The Development of Skull Base Surgery as a Discipline: Remembrances of Dr Jon H. Robertson.

Skull base surgery is a young surgical subspecialty currently led by its second generation of surgeons. At present, there is no literature that narrates the connection of the present to the past. An extended interview was held with Dr Jon H. Robertson, who helped establish the subspecialty in Memphis, TN, to aid in identifying and connecting sentinel events and key figures in the development of the discipline. The field drastically evolved during his era of practice (1975-present), with the advent of advanced imaging and technology, as well as the emergence of multidisciplinary skull base surgical teams. The intersection of the careers of Jon H. Robertson, James T. Robertson, Gale Gardner, Edwin Cocke, John Shea, Jr., and Jerrall Crook in Memphis catalyzed the standardization of a multidisciplinary approach to cranial base pathology. We report the findings of Dr Jon H. Robertson's extended interview, told against the backdrop of the history of the subspecialty. The story of the development of skull base surgery is told from the unique perspective of one who lived and shaped a pivotal segment in this historical timeline.

Effect of Body Mass Index on Chiari Malformation 1 Tonsil Ectopia Length in Adults.

OBJECTIVE: Diagnosis of Chiari I malformation (CM-1) is based on measurements of the inferior extension of the cerebellar tonsils into the foramen magnum on cranial or cervical spine magnetic resonance imaging. Imaging may be obtained before the patient is referred to the neurosurgical specialist. The length of time raises questions about the possibility that body mass index (BMI) fluctuations could affect the measurement of ectopia length. However, previous literature on BMI and CM-1 has reported conflicting findings on BMI. METHODS: We conducted a retrospective chart review of 161 patients who were referred to a single neurosurgeon for CM-1 consultation. Patients with multiple recorded BMI values (n = 71) were compared to see if BMI changes correlated with changes in ectopia length. In addition, we compared and tested 154 recorded ectopia lengths from the patients (1 per patient) and patient BMI values with Pearson correlation and Welch t tests to determine if BMI changes either influenced or were associated with ectopia changes. RESULTS: For the 71 patients with multiple BMI values, change in ectopia length ranged from -4.6-9.8 mm but was not statistically significant (r = 0.019; P = 0.88). For the 154 measured ectopia lengths, changes in BMI did not correlate with ectopia length (P > 0.05). Likewise, differences in ectopia length between patients in normal, overweight, and obese categories were not statistically significant (|tstat| < |tcrit|, P > 0.05). CONCLUSIONS: In individual patients, we found that BMI and changes in BMI were not accompanied by changes in tonsil ectopia length.

Bibliometric Analysis of 6 Major European Neurosurgical Publications from 2011-2020 (part 3): a Comparative Metrics Review.

Background: We previously conducted bibliometric analysis of 6 North American neurosurgical journals. Objective: To perform a bibliometric analysis of 6 European neurosurgical journals to build on our previous studies. Methods: We searched Web of Science for articles published in Acta Neurochirurgica, British Journal of Neurosurgery, Child's Nervous System, Journal of Neurological Surgery Part A: Central European Neurosurgery, Journal of Neurosurgical Sciences, and Neurosurgical Review between 2011 and 2020. We analyzed bibliometric parameters related to total annual document distribution, author metrics, journal metrics, country and continental distribution, institution, keywords, and journal impact. Results: European countries provided the greatest contributions. Acta Neurochirurgica followed by Child's Nervous System published the greatest number of articles and had the highest h-index and number of citations. From 2018 to 2020, total documents increased 79.6%, original articles increased 86.5%, review articles increased 103.6%, citations increased 79.6%, number of publishing authors increased 72.1%, number of authors in multi-author documents increased 72.4%, and author's keywords and keywords plus increased 72.4% and 27.0%, respectively. The collaboration index decreased 5.3% from 4.49 to 4.25. Annual published documents and citations were lower for European journals versus North American journals. Conclusion: Several parameters of the European journals increased by 2020. One interesting finding is that growth for the 6 journals dramatically increased in the 2 years prior to the COVID-19 pandemic. While neurosurgeon free time during lockdowns may account for much of the increase in 2020, the trend began before this. Our analysis did not identify a cause for the pre-COVID increases.

Cranial Versus Cervical Spine Magnetic Resonance Imaging in Adult Chiari Malformation Type I Diagnostics: Is There a Difference in Tonsil Ectopia Length?

BACKGROUND: Chiari malformation type 1 (CM-1) diagnosis is based on measurement of the cerebellar tonsils on cranial or cervical spine magnetic resonance imaging (MRI). However, imaging parameters of cranial and cervical spine MRI could differ because spine MRI has greater resolution. METHODS: We conducted a retrospective chart review of 161 patients of a single neurosurgeon for adult CM-I consultation between February 2006 and March 2019. Patients were selected based on receiving both cranial and cervical spine MRI within a month of each other to determine tonsillar ectopia length for CM-1. Ectopias were measured to determine if differences in values were statistically significant. RESULTS: From the 161 total patients, 81 had cranial and cervical spine MRI for a total of 162 tonsil ectopia measurements (81 cranial and 81 spinal). Average ectopia length on a cranial MRI was 9.1 mm (±5.2 mm); average ectopia length on a spinal MRI was 8.9 mm (±5.3 mm). Average cranial and spinal MRI values were found to be <1 standard deviation apart. Two-tailed, nonequal variances t test determined that differences between the cranial and spinal ectopia measurements were insignificant (P = 0.2403). CONCLUSIONS: This study confirmed that the added resolution offered by spine MRI did not make better or more refined measurements over cranial MRI that could lead to measurement differences, which can instead be attributed to chance. Cranial and cervical spine MRI can be used to determine the degree of the tonsil ectopia.

Brachial Plexus Birth Injury: A Single-Center Study.

Infants can sustain traction injury to brachial plexus nerves during birth, called brachial plexus birth injury (BPBI). While spontaneous recovery is possible, upper extremity weakness can linger. We report our experience at a brachial plexus clinic from a retrospective chart review of infants with BPBI from September 2017 to September 2019. We determined Narakas Classification (NC) and Active Movement Scale (AMS) at predetermined follow-up points. Of 15 patients, 8 presented with NC-I, 5 with NC-II, and 2 with NC-III without Horner's syndrome. By 7 months, 3 had spontaneous recovery, and 4 achieved all and another 4 achieved most AMS5-7 scores. Eleven patients undergoing surgery had little-to-no improvement of shoulder abduction and shoulder external rotation AMS categories by 6 months. Our small sample size prevents us from making definitive conclusions but gave beneficial insight into our clinic barriers to follow-up, data collection, and collaboration with physical and occupational therapy.

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.

Legacy of Syriac-Aramaic Scholars in Transmitting Neurosurgical Knowledge Between Antiquity and the Middle Ages.

The link between ancient Greek medicine and the Arabic translation period in the 9th century cannot be understood without studying the contributions of Syriac scholars. With their mastery of Greek and the related Semitic languages of Syriac and Arabic, they initiated a scientific translation process with methods that prevail to this day. In this paper, we reviewed Hunayn Ibn Isshaq's Ten Treatises on the Eye to elucidate the original contributions of the Syriac physicians to the field of neurologic surgery. We analyzed the oldest known diagram of orbital anatomy along with Hunayn's genuine ideas on the optic nerve anatomy and pathology, optic chiasm, afferent pupillary reflex, and papilledema and venous congestion. We also reviewed the neurosurgical elements found in the Syriac Book of Medicines including the thought process in localizing neurologic deficits based on clinical experience and anatomic dissections and the earliest recorded description of brachial plexus pathology.

The overshadowed scientific endeavours of Berengario Da Carpi, a renaissance physician and the Forerunner of neurosurgery: a historical vignette.

Jacopo Berengario da Carpi was Renaissance-era physician, surgeon, and anatomy lecturer who transformed medieval anatomy and surgery-which were, at the time, dominated mostly by religious dogma-into a modern science based on direct observation, experience, and cadaveric dissection. He was an accomplished and innovative neuroanatomist and educator, a prolific researcher and publisher, and a successful practicing surgeon who treated the head injuries of many renowned patients of that period. He published a landmark commentary on skull fractures that was the first printed book in history devoted to head injuries, which became a model of new medical understanding. Nonetheless, Berengario's achievements in anatomy, medicine, neuroanatomy, and what would later become neurotraumatology and neurosurgery, would have been more widely known had his work and research not been surpassed by Andreas Vesalius and Ambroise Paré, both of whom advanced anatomic and medical knowledge even further. In this historical vignette, we discuss the political conditions of sixteenth Century Italy and pay a homage to Berengario da Carpi, emphasizing his work in establishing neuroanatomy as a field of medicine that became a precursor to modern neuroscience. We also describe the improvements he made in neurotraumatology technique and instrumentation, and his explanations of skull fractures and other brain injuries outlined in ground-breaking clinical books he published. Finally, we try to elucidate possible reasons why his scientific and professional achievements-despite of their enormous impact-were overshadowed by the achievements of his more famous immediate successors.

Microscopic and Endoscopic Skull Base Approaches Hands-On Cadaver Course at 30: Historical Vignette.

Laboratory-based cadaveric training is essential for the development and refinement of neurosurgical technical skills in the operating room and has become an integral training component around the world. Postresidency fellowship-the first pillar of skull base surgery training-includes both hands-on clinical care and surgery supervised by an experienced skull base surgeon. Time is spent in a skull base laboratory practicing approaches and developing anatomic mastery. The second pillar includes formal skull-base courses-institutional dissection laboratories provide continuous anatomic and surgical education while complementary annual or semiannual cadaver courses gather recognized experts to share their knowledge and experience in an essential 2- to 3-day setting. In this paper, we present the history of the longest running annual skull-base cadaver microsurgical course, which was started by Dr. Ossama Al-Mefty: Annual Surgical Approaches to the Skull Base Course. At the Microscopic and Endoscopic Hands-on Cadaver Workshop, held in St. Louis, Missouri, we celebrated its 30th anniversary in April 2019. We also present the impact this course has had on neurosurgery and skull base surgery and on the professional and scientific developments of its participants in particular.

A Survey of Neurological Surgery Residency Program Mentorship Practices Compared to Accreditation Council for Graduate Medical Education Resident Outcome Data.

Mentorship can be a powerful and life-altering experience during residency training, but there are few articles discussing mentorship models within neurosurgery. In this study, we surveyed US neurosurgical department mentorship practices and linked them to resident outcomes from the Accreditation Council for Graduate Medical Education (ACGME), including resident survey responses, board pass rates, and scholarly activity. A 19-question survey was conducted from October to December 2017 with the assistance of the Society of Neurological Surgeons. De-identified data were then obtained from the ACGME and correlated to these results. Out of 110 programs, 80 (73%) responded to the survey and gave informed consent. The majority (65%) had a formal mentorship program and assigned mentor relationships based on subspecialty or research interest. Barriers to mentorship were identified as time and faculty/resident "buy-in." Mentorship programs established for 5 or more years had superior resident ACGME outcomes, such as board pass rates, survey results, and scholarly activity. There was not a significant difference in ACGME outcomes among programs with formal or informal/no mentorship model (P = .17). Programs that self-identified as having an "unsuccessful" mentorship program had significant increases in overall negative resident evaluations (P = .02). Programs with well-established mentorship programs were found to have superior ACGME resident survey results, board pass rates, and more scholarly activity. There was not a significant difference among outcomes and the different models of formal mentorship practices. Barriers to mentorship, such as time and faculty/resident "buy-in," are identified.

Ambroise Paré: His Contribution to the Future Advancement of Neurosurgery and the Hardships of His Times Affecting His Life and Brilliant Career.

Ambroise Paré was celebrated surgeon of the 16th century whose practical accomplishments, books, and ideas transformed surgery and was a precursor for the later development of neurosurgery. He developed many surgical innovations related to wound management, arterial ligation for the prevention of hemorrhage during limb amputations, and the treatment of war-related head and spine injuries. He maintained that a surgeon should operate gently to reduce pain and improve outcome, and he dedicated his career to the wounded, sick, and poor. He also served 4 consecutive French monarchs-Henri II and his 3 sons François II, Charles IX, and Henri III. As a Huguenot (a Reformed Protestant) by faith, he lived in an environment dominated by Catholicism. Hence, his practice and life were sometimes hindered by political circumstances and religious prejudice. In this historical vignette, we will discuss the professional accomplishments of Ambroise Paré that influenced the future development of neurosurgery, including his descriptions of phantom-limb pain and peripheral nerve injury, his innovations in neurotraumatology, and the saws he invented for use in skull surgery. We will also highlight Paré's broad neurosurgical contributions to the field. Finally, we will discuss his personal life during the difficult and dangerous political circumstances of 16th century France.

Vagus nerve stimulation (VNS) therapy update.

Epilepsy affects millions of people worldwide. Approximately one-third have pharmacoresistant epilepsy, and of these, the majority are not candidates for epilepsy surgery. Vagus nerve stimulation (VNS) therapy has been an option to treat pharmacoresistant seizures for 30 years. In this update, we will review the clinical data that support the device's efficacy in children, adolescents, and adults. We will also review its side-effect profile, quality of life and cost benefits, and the impact the device has on sudden unexpected death in epilepsy (SUDEP). We will then discuss candidate selection and provide guidance on dosing and future models. Vagus nerve stimulation therapy is an effective treatment for many seizure types and epilepsy syndromes with a predictable and benign side-effect profile that supports its role as the most commonly prescribed device to treat pharmacoresistant epilepsy. "This article is part of the Supplement issue Neurostimulation for Epilepsy."