Gender Differences in Perceptions and Attitudes of Medical Students Toward Neurosurgery: A German Nationwide Survey.

BACKGROUND: Despite advances in gender equity, the paucity of women neurosurgeons remains. In Germany, women accounted for only 24% of the specialists who completed their neurosurgical training in 2019. We sought to explore the perceptions of medical students in Germany toward a neurosurgical career, focusing on gender-specific differences. METHODS: A digital 26-item questionnaire with a Likert 4-point scale and open-ended questions was distributed to the German medical school student bodies. Data were analyzed to determine statistically significant intragroup variability between women and men. RESULTS: Two hundred ten medical students participated in the survey. Women and men were equally interested in brain pathologies (38% vs. 47%, strongly agreed), whereas interest in neurosurgery was significantly greater in men (12% vs. 26%, strongly agreed). Men were less likely to believe that women neurosurgery residents would face inequality at work. They were also less likely to support a gender quota in neurosurgery. Yet, both women and men were convinced that a rise in the number of women would positively impact the field. No gender dependency was seen in students' strive for success and prestige. Men felt discouraged from pursuing neurosurgery because they feared an unpleasant work environment, whereas women were concerned about neurosurgery not being family-friendly. Regardless of gender, the greatest factor deterring students from neurosurgery was poor work-life balance. CONCLUSIONS: Awareness must be raised concerning gender inequity and discrimination in our specialty. A multifaceted approach is imperative to develop neurosurgery into a profession where gender no longer hinders access to training and success in the field.

"Crimes against the Nervous System": Neurological References During the Nuremberg Doctors' Trials.

The Nuremberg Trials were a sequence of tribunal sessions held by the Allied Forces between November 1945 and October 1946 with the intent of prosecuting prominent representatives of the Nazi Party for crimes committed before and during the war. Because medical experiments in human prisoners were among the most heinous offenses, a specific series of court cases, known as the Doctor's Trials (the USA vs. Karl Brandt et al), was carried out. A considerable part of the official documents of the Nuremberg Trials has been recently made publicly available through the Nuremberg Trials Project, an initiative of the Harvard Law School Library. We performed a comprehensive analysis of the Doctors' Trials original documents (NMT 1: Medical Case) as well as other available academic and historical sources focusing on references to the nervous system, neurosurgical, and neurologic diseases. Besides providing a brief glance of a unique source of original historical documents, this historical vignette also attempts to fulfill, at least in some limited sense, the moral duty toward the Holocaust victims laid on our generation by remembering their fate.

Minimally invasive superficial temporal artery to middle cerebral artery bypass through an enlarged bur hole: the use of computed tomography angiography neuronavigation in surgical planning.

The authors describe their minimally invasive technique for performing a superficial temporal artery (STA) to middle cerebral artery (MCA) bypass, which relies on an enlarged bur hole (2-2.5 cm) rather than the standard craniotomy. They perform this procedure in a minimally invasive fashion, using CT angiography for intraoperative neuronavigation as well as for preoperative identification of the donor and recipient vessels and planning of bur hole location. They present 2 cases in which this procedure was used, including one involving a patient with multivessel occlusive disease and significant cerebrovascular hemodynamic compromise in whom they performed the procedure using only local anesthetic and propofol sedation in order to minimize the risk of hypotension associated with the use of general anesthetic agents. A comprehensive literature search revealed no previously published case of an extracranial-intracranial arterial bypass procedure performed in an awake patient. The authors have adopted the described minimally invasive method for all STA-MCA bypass procedures. The awake setting, however, is reserved for specific indications, primarily patients with severe moyamoya disease, in whom ventilator-related hypocarbia can result in intraoperative ischemia, or patients with multivessel occlusive disease and significant cerebral hemodynamic compromise, in whom general anesthesia-related hypotension can lead to intraoperative ischemia.

Awake Microvascular Decompression for Trigeminal Neuralgia: Concept and Initial Results.

BACKGROUND: In this initial series, we evaluated the use of microvascular decompression (MVD) under an awake anesthesia protocol ("awake" MVD) to assess whether intraoperative pain evaluation can identify and mitigate insufficient decompression of the trigeminal nerve, improving surgical outcomes, and possibly expand the indications of MVD in patients with comorbidities that would preclude the use of general endotracheal anesthesia (GEA). METHODS: An Institutional Review Board-approved prospective study of 10 consecutive adults who underwent MVD for trigeminal neuralgia (TN) was conducted. The primary outcome measure was postoperative TN pain quantified on the Barrow Neurological Institute (BNI) Pain Severity Scale. RESULTS: The median patient age was 65.5 years, with a female:male ratio of 6:4. All 10 patients tolerated the procedure well and did not require GEA intraoperatively or postoperatively. Nine patients had a successful surgical outcome (BNI score I, n = 5; BNI score II, n = 4). One patient did not have pain relief (BNI score IV). This same patient also developed a pseudomeningocele, which was the sole surgical complication observed in this series. One patient experienced recurrence of pain at 11 months, with BNI score increasing from I to II. The median duration of follow-up was 16.5 months. Two patients did not experienced resolution of evoked pain during intraoperative awake testing following decompression. Further intraoperative exploration revealed secondary offending vessels that were subsequently decompressed, leading to resolution of pain. CONCLUSIONS: Intraoperative awake testing for treatment efficacy may increase the success rate of MVD by rapidly identifying and mitigating insufficient cranial nerve V decompression.

"Awake" clipping of cerebral aneurysms: report of initial series.

OBJECTIVE Risk of ischemia during aneurysm surgery is significantly related to temporary clipping time and final clipping that might incorporate a perforator. In this study, the authors attempted to assess the potential added benefit to patient outcomes of "awake" neurological testing when compared with standard neurophysiological testing performed under general anesthesia. The procedure is performed after the induction of conscious sedation, and for the neurological testing, the patient is fully awake. METHODS The authors conducted an institutional review board-approved prospective study of clipping unruptured intracranial aneurysms (UIAs) in 30 consecutive adult patients who underwent awake clipping. The end points were the incidence of stroke/cerebrovascular accident (CVA), death, discharge to a long-term facility, length of stay, and 30-day modified Rankin Scale score. All clinical and neurophysiological intraoperative monitoring data were recorded. RESULTS The median patient age was 52 years (range 27-63 years); 19 (63%) female and 11 (37%) male patients were included. Twenty-seven (90%) aneurysms were anterior, and 3 (10%) were posterior circulation aneurysms. Five (17%) had been coiled previously, 3 (10%) had been clipped previously, 2 (7%) were partially calcified, and 2 (7%) were fusiform aneurysms. Three patients developed synchronous clinical neurological and neurophysiological changes during temporary clipping with consequent removal of the temporary clip and reversal of those clinical and neurophysiological changes. Three patients developed asynchronous clinical neurological and neurophysiological changes. These 3 patients developed hemiparesis without changes in neurophysiological monitoring results. One patient developed linked clinical neurological and neurophysiological changes during final clipping that were not reversed by reapplication of the clip, and the patient had a CVA. Four patients with internal carotid artery ophthalmic segment aneurysms underwent visual testing with final clipping, and 1 of these patients required repositioning of the clip. Three patients who required permanent occlusion of a vessel as part of their aneurysm treatment underwent a 10-minute intraoperative clinical respective-vessel test occlusion. The median length of stay was 3 days (range 1-5 days). The median modified Rankin Scale score was 1 (range 0-3). All of the patients were discharged to home from the hospital except for 1 who developed a CVA and was discharged to a rehabilitation facility. There were no deaths in this series. CONCLUSIONS The 3 patients who developed neurological deterioration without a concomitant neurophysiological finding during temporary clipping revealed a potential advantage of awake aneurysm surgery (i.e., in decreasing the risk of ischemic injury).

Awake High-Flow Extracranial to Intracranial Bypass for Complex Cerebral Aneurysms: Institutional Clinical Trial Results.

OBJECTIVE: Assess the potential added benefit to patient outcomes of "awake" neurological testing when compared with standard neurophysiologic testing performed under general endotracheal anesthesia. METHODS: Prospective study of 30 consecutive adult patients who underwent awake high flow extracranial to intracranial (HFEC-IC) bypass. Clinical neurological and neurophysiologic findings were recorded. Primary outcome measures were the incidence of stroke/cerebrovascular accident (CVA), length of stay, discharge to rehabilitation, 30-day modified Rankin scale score, and death. An analysis was also performed of a retrospective control cohort (n = 110 patients who underwent HFEC-IC for internal carotid artery (ICA) aneurysms under standard general endotracheal anesthesia). RESULTS: Five patients (16.6%) developed clinical awake neurological changes (4, contralateral hemiparesis; 1, ipsilateral visual changes) during the 10-minute ICA occlusion test. These patients had 2 kinks in the graft, 1 vasospasm, 1 requiring reconstruction of the distal anastomosis, and 1 developed blurring of vision that reversed after the removal of the distal permanent clip on the ICA. Three of these 5 patients had asynchronous clinical "awake" neurological and neurophysiologic changes. Two patients (7%) developed CVA. Median length of stay was 4 days. Twenty-eight of 30 patients were discharged to home. Median modified Rankin scale score was 1. There were no deaths in this series. Absolute risk reduction in the awake craniotomy group (n = 30) relative to control retrospective group (n = 110) was 7% for CVA, 9% for discharge to rehabilitation, and 10% for graft patency. CONCLUSIONS: Temporary ICA occlusion during HFEC-IC bypass for ICA aneurysms in conjunction with awake intraoperative clinical testing was effective in detecting a subset of patients (n = 3, 10%) in whom neurological deficit was not detected by neurophysiologic monitoring alone.

Proposed clinical internal carotid artery classification system.

INTRODUCTION: Numerical classification systems for the internal carotid artery (ICA) are available, but modifications have added confusion to the numerical systems. Furthermore, previous classifications may not be applicable uniformly to microsurgical and endoscopic procedures. The purpose of this study was to develop a clinically useful classification system. MATERIALS AND METHODS: We performed cadaver dissections of the ICA in 5 heads (10 sides) and evaluated 648 internal carotid arteries with computed tomography angiography. We identified specific anatomic landmarks to define the beginning and end of each ICA segment. RESULTS: The ICA was classified into eight segments based on the cadaver and imaging findings: (1) Cervical segment; (2) cochlear segment (ascending segment of the ICA in the temporal bone) (relation of the start of this segment to the base of the styloid process: Above, 425 sides [80%]; below, 2 sides [0.4%]; at same level, 107 sides [20%]; P < 0.0001) (relation of cochlea to ICA: Posterior, 501 sides [85%]; posteromedial, 84 sides [14%]; P < 0.0001); (3) petrous segment (horizontal segment of ICA in the temporal bone) starting at the crossing of the eustachian tube superolateral to the ICA turn in all 10 samples; (4) Gasserian-Clival segment (ascending segment of ICA in the cavernous sinus) starting at the petrolingual ligament (PLL) (relation to vidian canal on imaging: At same level, 360 sides [63%]; below, 154 sides [27%]; above, 53 sides [9%]; P < 0.0001); in this segment, the ICA projected medially toward the clivus in 275 sides (52%) or parallel to the clivus with no deviation in 256 sides (48%; P < 0.0001); (5) sellar segment (medial loop of ICA in the cavernous sinus) starting at the takeoff of the meningeal hypophyseal trunk (ICA was medial into the sella in 271 cases [46%], lateral without touching the sella in 127 cases [23%], and abutting the sella in 182 cases [31%]; P < 0.0001); (6) sphenoid segment (lateral loop of ICA within the cavernous sinus) starting at the crossing of the fourth cranial nerve on the lateral aspect of the cavernous ICA and located directly lateral to the sphenoid sinus; (7) ring segment (ICA between the 2 dural rings) starting at the crossing of the third cranial nerve on the lateral aspect of the ICA; (8) cisternal segment starting at the distal dural ring. CONCLUSIONS: The classification may be applied uniformly to all skull base surgical approaches including lateral microsurgical and ventral endoscopic approaches, obviating the need for 2 separate classification systems. The classification allows extrapolation of relevant clinical information because each named segment may indicate potential surgical risk to specific structures.

An anteromedial approach to the temporal horn to avoid injury to the optic radiation fibers and uncinate fasciculus: anatomical and technical note.

OBJECT: The aim of this study was to define an anteromedial approach to the temporal horn via a transsylvian approach to avoid injury to the optic radiation fibers as well as the uncinate fasciculus. This route was compared with standard surgical approaches to the temporal horn, and their relationship to the optic radiation and uncinate fasciculus was reviewed. METHODS: Three cadaveric brain specimens were prepared with freezing and thawing cycles according to the Klingler technique. Dissection was performed in a lateral-to-medial fashion with the help of wooden spatulas. Photographs were taken through the operating microscope at every level of the dissection. The dissection was continued until the optic radiation was encountered. Particular attention was paid to the relationship of the uncinate fasciculus with the optic radiation. An anteromedial transsylvian approach was defined to enter the temporal horn without injuring the optic radiation or the uncinate fasciculus. CONCLUSIONS: A transsylvian anteromedial approach through the pyriform cortex at the level of the anterior and superior surface of the uncus enables a safe entry into the temporal horn without injury to the optic radiation fibers or the main part of the uncinate fasciculus.

Extracranial-to-intracranial bypass using radial artery grafting for complex skull base tumors: technical note.

The management of complex skull base tumors that incorporate large intracranial vessels poses challenging questions. Patients who fail initial surgical resection and adjunctive therapies (i.e., radiosurgery) who present with tumor regrowth may be candidates for parent vessel occlusion and total tumor resection in combination with extracranial-to-intracranial (EC-IC) bypass to augment the sacrificed vessel territory. In this technical report, we delineate the surgical technique of performing an EC-IC bypass using a radial artery graft. Our protocol of simultaneous cranial, neck, and forearm dissections by the surgical team to perform this procedure is described in detail.

Intractable vomiting caused by vertebral artery compressing the medulla: A case report.

Vertebral artery compressing the medulla and causing intractable vomiting has only been reported once previously. We report a case of a 69-year-old woman with intractable nausea and vomiting causing a 50 pound weight loss and who failed medical management and whose symptoms were completely reversed following microvascular decompression (MVD).

N-butylcyanoacrylate embolization of a middle meningeal artery aneurysm in a patient with neurofibromatosis type 2.

Aneurysms of the middle meningeal artery are rare, with no documented association with neurofibromatosis type 2 (NF2). Middle meningeal artery aneurysm embolization with N-butylcyanoacrylate has not been described, and altogether, few accounts exist regarding the endovascular management of these unusual aneurysms. In this case report of a patient with NF2, an unruptured middle meningeal artery aneurysm was prophylactically embolized in a previously unreported fashion by using N-butylcyanoacrylate acrylic glue.

White matter fiber dissection of the optic radiations of the temporal lobe and implications for surgical approaches to the temporal horn.

OBJECT: The aim of this anatomical study was to define more fully the three-dimensional (3D) relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe by using the Klingler white matter fiber dissection technique. These findings were correlated with established surgical trajectories to the temporal horn. Such surgical trajectories have implications for amygdalohippocampectomy and other procedures that involve entering the temporal horn for the resection of tumors or vascular lesions. METHODS: Ten human cadaveric hemispheres were prepared with several cycles of freezing and thawing by using a modification of the method described by Klingler. Wooden spatulas were used to strip away the deeper layers of white matter progressively in a lateromedial direction, and various association, projection, and commissural fibers were demonstrated. As the dissection progressed, photographs of each progressive layer were obtained. Special attention was given to the optic radiation and to the sagittal stratum of which the optic radiation is a part. The trajectories of fibers in the optic radiation were specifically studied in relation to the lateral, medial, superior, and inferior walls of the temporal horn as well as to the superficial anatomy of the temporal lobe. In three of the hemispheres coronal sections were made so that the relationship between the optic radiation and the temporal horn could be studied more fully. In all 10 hemispheres that were dissected the following observations were made. 1) The optic radiation covered the entire lateral aspect of the temporal horn as it extends to the occipital horn. 2) The anterior tip of the temporal horn was covered by the anterior optic radiation along its lateral half. 3) The entire medial wall of the temporal horn was free from optic radiation fibers, except at the level at which these fibers arise from the lateral geniculate body to ascend over the roof of the temporal horn. 4) The superior wall of the temporal horn was covered by optic radiation fibers. 5) The entire inferior wall of the temporal horn was free from optic radiation fibers anterior to the level of the lateral geniculate body. CONCLUSIONS: Fiber dissections of the temporal lobe and horn demonstrated the complex 3D relationships between the optic radiations and the temporal horn and superficial anatomy of the temporal lobe. Based on the results of this study, the authors define two anatomical surgical trajectories to the temporal horn that would avoid the optic radiations. The first of these involves a transsylvian anterior medial approach and the second a pure inferior trajectory through a fusiform gyrus. Lateral approaches to the temporal horn through the superior and middle gyri, based on the authors' findings, would traverse the optic radiations.

Localization of the Internal Maxillary Artery for Extracranial-to-Intracranial Bypass through the Middle Cranial Fossa: A Cadaveric Study.

The internal maxillary artery (IMAX) is a promising arterial pedicle to function as a donor vessel for extracranial-to-intracranial (EC-IC) bypass procedures. The access to the IMAX through the anterior portion of the middle cranial fossa floor allows a much shorter interposition graft to be used to create a bypass to the ipsilateral middle cerebral artery and prevents a second incision in the neck. One of the challenges of this technique, however, is the difficulty to find the IMAX through an intracranial approach. The purpose of this cadaveric study is to establish a reliable method to localize the IMAX through a middle fossa floor approach based on skull base bone landmarks. In this study 5 latex-injected fixated cadaveric specimens were dissected bilaterally (providing a total of 10 IMAX dissections) to determine the precise location of the IMAX in the pterygopalatine fossa in relationship to bone landmarks of the middle fossa floor as seen through an intracranial approach. Drilling of the middle fossa floor was undertaken through both the originally described "anteromedial" approach, and a new "anterolateral" approach. Measurements were taken correlating the position of the IMAX to ipsilateral foramen rotundum, ipsilateral foramen ovale, posterior wall of the maxillary sinus, and distal V2 branches. Median and standard deviation were calculated for each dataset. The IMAX was found, within the pterygopalatine fossa, by drilling the greater wing of the sphenoid bone on average 10 mm anteriorly and 5 mm laterally to foramen rotundum, at an average depth of 8 mm. The IMAX was also found inferiorly to the maxillary nerve and laterally to the pterygoid head of the lateral pterygoid muscle. A more laterally oriented approach, consisting of drilling the greater wing of the sphenoid bone from a point perpendicular to foramen rotundum posteriorly to the sphenotemporal suture anteriorly, allowed for a longer segment of the IMAX to be easily identified and exposed facilitating its use as a donor vessel in bypass procedures. This cadaveric study provides a reliable and reproducible set of measurements to localize the IMAX within the pterygopalatine fossa through an intracranial middle fossa approach. The ability to find the IMAX consistently is an important step in exploring the possibility of using the IMAX as a routine donor vessel for EC-IC bypass procedures.

A national fundamentals curriculum for neurosurgery PGY1 residents: the 2010 Society of Neurological Surgeons boot camp courses.

BACKGROUND: In July 2009, the Accreditation Council for Graduate Medical Education (ACGME) incorporated postgraduate year 1 (PGY1 intern) level training into all U.S. neurosurgery residency programs. OBJECTIVE: To provide a fundamentals curriculum for all incoming neurosurgery PGY1 residents in ACGME-accredited programs, including skills, knowledge, and attitudes that promote quality, patient safety, and professionalism. METHODS: The Society of Neurological Surgeons organized 6 regional "boot camp" courses for incoming neurosurgery PGY1 residents in July 2010 that consisted of 9 lectures on clinical and nonclinical competencies plus 10 procedural and 6 surgical skills stations. Resident and faculty participants were surveyed to assess knowledge and course effectiveness. RESULTS: A total of 186 of 197 U.S. neurosurgical PGY1 residents (94%) and 75 neurosurgical faculty from 36 of 99 programs (36%) participated in the inaugural boot camp courses. All residents and 83% of faculty participants completed course surveys. All resident and faculty respondents thought that the boot camp courses fulfilled their purpose and objectives and imparted skills and knowledge that would improve patient care. PGY1 residents' knowledge of information taught in the courses improved significantly in postcourse testing (P < .0001). Residents and faculty particularly valued simulated and other hands-on skills training. CONCLUSION: Regional organization facilitated an unprecedented degree of participation in a national fundamental skills program for entering neurosurgery residents. One hundred percent of resident and faculty respondents positively reviewed the courses. The boot camp courses may provide a model for enhanced learning, professionalism, and safety at the inception of training in other procedural specialties.

Short segment internal maxillary artery to middle cerebral artery bypass: a novel technique for extracranial-to-intracranial bypass.

BACKGROUND: Traditional high-flow extracranial-to-intracranial (EC-IC) bypass procedures require a cervical incision and a long (20-25 cm) radial artery or saphenous vein graft. This technical note describes a less invasive, EC-IC bypass technique using a short-segment (8-10 cm) of the radial artery to anastomose the internal maxillary artery (IMAX) to the middle cerebral artery. CLINICAL PRESENTATION: Anatomic dissections were performed on 6 cadaveric specimens to assess the location of the IMAX artery using an extradural middle fossa approach. Subsequently, the procedure was implemented in a patient with a giant fusiform internal carotid artery aneurysm. TECHNIQUE: A straight line was drawn anteriorly from the V2/V3 apex along the inferior edge of V2. The IMAX was found 8.6 mm on average anteriorly from the lateral edge of the foramen rotundum. We drilled to a depth of 4.2 mm on average to find the medial extent of the artery and then lateral and deep drilling exposed an average of 7.8 mm of graft. The IMAX was consistently found running just anterior and parallel to a line between the foramens rotundum and ovale. In the clinical case presented, both intraoperative indocyanine green and postoperative conventional angiography revealed a patent graft. The patient did well clinically without any new deficits. CONCLUSION: The advantages of this new technique include the avoidance of a long cervical incision and potentially higher patency rates secondary to shorter graft length than currently practiced.

Meckel's cave.

OBJECTIVE: To review the microsurgical anatomy of Meckel's cave, a detailed knowledge of which is a prerequisite to devising an appropriate surgical strategy and performing successful surgery. METHODS: The microsurgical anatomy of Meckel's cave was studied under an operating microscope in 15 human cadaver heads (30 sides). To understand the meningeal architecture and the cross-sectional anatomy of Meckel's cave, serial histologic sections were made in an additional adult human cadaver specimen. RESULTS: Meckel's cave is a natural mouth-shaped aperture connecting with the posterior fossa that is located in the medial portion of the middle cranial fossa. The cave extends forward similar to an open-ended three-fingered glove and provides a channel for the rootlets of the trigeminal nerve; the trigeminal ganglion; and the ophthalmic (cranial nerve V(1)), maxillary (cranial nerve V(2)), and mandibular (cranial nerve V(3)) divisions until they reach their respective foramina. The average height of this oval mouth was found to be 4.2 mm (range 3-5 mm) and the average width was 7.6 mm (range 6-8 mm). The mouth of Meckel's cave was located 12 mm (range 10-15 mm) superior and medial to the internal acoustic meatus and 6.5 mm (range 5-8 mm) superior and medial to the dural point of entrance of the nervus abducens and 20 mm (range 18-23 mm) medial to the arcuate eminence. CONCLUSIONS: Detailed and sound knowledge of the microsurgical anatomy of Meckel's cave, which borders on surgically important structures, such as the internal carotid artery and cavernous sinus, is essential to performing precise microneurosurgery in this region. This study describes the complex anatomy of Meckel's cave and surrounding structures to provide the knowledge needed to devise a more complete surgical strategy and establish accurate orientation during the surgical procedure.

Management of nonmissile penetrating brain injuries: a description of three cases and review of the literature.

Nonmissile penetrating intracranial injuries are uncommon events in modern times. Most reported cases describe trajectories through the orbit, skull base foramina, or areas of thin bone such as the temporal squama. Patients who survive such injuries and come to medical attention often require foreign body removal. Critical neurovascular structures are often damaged or at risk of additional injury resulting in further neurological deterioration, life-threatening hemorrhage, or death. Delayed complications can also be significant and include traumatic pseudoaneurysms, arteriovenous fistulas, vasospasm, cerebrospinal fluid leak, and infection. Despite this, given the rarity of these lesions, there is a paucity of literature describing the management of neurovascular injury and skull base repair in this setting. The authors describe three cases of nonmissile penetrating brain injury and review the pertinent literature to describe the management strategies from a contemporary cerebrovascular and skull base surgery perspective.