Advances in Cranial Surgery.

The landscape of the cranial neurosurgery has changed tremendously in past couple of decades. The main frontiers including introduction of neuro-endoscopy, minimally invasive skull base approaches, SRS, laser interstitial thermal therapy and use of tubular retractors have revolutionized the management of intracerebral hemorrhages, deep seated tumors other intracranial pathologies. Introduction of these novel techniques is based on smaller incisions with maximal operative corridors, decreased blood loss, shorter hospital stays, decreased post-operative pain and cosmetically appealing scars that improves patient satisfaction and clinical outcomes. The sophisticated tools like neuroendoscopy have improved light source, and better visualization around the corners. Advanced navigated tools and channel-based retractors help us to target deeply seated lesions with increased precision and minimal disruption of the surrounding neurovascular tissues. Advent of stereotactic radiosurgery has provided us alternative feasible, safe and effective options for treatment of patients who are otherwise not medically stable to undergo complex cranial surgical interventions. This paper review advances in treatment of intracranial pathologies, and how the neurosurgeons and other medical providers at the University of Missouri-Columbia (UMC) are optimizing these treatments for their patients.

Gearing Up for the U.S. Medical Licensing Examination Step 1 Pass/Fail Transition, Evaluating the Role of Research Productivity as an Alternative During the Neurosurgical Residency Selection Process: An Overview.

Neurosurgery residency programs are the most competitive among the surgical specialties for applicants to match into. U.S. Medical Licensing Examination (USMLE) step 1 scores are staple and pivotal in narrowing down applicants for granting interviews and ranking in the match process. The upcoming transition from a numeric to binary step 1 scoring shifts the emphasis on using the status quo Step 2 Clinical Knowledge numeric scoring as the only objective measure. It can prove insubstantial for accurate assessment of competencies, further urging residency programs to widen their selection protocols to allow multiple assessments of competency. Research experience has consistently proved to result in higher successful match rates, and a positive correlation is seen with the number of research publications and Hirsch indices. However, with a predicted emphasis on research with the shift in scoring practices, these tools provide inadequate insight into authorship, contributions, type of publications, and community impact, warranting the need to include supplementary modifications, surrogates, or alternatives to such tools for a more comprehensive and equitable assessment of research. This study summarizes the role of research in the neurosurgical match process, describes nuances in research evaluation, and introduces novel Hirsch indices and additional strategies to address these nuances for equitable evaluation of research productions.

A modern history of neurosurgery and neurology in India: lessons for the world.

The compendia of medical knowledge of the great ancient Indian physicians Susruta, Caraka, Jivaka, and Vagbhata all attest to the practice of neurosurgery and neurology starting in the 1st millennium bce. Although a period of scientific stagnation ensued between the 12th and 20th centuries ce, Indian medical neurosciences once again flourished after India's independence from British rule in 1947. The pioneers of modern Indian neurosurgery, neurology, and their ancillary fields made numerous scientific and clinical discoveries, advancements, and innovations that proved influential on a global scale. Most importantly, the efforts of Indian neurosurgeons and neurologists were unified at the national level through the Neurological Society of India, which was established in 1951 and enabled an unprecedented degree of collaboration within the aforementioned medical specialties. The growth and success of the Indian model bears several lessons that can be applied to other nations in order to garner better collaboration among neurosurgeons, neurologists, and physicians in related fields. Here, the authors elaborate on the origins, growth, and development of neurosurgery and neurology in India and discuss their current state in order to glean valuable lessons on interdisciplinary collaboration, which forms the basis of the authors' proposal for the continued growth of societies dedicated to medical neurosciences across the world.

The role of non-stenosing carotid artery plaques in embolic stroke of undetermined source, is it a silent offender? A review of literature.

PURPOSE: Atherosclerotic cervical internal carotid artery disease is one of the major causes of ischemic stroke and transient ischemic attacks. The risk of stroke from mild to moderate stenoses (i.e. <50% stenosis) might be underestimated. There is increasing evidence that plaque morphological features reflect plaque instability that may harbor high risk for embolization. In this narrative review, we will review the literature on plaque features that predict vulnerability beyond the degree of stenosis, discuss the clinical association with stroke, and evaluate the evidence that these lesions serve as a source for embolic stroke of unknown source (ESUS). METHODS: We performed a literature search using PubMed, EMBASE, and Web of Science. The terms "embolic stroke of undetermined source" and "plaque morphology" were used either alone or in combination with "non-flow limiting stenosis," "non-stenosing plaques," "high-risk plaque features" or "internal carotid artery plaque." Data on plaque morphology and ESUS were mainly taken from review articles, observational studies including retrospective cohort and cross-sectional studies, meta-analyses, and systematic reviews. CONCLUSION: Nonstenosing carotid artery plaques with high-risk features carry a remarkable risk for stroke occurrence and randomized clinical trials are warranted for further evaluation of using carotid artery stenting or carotid endarterectomy to mitigate the risk of stroke.

Surgical Resection and Clipping of an Atherosclerotic Partially Calcified Middle Cerebral Artery Trifurcation Aneurysm with Clipping of an Anterior Communicating Artery Aneurysm: 2-Dimensional Operative Video.

It is estimated within the western population that 10%-13% of patients possess multiple intracranial aneurysms1 and are linked to certain risk factors. Thrombotic aneurysms are a rare subgroup of complex aneurysms characterized by an organized intraluminal thrombus.2,3 They differ from typical saccular aneurysms in terms of morphology, natural history, symptomatology, and difficulty in treatment with conventional strategies.2,4 The risk of rupture is poorly characterized and assumed to be comparable with that of nonthrombotic aneurysms.2 A subset of thrombotic aneurysms can be treated surgically with conventional clipping, and direct clipping has been associated with the best surgical outcome.2 Despite its safety, endovascular treatment is associated with a high risk of recurrence and retreatment compared with surgical treatment,5 with recanalization rates up to 5× higher compared with nonthrombosed aneurysms.6,7 A 64-year-old male presented with headaches and dizziness for 6 months. He was neurologically intact. Imaging revealed a calcified thrombosed right middle cerebral artery aneurysm and an anterior communicating artery aneurysm, both of which underwent clipping. The patient consented to the procedure. Preservation of blood flow in branch arteries in thrombosed aneurysms is challenging. Thrombectomy and clip reconstruction in such cases can occlude the branch vessels, compromising blood flow. Achieving adequate proximal control and meticulous dissection of the branches is necessary before reconstruction. We present a 2-dimensional video demonstrating the surgical steps of clipping and reconstruction of the giant thrombosed middle cerebral artery aneurysm. Complete occlusion was achieved, and the patient tolerated the operation well with an uneventful postoperative course.

Characteristics and Outcomes of Discharge Against Medical Advice and 30-Day Readmissions After Concussion: Analysis of the Nationwide Readmissions Database.

BACKGROUND: Little is known about the impact of discharge against medical advice (DAMA) in patients admitted with concussion. OBJECTIVE: To explore the prevalence of DAMA and its effect on 30-day readmissions and cost in concussion using a nationally representative sample. METHODS: The Nationwide Readmissions Database was queried for concussion admissions and their disposition at discharge between 2010 and 2014. Included patients were ≥18 years old who were admitted with concussion and had <1 hour loss of consciousness. We excluded in-hospital deaths or discharge dispositions other than home or against medical advice. Univariate and multivariate analyses were performed to determine characteristics associated with DAMA and 30-day readmissions. RESULTS: A total of 38 919 index admissions were identified, which resulted in 998 (2.6%) DAMA. In multivariate analysis, characteristics associated with DAMA included younger age (odds ratio [OR] = 0.84, 95% CI 0.80-0.88), male sex (1.47, 1.22-1.76), an Elixhauser comorbidity index >3 (1.67, 1.15-1.60), and assault (2.02, 1.48-2.75) and fall injuries (1.28, 1.03-1.60). The highest-income quartile was negatively associated with DAMA (0.91, 0.73-1.13). In multivariate analysis, DAMA (1.63, 1.29-2.06), higher comorbidity index (2.61, 2.22-3.06), and self-inflicted mode of injury (2.28, 1.30-4.02) were independently associated with 30-day readmission. The most common indication for readmission in both routine and DAMA groups was traumatic injury (21.1% and 24.5%, respectively). CONCLUSION: DAMA is an independent risk factor for readmission in patients admitted for concussion. The variables associated with DAMA identified in this study can be used to design patient-centered interventions that can be implemented to reduce DAMA and its impact on clinical outcomes in patients with traumatic brain injury.

Surgical Technique and Nuances of Resection of a Trochlear Schwannoma: Operative Video.

Cranial nerve schwannomas accounts for around 8% of all benign intracranial tumors, arising most commonly from the vestibular nerve, followed by the trigeminal nerve and other lower cranial nerves. However, trochlear schwannoma in a patient without neurofibromatosis-2 are extremely rare and to date, fewer than 100 cases have been reported in the literature. They are either asymptomatic or present with ophthalmologic or neurologic symptoms. Diplopia is the most common initial symptom. As the tumor grows, it can compress the surrounding brainstem and other cranial nerves, causing neurologic symptoms. Asymptomatic lesions are detected incidentally following imaging for some other reason. There are no clear guidelines for the management of these tumors. In general, small asymptomatic tumors are closely observed by serial imaging and symptomatic or larger tumors are managed by surgical excision and/or stereotactic radiosurgery.1-7 Here we present a 41-year-old female patient with incidentally detected left trochlear schwannoma during the follow-up magnetic resonance imaging (MRI) scans. She was followed up regularly with multiple repeat MRI. Recently she started complaining of occasional headaches, and MRI showed a left peimesencephalic cistern tumor causing mass effect on the ipsilateral midbrain. There was also significant brainstem edema. Hence she underwent left retromastoid suboccipital craniectomy, lateral supracerbellar approach, and complete excision of the tumor. Postoperatively the patient had an uneventful recovery without any new neurologic deficits. At 6 months' follow-up the patient is doing well.

Interhemispheric Approach for Clipping of a Pericallosal Artery Aneurysm: 2-Dimensional Operative Video.

Pericallosal artery aneurysms are rare, accounting for 2%-9% of all intracranial aneurysms. They are most commonly saccular and wide necked. Although typically small, they are more prone to rupture compared with other aneurysms in the anterior circulation. They are more common in people with unpaired or azygous arteries. Rupture of pericallosal artery aneurysm results in intracerebral hematoma in approximately 50% of patients, usually in the frontal lobe, anterior interhemispheric fissure, pericallosal cistern, or cingulate gyrus. Compared with other supratentorial aneurysms, surgical clipping of pericallosal aneurysms carries a higher morbidity and mortality. A 47-year-old female presented with sudden-onset worst headache of her life followed by dizziness, syncope, transient weakness, and numbness over the left lower extremity. She was neurologically intact, and imaging revealed a right pericallosal artery aneurysm. The patient consented to the procedure. The 2-dimensional Video 1 demonstrates the interhemispheric approach for clipping of a pericallosal artery aneurysm. These aneurysms are approached in the distal-to-proximal direction along with the distal anterior cerebral artery. Meticulous dissection avoids rupture without proximal control. We highlight the key surgical steps and microsurgical techniques in approaching these aneurysms. The patient tolerated the operation well with an uneventful postoperative course.

Uncharted Waters of Machine and Deep Learning for Surgical Phase Recognition in Neurosurgery.

Recent years have witnessed artificial intelligence (AI) make meteoric leaps in both medicine and surgery, bridging the gap between the capabilities of humans and machines. Digitization of operating rooms and the creation of massive quantities of data have paved the way for machine learning and computer vision applications in surgery. Surgical phase recognition (SPR) is a newly emerging technology that uses data derived from operative videos to train machine and deep learning algorithms to identify the phases of surgery. Advancement of this technology will be key in establishing context-aware surgical systems in the future. By automatically recognizing and evaluating the current surgical scenario, these intelligent systems are able to provide intraoperative decision support, improve operating room efficiency, assess surgical skills, and aid in surgical training and education. Still in its infancy, SPR has been mainly studied in laparoscopic surgeries, with a contrasting stark lack of research within neurosurgery. Given the high-tech and rapidly advancing nature of neurosurgery, we believe SPR has a tremendous untapped potential in this field. Herein, we present an overview of the SPR technology, its potential applications in neurosurgery, and the challenges that lie ahead.

Tribute to William Edward Hunt and Robert McDonald Hess Jr.: Pioneers in the Clinical Classification of Ruptured Intracranial Aneurysms.

William Edward Hunt (1921-1999) and Robert McDonald Hess Jr. (1931-2019) were pioneers in revolutionizing the early surgical management of ruptured intracranial aneurysms. Early on in his career as a professor of neurosurgery at Ohio State University, Dr. Hunt adopted a systematic method to identify clinical symptoms of patients presenting with subarachnoid hemorrhage as candidates for either immediate or delayed surgery. As an Ohio State University neurosurgery resident, Dr. Hess was an active key collaborator in Dr. Hunt's aneurysm studies. Described as a modification of the Botterell classification system, the Hunt-Hess scale grading the survival risk of undergoing immediate intracranial aneurysm surgery was implemented and validated across an 18-year consecutive patient series at White Cross Hospital, Columbus, Ohio. Dr. Hunt and Dr. Hess demonstrated that for patients with subarachnoid hemorrhage on admission with Hunt-Hess grades I and II, indicating retained consciousness and minimal neurological deficits, immediate surgical management afforded a <20% mortality rate. In comparison, patients with grade III or higher had a >50% mortality rate, suggesting that conservative management should be instead pursued. As the principal investigator, Dr. Hunt was widely regarded internationally as an expert in the field of treating intracranial aneurysms, eventually serving as a World Federation of Neurosurgical Societies (WFNS) committee member to also publish a universal subarachnoid hemorrhage grading scale. To pay tribute to Drs. Hunt and Hess for their substantial contributions, we present historical vignettes of their lives along with highlighting the role of the Hunt-Hess classification system in transforming management of ruptured aneurysms.

Outcomes of Mechanical Thrombectomy for Ischemic Stroke in Nonagenarians: A 10-Year Institutional Experience.

BACKGROUND: Nonagenarians have been underrepresented in stroke trials that established endovascular treatment as the standard for acute ischemic stroke (AIS). Evidence remains inconclusive regarding the efficacy of thrombectomy in this population. OBJECTIVES: To report our experience with thrombectomy in nonagenarians with stroke, and to identify predictors of mortality. We further investigated the effects of first-pass reperfusion and the addition of intravenous thrombolysis (IVT) on achieving better outcomes. MATERIALS AND METHODS: Data was collected for consecutively treated patients at three affiliated comprehensive stroke centers from 2010 to 2021. We included patients ≥90 years-old with AIS secondary to large vessel occlusion. Bivariate analyses were performed using the Mann-Whitney U test for continuous variables, and χ2 and Fisher's exact tests, respectively, for nominal and ordinal variables. RESULTS: Thirty-two nonagenarians underwent thrombectomy, of whom 25 (81%) had prestroke mRS ≤2. Thrombectomies were performed using stents (2, 6.7%), aspiration (8, 26.7%), or a combination of both (20, 66.7%). Successful recanalization was achieved in 97%. Procedural complications occurred in 2 (6.3%) and intracranial hemorrhage in 3 (9.4%). Sixteen patients (50%) were discharged home or to rehabilitation, 9 (28.2%) to nursing home or hospice, and 7 (21.9%) died during hospitalization. Only 2 (6%) patients had mRS ≤2 at discharge. No independent predictors of in-hospital mortality were identified, and neither first-pass reperfusion nor the addition of IVT correlated with improvement in clinical outcome. CONCLUSIONS: Although thrombectomy is safe for nonagenarian stroke and can achieve excellent recanalization, high mortality and poor functional status remain high given the advanced age and frailty of this population.

Gamma Knife Radiosurgery in the Management of Hypothalamic Glioma: A Case Report with Long-Term Follow-Up.

BACKGROUND: Optic pathway/hypothalamic gliomas are rare pediatric brain tumors. The management paradigm for these challenging tumors includes chemotherapy, radiotherapy, or surgical resection, but the optimal management strategy remains elusive. Gamma knife radiosurgery (GKRS) has emerged as a promising treatment for such lesions as documented by a small number of cases in the literature. CASE PRESENTATION: We present a rare case of hypothalamic glioma in a 13-year-old girl who was referred to our service due to growth of an incidentally diagnosed hypothalamic lesion following head injury at the age of 8 years. The lesion demonstrated hypointensity on T1- and hyperintensity on T2-weighted imaging without contrast enhancement. Given the growth of the lesion on serial imaging, a stereotactic biopsy was performed demonstrating low-grade glioma. The patient underwent GKRS treatment with a marginal dose of 15 Gy at 50% isodose line for a tumor volume of 2.2 mL. Annual radiological surveillance over the next 17 years demonstrated a gradual shrinkage of the lesion until it completely disappeared. The patient is currently a healthy 31-year-old female without any visual, endocrine, or neurocognitive deficits. CONCLUSION: The outcome obtained after extended follow-up in our patient highlights the safety and efficacy of GKRS in the management of hypothalamic gliomas in pediatrics, which in turn can avoid potentially serious complications of surgery in this vulnerable patient population, especially in this sensitive location.

Charles Jacques Bouchard (1837-1915) and the Charcot-Bouchard aneurysm.

Charles Jacques Bouchard was a distinguished French physician and scientist of the early 19th century. Despite his humble beginnings, Bouchard was able to achieve meteoric success within the scientific and medical fields, establishing himself as one of the most influential physician-scientists of his time. This was in part due to his superb commitment, as well as the prosperity engendered by the strong influence of his teachers, which can be seen as a testament to the importance of mentorship in medicine. Besides his myriad contributions, Bouchard is most well known for describing the Charcot-Bouchard aneurysm in 1866 alongside his mentor Jean-Martin Charcot, linking them for the first time to intracranial hemorrhage. Bouchard's thesis entitled "A Study of Some Points in the Pathology of Cerebral Hemorrhage" was regarded by some as the most original and important of all recent works on the subject of cerebral hemorrhage at the time of publication. Sadly, the great relationship Bouchard shared with his mentor Charcot would later deteriorate into perhaps one of the most well-known student-mentor quarrels in the history of medicine. Herein, the authors present a historical recollection of Bouchard's life, career, and contributions to medicine, as well as the famous controversy with Jean-Martin Charcot.

Aortic arch anomalies, embryology and their relevance in neuro-interventional surgery and stroke: A review.

BACKGROUND: Congenital aortic arch anomalies are commonly encountered during neurointerventional procedures. While some anomalies are identified at an early age, many are incidentally discovered later in adulthood during endovascular evaluations or interventions. Proper understanding of the normal arch anatomy and its variants is pivotal to safely navigate normal aortic arch branches and to negotiate the catheter through anomalies during neurointerventional procedures. This is particularly relevant in the increasingly "transradial first" culture of neurointerventional surgery. Moreover, some of these anomalies have a peculiar predilection for complications including aneurysm formation, dissection, and rupture during the procedure. Therefore, an understanding of these anomalies, their underlying embryological basis and associations, and pattern of circulation will help endovascular neurosurgeons and interventional radiologists navigate with confidence and consider relevant pathologic associations that may inform risk of cerebrovascular disease. METHODS: Here, we present a brief review of the basic embryology of the common anomalies of the aortic arch along with their neurological significances and discuss, through illustrative cases, the association of aortic arch anomalies with cerebral vascular pathology. CONCLUSIONS: Understanding the aortic arch anomalies and its embryological basis is essential to safely navigate the cerebral vascular system during neurointerventional surgeries.

Terson's syndrome, the current concepts and management strategies: A review of literature.

Terson's Syndrome describes intraocular hemorrhage secondary to an acutely raised intracranial pressure (ICP). Although Terson's Syndrome is common amongst patients with subarachnoid hemorrhage (SAH), it is underdiagnosed and often overlooked. This review discusses the current understanding of the etiopathogenesis, clinical features, and management of Terson's Syndrome and highlights the visual and prognostic implications to stress the importance of timely diagnosis and management. The origin of intraocular hemorrhage in Terson's Syndrome has been debated. A recognized theory suggests that an acutely raised ICP induces effusion of cerebrospinal fluid into the optic nerve sheath which dilates the retrobulbar aspect of the sheath in the orbit. Dilatation mechanically compresses the central retinal vein and retinochoroidal veins resulting in venous hypertension and rupture of thin retinal vessels. A commonly reported clinical feature is decreased visual acuity and blurred vision. These may be accompanied by symptoms of increased ICP including loss of consciousness and headache. Diagnosis is established using evidence from the clinical presentation, ophthalmoscopy, and, when required, imaging including B-mode ultrasound, CT, MRI, and fluorescein angiography. Terson's Syndrome is managed conservatively by observation for mild cases and with vitrectomy for bilateral cases and for patients whose hemorrhage has not spontaneously resolved after an observational period. Terson's Syndrome can be used as a prognostic indicator of morbidity and mortality in underlying pathology like SAH. Fundoscopy of patients with SAH, acutely raised ICP or visual disturbance with unknown etiology can help establish a timely Terson's Syndrome diagnosis. This may avoid the risk of permanent visual impairment.

The Evolution of 3D Anatomical Models: A Brief Historical Overview.

For thousands of years, anatomical models have served as essential tools in medical instruction. While human dissections have been the regular source of information for medical students for the last few centuries, the scarcity of bodies and the religious and social taboos of previous times made the process of acquiring human cadavers a challenge. The dissection process was dependent on the availability of fresh cadavers and thus was met with a major time constraint; with poor preservation techniques, decomposition turned the process of employing bodies for instruction into a race against time. However, the advent of anatomical models has countered this issue by supplying accurate anatomical detail in a physical, three-dimensional form superior to that of the two-dimensional illustrations previously used as the primary adjunct to dissection. Artists worked with physicians and anatomists to prepare these models, creating an interdisciplinary interaction that advanced anatomical instruction at a tremendous rate. These models have taken the form of metal, wood, ivory, wax, papier-mâché, plaster, and plastic and have ultimately evolved into computerized and digital representations currently. We provide a brief historical overview of the evolution of anatomical models from a unique neuroanatomical perspective.

The contributions of William A. Hammond (1828-1900) to Civil War medicine & modern neurology.

William Alexander Hammond was an American military physician and a main driving force for the development of modern-day clinical Neurology in America. Hammond served as the 11th Surgeon General of the United States Army, acting during the Civil War. Throughout his time as Surgeon General, with influence from Florence Nightingale, Hammond enforced strict hygienic measures and called for the construction of pavilion style hospitals in order to decrease non-wound mortalities. He implemented further reformation of the American Medical Service that would improve efficiency and decrease general mortality for years to come. After his dismissal from the military service, Hammond continued to make meaningful achievements, spearheading the specialization of Neurology. He established the first private practice limited to diseases of the nervous system, published the first American Neurology textbook, coined the term "athetosis", and was the impetus for the formation of the American Neurological Association.

Current applications and safety profile of laser interstitial thermal therapy in the pediatric population: a systematic review of the literature.

OBJECTIVE: Laser interstitial thermal therapy (LITT) provides a minimally invasive alternative to open brain surgery, making it a powerful neurosurgical tool especially in pediatric patients. This systematic review aimed to highlight the indications and complications of LITT in the pediatric population. METHODS: In line with the PRISMA guidelines, the authors conducted a systematic review to summarize the current applications and safety profiles of LITT in pediatrics. PubMed and Embase were searched for studies that reported the outcomes of LITT in patients < 21 years of age. Retrospective studies, case series, and case reports were included. Two authors independently screened the articles by title and abstract followed by full text. Relevant variables were extracted from studies that met final eligibility, and results were pooled using descriptive statistics. RESULTS: The selection process captured 303 pediatric LITT procedures across 35 studies. Males comprised approximately 60% of the aggregate sample, with a mean age of 10.5 years (range 0.5-21 years). The LITT technologies used included Visualase (89%), NeuroBlate (9%), and Multilase 2100 (2%). The most common indication was treatment of seizures (86%), followed by brain tumors (16%). The mean follow-up duration was 15.6 months (range 1.3-48 months). The overall complication rate was 15.8%, which comprised transient neurological deficits, cognitive and electrolyte disturbances, hemorrhage, edema, and hydrocephalus. No deaths were reported. CONCLUSIONS: As of now, LITT's most common applications in pediatrics are focused on treating medically refractory epilepsy and brain tumors that can be difficult to resect. The safety of LITT can provide an attractive alternative to open brain surgery in the pediatric population.