend on initial trauma severity. This study was performed to evaluate differences in autonomic modulation at rest and upon standing between patients with a history of mild TBI (post-mild-TBI patients), moderate or severe TBI (post-moderate-severe-TBI patients), and healthy controls. In 20 post-mild-TBI patients (6-78 months after TBI), age-matched 20 post-moderate-severe-TBI patients (6-94 months after TBI) and 20 controls, we monitored respiration, RR intervals (RRI) and systolic blood pressure (BPsys) at supine rest and upon standing. We determined mainly sympathetic low (LF) and parasympathetic high (HF) frequency powers of RRI fluctuations, sympathetically mediated LF-BPsys powers, LF/HF-RRI ratios, normalized (nu) LF-RRI and HF-RRI powers, and compared data between groups, at rest and upon standing (ANOVA with post hoc testing). We correlated autonomic parameters with initial Glasgow Coma Scale (GCS) scores (Spearman test; significance: p < 0.05). Supine BPsys and LFnu-RRI powers were higher while HFnu-RRI powers were lower in post-moderate-severe-TBI patients than post-mild-TBI patients and controls. LFnu-RRI powers were higher and HFnu-RRI powers were lower in post-mild-TBI patients than controls. Upon standing, only post-mild-TBI patients and controls increased LF-BPsys powers and BPsys and decreased HF-RRI powers. GCS scores correlated positively with LFnu-RRI powers, LF/HF-RRI ratios, and inversely with HFnu-RRI powers, at standing position. More than 6 months after TBI, there is autonomic dysfunction at rest and upon standing which is more pronounced after moderate-severe than mild TBI and in part correlates with initial trauma severity.

OBJECTIVE: This study investigated the utility of sideline concussion tests, including components of the Sports Concussion Assessment Tool, 3rd Edition (SCAT3) and the King-Devick (K-D), a vision-based test of rapid number naming, in an outpatient, multidisciplinary concussion center treating patients with both sports-related and non-sports related concussions. The ability of these tests to predict clinical outcomes based on the scores at the initial visit was evaluated. METHODS: Scores for components of the SCAT3 and the K-D were fit into regression models accounting for age, gender, and sport/non-sport etiology in order to predict clinical outcome measures including total number of visits to the concussion center, whether the patient reached a SCAT3 symptom severity score