Acute Traumatic Subdural Hematoma and Anticoagulation Risk.

BACKGROUND: Anticoagulation is used to prevent thromboembolic events. It is a common practice to hold anticoagulation in the first few days following a traumatic brain injury (TBI) with intracranial hemorrhage. However, traumatic subdural hematomas (SDH) are prone to re-hemorrhage long after the trauma. Data are scarce in the literature on the best timing to resume anticoagulation following a TBI. METHODS: Review of 95 consecutive patients admitted to a level 1 trauma center with a diagnosis of traumatic SDH and requiring anticoagulation. The reasons for anticoagulation, the amount of time without anticoagulation, CT characteristics, and the incidence of thromboembolic events or SDH re-hemorrhage were collected. RESULTS: 41.3% used anticoagulation for coronary artery disease and peripheral vascular disease, 24% for atrial fibrillation, 12% for cardiac valve replacement, and 12% for venous thromboembolic events. Anticoagulation was held a median of 67 days. For most patients (82.1%), anticoagulation was re-introduced once the SDH had completely resolved. For 17.9%, anticoagulation was restarted while the SDH had not completely resolved. One (1.1%) patient suffered from an atrial clot while anticoagulation was held. For those with residual SDH, 41.2% suffered from a SDH re-hemorrhage and 17.6% required surgery. The risk of re-hemorrhage climbed to 62.5% if the SDH remnant was large. CONCLUSION: Anticoagulation while there is a residual SDH was associated with a significant risk of re-hemorrhage. This risk should be weighed against the risk of holding anticoagulation.

Noninvasive magnetic resonance imaging techniques in mild traumatic brain injury research and diagnosis.

Mild traumatic brain injury (mTBI), frequently referred to as concussion, is one of the most common neurological disorders. The underlying neural mechanisms of functional disturbances in the brains of concussed individuals remain elusive. Novel forms of brain imaging have been developed to assess patients postconcussion, including functional magnetic resonance imaging (fMRI), susceptibility-weighted imaging (SWI), diffusion MRI (dMRI), and perfusion MRI [arterial spin labeling (ASL)], but results have been mixed with a more common utilization in the research environment and a slower integration into the clinical setting. In this review, the benefits and drawbacks of the methods are described: fMRI is an effective method in the diagnosis of concussion but it is expensive and time-consuming making it difficult for regular use in everyday practice; SWI allows detection of microhemorrhages in acute and chronic phases of concussion; dMRI is primarily used for the detection of white matter abnormalities, especially axonal injury, specific for mTBI; and ASL is an alternative to the BOLD method with its ability to track cerebral blood flow alterations. Thus, the absence of a universal diagnostic neuroimaging method suggests a need for the adoption of a multimodal approach to the neuroimaging of mTBI. Taken together, these methods, with their underlying functional and structural features, can contribute from different angles to a deeper understanding of mTBI mechanisms such that a comprehensive diagnosis of mTBI becomes feasible for the clinician.

Atypical resting state functional connectivity in mild traumatic brain injury.

OBJECTIVES: This study aimed to investigate changes in three intrinsic functional connectivity networks (IFCNs; default mode network [DMN], salience network [SN], and task-positive network [TPN]) in individuals who had sustained a mild traumatic brain injury (mTBI). METHODS: Resting-state functional magnetic resonance imaging (rs-fMRI) data were acquired from 27 mTBI patients with persistent postconcussive symptoms, along with 26 age- and sex-matched controls. These individuals were recruited from a Level-1 trauma center, at least 3 months after a traumatic episode. IFCNs were established based on seed-to-voxel, region-of-interest (ROI) to ROI, and independent component analyses (ICA). Subsequently, we analyzed the relationship between functional connectivity and postconcussive symptoms. RESULTS: Seed-to-voxel analysis of rs-fMRI demonstrated decreased functional connectivity in the right lateral parietal lobe, part of the DMN, and increased functional connectivity in the supramarginal gyrus, part of the SN. Our TPN showed both hypo- and hyperconnectivity dependent on seed location. Within network hypoconnectivity was observed in the visual network also using group comparison. Using an ICA, we identified altered network functional connectivity in regions within four IFCNs (sensorimotor, visual, DMN, and dorsal attentional). A significant negative correlation between dorsal attentional network connectivity and behavioral symptoms score was also found. CONCLUSIONS: Our findings indicate that rs-fMRI may be of use clinically in order to assess disrupted functional connectivity among IFCNs in mTBI patients. Improved mTBI diagnostic and prognostic information could be especially relevant for athletes looking to safely return to play, as well for individuals from the general population with persistent postconcussive symptoms months after injury, who hope to resume activity.

Epidural Hematoma Treated Conservatively: When to Expect the Worst.

BACKGROUND: The Brain Trauma Foundation's 2006 surgical guidelines have objectively defined the epidural hematoma (EDH) patients who can be treated conservatively. Since then, the literature has not provided adequate clues to identify patients who are at higher risk for EDH progression (EDHP) and conversion to surgical therapy. The goal of our study was to identify those patients. METHODS: We carried a retrospective review over a 5-year period of all EDH who were initially triaged for conservative management. Demographic data, injury severity and history, neurological status, use of anticoagulants or anti-platelets, radiological parameters, conversion to surgery and its timing, and Glasgow Outcome Scale were analyzed. Bivariate association and further logistic regression were used to point out the significant predictors of EDHP and conversion to surgery. RESULTS: 125 patients (75% of all EDH) were included. The mean age was 39.1 years. The brain injury was mild in 62.4% of our sample and severe in 14.4%. Only 11.2% of the patients required surgery. Statistical comparison showed that younger age (p< 0.0001) and coagulopathy (p=0.009) were the only significant factors for conversion to surgery. There was no difference in outcomes between patients who had EDHP and those who did not. CONCLUSIONS: Most traumatic EDH are not surgical at presentation. The rate of conversion to surgery is low. Significant predictors of EDHP are coagulopathy and younger age. These patients need closer observation because of a higher risk of EDHP. Outcome of surgical conversion was similar to successful conservative management.

Does Balloon Kyphoplasty Deliver More Cement Safely into Osteoporotic Vertebrae with Compression Fractures Compared with Vertebroplasty? A Study in Vertebral Analogues.

Study Design A biomechanical and radiographic study using vertebral analogues. Objectives Kyphoplasty and vertebroplasty are widely used techniques to alleviate pain in fractures secondary to osteoporosis. However, cement leakage toward vital structures like the spinal cord can be a major source of morbidity and even mortality. We define safe cement injection as the volume of the cement injected into a vertebra before the cement leakage occurs. Our objective is to compare the amount of cement that can be safely injected into an osteoporotic vertebra with simulated compression fracture using either vertebroplasty or balloon kyphoplasty techniques. Methods Forty artificial vertebral analogues made of polyurethane with osteoporotic cancellous matrix representing the L3 vertebrae were used for this study and were divided into four groups of 10 vertebrae each. The four groups tested were: low-viscosity cement injected using vertebroplasty, high-viscosity cement injected using vertebroplasty, low-viscosity cement injected using balloon kyphoplasty, and high-viscosity cement injected using balloon kyphoplasty. The procedures were performed under fluoroscopic guidance. The injection was stopped when the cement started protruding from the created vascular channel in the osteoporotic vertebral fracture model. The main outcome measured was the volume of the cement injected safely into a vertebra before leakage through the posterior vascular channel. Results The highest volume of the cement injected was in the vertebroplasty group using high-viscosity cement, which was almost twice the injected volume in the other three groups. One-way analysis of variance comparing the four groups showed a statistically significant difference (p < 0.005). Conclusions High-viscosity cement injected using vertebroplasty delivers more cement volume before cement leakage and fills the vertebral body more uniformly when compared with balloon kyphoplasty in osteoporotic vertebrae with compression fractures.

Nonsurgical acute traumatic subdural hematoma: what is the risk?

OBJECT: The Brain Trauma Foundation has published guidelines on the surgical management of traumatic subdural hematoma (SDH). However, no data exist on the proportion of patients with SDH that can be selected for conservative management and what is the outcome of these patients. The goals of this study were as follows: 1) to establish what proportion of patients are initially treated conservatively; 2) to determine what proportion of patients will deteriorate and require surgical evacuation; and 3) to identify risk factors associated with deterioration and delayed surgery. METHODS: All cases of acute traumatic SDH (869 when inclusion criteria were met) presenting over a 4-year period were reviewed. For all conservatively treated SDH, the proportion of delayed surgical intervention and the Glasgow Outcome Scale score were taken as outcome measures. Multiple factors were compared between patients who required delayed surgery and patients without surgery. RESULTS: Of the 869 patients with acute traumatic SDH, 646 (74.3%) were initially treated conservatively. A good outcome was achieved in 76.7% of the patients. Only 6.5% eventually required delayed surgery, and the median delay for surgery was 9.5 days. Factors associated with deterioration were as follows: 1) thicker SDH (p<0.001); 2) greater midline shift (p<0.001); 3) location at the convexity (p=0.001); 4) alcohol abuse (p=0.0260); and 5) history of falls (p=0.018). There was no significant difference in regard to age, sex, Glasgow Coma Scale score, Injury Severity Score, abnormal coagulation, use of blood thinners, and presence of cerebral atrophy or white matter disease. CONCLUSIONS: The majority of patients with SDH are treated conservatively. Of those, only 6.5% later required surgery, for raised intracranial pressure or SDH progression. Patients at risk can be identified and followed more carefully.

Navigational memory functional magnetic resonance imaging: a test for concussion in children.

Concussions are high incidence injuries with potentially devastating consequences. Youths are at risk because of a higher threat of repeated injury, and cumulative effects of concussions exist, making accurate diagnosis and follow-up essential. This study examines a navigational memory functional magnetic resonance imaging (fMRI) task to determine whether activation differences exist between children with concussion and uninjured controls. Fifty adolescents were recruited-35 controls and 15 with concussion. All subjects underwent structural and fMRI testing using our navigational memory task, and a battery of neuropsychological testing. The activation patterns of the 15 subjects with concussion were compared with those of 15 age and sex-matched controls. Subtraction and regression analyses were performed using the matched controls along with scatter-plots using means and 95% quantiles of the 35 controls. While no differences were seen with neuropsychological testing or task performance, subjects with concussion had significantly diminished activation in the retrosplenial, thalamic, and parahippocampal areas bilaterally, along with the right dorsolateral prefrontal cortex and left precuneus. Interestingly, they had increased activation in the left hippocampus and right middle temporal gyrus. Regression analysis demonstrated negative correlations between activation and post-concussive symptoms in the left premotor cortex, superior and inferior parietal lobules, and parahippocampal gyrus. Subjects with concussion show both diminished and increased activation in specific cerebral regions, differentiating them from controls. This is one of the first studies to look at such a task using fMRI and its applicability in testing for concussion in children. These findings support navigational memory fMRI as a potential objective test for concussions.

A functional magnetic resonance imaging study of working memory in youth after sports-related concussion: is it still working?

Abstract In children, the importance of detecting deficits after mild traumatic brain injury (mTBI) or concussion has grown with the increasing popularity of leisure physical activities and contact sports. Whereas most postconcussive symptoms (PCS) are similar for children and adults, the breadth of consequences to children remains largely unknown. To investigate the effect of mTBI on brain function, we compared working memory performance and related brain activity using blood-oxygen-level-dependent (BOLD) functional magnetic resonance imaging (fMRI) in 15 concussed youths and 15 healthy age-matched control subjects. Neuropsychological tests, self-perceived PCS, and levels of anxiety and depression were also assessed. Our results showed that, behaviorally, concussed youths had significantly worse performances on the working memory tasks, as well as on the Rey figure delayed recall and verbal fluency. fMRI results revealed that, compared to healthy children, concussed youths had significantly reduced task-related activity in bilateral dorsolateral prefrontal cortex, left premotor cortex, supplementary motor area, and left superior parietal lobule during performance of verbal and nonverbal working memory tasks. Additionally, concussed youths also showed less activation than healthy controls in the dorsal anterior cingulate cortex, left thalamus, and left caudate nucleus during the nonverbal task. Regression analysis indicated that BOLD signal changes in bilateral dorsolateral prefrontal cortex were significantly correlated with performance such that greater activities in these regions, relative to the control condition, were associated with greater accuracy. Our findings confirmed functional alterations in brain activity after concussion in youths, a result similar to that observed in adults. However, significant differences were noted. In particular, the observation of reduced working memory accuracy suggests that youths may be unable to engage compensatory strategies to maintain cognitive performance after mTBI. This has significant implications for safe return to daily activities, including competitive sport.

Primary or secondary decompressive craniectomy: different indication and outcome.

BACKGROUND: Intracranial hypertension can cause secondary damage after a traumatic brain injury. Aggressive medical management might not be sufficient to alleviate the increasing intracranial pressure (ICP), and decompressive craniectomy (DC) can be considered. Decompressive craniectomy can be divided into categories, according to the timing and rationale for performing the procedure: primary (done at the time of mass lesion evacuation) and secondary craniectomy (done to treat refractory ICP). Most studies analyze primary and secondary DC together. Our hypothesis is that these two groups are distinct and the aim of this retrospective study is to evaluate the differences in order to better predict outcome after DC. METHODS: Seventy patients had DC over a period of four years at our center. They were divided into two groups based on the timing of the DC. Primary DC (44 patients) was done within 24 hours of the injury for mass lesion evacuation. Secondary DC (26 patients) was done after 24 hours and purely for the treatment of refractory ICP. Pre-op characteristics and post-op outcomes were compared between the two groups. RESULTS: There was a significant difference in the mechanism of injury, the pupil abnormalities and Marshall grade between primary and secondary DC. There was also a significant difference in outcome with primary DC showing 45.5% good outcome and 40.9% mortality and secondary DC showing 73.1% good outcome and 15.4% mortality. CONCLUSIONS: Primary and secondary DC have different indications and patients characteristics. Outcome prediction following DC should be adjusted according to the surgical indication.

Brain functions after sports-related concussion: insights from event-related potentials and functional MRI.

The high incidence of concussions in contact sports and their impact on brain functions are a major cause for concern. To improve our understanding of brain functioning after sports-related concussion, advanced functional assessment techniques, namely event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), have been recently used in research studies. Contrary to neuropsychological tests that measure verbal and/or motor responses, ERPs and fMRI assess the neural activities associated with cognitive/behavioral demands, and thus provide access to better comprehension of brain functioning. In fact, ERPs have excellent temporal resolution, and fMRI identifies the involved structures during a task. This article describes ERP and fMRI techniques and reviews the results obtained with these tools in sports-related concussion. Although these techniques are not yet readily available, they offer a unique clinical approach, particularly for complex cases (ie, athletes with multiple concussions, chronic symptoms) and objective measures that provide valuable information to guide management and return-to-play decision making.