BACKGROUND: Primary spinal melanoma is extremely rare, accounting for ∼1% of all primary melanomas. Typically presenting insidiously in the thoracic spinal cord, primary spinal melanomas can have an acute presentation due to their propensity to hemorrhage.
METHODS: Despite its rarity, primary spinal melanoma should be included in the differential diagnosis when a hemorrhagic pattern of T1 and T2 intensities is seen on magnetic resonance imaging. Furthermore, the complete diagnosis is crucial because the prognosis of a primary spinal melanoma is considerably more favorable than that of a primary cutaneous melanoma with metastatic spread.
CONCLUSIONS: Resection is the treatment of choice, with some authors advocating for postoperative chemotherapy, immunotherapy, and/or radiation. We describe a case of acute quadriplegia from hemorrhagic primary spinal melanoma requiring resection.

BACKGROUND: Virtual reality (VR) offers an interactive environment for visualizing the intimate three-dimensional (3D) relationship between a patient\'s pathology and surrounding anatomy. The authors present a model for using personalized VR technology, applied across the neurosurgical treatment continuum from the initial consultation to preoperative surgical planning, then to intraoperative navigation, and finally to postoperative visits, for various tumor and vascular pathologies.
METHODS: Five adult patients undergoing procedures for spinal cord cavernoma, clinoidal meningioma, anaplastic oligodendroglioma, giant aneurysm, and arteriovenous malformation were included. For each case, 360-degree VR (360°VR) environments developed using Surgical Theater were used for patient consultation, preoperative planning, and/or intraoperative 3D navigation. The custom 360°VR model was rendered from the patient\'s preoperative imaging. For two cases, the plan changed after reviewing the patient\'s 360°VR model from one based on conventional Digital Imaging and Communications in Medicine imaging.
CONCLUSIONS: Live 360° visualization with Surgical Theater in conjunction with surgical navigation helped validate the decisions made intraoperatively. The 360°VR models provided visualization to better understand the lesion\'s 3D anatomy, as well as to plan and execute the safest patient-specific approach, rather than a less detailed, more standardized one. In all cases, preoperative planning using the patient\'s 360°VR model had a significant impact on the surgical approach.

BACKGROUND: Meningiomas are the most commonly encountered nonglial primary intracranial tumors. The authors report on the usefulness of intraoperative magnetic resonance imaging (iMRI) during microsurgical resection of meningiomas located close to eloquent areas or dural sinuses and on the feasibility of further radiation therapy.
METHODS: Six patients benefited from this approach. The mean follow-up period after surgery was 3.3 (median 3.2, range 2.1-4.6) years. Five patients had no postoperative neurological deficit, of whom two with preoperative motor deficit completely recovered. One patient with preoperative left inferior limb deficit partially recovered. The mean interval between surgery and radiation therapy was 15.8 (median 16.9, range 1.4-40.5) months. Additional radiation therapy was required in five cases after surgery. The mean preoperative tumor volume was 38.7 (median 27.5, range 8.6-75.6) mL. The mean postoperative tumor volume was 1.2 (median 0.8, range 0-4.3) mL. At the last follow-up, all tumors were controlled.
CONCLUSIONS: The use of iMRI was particularly helpful to (1) decide on additional tumor resection according to iMRI findings during the surgical procedure; (2) evaluate the residual tumor volume at the end of the surgery; and (3) judge the need for further radiation and, in particular, the feasibility of single-fraction radiosurgery.

BACKGROUND: Providencia rettgeri is a rare cause of nosocomial infection in humans. These organisms are capable of biofilm production and are intrinsically resistant to commonly used antibiotics, leading to high rates of morbidity and mortality. P. rettgeri may very rarely cause postneurosurgical infection.
METHODS: In this report, the authors describe two patients in whom P. rettgeri infection complicated the postoperative course. Both the patients underwent craniotomy at approximately the same time under similar environments. The organism isolated was resistant to most of the commonly used antibiotics, and therapy tailored to the results of susceptibility testing led to resolution of infection in both cases.
CONCLUSIONS: P. rettgeri is a rare cause of postneurosurgical nosocomial infection. Timely identification and early tailoring of antibiotic therapy based on susceptibility testing is the key to treatment. Every effort should be made to identify the source of infection and rectify it so that mortality, morbidity, and financial burden are reduced. Contact isolation and use of sterile gloves after each patient contact are effective in preventing its spread, as in most cases of nosocomial infection.

Although French psychiatrist-turned-neurosurgeon Jean Talairach (1911-2007) is perhaps best known for the stereotaxic atlas he produced with Pierre Tournoux and Gábor Szikla, he has left his mark on most aspects of modern stereotactic and functional neurosurgery. In the field of psychosurgery, he expressed critique of the practice of prefrontal lobotomy and subsequently was the first to describe the more selective approach using stereotactic bilateral anterior capsulotomy. Turning his attention to stereotaxy, Talairach spearheaded the team at Hôpital Sainte-Anne in the construction of novel stereotaxic apparatus. Cadaveric investigation using these tools and methods resulted in the first human stereotaxic atlas where the use of the anterior and posterior commissures as intracranial reference points was established. This work revolutionized the approach to cerebral localization as well as leading to the development of numerous novel stereotactic interventions by the Sainte-Anne team, including tumor biopsy, interstitial irradiation, thermal ablation, and endonasal procedures. Together with epileptologist Jean Bancaud, Talairach invented the field of stereo-electroencephalography and developed a robust scientific methodology for the assessment and treatment of epilepsy. In this article the authors review Talairach\'s career trajectory in its historical context and in view of its impact on modern stereotactic and functional neurosurgery.

External ventricular drains (EVDs) are commonly used in the neurosurgical population. However, very few pediatric neurosurgery studies are available regarding EVD-associated infection rates with antibiotic-impregnated EVD catheters. The authors previously published a large pediatric cohort study analyzing nonantibiotic-impregnated EVD catheters and risk factors associated with infections. In this study, they aimed to analyze the EVD-associated infection rate after implementation of antibiotic-impregnated EVD catheters.
A retrospective observational cohort of pediatric patients (younger than 18 years of age) who underwent a burr hole for antibiotic-impregnated EVD placement and who were admitted to a quaternary care ICU between January 2011 and January 2019 were reviewed. The ventriculostomy-associated infection rate in patients with antibiotic-impregnated EVD catheters was compared to the authors\' historical control of patients with nonantibiotic-impregnated EVD catheters.
Two hundred twenty-nine patients with antibiotic-impregnated EVD catheters were identified. Neurological diagnostic categories included externalization of an existing shunt (externalized shunt) in 34 patients (14.9%); brain tumor (tumor) in 77 patients (33.6%); intracranial hemorrhage (ICH) in 27 patients (11.8%); traumatic brain injury (TBI) in 6 patients (2.6%); and 85 patients (37.1%) were captured in an \"other\" category. Two of 229 patients (0.9% of all patients) had CSF infections associated with EVD management, totaling an infection rate of 0.99 per 1000 catheter days. This is a significantly lower infection rate than was reported in the authors\' previously published analysis of the use of nonantibiotic-impregnated EVD catheters (0.9% vs 6%, p = 0.00128).
In their large pediatric cohort, the authors demonstrated a significant decline in ventriculostomy-associated CSF infection rate after implementation of antibiotic-impregnated EVD catheters at their institution.

The goal of this study was to develop and validate a system for automatic segmentation of the spine, pedicle identification, and screw path suggestion for use with an intraoperative 3D surgical navigation system.
Cone-beam CT (CBCT) images of the spines of 21 cadavers were obtained. An automated model-based approach was used for segmentation. Using machine learning methodology, the algorithm was trained and validated on the image data sets. For measuring accuracy, surface area errors of the automatic segmentation were compared to the manually outlined reference surface on CBCT. To further test both technical and clinical accuracy, the algorithm was applied to a set of 20 clinical cases. The authors evaluated the system\'s accuracy in pedicle identification by measuring the distance between the user-defined midpoint of each pedicle and the automatically segmented midpoint. Finally, 2 independent surgeons performed a qualitative evaluation of the segmentation to judge whether it was adequate to guide surgical navigation and whether it would have resulted in a clinically acceptable pedicle screw placement.
The clinically relevant pedicle identification and automatic pedicle screw planning accuracy was 86.1%. By excluding patients with severe spinal deformities (i.e., Cobb angle > 75° and severe spinal degeneration) and previous surgeries, a success rate of 95.4% was achieved. The mean time (± SD) for automatic segmentation and screw planning in 5 vertebrae was 11 ± 4 seconds.
The technology investigated has the potential to aid surgeons in navigational planning and improve surgical navigation workflow while maintaining patient safety.

Internal carotid artery (ICA) injuries during endoscopic endonasal surgery (EES) are catastrophic complications. Alongside the advancements in medical instrumentation and material, there is a need to modify previous treatment modalities and principles.
A retrospective review of 3658 patients who underwent EES performed at the authors\' institution between January 2012 and December 2017 was conducted. Ultimately, 20 patients (0.55%) with ICA injury following EES were enrolled for analysis. Data collection included demographic data, preoperative diagnosis, injury setting, repair method, and immediate and follow-up angiographic and clinical outcomes.
Among the 20 patients, 11 received immediate endovascular therapy and 9 were treated only with packing. Of the 11 patients who received endovascular treatment, 6 were treated by covered stent and 5 by parent artery occlusion (PAO). The preservation rate of injured ICA increased from 20.0% (1 of 5) to 83.3% (5 of 6) after the Willis covered stent graft became available in January 2016. Of the 20 patients in the study, 19 recovered well and 1 patient-who had a pseudoaneurysm and was treated by PAO with a detachable balloon-suffered epistaxis after the hemostat in her nasal cavity was removed in ward, and she died later that day. The authors speculated that the detachable balloon had shifted to the distal part of ICA, although the patient could not undergo a repeat angiogram because she quickly suffered shock and could not be transferred to the catheter room. After the introduction of a hybrid operating room (OR), one patient whose first angiogram showed no ICA injury was found to have a pseudoaneurysm. He received endovascular treatment when he was brought for a repeat angiogram 5 days later in the hybrid OR after removing the hemostat in his nasal cavity. Of the 4 surviving patients treated with PAO, no external carotid artery-ICA bypass was required. The authors propose a modified endovascular treatment protocol for ICA injuries suffered during EES that exploits the advantage of the covered stent graft and the hybrid OR.
The endovascular treatment protocol used in this study for ICA injuries during EES was helpful in the management of this rare complication. Willis stent placement improved the preservation rate of injured ICA during EES. It would be highly advantageous to manage this complication in a hybrid OR or by a mobile C-arm to get a clear intraoperative angiogram.

Corpus callosotomy has been used as a form of surgical palliation for patients suffering from medically refractory generalized seizures, including drop attacks. Callosotomy has traditionally been described as involving a craniotomy with microdissection. MR-guided laser interstitial thermal therapy (MRg-LITT) has recently been used as a minimally invasive method for performing surgical ablation of epileptogenic foci and corpus callosotomy. The authors present 3 cases in which MRg-LITT was used to perform a corpus callosotomy as part of a staged surgical procedure for a patient with multiple seizure types and in instances when further ablation of residual corpus callosum is necessary after a prior open surgical procedure. To the authors\' knowledge, this is the first case series of corpus callosotomy performed using the MRg-LITT system with a 3.3-year average follow-up. Although MRg-LITT is not expected to replace the traditional corpus callosotomy in all cases, it is a safe, effective, and durable alternative to the traditional open corpus callosotomy, particularly in the setting of a prior craniotomy.

OBJECTIVEActive-duty neurosurgical coverage has been provided at Bagram Air Force Base in Afghanistan since 2007. Early operative logs were reflective of a large number of surgical procedures performed to treat battlefield injuries. However, with maturation of the war effort, the number of operations for battlefield injuries has decreased with time. Consequently, procedures performed for elective neurosurgical humanitarian care (NHC) increased in number and complexity prior to closure of the Korean Hospital in 2015, which resulted in effective termination of NHC at Bagram. Monthly neurosurgical caseloads for deployed personnel have dropped precipitously since this time, renewing a debate as to whether the benefits of providing elective NHC in Afghanistan outweigh the costs of such a strategy. To date, there is a paucity of information in the literature discussing the overall context of such a determination.METHODSThe author retrospectively reviewed his personal database of all patients who underwent neurosurgical procedures at Bagram during his deployment there from April 17 to October 29, 2014. Standardized clinical parameters had been recorded in the ABNS NeuroLog system. All cases of nonelective surgical care for battlefield injuries were identified and excluded. Records of all other procedures, which represented elective NHC delivered during this period, were accessed to extract salient clinical and radiological data.RESULTSDuring the 6-month deployment, 49 patients (29 male and 20 female, age range 18 months to 63 years) were treated by the author in elective NHC. Procedures were performed for spinal degenerative disease (n = 28), cranial tumors (n = 11), pediatric conditions (n = 6), Pott\'s disease (n = 2), peripheral nerve impingement (n = 1), and adult hydrocephalus (n = 1). The duration of follow-up ranged from 3 to 23 weeks. Complications referable to surgery included asymptomatic, unilateral lumbar screw fracture detected 3 months postoperatively and treated with revision of hardware (n = 1); wound infection requiring cranial flap explantation and staged cranioplasty (n = 1); and unanticipated return to the operating room for resection of residual tumor in a patient with a solitary metastatic lesion involving the mesial temporal lobe/ambient cistern (n = 1). There were no instances of postoperative neurological decline.CONCLUSIONSElective NHC can be safely and effectively implemented in the deployed setting. Benefits of a military strategy that supports humanitarian care include strengthening of the bond between the US/Afghan military communities and the local civilian population as well as maintenance of skills of the neurosurgical team during the sometimes-lengthy intervals between cases in which emergent neurosurgical care is provided for treatment of battlefield injuries.