Brain injury from explosive blast: description and clinical management.

Accumulating clinical experience is indicating that explosive blast brain injury is becoming recognized as a disease distinct from the penetrating form of blast injury as well as the classic closed head injury (CHI). In recent US conflicts in Iraq and Afghanistan, over 60% of combat casualties were from explosive blast with the hallmark explosive weapon being the improvised explosive device (IED). Explosive blast TBI is a condition afflicting many combat injured warfighters potentially constituting another category of TBI. Clinically, it shares many features with conventional TBI but possesses some unique aspects. In its mild form, it also shares many clinical features with PTSD but here again has distinct aspects. Although military medical providers depend on civilian standard of care guidelines when managing explosive blast mTBI, they are continually adapting their medical practice in order to optimize the treatment of this disease, particularly in a theater of war. It is clear that further rigorous scientific study of explosive blast mTBI at both the basic science and clinical levels is needed. This research must include improved understanding of the causes and mechanisms of explosive blast TBI as well as comprehensive epidemiologic studies to determine the prevalence of this disease and its risk factors. A widely accepted unambiguous clinical description of explosive blast mTBI with diagnostic criteria would greatly improve diagnosis. It is hoped that through appropriate research meaningful prevention, mitigation, and treatment strategies for explosive blast mTBI can be speedily realized.

Use of a nitrogen arm-stabilized endoscopic microdriver in neuroendoscopic surgery.

Stabilization and manipulation of instruments in endoscopic neurosurgery has traditionally been a manual task. Conventional self-retaining retractors have failed to provide reliable fixation for endoscopic procedures. Most surgeons rely on a team approach to endoscopy with one individual controlling the endoscope while the other manipulates instruments within the field of view. This two-surgeon approach is manpower intensive and not an option at many facilities. Recently developed technology provides the independent practitioner with another option. Several nitrogen-powered stabilizing arms have been introduced which decrease or eliminate problems with post-positioning drift. To facilitate fine maneuvering of the endoscope, a new positioning arm is available with an incorporated microdriver capable of sub-millimeter adjustments. We present an illustrative case of the utility of this device in selected endoscopic procedures.

Persistent prolongation of simple reaction time in sports concussion.

A baseline computerized cognitive assessment was completed by 483 military cadets before their initial school year. Fourteen cadets concussed during physical education boxing were retested <1 hour after injury and again on return to full activity 4 days later. Compared with baseline testing, postinjury performance on simple reaction time and continuous performance tests was significantly slowed, even after cadets experienced resolution of physical symptoms and were cleared to resume full activity. These findings may be relevant to current concussion management guidelines.

History of peripheral nerve surgery techniques.

The nineteenth century witnessed significant discoveries in the understanding of the peripheral nerve response to injury. Unfortunately, these discoveries were not widely accepted and several physiologically implausible nerve repair procedures survived into the first decades of the twentieth century. The surgical experience in World War I winnowed out most of these unsound techniques and laid the foundations for modern direct nerve repair. The surgical experience of World War II led to a rational classification of nerve injuries and refined the timing for surgical intervention. Major postwar developments that led to the modern era include improved nerve grafting techniques, intraoperative nerve action potential recording, and strategies for the repair of brachial plexus lesions.

Cognitive rehabilitation for traumatic brain injury: A randomized trial. Defense and Veterans Head Injury Program (DVHIP) Study Group.

CONTEXT: Traumatic brain injury (TBI) is a principal cause of death and disability in young adults. Rehabilitation for TBI has not received the same level of scientific scrutiny for efficacy and cost-efficiency that is expected in other medical fields. OBJECTIVE: To evaluate the efficacy of inpatient cognitive rehabilitation for patients with TBI. DESIGN AND SETTING: Single-center, parallel-group, randomized trial conducted from January 1992 through February 1997 at a US military medical referral center. PATIENTS: One hundred twenty active-duty military personnel who had sustained a moderate-to-severe closed head injury, manifested by a Glasgow Coma Scale score of 13 or less, or posttraumatic amnesia lasting at least 24 hours, or focal cerebral contusion or hemorrhage on computed tomography or magnetic resonance imaging. INTERVENTIONS: Patients were randomly assigned to an intensive, standardized, 8-week, in-hospital cognitive rehabilitation program (n=67) or a limited home rehabilitation program with weekly telephone support from a psychiatric nurse (n=53). MAIN OUTCOME MEASURES: Return to gainful employment and fitness for military duty at 1-year follow-up, compared by intervention group. RESULTS: At 1-year follow-up, there was no significant difference between patients who had received the intensive in-hospital cognitive rehabilitation program vs the limited home rehabilitation program in return to employment (90% vs 94%, respectively; P=.51; difference, 4% [95% confidence interval ¿CI¿, -5% to 14%]) or fitness for duty (73% vs 66%, respectively; P=. 43; difference, 7% [95% CI, -10% to 24%]). There also were no significant differences in cognitive, behavioral, or quality-of-life measures. In a post-hoc subset analysis of patients who were unconscious for more than 1 hour (n = 75) following TBI, the in-hospital group had a greater return-to-duty rate (80% vs 58%; P=. 05). CONCLUSIONS: In this study, the overall benefit of in-hospital cognitive rehabilitation for patients with moderate-to-severe TBI was similar to that of home rehabilitation. These findings emphasize the importance of conducting randomized trials to evaluate TBI rehabilitation interventions. JAMA. 2000;283:3075-3081

Cerebral abscess after presumed superficial periorbital wound.

Penetrating wounds in the periorbital region may appear superficial and minor at first glance. The unique shape and thin bony roof of the orbit give these injuries a significant risk of associated intracranial penetration. This can initially be asymptomatic, and a high index of suspicion is essential to properly diagnose and treat these injuries. We report a case of an 8-year-old female who presented with delayed seizures from a frontal abscess resulting from such an injury. This article reviews the literature and discusses the appropriate management that should be used by emergency room and military physicians.

Ethanol endovascular management of brain arteriovenous malformations: initial results.

OBJECTIVE: The goal was to determine the safety and efficacy of absolute ethyl alcohol treatment in the management of intra-axial brain arteriovenous malformations (AVMs). METHODS: Seventeen patients (eight female and nine male patients; mean age, 41 yr) underwent ethanol endovascular therapy for treatment of their brain AVMs. Superselective amytal testing preceded all procedures. Neuroleptic intravenous anesthesia was used for 16 patients, and general anesthesia was used for 1 patient. Follow-up monitoring consisted of clinical evaluations, magnetic resonance imaging, and arteriography. RESULTS: In follow-up evaluations (mean follow-up period, 13 mo) after embolization of brain AVMs, neither vascular recanalization nor the neovascular recruitment phenomenon was observed in any patient. Progressive AVM thrombosis at arteriographic follow-up evaluation was a constant feature. Seven patients were cured of their AVMs with ethanol endovascular therapy alone. Three patients were cured of their lesions with ethanol embolization plus surgical resection. One patient was cured of his lesion with ethanol embolization and radiation therapy of the residual nidus. Three patients underwent only partial therapy, with significant improvement in symptoms. Three patients are currently undergoing ethanol endovascular therapy. Complications occurred with 8 of 17 patients, most of which were transient. Two patients died because of late subarachnoid hemorrhages, one patient 4 months and one patient 14 months after partial therapy. CONCLUSION: Progressive and permanent AVM occlusion is a common finding in arteriographic follow-up evaluations. In no patients did arterial recanalization or the neovascular recruitment phenomenon occur. Our initial results indicate that ethanol has a permanence that is seldom encountered with other embolic agents. With aggressive decadron therapy, the complications related to swelling in the brain are largely reversible.

Adding hetastarch to the adult cardiopulmonary bypass prime does not affect patient outcomes.

Hespan (hetastarch), a synthetic colloid, is often used in priming cardiopulmonary bypass circuits. The purpose of this study is to determine the efficacy of adding hetastarch to the prime compared to adding no hetastarch. Twenty-four adult patients undergoing cardiopulmonary bypass received Hespan in the prime, while twenty-nine patients did not. Outcomes were compared using paired t-test, analysis of variance, analysis of covariance, and descriptive statistics, where p < 0.05 was considered significant. There were no significant differences in change in lung compliance, weight gain, time on the ventilator, or length of stay in the intensive care unit. Adding colloids to the adult CPB prime does not improve patient outcomes over priming exclusively with crystalloids.

Tranexamic acid reduces bleeding after cardiopulmonary bypass when compared to epsilon aminocaproic acid and placebo.

UNLABELLED: Perioperative bleeding following coronary artery bypass grafting (CABG) is associated with increased blood product usage. Although aprotonin is effective in reducing perioperative blood loss, excessive cost prohibits routine utilization. Epsilon aminocaproic acid (EACA) and tranexamic acid (TA) are inexpensive antifibrinolytic agents, which, when given prophylactically, may reduce blood loss. The present study was undertaken to compare the efficacy of TA and EACA in reducing perioperative blood loss. METHODS: The study population consisted of first-time CABG patients. Patients were allocated in a prospective double-blind fashion: (1) group EACA (loading dose 15 mg/kg, continuous infusion 10 mg/kg per hour for 6 hours, N = 20); (2) group TA (loading dose 15 mg/kg, continuous infusion 1 mg/kg per hour for 6 hours, N = 20); (3) control group (infusion of normal saline for 6 hours, N = 19). RESULTS: Treatment groups were similar preoperatively. No significant difference in intraoperative blood loss or perioperative use of blood products was noted. D-dimer concentration was elevated in the control group compared to the EACA and TA groups (p < 0.05). Group TA had less postoperative blood loss than the EACA and control groups at 6 and 12 hours postoperatively (p < 0.05). TA had reduced total blood loss (600 +/- 49 mL) postoperatively compared to EACA (961 +/- 148 mL) and control (1060 +/- 127 mL, p < 0.05). CONCLUSION: TA and EACA effectively inhibited fibrinolytic activity intraoperatively and throughout the first 24 hours postoperatively. TA was more effective in reducing blood loss postoperatively following CABG. This suggests that TA may be beneficial as an effective and inexpensive antifibrinolytic in first-time CABG patients.

In vitro testing of a current cell salvaging device for the removal of malignant cells from contaminated blood.

The efficiency of a current cell washing device for removing tumor cells from bovine blood was examined under laboratory conditions. In the in-vitro laboratory, anticoagulated bovine blood was seeded with known numbers of immunocytochemical stained human malignant epithelial cells (KB) grown in culture. The blood was subjected to cell washing. Blood samples were taken before and after cell washing for identification of the tumor cells. The samples were then analyzed under florescence microscopy and pre- and post-cell washing tumor cell counts in 20 microscopic fields were recorded. It was determined that the mean tumor cell removal efficiency was 86% +/- 13% using the cell salvaging technique. Two-way ANOVA revealed a significant difference between the pre- and post-cell washing samples (p < 0.001) with no difference between trials (p = NS). The results are discussed in terms of the potential safety of cell salvaged blood for the surgical care patient.

Comparison of three methods to estimate heparin loading dose for cardiopulmonary bypass.

Three available methods used to determine heparin loading dose were studied to determine the most reliable method for reaching a target pre-bypass activated clotting time (ACT) of 510 seconds. One hundred and seven patients were randomly assigned to one of three treatment methods: A) 300 units/kg; B) Hemostasis Management System (HMS); C) RX/DX. Five different lots of heparin were assigned to Groups A and B, and Group C had one heparin lot. Different lots were used to account for possible variations in heparin activity. Post-skin incision ACTs, post-heparin pre-bypass ACTs, and heparin loading doses were compared. The mean and standard deviation of the post-heparin pre-bypass ACTs were used to determine which method was most reliable to obtain a desired ACT. There was no statistical difference between different heparin lots. There was no difference in the post-heparin ACTs for the three methods (A:487 +/- 135 vs. B:474 +/- 105 vs. C:474 +/- 111 sec). There was a statistically significant difference between the standard deviation for the HMS and 300 u/kg standard deviations (p < 0.05). The HMS has the smallest deviation which makes it the most reliable predictor of heparin loading doses to reach a target ACT for cardiopulmonary bypass.

Cervical spine injury in a boxer: should mandatory screening be instituted?

Cervical spine fracture is a rare, yet potentially catastrophic complication associated with boxing. Neurologic deficits, ocular injuries, or other traumatic musculoskeletal injuries have been commonly reported. Symptoms of cervical spine injury may be minimal or absent. Cervical spine fracture may be undiagnosed and unreported in boxers with presumed soft-tissue injury to the head and neck. We describe a young athlete who sustained a transient spinal cord injury while boxing, which required a cervical spine fusion and postoperative immobilization in a halo vest. This athlete also had an os odontoideum, which placed him at significant risk for such an injury. Pre- and postparticipation screening of the cervical spine should be considered in all boxers.

Clinical comparison of patient-side fibrinogen assay and common laboratory analyzer in pediatric cardiopulmonary bypass.

The coagulation status of infant and pediatric patients can be severely compromised during the course of cardiopulmonary bypass due primarily to hemodilution and hypothermia. Fibrinogen level is one source of information necessary to assess the coagulation status of a patient. An accurate and expedient method to determine the fibrinogen level would allow for earlier initiation of coagulation therapy to prevent excessive postoperative bleeding. The purpose of this study was to compare two methods of determining fibrinogen level: a patient-side assay and a common laboratory analyzer. The patient-side test utilized the HemoChron Fibrinogen Assay and was performed in the operating room. The MLA 1000C was the laboratory method utilized in the hospital's coagulation laboratory. Simultaneous testing was conducted prebypass and intraoperatively on 26 infant and pediatric patients undergoing cardiopulmonary bypass for palliation and correction of congenital heart defects. The resulting values were compared using paired t-test, regression and correlation analysis, and descriptive analysis. The values obtained by the two methods were significantly different (p < .05) at each collection time. Further analysis revealed that other variables, such as hematocrit and platelet count, affected the differences between the results of the methods. The HemoChron Fibrinogen Assay may not be a viable tool for the assessment of fibrinogen level on infant and pediatric patients undergoing cardiopulmonary bypass surgery. Further studies should be done in this patient population incorporating other confounding variables.

An evaluation of three methods for determining colloid osmotic pressure.

Plasma colloid osmotic pressure (COP) is an important determinant in edema formation. Three methods for assessing the COP were evaluated. Direct measurement of COP using the 4420 Wescor Colloid Osmometer was compared to the estimation of COP from both serum total protein and total serum solids (TSS) determinations. Blood samples from twenty adult patients (mean age = 64 years) undergoing cardiopulmonary bypass surgery were collected for COP assessment. Sample collection was performed prior to heparinization/hemodilution, during hypothermic bypass and at the conclusion of bypass following protamine administration. The results obtained from each method were analyzed by a two-way analysis of variance. The Bonferroni technique was used for comparison of sample means when the difference was significant (p less than 0.05). Correlations were reported by linear regression analysis. A statistically significant difference (p less than 0.01) was found between the three methods. A regression equation for the estimation of COP from total serum solids is offered: COP = (3.02 * TSS) + 0.65. Prospective clinical testing between the direct COP measurement and the estimation of COP from TSS using the equation (n = 38) revealed a significant correlation (R2 = .932) and no significant difference between the two (p greater than 0.05).

Associated vascular malformations and neoplasms in children.

Primary CNS neoplasms can rarely be associated with abnormal vascularity which is more striking than usual hypervascularity or neovascularization. These lesions are sometimes reported as angiogliomas, angiomatous astrocytomas, or descriptively as two distinct pathological entities. This vascular pattern has been reported with astrocytomas, oligodendrogliomas, neurilemmomas, meningiomas, pituitary adenomas, gangliogliomas, hemangioblastomas, mixed gliomas, gliosarcomas, and craniopharyngiomas. These lesions are classically found to be extremely vascular, both radiographically and at surgery. The true nature of these lesions is a point of controversy with some interpreting them merely as intensely vascularized tumors. Most agree, however, that unlike neovascularity in astrocytomas, the vascularity in these lesions does not carry any significant prognostic importance. In this report we present six such cases from The Children's Hospital of Philadelphia seen in the pediatric population. Four patients had vascular malformations associated with diffuse astrocytomas, and in 2 patients they were associated with subependymal giant cell astrocytomas. Five of the lesions were supratentorial, and 1 was located in the posterior fossa. The history and theories surrounding these lesions are explored.

Posterior spinal osteosynthesis for cervical fracture/dislocation using a flexible multistrand cable system: technical note.

Cervical instability secondary to fracture/dislocation or traumatic subluxation involving the posterior elements may be treated by a variety of fusion techniques. The rigidity of the stainless steel wires used in posterior cervical fusions often leads to difficulty with insertion, adequate tension, and conformation of the graft construct. This report describes a technique of posterior cervical fusion employing a wire system using flexible stainless steel cables. The wire consists of a flexible, 49-strand, stainless steel cable connected on one end to a short, malleable, blunt leader with the opposite end connected to a small islet. The cable may be used in occipitocervical, atlantoaxial, facet-to-spinous process, and interspinous fusion techniques. The cable loop is secured by using a tension/crimper device that sets the desired tension in the cable. In addition to superior biomechanical strength, the flexibility of the cable allows greater ease of insertion and tension adjustment. In terms of direct operative instrumentation in posterior cervical arthrodesis, involving both the upper and lower cervical spine, the cable system appears to be a safe and efficient alternative to monofilament wires.

Cervical spondylotic myelopathy: treatment with posterior decompression and Luque rectangle bone fusion.

Cervical spondylotic myelopathy appears to result from a combination of factors. The two major components are 1) compressive forces resulting from narrowing of the spinal canal, and 2) dynamic forces owing to mobility of the cervical spine. There is substantial evidence to suggest that the repetitive trauma to the spinal cord that is sustained with movement in a spondylotic canal may be a major cause of progressive myelopathy. Utilization of extensive anterior procedures that remove the diseased ventral features as well as eliminate the dynamic forces owing to the accompanying fusion have grown in popularity. Cervical laminectomy enlarges the spinal canal, but does not reduce the dynamic forces affecting the spinal cord, and may actually increase cervical mobility, leading to a perpetuation of the myelopathy. The authors propose the combination of posterior decompression and Luque rectangle bone fusion to deal with both the compressive and the dynamic factors that lead to cervical spondylotic myelopathy. Ten patients who had advanced myelopathy underwent the combined procedures. Nine of the 10 experienced significant neurological improvement, and the 10th has had no progression. The combination of posterior decompression and Luque rectangle bone fusion may offer a simple, safe, and effective alternative treatment for cervical spondylotic myelopathy.

Symptomatic pineal cyst: case report.

Pineal cysts are being described with increasing frequency since the advent of magnetic resonance imaging. Although pineal cysts are incidental findings in as many as 4% of magnetic resonance imaging studies, symptomatic pineal cysts are quite rare. We present a case of pineal cyst causing aqueductal obstruction with symptomatic hydrocephalus and resultant headache and syncope, which was treated by surgical resection. A review of the relevant literature and discussion follow.