Attitudes Toward Neurosurgery Education for the Nonneurosurgeon: A Survey Study and Critical Analysis of U.S. Military Training Techniques and Future Prospects.

BACKGROUND: The U.S. military requires medical readiness to support forward-deployed combat operations. Because time and distance to neurosurgical capabilities vary within the deployed trauma system, nonneurosurgeons are required to perform emergent cranial procedures in select cases. It is unclear whether these surgeons have sufficient training in these procedures. METHODS: This quality-improvement study involved a voluntary, anonymized specialty-specific survey of active-duty surgeons about their experience and attitudes toward U.S. military emergency neurosurgical training. RESULTS: Survey responses were received from 104 general surgeons and 26 neurosurgeons. Among general surgeons, 81% have deployed and 53% received training in emergency neurosurgical procedures before deployment. Only 16% of general surgeons reported participating in craniotomy/craniectomy procedures in the last year. Nine general surgeons reported performing an emergency neurosurgical procedure while on deployment/humanitarian mission, and 87% of respondents expressed interest in further predeployment emergency neurosurgery training. Among neurosurgeons, 81% had participated in training nonneurosurgeons and 73% believe that more comprehensive training for nonneurosurgeons before deployment is needed. General surgeons proposed lower procedure minimums for competency for external ventricular drain placement and craniotomy/craniectomy than did neurosurgeons. Only 37% of general surgeons had used mixed/augmented reality in any capacity previously; for combat procedures, most (90%) would prefer using synchronous supervision via high-fidelity video teleconferencing over mixed reality. CONCLUSIONS: These survey results show a gap in readiness for neurosurgical procedures for forward-deployed general surgeons. Capitalizing on capabilities such as mixed/augmented reality would be a force multiplier and a potential means of improving neurosurgical capabilities in the forward-deployed environments.

Traumatic ischemic injury in a top of the basilar distribution: a case report.

BACKGROUND: Top of the basilar syndrome is a rare, heterogeneous disorder that has previously only been described in the setting of acute ischemic stroke in predominantly elderly patients. We present the first reported case of traumatic brain injury (TBI) causing ischemia in a top of the basilar distribution. CASE PRESENTATION: A 19-year-old woman suffered an acute subdural hematoma and sustained hypoxemia after being struck by a motor vehicle. Neurosurgical evacuation of the hematoma was undertaken. Magnetic resonance imaging revealed ischemic injury in the midbrain and diencephalic structures fitting a top of the basilar distribution. No associated vascular injury was identified. The patient was eventually discharged in a state of persistent unresponsive wakefulness. CONCLUSIONS: Ischemia in a top of the basilar distribution may occur in the setting of TBI. A high degree of clinical suspicion is required to identify this disorder. Further study of the complex inflammatory microenvironment and associated tissue perfusion dynamics in TBI are needed in order to elucidate the mechanisms underlying ischemic injury patterns, develop management paradigms and predict prognosis.

U.S. Neurosurgical Response to COVID-19: Forging a Path Toward Disaster Preparedness.

INTRODUCTION: The worldwide COVID-19 pandemic poses challenges to healthcare capacity and infrastructure. The authors discuss the structure and efficacy of the U.S. Navy's response to COVID-19 and evaluate the utility of this endeavor, with the objective of providing future recommendations for managing worldwide healthcare and medical operational demands from the perspective of Navy Neurosurgery. MATERIALS AND METHODS: The authors present an extensive review of topics and objectively highlight the efforts of U.S. Navy Neurosurgery as it pertains to the humanitarian mission during the COVID-19 pandemic. RESULTS: During the humanitarian mission (March 27, 2020-April 14, 2020), the response of active duty and reserve neurosurgeons in the U.S. Navy was robust. Neurosurgical coverage was present on board the U.S. Navy Ships Mercy and Comfort, with additional neurosurgical deployment to New York City for intensive care unit management and coverage. CONCLUSIONS: The U.S. Navy neurosurgical response to the COVID-19 pandemic was swift and altruistic. Although neurosurgical pathologies were limited among the presenting patients, readiness and manpower continue to be strong influences within the Armed Forces. The COVID-19 response demonstrates that neurosurgical assets can be rapidly mobilized and deployed in support of wartime, domestic, and global humanitarian crises to augment both trauma and critical care capabilities.

Rate of Return to Military Active Duty After Single and 2-Level Anterior Cervical Discectomy and Fusion: A 4-Year Retrospective Review.

BACKGROUND: Over the years of rigorous of military service, military personnel may experience cervical spondylosis and radiculopathy. Given the frequency of this occurrence, the capacity to return to unrestricted full duty in the military after anterior cervical discectomy and fusion (ACDF) is worthy of analysis. OBJECTIVE: To identify the rate of return to full, unrestricted active duty after single and 2-level anterior cervical discectomy, and fusion surgery in military personnel. METHODS: A retrospective chart review was performed at a tertiary care military treatment facility for all active duty personnel who underwent a single or 2-level ACDF over a 4-yr period. Patient and procedural data were collected to include single or 2-level fusion, indication for surgery, fusion level, tobacco use, age, and military rank. Fischer's Exact and Wilcoxon Rank Sum tests were used to identify statistically significant differences in the rate of return to active duty. RESULTS: A total of 132 anterior cervical discectomy and fusions were analyzed. One hundred sixteen patients (88%) were able to return to unrestricted full active duty, while the remaining 16 required separation from the military for continued pain or disability. The return to active duty rate was significantly higher in service members with a rank of E7 or above (99%) than those E6 and below (73%). There was a strong association between the presence of a pseudoarthrosis and the capacity to return to full duty (P = .013). CONCLUSION: Both single and 2-level ACDFs have high overall success with an 88% rate of return to full duty.

Direct enhancement of readiness for wartime critical specialties by civilian-military partnerships for neurosurgical care: residency training and beyond.

Military neurosurgery has played an integral role in the development and innovation of neurosurgery and neurocritical care in treating battlefield injuries. It is of paramount importance to continue to train and prepare the next generation of military neurosurgeons. For the Army, this is currently primarily achieved through the military neurosurgery residency at the National Capital Consortium and through full-time out-service positions at the Veterans Affairs-Department of Defense partnerships with the University of Florida, the University of Texas-San Antonio, and Baylor University. The authors describe the application process for military neurosurgery residency and highlight the training imparted to residents in a busy academic and level I trauma center at the University of Florida, with a focus on how case variety and volume at this particular civilian-partnered institution produces neurosurgeons who are prepared for the complexities of the battlefield. Further emphasis is also placed on collaboration for research as well as continuing education to maintain the skills of nondeployed neurosurgeons. With ongoing uncertainty regarding future conflict, it is critical to preserve and expand these civilian-military partnerships to maintain a standard level of readiness in order to face the unknown with the confidence befitting a military neurosurgeon.

Early venous thromboembolism chemoprophylaxis in combat-related penetrating brain injury.

OBJECTIVE Traumatic brain injury (TBI) is independently associated with deep vein thrombosis (DVT) and pulmonary embolism (PE). Given the numerous studies of civilian closed-head injury, the Brain Trauma Foundation recommends venous thromboembolism chemoprophylaxis (VTC) after severe TBI. No studies have specifically examined this practice in penetrating brain injury (PBI). Therefore, the authors examined the safety and effectiveness of early VTC after PBI with respect to worsening intracranial hemorrhage and DVT or PE. METHODS The Kandahar Airfield neurosurgery service managed 908 consults between January 2010 and March 2013. Eighty of these were US active duty members with PBI, 13 of whom were excluded from analysis because they presented with frankly nonsurvivable CNS injury or they died during initial resuscitation. This is a retrospective analysis of the remaining 67 patients. RESULTS Thirty-two patients received early VTC and 35 did not. Mean time to the first dose was 24 hours. Fifty-two patients had blast-related PBI and 15 had gunshot wounds (GSWs) to the head. The incidence of worsened intracranial hemorrhage was 16% after early VTC and 17% when it was not given, with the relative risk approaching 1 (RR = 0.91). The incidence of DVT or PE was 12% after early VTC and 17% when it was not given (RR = 0.73), though this difference was not statistically significant. CONCLUSIONS Early VTC was safe with regard to the progression of intracranial hemorrhage in this cohort of combat-related PBI patients. Data in this study suggest that this intervention may have been effective for the prevention of DVT or PE but not statistically significantly so. More research is needed to clarify the safety and efficacy of this practice.

The Intraoperative Effect of Methadone on Somatosensory Evoked Potentials.

BACKGROUND: Evoked potentials (EP), both somatosensory evoked potentials (SSEP) and transcranial motor evoked potentials (TcMEP), are often used during complex spine surgery to monitor the integrity of spinal pathways during operations in or around the spine. Changes in these monitored EP signals (increased latency and decreased amplitude) may result from ischemia, direct surgical injury, changes in blood pressure, hypoxia, changes in CO2 tension, and anesthetic agents. Typically, a clinically significant change for SSEPs is defined as an increase in latency >10% or a decrease of amplitude >50%. A clinically significant change for TcMEPs is much more complex but is also described in terms of large signal loss or decrease. Opioids have been shown to both increase latency and decrease the amplitude of SSEPs, although this change is usually not clinically significant. There has been a renewed interest in methadone for use in spine and other complex surgeries. However, the effect of methadone on intraoperative monitoring of SSEPs and TcMEPs is unknown. We present the first study to directly look at the effects of methadone on SSEP and TcMEP monitoring during complex spine surgery. METHODS: The goal of this study was to observe the effect of methadone on an unrandomized set of patients. The primary endpoint was methadone's effect on SSEPs, and the secondary endpoint was methadone's effect on TcMEPs. Adult patients undergoing spine surgery requiring intraoperative neuromonitoring were induced with general anesthesia and had a baseline set of SSEPs and TcMEPs recorded. Next, methadone dosed 0.2 mg/kg/lean body weight was given. Repeat SSEPs and TcMEPs were recorded at 5, 10, and 15 minutes, with the timing based on distribution half-life of methadone between 6 and 8 minutes. Postoperatively, adverse events from methadone administration were collected. RESULTS: There was a statistically significant difference found in SSEPs for N20 latency (95% confidence interval [CI], 0.17-0.53; P=0.028), P37 latency (95% CI, 0.65-1.25; P=0.001), and N20 amplitude (95% CI, 0.09-0.32; P=<0.001), but not for P37 amplitude (95% CI, -0.19 to 0.00; P=0.634). There was no significant effect found for TcMEPs, the secondary endpoint of the study, and there were minimal adverse events recorded postoperatively. CONCLUSIONS: The data demonstrate that a single intravenous dose of methadone has a statistically significant difference on the amplitude and latency of SSEPs. However, this statistical difference does not translate into a clinical significance.

Pneumocephalus and neurosurgery in rotary aircrew.

BACKGROUND: Pneumocephalus secondary to trauma or tumors can have varied symptom severity. It is important to recognize and quantify pneumocephalus for medical evacuation and treatment. This case presents current recommendations for travel in the literature and how they are applicable in returning to flying duties after neurosurgical interventions. CASE REPORT: This is the case of a Naval aircrew member who developed an osteoma and subsequently periorbital emphysema and pneumocephalus. This required medical evacuation from a remote territory, a team surgical approach, and later testing to allow him to return to flight duties in rotary aircraft. DISCUSSION: A search of the literature did not reveal any previous cases of civilian or military flight crew having returned to flying duties after pneumocephalus or neurosurgery. Barometric chamber testing was performed post-operatively to provide clearance. Literature review revealed mixed advice on when one can safely fly commercially after neurosurgery and may be applicable in a case series of medical evacuation or future clearance in returning to flight duties. Ruddick B, Tomlin J. Pneumocephalus and neurosurgery in rotary aircrew.

Contemporary imaging of mild TBI: the journey toward diffusion tensor imaging to assess neuronal damage.

OBJECTIVES: To follow the progression of neuroimaging as a means of non-invasive evaluation of mild traumatic brain injury (mTBI) in order to provide recommendations based on reproducible, defined imaging findings. METHODS: A comprehensive literature review and analysis of contemporary published articles was performed to study the progression of neuroimaging findings as a non-invasive 'biomarker' for mTBI. RESULTS: Multiple imaging modalities exist to support the evaluation of patients with mTBI, including ultrasound (US), computed tomography (CT), single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI). These techniques continue to evolve with the development of fractional anisotropy (FA), fiber tractography (FT), and diffusion tensor imaging (DTI). DISCUSSION: Modern imaging techniques, when applied in the appropriate clinical setting, may serve as a valuable tool for diagnosis and management of patients with mTBI. An understanding of modern neuroanatomical imaging will enhance our ability to analyse injury and recognize the manifestations of mTBI.

Transdural metastasis from adenocarcinoma of the prostate mimicking subdural hematoma: case report.

BACKGROUND: Metastasis of prostatic adenocarcinoma to the nervous system is extremely rare and has been infrequently reported over the last several years. We describe the presentation, evaluation, and surgical intervention of a case of metastatic prostate carcinoma to the dura. CASE DESCRIPTION: This patient presented with symptoms and physical findings consistent with a subacute subdural hematoma in the setting of recently diagnosed adenocarcinoma of the prostate. He underwent a craniotomy for presumed subdural hematoma. The pathologic diagnosis was consistent with metastatic prostatic carcinoma. CONCLUSION: This case report demonstrates the need for broad differential diagnosis in the evaluation and treatment of patients presenting with seemingly straightforward subacute subdural hematomas.