Upward Translation of Cerebellar Tonsils following Surgical Expansion of Supratentorial Cranial Vault: A Unified Biomechanical Explanation of Chiari Type I.

Cerebellar tonsils moved significantly upward in 3 patients with Chiari type I who underwent supratentorial cranial vault expansion to alleviate intracranial pressure related to multisutural craniosynostosis. The Chiari type I deformities in these patients were the biomechanical consequence of posterior fossa-cerebellar disproportion caused by supratentorial craniocerebral disproportion secondary to multisutural craniosynostosis. The authors postulate that all cases of Chiari type I deformity share the sine qua non feature of posterior fossa-cerebellar disproportion.

Cranioplasty after postinjury decompressive craniectomy: is timing of the essence?

BACKGROUND: The appropriate timing of cranioplasty after decompressive craniectomy for trauma is unknown. Potential benefits of delayed intervention (>6 weeks) for reducing the risk of infection must be balanced by persistent altered cerebrospinal fluid dynamics leading to hydrocephalus. We reviewed our recent 5-year experience in an effort to improve patient throughput and develop a rational decision making plan. METHODS: A 5-year query (2003-2007) of our level I neurotrauma database. From 2,400 head injuries, we performed a total of 350 craniotomies. Of the 350 patients who underwent craniotomy for trauma, 70 patients (20%) underwent decompressive craniectomy requiring cranioplasty. Timing of cranioplasty, cranioplasty material, postoperative infections, and incidence of hydrocephalus were evaluated with logistic regression to study potential associations between complications and timing, adjusted for risk factors. RESULTS: No specific time frame was predictive of hydrocephalus or infection, and logistic regression failed to identify significant predictors among the collected variables. CONCLUSION: In our experience, the prior practice of delayed cranioplasty (3-6 months postdecompressive craniectomy), requiring repeat hospital admission, does not seem to lower postcranioplasty infection rates nor the need for cerebrospinal fluid diversion procedures. Our current practice emphasizes cranioplasty during the initial hospital admission, as soon as there is resolution on computed tomography scan of brain swelling outside of the cranial vault with concurrent clinical examination. This occurs as early as 2 weeks postcraniectomy and should lower the overall cost of care by eliminating the need for additional hospital admissions.

Bench-to-bedside review: Burn-induced cerebral inflammation--a neglected entity?

Severe burn injury remains a major burden on patients and healthcare systems. Following severe burns, the injured tissues mount a local inflammatory response aiming to restore homeostasis. With excessive burn load, the immune response becomes disproportionate and patients may develop an overshooting systemic inflammatory response, compromising multiple physiological barriers in the lung, kidney, liver, and brain. If the blood-brain barrier is breached, systemic inflammatory molecules and phagocytes readily enter the brain and activate sessile cells of the central nervous system. Copious amounts of reactive oxygen species, reactive nitrogen species, proteases, cytokines/chemokines, and complement proteins are being released by these inflammatory cells, resulting in additional neuronal damage and life-threatening cerebral edema. Despite the correlation between cerebral complications in severe burn victims with mortality, burn-induced neuroinflammation continues to fly under the radar as an underestimated entity in the critically ill burn patient. In this paper, we illustrate the molecular events leading to blood-brain barrier breakdown, with a focus on the subsequent neuroinflammatory changes leading to cerebral edema in patients with severe burns.

Endovascular stenting is rarely necessary for the management of blunt cerebrovascular injuries.

BACKGROUND: The role of stenting for blunt cerebrovascular injuries (BCVI) continues to be debated, with a trend toward more endovascular stenting. With the recent intracranial stenting trial halted in favor of medical therapy, however, management of BCVI warrants reassessment. The study purpose was to determine if antithrombotic therapy, rather than stenting, was effective in post-injury patients with high-grade vascular dissections and pseudoaneurysms. STUDY DESIGN: In 1996, we began screening for BCVI. After the 2005 report on the risks of carotid stenting for BCVI, a virtual moratorium was placed on stenting at our institution; our primary therapy for BCVI has been antithrombotics. Patients with grade II (luminal narrowing >25%) and grade III (pseudoaneurysms) injuries were included in the analysis. RESULTS: Grade II or III BCVIs were diagnosed in 195 patients. Before 2005, 25% (21 of 86) of patients underwent stent placement, with 2 patients suffering stroke. Of patients treated with antithrombotics, 1 had a stroke. After 2005, only 2% (2 of 109) of patients with high-grade injuries had stents placed. After 2005, no patient treated with antithrombotics suffered a stroke and there was no rupture of a pseudoaneurysm. CONCLUSIONS: Antithrombotic treatment for BCVI is effective for stroke prevention. Routine stenting entails increased costs and potential risk for stroke, and does not appear to provide additional benefit. Intravascular stents should be reserved for the rare patient with symptomatology or a markedly enlarging pseudoaneurysm.

Early repeat imaging is not warranted for high-grade blunt cerebrovascular injuries.

BACKGROUND: The current management for blunt cerebrovascular injuries (BCVIs) includes repeat imaging 7 days to 10 days after initial diagnosis. This recommendation, however, has not been systematically evaluated. The purpose of this study was to evaluate the impact of early repeat imaging on treatment course. We hypothesized that a minority of patients with high-grade injuries (Grades III and IV) have complete resolution of their injuries early in their treatment course and hence repeat imaging does not alter their therapy. METHODS: Our prospective BCVI database was queried from January 1, 1997, to January 1, 2013. Injuries were graded according to the Denver scale. Injuries, treatment, and imaging results were analyzed. BCVI healing was defined as a complete resolution of the injury. RESULTS: During the 16-year study, 582 patients sustained 829 BCVIs; there were 420 carotid artery injuries and 409 vertebral artery injuries. The majority (78%) received antithrombotic therapy. For the 296 carotid artery injuries (70%) with repeat imaging, there was complete healing of the injury in 56% of Grade I, 20% of Grade II, 5% of Grade III, and 0% of Grade IV injuries. For the 255 vertebral artery injuries (62%) with repeat imaging, there was a resolution of the injury in 56% of Grade I, 17% of Grade II, 14% of Grade III, and 3% of Grade IV injuries. For BCVIs overall, there was healing documented in 56% of Grade I, 18% of Grade II, 8% of Grade III, and 2% of Grade IV injuries. CONCLUSION: Injury grade of BCVIs is associated with the healing rate of the injury. While approximately half of Grade I BCVIs resolved, only 7% of all high-grade injuries healed. Early repeat imaging may not be warranted in high-grade BCVI; the vast majority of injuries do not resolve. The cost, radiation, and transport risk of early repeat imaging should be weighed against the potential treatment impact for individual patients. LEVEL OF EVIDENCE: Therapeutic/care management study, level IV.

Fatal outcome after brain stem infarction related to bilateral vertebral artery occlusion - case report of a detrimental complication of cervical spine trauma.

BACKGROUND: Vertebral artery injury (VAI) after blunt cervical trauma occurs more frequently than historically believed. The symptoms due to vertebral artery (VA) occlusion usually manifest within the first 24 hours after trauma. Misdiagnosed VAI or delay in diagnosis has been reported to cause acute deterioration of previously conscious and neurologically intact patients. CASE PRESENTATION: A 67 year-old male was involved in a motor vehicle crash (MVC) sustaining multiple injuries. Initial evaluation by the emergency medical response team revealed that he was alert, oriented, and neurologically intact. He was transferred to the local hospital where cervical spine computed tomography (CT) revealed several abnormalities. Distraction and subluxation was present at C5-C6 and a comminuted fracture of the left lateral mass of C6 with violation of the transverse foramen was noted. Unavailability of a spine specialist prompted the patient's transfer to an area medical center equipped with spine care capabilities. After arrival, the patient became unresponsive and neurological deficits were noted. His continued deterioration prompted yet another transfer to our Level 1 regional trauma center. A repeat cervical spine CT at our institution revealed significantly worsened subluxation at C5-C6. CT angiogram also revealed complete occlusion of bilateral VA. The following day, a repeat CT of the head revealed brain stem infarction due to bilateral VA occlusion. Shortly following, the patient was diagnosed with brain death and care was withdrawn. CONCLUSION: Brain stem infarction secondary to bilateral VA occlusion following cervical spine trauma resulted in fatal outcome. Prompt imaging evaluation is necessary to assess for VAI in cervical trauma cases with facet joint subluxation/dislocation or transverse foramen fracture so that treatment is not delayed. Additionally, multiple transportation events are risk factors for worsening when unstable cervical injuries are present. Close attention to proper immobilization and neck position depending on the mechanism of injury is mandatory.

Femur shaft fracture fixation in head-injured patients: when is the right time?

The ideal timing and modality of femur shaft fracture fixation in head-injured patients remains a topic of debate. Several groups advocate the immediate definitive fixation of femur fractures ("early total care"), whereas others support the concept of "damage control orthopaedics" with temporary fracture fixation by means of external fixation and staged, planned conversion to internal fixation. The present review was designed to address this unresolved controversy by outlining the underlying immunopathophysiology of traumatic brain injury and providing clinical recommendations on the timing of femur shaft fracture fixation in patients with severe head injuries.

Advocating "spine damage control" as a safe and effective treatment modality for unstable thoracolumbar fractures in polytrauma patients: a hypothesis.

BACKGROUND: The "ideal" timing and modality of fracture fixation for unstable thoracolumbar spine fractures in multiply injured patients remains controversial. The concept of "damage control orthopedics" (DCO), which has evolved globally in the past decade, provides a safe guidance for temporary external fixation of long bone or pelvic fractures in multisystem trauma. In contrast, "damage control" concepts for unstable spine injuries have not been widely implemented, and the scarce literature in the field remains largely anecdotal. The current practice standards are reflected by two distinct positions, either (1) immediate "early total care" or (2) delayed spine fixation after recovery from associated injuries. Both concepts have inherent risks which may contribute to adverse outcome. PRESENTATION OF HYPOTHESIS: We hypothesize that the concept of "spine damage control" - consisting of immediate posterior fracture reduction and instrumentation, followed by scheduled 360 degrees completion fusion during a physiological "time-window of opportunity" - will be associated with less complications and improved outcomes of polytrauma patients with unstable thoracolumbar fractures, compared to conventional treatment strategies. TESTING OF HYPOTHESIS: We propose a prospective multicenter trial on a large cohort of multiply injured patients with an associated unstable thoracolumbar fracture. Patients will be assigned to one of three distinct study arms: (1) Immediate definitive (anterior and/or posterior) fracture fixation within 24 hours of admission; (2) Delayed definitive (anterior and/or posterior) fracture fixation at > 3 days after admission; (3) "Spine damage control" procedure by posterior reduction and instrumentation within 24 hours of admission, followed by anterior 360 degrees completion fusion at > 3 days after admission, if indicated. The primary and secondary endpoints include length of ventilator-free days, length of ICU and hospital stay, mortality, incidence of complications, neurological status and functional recovery. IMPLICATIONS OF HYPOTHESIS: A "spine damage control" protocol may save lives and improve outcomes in severely injured patients with associated spine injuries.

Fatal outcome after insufficient spine fixation for pyogenic thoracic spondylodiscitis: an imperative for 360 degrees fusion of the infected spine.

BACKGROUND: Pyogenic spondylodiscitis represents a potentially life-threatening condition. Due to the low incidence, evidence-based surgical recommendations in the literature are equivocal, and the treatment modalities remain controversial. CASE PRESENTATION: A 59 year-old patient presented with a history of thoracic spondylodiscitis resistant to antibiotic treatment for 6 weeks, progressive severe back pain, and a new onset of bilateral lower extremity weakness. Clinically, the patient showed a deteriorating spastic paraparesis of her lower extremities. An emergent MRI revealed a kyphotic wedge compression fracture at T7/T8 with significant spinal cord compression, paravertebral and epidural abscess, and signs of myelopathy. The patient underwent surgical debridement with stabilization of the anterior column from T6-T9 using an expandable titanium cage, autologous bone graft, and an anterolateral locking plate. The patient recovered well under adjunctive antibiotic treatment. She presented again to the emergency department 6 months later, secondary to a repeat fall, with acute paraplegia of the lower extremities and radiographic evidence of failure of fixation of the anterior T-spine. She underwent antero-posterior revision fixation with hardware removal, correction of kyphotic malunion, evacuation of a recurrent epidural abscess, decompression of the spinal canal, and 360 degrees fusion from T2-T11. Despite the successful salvage procedure, the patient deteriorated in the postoperative phase, when she developed multiple complications including pneumonia, acute respiratory distress syndrome, bacterial meningitis, abdominal compartment syndrome, followed by septic shock with multiple organ failure and a lethal outcome within two weeks after revision surgery. CONCLUSION: This catastrophic example of a lethal outcome secondary to failure of anterior column fixation for pyogenic thoracic spondylodiscitis underlines the notion that surgical strategies for the infected spine must be aimed at achieving absolute stability by a 360 degrees fusion. This aggressive - albeit controversial - concept allows for an adequate infection control by adjunctive antibiotics and reduces the imminent risk of a secondary loss of fixation due to compromises in initial fixation techniques.

Mouse closed head injury model induced by a weight-drop device.

Traumatic brain injury represents the leading cause of death in young individuals. Various animal models have been developed to mimic human closed head injury (CHI). Widely used models induce head injury by lateral fluid percussion, a controlled cortical impact or impact acceleration. The presented model induces a CHI by a standardized weight-drop device inducing a focal blunt injury over an intact skull without pre-injury manipulations. The resulting impact triggers a profound neuroinflammatory response within the intrathecal compartment with high consistency and reproducibility, leading to neurological impairment and breakdown of the blood-brain barrier. In this protocol, we define standardized procedures for inducing CHI in mice and determine various severity grades of CHI through modulation of the weight falling height. In experienced hands, this CHI model can be carried out in as little as 30 s per animal, with additional time required for subsequent posttraumatic analysis and data collection.