Rosai-Dorfman disease of the cauda equina: illustrative case.

BACKGROUND: Rosai-Dorfman disease (RDD) is a rare, nonmalignant histiocytosis. It typically occurs in lymph nodes, skin, and soft tissues, but numerous reports of central nervous system involvement exist in the literature. The peripheral nervous system has rarely been involved. In this study, the authors present a case of RDD isolated to the cauda equina. The presentation, management, surgical technique, and adjunctive treatment strategy are described. OBSERVATIONS: A 31-year-old female presented with 6 months of progressive left lower-extremity numbness involving the lateral aspect of the foot and weakness of the left toes. Magnetic resonance imaging of the lumbar spine demonstrated a homogeneously enhancing intradural lesion involving the cauda equina at the L2-3 levels. Histopathology after resection revealed a histiocytic infiltrate, positive for CD68 and S100, and emperipolesis consistent with RDD. No adjuvant therapy was administered, and the patient had full remission at the 1-year follow-up. Only five other cases of intradural RDD lesions of the cauda equina have been reported in the literature. LESSONS: RDD of the cauda equina is an especially rare and challenging diagnosis that can mimic other dura-based lesions, such as meningiomas. A definitive diagnosis of RDD relies on pathognomonic histopathological and immunohistochemical findings.

A Scoping Review of Professionalism in Neurosurgery.

BACKGROUND AND OBJECTIVES: The Accreditation Council for Graduate Medical Education's Milestones provides a foundation for professionalism in residency training. Specific professionalism concepts from neurosurgery could augment and expand milestones for the specialty. We reviewed the current literature and identified professionalism concepts within the context of neurosurgical practice and training. METHODS: We used a scoping review methodology to search PubMed/MEDLINE and Scopus and identify English-language articles with the search terms "professionalism" and "neurosurgery." We excluded articles that were not in English, not relevant to professionalism within neurosurgery, or could not be accessed. Non-peer-reviewed and qualitative publications, such as commentaries, were included in the review. RESULTS: A total of 193 articles were included in the review. We identified 6 professionalism themes among these results: professional identity (n = 53), burnout and wellness (n = 51), professional development (n = 34), ethics and conflicts of interest (n = 27), diversity and gender (n = 19), and misconduct (n = 9). CONCLUSION: These 6 concepts illustrate concerns that neurosurgeons have concerning professionalism. Diversity and gender, professional identity, and misconduct are not specifically addressed in the Accreditation Council for Graduate Medical Education's Milestones. This review could be used to aid the development of organizational policy statements on professionalism.

Pre-operative embolization for staged treatment of infantile choroid plexus papilloma.

Choroid plexus papillomas (CPPs) are benign but rare neuroepithelial neoplasms of the choroid plexus that represent the non-malignant form of a spectrum of tumors of the choroid plexus. The vast majority of CPPs present in children under 5 years of age. Some CPPs are diagnosed prenatally, but many of them reach a large size before diagnosis. CPPs typically present with signs and symptoms of hydrocephalus. Treatment of these tumors has traditionally been with surgical resection. Large CPPs in young children present a challenge due to risk of high blood loss during resection. Here, the authors describe the case of a 3-month-old presenting with hydrocephalus and a large CPP of the third ventricle that was managed with a staged strategy of embolization followed by a delayed resection, allowing the tumor to involute prior to surgery.

Intracranial gunshot wounds in utero: case report and review.

BACKGROUND AND IMPORTANCE: We present a rare case of an in utero intracranial gunshot wound with survival of the baby and neurosurgical intervention in the first 6 h of life. CLINICAL PRESENTATION: A pregnant 19-year old sustained multiple gunshot wounds and underwent an emergency cesarean section. At the time of delivery, there was a penetrating wound noted to the uterus and to the left side of the baby's head. The baby was taken urgently for craniotomy. Thorough washout was performed, and a pericranial graft was harvested from the frontal vertex to assist in dural closure. The largest displaced bone fragment was soaked in betadine and sutured back into place. The baby was observed for several days and then discharged home with normal neurological examination. CONCLUSION: There are scattered reports of in utero intracranial gunshot wounds in the literature dating back to the nineteenth century; however, our case appears to be the first reported that involved urgent surgical intervention.

Far Lateral Approach for Resection of Transverse Ligament Cyst.

Objectives This study was aimed to describe a far lateral approach for microsurgical resection of a transverse ligament cyst, with emphasis on the microsurgical anatomy and technique. Design A far lateral craniotomy is performed in the lateral decubitus position. After opening the dura laterally, dural sutures are placed for retraction. A stitch placed through the dentate ligament is advantageous to rotate the spinal cord to allow access to the ventral cyst. The cyst is marsupirlized and mass effect on the spinal cord is relieved. Photographs of the region are borrowed from Dr Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The first author performed the surgery and edited the video. Chart review and literature review were performed by the other authors. Outcome Measures Outcome was assessed with postoperative neurological function. Results The patient was discharged home after an uneventful hospital course. At short-term follow-up, the patient had a significant improvement in postoperative strength. Conclusion The far lateral approach provides an adequate corridor to the ventrolateral brainstem in combination with utilization of the dentate ligament to reach ventral cysts compressing the spinal cord. An adequate understanding of the relevant microsurgical anatomy is a key to safe surgery in this region. The link to the video can be found at: https://youtu.be/5MGVPO2Q2pI .

Resection of a Recurrent Cervicomedullary Junction Fibromyxoid Sarcoma through a Far Lateral Approach.

Objectives This study describes a far lateral approach for the resection of a recurrent fibromyxoid sarcoma involving the ventrolateral brainstem, with emphasis on the microsurgical anatomy and technique. Design A far lateral craniotomy is performed in the lateral decubitus position and the transverse and sigmoid sinuses exposed. After opening the dura, sutures are placed to allow gentle mobilization of the sinuses. The recurrent tumor is immediately visible. The involved dura is resected and aggressive internal debulking is performed. Subarachnoid dissection gives access to the lower cranial nerves. The tumor is dissected off the affected portions of the brainstem. A dural graft is used to reconstitute the dura. Photographs of the region are borrowed from Dr. Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior author performed the surgery. The video was edited by Dr. V.N. chart review, and literature review were performed by Drs. W.M. and J.B. Outcome measures Outcome was assessed with the extent of resection and postoperative neurological function. Results A near gross total resection of the lesion was achieved. The patient developed a left vocal cord paresis, but her voice was improving at 3-month follow-up. Conclusion Understanding the microsurgical anatomy of the craniocervical junction and ventrolateral brainstem and meticulous microneurosurgical technique are necessary to achieve adequate resection of lesions involving the ventrolateral brainstem. The far lateral approach provides an adequate corridor to this region. The link to the video can be found at: https://youtube/uYEhgPbgrTs .

The economic value of an on-call neurosurgical resident physician.

OBJECTIVE: The cost of training neurosurgical residents is especially high considering the duration of training and the technical nature of the specialty. Despite these costs, on-call residents are a source of significant economic value, through both indirectly and directly supervised activities. The authors sought to identify the economic value of on-call services provided by neurosurgical residents. METHODS: A personal call log kept by a single junior neurosurgical resident over a 2-year period was used to obtain the total number of consultations, admissions, and procedures. Current Procedural Terminology (CPT) codes were used to estimate the resident's on-call economic value. RESULTS: A single on-call neurosurgical resident at the authors' institution produced 8172 work relative value units (wRVUs) over the study period from indirectly and directly supervised activities. Indirectly supervised procedures produced 7052 wRVUs, and directly supervised activities using the CPT modifier 80 yielded an additional 1120 wRVUs. Using the assistant surgeon billing rate for directly supervised activities and the Medical Group Management Association nationwide median neurosurgery reimbursement rate, the on-call activities of a single resident generated a theoretical billing value of $689,514 over the 2-year period, or $344,757 annually. As a program, the on-call residents collectively produced 39,550 wRVUs over the study period, or 19,775 wRVUs annually, which equates to potential reimbursements of $1,668,386 annually. CONCLUSIONS: Neurosurgery residents at the authors' institution theoretically produce enough economic value exclusively from on-call activities to far exceed the cost of their education. This information could be used to more precisely estimate the true overall cost of neurosurgical training and determine future graduate medical education funding.

Application of the Preventable Shunt Revision Rate to an Adult Population.

BACKGROUND: The preventable shunt revision rate (PSRR) was recently introduced in pediatric hydrocephalus as a quality metric for shunt surgery. We evaluated the PSRR in an adult hydrocephalus population. METHODS: All ventricular shunt operations (January 1, 2013 to March 31, 2018) performed at a university-based teaching hospital were included. For any index surgery (de novo or revision) resulting in reoperation within 90 days, the index surgery details were collected, and a consensus decision was reached regarding whether the failure had been potentially avoidable. Preventable failure was defined as failure due to infection, malposition, disconnection, migration, or kinking. The 90-day shunt failure rate and PSRR were calculated. Bivariate analyses were performed to evaluate the individual effects of each independent variable on preventable shunt failure. RESULTS: A total of 318 shunt operations had been performed in 245 patients. Most patients were women (62%), with a median age of 48.2 years (interquartile range, 31.2-63.2 years). Most had had ventriculoperitoneal shunts placed (86.5%), and just more than one half were new shunts (51.6%). A total of 53 cases (16.7%) in 42 patients experienced shunt failure within 90 days of the index operation. Of these, 27 failures (8.5% of the total cases; 51% of the failures) were considered potentially preventable. The most common reasons were infection (37%; n = 10) and malposition of the proximal and distal catheters (both 25.9%; n = 7). Age was the only statistically significant difference between the 2 groups, with the patients experiencing preventable shunt failure older than those without preventable shunt failure (51.4 vs. 37.1 years; P = 0.017). CONCLUSIONS: The 90-day PSRR can be applied to an adult population and serve as a quality metric.

Far Lateral Approach for Clipping of a Posterior Inferior Cerebellar Artery Aneurysm.

Objectives To describe a far lateral approach for microsurgical clipping of a ruptured posterior inferior cerebellar artery (PICA) aneurysm involving the hypoglossal nerve, with emphasis on the microsurgical anatomy, and technique. Design A far lateral craniotomy is performed in the lateral decubitus position and the transverse and sigmoid sinuses were exposed. After opening the dura, sutures are placed to allow gentle mobilization of the sinuses. The ipsilateral cerebellar tonsil is mobilized and the PICA is followed to its junction with the vertebral artery. Hypoglossal nerve rootlets are draped over the dome of the aneurysm. Mobilization of the PICA and the hypoglossal nerve away from the lateral medulla allows microsurgical clipping of the aneurysm neck. Photographs of the region are borrowed from Dr Rhoton's laboratory to illustrate the microsurgical anatomy. Participants The senior authors performed the surgery. The video was edited by Drs. V.N. and J.B. Chart review and literature review were performed by Drs. W.M. and J.B. Outcome Measures Outcome was assessed with successful clip occlusion and postoperative neurological function. Results There was complete clip occlusion of the PICA aneurysm with no postoperative neurological deficits. The patient was discharged home after an uneventful hospital course. Conclusion The far lateral approach provides an adequate corridor to the ventrolateral brainstem for microsurgical treatment of PICA aneurysms. An adequate understanding of the relevant microsurgical anatomy is the key to safe and effective clipping in this region. The link to the video can be found at: https://youtu.be/yhjKRIG5H74 .

Subdural hematoma as a major determinant of short-term outcomes in traumatic brain injury.

OBJECTIVE Early radiographic findings in patients with traumatic brain injury (TBI) have been studied in hopes of better predicting injury severity and outcome. However, prior attempts have generally not considered the various types of intracranial hemorrhage in isolation and have typically not excluded patients with potentially confounding extracranial injuries. Therefore, the authors examined the associations of various radiographic findings with short-term outcome to assess the potential utility of these findings in future prognostic models. METHODS The authors retrospectively identified 1716 patients who had experienced TBI without major extracranial injuries, and categorized them into the following TBI subtypes: subdural hematoma (SDH), traumatic subarachnoid hemorrhage, intraparenchymal hemorrhage (which included intraventricular hemorrhage), and epidural hematoma. They specifically considered isolated forms of hemorrhage, in which only 1 subtype was present. RESULTS In general, the presence of an isolated SDH was more likely to result in worse outcomes than the presence of other isolated forms of traumatic intracranial hemorrhage. Discharge to home was less likely and perihospital mortality rates were generally higher in patients with SDH. These findings were not simply related to age and were not fully captured by the admission Glasgow Coma Scale (GCS) score. The presence of SDH had a much higher sensitivity for poor outcome than the presence of other TBI subtypes, and was more sensitive for these poor outcomes than having a low GCS score (3-8). CONCLUSIONS In these ways, SDH was the most important finding associated with poor outcome, and the authors show that consideration of SDH, specifically, can augment age and GCS score in classification and prognostic models for TBI.

Interdisciplinary Management of Minimally Displaced Orbital Roof Fractures: Delayed Pulsatile Exophthalmos and Orbital Encephalocele.

Traumatic orbital roof fractures are rare and are managed nonoperatively in most cases. They are typically associated with severe mechanisms of injury and may be associated with significant neurologic or ophthalmologic compromise including traumatic brain injury and vision loss. Rarely, traumatic encephalocele or pulsatile exophthalmos may be present at the time of injury or develop in delayed fashion, necessitating close observation of these patients. In this article, we describe two patients with minimally displaced blow-in type orbital roof fractures that were later complicated by orbital encephalocele and pulsatile exophthalmos, prompting urgent surgical intervention. We also suggest a management algorithm for adult patients with orbital roof fractures, emphasizing careful observation and interdisciplinary management involving plastic surgery, neurosurgery, and ophthalmology.