Balance Assessment in Traumatic Brain Injury: A Comparison of the Sensory Organization and Limits of Stability Tests.

Balance problems are common after a traumatic brain injury (TBI). Symptoms of dizziness, unsteadiness, or imbalance have been most frequently attributed to sensory organization problems involving the use of visual, proprioceptive, and/or vestibular information for postural control. These problems can be assessed with the Sensory Organization Test (SOT). However, as head trauma can affect any brain region, areas responsible for voluntary control of movements involved in dynamic balance tasks, such as the motor cortex and its projections, could also be compromised, which would likely affect one's limits of stability. The Limits of Stability (LOS) balance test has received little attention in TBI. In the present study, we compared the prevalence of SOT versus LOS abnormalities in a cohort of 48 patients, the majority classified as having mild or moderate chronic TBI. Compared with a normative database provided by the balance testing manufacturer, a larger portion of our cohort presented abnormalities in the LOS test. Dizziness Handicap Inventory (DHI) results indicated mild disability, with the five activities most frequently endorsed as problematic being: looking up, performing quick head movements, performing ambitious such as sports or dancing activities, feeling frustrated, and performing strenuous house/yard work. Although regression analysis revealed that both tests significantly predicted subjective scores on the DHI, more LOS than SOT testing variables were important predictors of DHI results indicating disability. These results suggest that the LOS test is an informative tool that should be included in any objective balance evaluations that screen TBI patients with balance complaints.

Phosphodiesterase-5 inhibition potentiates cerebrovascular reactivity in chronic traumatic brain injury.

BACKGROUND: Traumatic cerebrovascular injury (TCVI), a common consequence of traumatic brain injury (TBI), presents an attractive therapeutic target. Because phosphodiesterase-5 (PDE5) inhibitors potentiate the action of nitric oxide (NO) produced by endothelial cells, they are candidate therapies for TCVI. This study aims to: (1) measure cerebral blood flow (CBF), cerebrovascular reactivity (CVR), and change in CVR after a single dose of sildenafil (ΔCVR) in chronic TBI compared to uninjured controls; (2) examine the safety and tolerability of 8-week sildenafil administration in chronic symptomatic moderate/severe TBI patients; and as an exploratory aim, (3) assess the effect of an 8-week course of sildenafil on chronic TBI symptoms. METHODS: Forty-six subjects (31 chronic TBI, 15 matched healthy volunteers) were enrolled. Baseline CBF and CVR before and after administration of sildenafil were measured. Symptomatic TBI subjects then completed an 8-week double-blind, placebo-controlled, crossover trial of sildenafil. A neuropsychological battery and neurobehavioral symptom questionnaires were administered at each study visit. RESULTS: After a single dose of sildenafil, TBI subjects showed a significant increase in global CVR compared to healthy controls (P < 0.001, d = 0.9). Post-sildenafil CVR maps showed near-normalization of CVR in many regions where baseline CVR was low, predominantly within areas without structural abnormalities. Sildenafil was well tolerated. Clinical Global Impression (CGI) scale showed a trend toward clinical improvement while on sildenafil treatment. FINDINGS: Single-dose sildenafil improves regional CVR deficits in chronic TBI patients. CVR and ΔCVR are potential predictive and pharmacodynamic biomarkers of PDE5 inhibitor therapy for TCVI. Sildenafil is a potential therapy for TCVI.

Imaging of Cerebrovascular Function in Chronic Traumatic Brain Injury.

Traumatic cerebrovascular injury (TCVI) is a common pathologic mechanism of traumatic brain injury (TBI) and presents an attractive target for intervention. The aims of this study were to assess cerebral blood flow (CBF) and cerebrovascular reactivity (CVR) using magnetic resonance imaging (MRI) to assess their value as biomarkers of TCVI in chronic TBI, characterize the spatial distribution of TCVI, and assess the relationships between each biomarker and neuropsychological and clinical assessments. Forty-two subjects (27 chronic TBI, 15 age- and gender-matched healthy volunteers) were studied cross-sectionally. CBF was measured by arterial spin labeling and CVR by assessing the MRI-blood oxygen level-dependent signal with hypercapnia challenge. A focused neuropsychological battery adapted from the TBI Common Data Elements and neurobehavioral symptom questionnaires were administered at the time of the imaging session. Chronic TBI subjects showed a significant reduction in mean global, gray matter (GM), and white matter (WM) CVR, compared with healthy volunteers (p < 0.001). Mean GM CVR had the greatest effect size (Cohen's d = 0.9). CVR maps in chronic TBI subjects showed patchy, multifocal CVR deficits. CBF discriminated poorly between TBI subjects and healthy volunteers and did not correlate with CVR. Mean global CVR correlated best with chronic neurobehavioral symptoms among TBI subjects. Global, GM, and WM CVR are reliable and potentially useful biomarkers of TCVI in the chronic stage after moderate-to-severe TBI. CBF is less useful as biomarker of TCVI. CVR correlates best with chronic TBI symptoms. CVR has potential as a predictive and pharmacodynamic biomarker for interventions targeting TCVI.

FDA Regulation of Neurological and Physical Medicine Devices: Access to Safe and Effective Neurotechnologies for All Americans.

The United States Food and Drug Administration (FDA) ensures that patients in the U.S. have access to safe and effective medical devices. The Division of Neurological and Physical Medicine Devices reviews medical technologies that interface with the nervous system. This article addresses how to navigate the FDA's regulatory landscape to successfully bring medical devices to patients.

Symptoms of Concussion and Comorbid Disorders.

Symptoms of concussion are divided into three major domains: physical, cognitive, and emotional. These symptoms including headache, neck pain, vision changes, cognitive deficits, and emotional changes can be seen immediately after the injury and usually resolve within the first 3 months. However, some of these symptoms may persist for several months afterward. Risk factors have been identified for prolonged symptoms. Certain early interventions may decrease persistent symptoms. In this chapter, we discuss common acute and persistent symptoms after concussion and provide an overview of assessment tools and management options.

Improved Cardiorespiratory Fitness With Aerobic Exercise Training in Individuals With Traumatic Brain Injury.

OBJECTIVE: To examine cardiorespiratory fitness in individuals with traumatic brain injury (TBI), before and following participation in a supervised 12-week aerobic exercise training program. METHODS: Ten subjects with nonpenetrating TBI (TBI severity: mild, 50%; moderate, 40%; severe, 10%; time since injury [mean ± SD]: 6.6 ± 6.8 years) performed exercise training on a treadmill 3 times a week for 30 minutes at vigorous intensity (70%-80% of heart rate reserve). All subjects completed a cardiopulmonary exercise test, with pulmonary gas exchange measured and a questionnaire related to fatigue (Fatigue Severity Scale) at baseline and following exercise training. RESULTS: After training, increases (P < .01) in peak oxygen consumption ((Equation is included in full-text article.); +3.1 ± 2.4 mL/min/kg), time to volitional fatigue (+1.4 ± 0.8 minutes), and peak work rate (+59 ± 43 W) were observed. At the anaerobic threshold, (Equation is included in full-text article.)(+3.6 ± 2.1 mL/kg/min), treadmill time (+1.8 ± 1.1 minutes), and work rate (+37 ± 39 W) were higher (P < .01) following exercise training. Subjects also reported significantly lower (P < .05) Fatigue Severity Scale composite scores (-0.9 ± 1.3) following exercise training. CONCLUSION: These findings suggest that individuals with TBI may benefit from participation in vigorous aerobic exercise training with improved cardiorespiratory fitness and diminished fatigue.

The effects of concussion legislation one year later--what have we learned: a descriptive pilot survey of youth soccer player associates.

OBJECTIVE: To assess the knowledge of youth soccer athletes' parents, coaches, and soccer officials regarding concussion and return-to-play guidelines contained in the Lystedt Law in Washington State. DESIGN: Survey study. SETTING: Surveys were distributed via the youth soccer association monthly electronic newsletter in September and October 2010. Links to the survey also were provided via the Washington Youth Soccer Facebook page and Twitter feed. PARTICIPANTS: Respondents were 18 years or older and were associated with Washington Youth Soccer. MAIN OUTCOME MEASURES: The percentage of correct responses to questions regarding the identification and management of concussion symptoms and return to play guidelines as outlined in the Lystedt Law. RESULTS: A total of 391 adults responded; 63% were exclusively parents, 20% were coaches, and 17% were noncoaches (eg, club officers, referees, or volunteers). A total of 96% knew that concussions were a type of traumatic brain injury, 93% identified concussions as serious, and 93% knew that loss of consciousness is not universal. From the responses, 98% identified neurological manifestations of concussions, 90% chose to delay return to play in the presence of neurological symptoms, 85% were aware of the Lystedt Law, and only 73% knew that players must receive written clearance to return to play. A total of 88% were aware that a parent or legal guardian was not allowed to clear an athlete to return to play if a trained professional was not available. Survey respondents were less sure of soccer association guidelines for reporting medical clearance to club officials. CONCLUSIONS: These data suggest that, although general knowledge of parents, coaches, and referees in youth soccer in Washington State is high, gaps in knowledge and practice regarding the prevention of concussion in youth soccer athletes still exist.