COVID-19 Vaccine Related Cervical Radiculitis and Parsonage-Turner Syndrome: Case Report and Review of the Literature.

Parsonage-Turner Syndrome, or neuralgic amyotrophy, is an acute-onset upper limb and shoulder girdle palsy that can occur in a post-viral, post-surgical or idiopathic setting. There have also been some reported cases of the syndrome occurring following vaccinations. The pathophysiology of neuralgic amyotrophy is not completely understood and many of the commonly used diagnostic imaging modalities we use to try and diagnose this syndrome are inaccurate and misleading. We present the case of a 40-year-old gentleman who presented with acute onset burning pain and fasciculations in his right upper extremity following vaccination with the second dose of the Pfizer-BioNTech COVID-19 vaccine. His symptoms progressed to weakness in isolated muscle groups with electromyographic evidence of decreased nerve conduction. MRI of the cervical spine demonstrated multilevel central and foraminal stenosis, suggesting a diagnosis of cervical radiculopathy. The patient underwent a C4-5/C5-6 and C6-7 laminoforaminotomy and tolerated the procedure well. Post-operatively, the patient has experienced gradual symptom improvement with residual right triceps and pectoralis muscle weakness as well as paresthesias of the right elbow and forearm. Parsonage-Turner Syndrome is a brachial plexus palsy that can affect one or multiple branches of the brachial plexus. It causes acute-onset pain and weakness, and the diagnosis can be difficult to make with the commonly used diagnostic imaging methods. We reviewed other case reports about neuralgic amyotrophy following vaccinations as well as the current literature on more accurate diagnostic imaging modalities that may help our diagnosis and understanding of the pathophysiology of this condition.

TN-RS: a novel scoring system predicts Gamma Knife Radiosurgery outcome for trigeminal neuralgia patients.

BACKGROUND: Gamma Knife Radiosurgery (GKRS) is an effective treatment option for medically refractory trigeminal neuralgia (TN). This study examines GKRS outcome in a large cohort of TN patients and highlights pretreatment factors associated with pain relief. METHODS: This is a single-center retrospective analysis of patients treated with GKRS for TN between 2011 and 2019. Pain relief was assessed at 1 year, and 2-3 years following GKRS. Multivariable analysis identified several factors that predicted pain relief. These predicting factors were applied to establish a pain relief scoring system. RESULTS: A total of 162 patients met inclusion criteria. At 1 year post-GKRS, the breakdown of Barrow Neurological Institute (BNI) score for pain relief was as follows: 77 (48%) score of I, 13 (8%) score of II, 37 (23%) score of III, 22 (14%) score of IV, and 13 (8%) score of V. Factors that were significantly associated with pain-free outcome at 1 year were: Typical form of TN (OR = 2.2 [1.1, 4.9], p = 0.049), No previous microvascular decompression (OR = 4.4 [1.6, 12.5], p = 0.005), Response to medical therapy (OR = 2.7 [1.1, 6.1], p = 0.018), and Seniority > 60 years (OR = 2.8 [1.4, 5.5], p = 0.003). The term "Trigeminal Neuralgia-RadioSurgery" was used to create the TN-RS acronym representing the significant factors. A stepwise increase in the median predicted probability of pain-free outcome at 1 year from 3% for patients with a score of 0 to 69% for patients with a maximum score of 4. CONCLUSION: The TN-RS scoring system can assist clinicians in identifying patients that may benefit from GNRS for TN by predicting 1-year pain-free outcomes.

The Petroclinoid Ligament: Its Morphometrics, Relationships, Variations, and Suggestion for New Terminology.

The anatomy and definition of the petroclinoid ligament (PCL) and its relationship with the abducens nerve are variably described. The goal of this study was to clarify the anatomy of the PCL and better elucidate its relationship with the abducens nerve. Thirty-six sides from 18 fresh-frozen adult cadaveric heads were used in this study. Specimens were all Caucasian and derived from 10 males and 8 females. The mean age at death was 79 years. Dissection of the PCL and abducens nerve was performed using a surgical microscope. The anterior and posterior attachments of the PCL, and position of the abducens nerve were noted. Subsequently, the width, thickness, and length of the ligament, and diameter of the abducens nerve were measured. Thirty-one sides (86.1%) were found to have a PCL, on two sides (5.6%), the PCL was ossified, and on three sides (8.3%), the PCL was absent. The width, thickness, and length of the PCL ranged from 0.54 to 3.39, 0.07 to 0.49, and 3.27 to 17.85 mm, respectively. No PCL had an anterior attachment onto the posterior clinoid process but rather, the clivus. Therefore, based on our findings, the PCL would be better described as the petroclival ligament.

Invasive Cryptococcal Meningitis Presenting as a Skull Base Mass in An Immunocompetent Host: A Case Report.

Introduction Encephalitis due to Cryptococcus neoformans has been seen almost exclusively in patients with severe compromise of their immune systems, such as acquired immune deficiency syndrome (AIDS). Fungal sinusitis with frank invasion through the cranial base and subsequent seeding of the central nervous system is rare, but should be considered in the differential of patients presenting with meningitis and sinus/skull base lesions even without obvious immune compromise. Improvements in diagnostic testing has increased the ability to correctly identify and new antimicrobials have allowed a condition that once carried a high morbidity and mortality to be managed with better outcomes. We present our treatment algorithm for successful management of an immunocompetent patient with extensive fungal encephalitis due to erosion through the skull base. Case Description The patient is a 59-year-old male presenting unresponsive with sphenoid mass erosive of the skull base and symptoms of meningitis and encephalitis due to C. neoformans . Magnetic resonance imaging (MRI) at presentation demonstrated extensive diencephalic invasion, and a sphenoid mass with erosion of the skull base. Lumbar puncture (LP) confirmed elevated opening pressure of 45 cm H2O, and cultures confirmed infection with C. neoformans . He underwent operative sinonasal debridement followed by placement of an external ventricular drain for management of hydrocephalus. He was treated aggressively with a combination of both intravenous (IV) amphotericin B daily and intrathecal amphotericin B via the ventriculostomy thrice weekly. By the 2nd week of treatment, patient regained consciousness. After 4 weeks of therapy, cerebrospinal fluid (CSF) cultures turned negative, and the external ventricular drain (EVD) was converted to a ventriculoperitoneal shunt (VPS) to manage chronic postinfectious hydrocephalus. We also placed a contralateral Ommaya reservoir to permit continued weekly intrathecal amphotericin B without violation of the shunt valve. With each instillation, the shunt was set to its highest setting to minimize CSF egress for 6 hours then reset to its "drainage" setting. After an additional 6 weeks of outpatient therapy, intrathecal therapy was discontinued. We continued CSF surveillance via Ommaya sampling monthly. At 9-month follow-up, he has remained clinically stable without evidence of recurrent infection. He has residual mild cognitive deficits, but is living semiindependently with his brother. Conclusions Fungal sinusitis is uncommon, especially in those without significantly compromised immune systems. Invasive fungal meningitis resulting in meningitis and encephalitis is even rarer. The condition carries high morbidity and mortality that can only be mitigated with a multidisciplinary effort by neurosurgery, otolaryngology, and infectious disease specialists. While there are no clear treatment guidelines, we present an approach that may permit longer term independent survival.

Internal Thoracic Artery to Vertebral Artery Bypass Surgery: A Cadaveric Feasibility Study.

OBJECTIVE: Posterior circulation strokes account for over one quarter of all ischemic strokes. The frequency of vertebral artery origin stenosis (VAOS) in patients with vertebrobasilar insufficiency (VBI) has been estimated to be as high 26%-32%, and VAOS is the direct cause of posterior circulation strokes in 9% of patients. This association could have a significant genetic component. This study examines the feasibility of the internal thoracic artery (ITA) as a donor vessel for revascularization in patients with VAOS. METHODS: Ten sides from 5 fresh-frozen white cadaveric necks derived from 3 women and 2 men were used in this study. The mean age of the cadavers at death was 77.2 years (range, 68-88 years). The subclavian artery, vertebral artery, and ITA were dissected. The length and diameter (proximal and distal) of the V1 segment and the length and diameter of the ITA were recorded. Finally, the ITA was transposed to the V1 segment of the vertebral artery (VA1). RESULTS: The mean length of the VA1 and its diameter at the proximal and distal parts were 35.51 and 3.69 mm, respectively. The mean length and diameter of the ITA were 26.53 and 3.27 mm, respectively. Rerouting the ITA to the VA1 was feasible without tension on all sides. CONCLUSIONS: This study indicates that the ITA is anatomically and hemodynamically an excellent option for bypass surgery in a VAOS scenario. We present convincing and reproducible data to aid neurosurgeons in choosing the procedure best suited to their patients.

The ABC's of Spinal Decompression: Pearls and Technical Notes.

OBJECTIVE: The foundation of spine surgery centers on the proper identification, decompression, and stabilization of bony and neural elements. We describe easily reproducible and reliable methods for optimal decompression and release of neural structures to alleviate symptoms and improve patients' quality of life. METHODS: Multiple spinal decompression techniques were described in procedures for which the goal of surgery was decompression alone or decompression and fusion. Eight fundamental techniques were described: inverted U-cut, J-cut, T-cut, L-cut, Z-cut, I-track cuts, C-cut, and O-cut. RESULTS: These foundational cuts may be combined, as needed, to develop an individually tailored approach to the patient's pathology. CONCLUSIONS: After properly identifying the anatomic structures, each of these techniques provides a consistent, reproducible, and efficient means to decompress the spine under various circumstances. These techniques provide surgical trainees with a framework for approaching surgical decompression.

Ectopic Pituitary Adenoma Presenting as a Clival Mass.

Pituitary adenomas are well described in the literature and are frequently observed and treated in clinical practice by neurosurgeons. On the other hand, ectopic adenomas are a diagnostic enigma; a good understanding of anatomy and radiological characteristics is crucial for the successful management of such pathologies. In this paper, we describe the case of a 77-year-old woman who presented with a clival mass invading the left cavernous sinus; we also discuss the associated diagnostic techniques, approaches, imaging options, and characteristics.

The Basal Subarachnoid Cisterns: Surgical and Anatomical Considerations.

The basal subarachnoid cisterns are expansions of the subarachnoid space and transmit cranial nerves and intracranial vessels. Providing neurosurgeons with key concepts, anatomical landmarks, and techniques can result in safer procedures and better patient outcomes. In this review, we discuss the major basal subarachnoid cisterns including their embryology, history, anatomical descriptions, and use during surgical approaches.

Neck movement during cervical transforaminal epidural injections and the position of the vertebral artery: an anatomical study.

BACKGROUND: Cervical transforaminal epidural steroid injections (CTFESIs) are sometimes performed in patients with cervical radiculopathy secondary to nerve-root compression. Neck movements for patient positioning may include rotation, flexion, and extension. As physicians performing such procedures do not move the neck for fear of injuring the vertebral artery, we performed fluoroscopy and cadaveric dissection to analyze any movement of the vertebral artery during head movement and its relation to the foramina in the setting of CTFESI. PURPOSE: To determine cervical rotational positioning for optimized vertebral artery location in the setting of cervical transforaminal epidural steroid injections. MATERIAL AND METHODS: Four sides from two Caucasian whole cadavers (all fresh-frozen) were used. Using a guide wire and digital subtraction fluoroscopy, we evaluated the vertebral artery mimicking a CTFESI, then we removed the transverse processes and evaluated the vertebral artery by direct observation. RESULTS: After performing such maneuvers, no displacement of the vertebral artery was seen throughout its course from the C6 to the C2 intervertebral foramina. To our knowledge, this is the first anatomical observation of its kind that evaluates the position of the vertebral artery inside the foramina during movement of the neck. CONCLUSION: Special caution should be given to the medial border of the intervertebral foramina when adjusting the target site and needle penetration for the injection. This is especially true for C6-C4 levels, whereas for the remaining upper vertebrae, the attention should be focused on the anterior aspect of the foramen. Since our study was centered on the vertebral artery, we do not discard the need for contrast injection and real-time digital subtraction fluoroscopy while performing the transforaminal epidural injection in order to prevent other vascular injuries.

The Great Auricular Nerve: Anatomical Study with Application to Nerve Grafting Procedures.

BACKGROUND: When it comes to autogenous nerve grafting, the sural and great auricular nerve (GAN) are the 2 nerves predominately used for trigeminal and facial nerve repair. Arising from the second and third cervical ventral rami, the GAN emerges from the posterior border of the sternocleidomastoid coursing superiorly and anteriorly toward the ear. METHODS: Eleven sides from 5 Caucasian and 1 Asian cadaveric heads (all fresh-frozen) were used. One man and 5 women were used with an age at death ranging from 57 to 91 years, with a mean of 80.3 years. Measurements were made from the inferior border of the ear to the GAN, the GAN to the external jugular vein, and the inferior border of the mastoid process to the GAN; the proximal, medial, and distal diameters of the GAN and the length of the GAN that was obtained from this exposure were also measured. RESULTS: The mean distance from the inferior border of the mastoid process to the GAN, inferior border of the ear to the GAN, and GAN to the external jugular vein was 27.71, 31.03, and 13.28 mm, respectively. The mean length of the GAN was 74.86 mm. The mean diameter of its distal, middle, and proximal portions was 1.51, 1.38, and 1.58 mm, respectively. CONCLUSIONS: The GAN is an excellent option for use in nerve grafting for repair of, for example, facial dysfunction. In this study, we review our measurements, techniques for identification, and dissecting techniques for the GAN. The proximity to the operative area and minimal complications associated with GAN grafting might contribute to improved patient satisfaction and better outcomes regarding functional restoration.

Transclival Venous Circulation: Anatomic Study.

INTRODUCTION: The clivus is a small, central area of the basal cranium with limited surgical access and high morbidity associated with pathologies of its surrounding structures. Therefore thorough knowledge and understanding of the anatomy in this region are crucial for the success of treatments and interpretation of imaging. As to our knowledge, there is no extant cadaveric examination of the transclival veins, so the present study was performed. METHODS: Fifteen lightly embalmed adult heads underwent blue latex injection of the left and right internal jugular veins. Special attention was given to the presence or absence of transclival vessels. When transclival veins were identified, their intracranial source, point of penetration of the clivus and anterior connections were documented. RESULTS: Ten (66.7%) specimens were found to have transclival veins. These connected the basilar venous plexus to the retropharyngeal venous plexus on all specimens. Eight of the 10 specimens had multiple transclival veins, and 2 had only 1 vessel. The majority of the transclival veins were found penetrating the clivus at its lower one third. However, 2 specimens also had transclival veins that pierced the clivus at its upper one third. CONCLUSIONS: An improved understanding of the skull base and its venous drainage can assist clinicians and surgeons in better understanding normal, pathologic, and variant anatomy in this region.

Pediatric glossopharyngeal neuralgia: a comprehensive review.

INTRODUCTION: Debilitating facial pain can seriously affect an individual's daily living. Given that the pathophysiology behind neuropathic and myofascial pain is not fully understood, when chronic facial pain goes undiagnosed, it has been proposed that one of the two is the likely cause. Since their discovery, glossopharyngeal neuralgia (GN) and Eagle's syndrome have been considered mostly conditions afflicting the adult population. However, when pediatric patients present with symptoms resembling GN or Eagle's syndrome, physicians are less apt to include these as a differential diagnosis simply due to the low prevalence and incidence in the pediatric population. MATERIALS AND METHODS: A literature review was performed with the aim to better understand the history of reported cases and to provide a comprehensive report of the anatomical variations that lead to these two conditions as well as the way these variations dictated medical and surgical management. Articles were obtained through Google Scholar and PubMed. Search criteria included key phrases such as pediatric glossopharyngeal neuralgia and pediatric Eagle syndrome. These key phrases were searched independently. PubMed was searched primarily then cross-referenced articles were found via Google Scholar. Results from non-English articles were excluded. RESULTS: A total of 58 articles were reviewed. Most of the articles focused on adult glossopharyngeal neuralgia, and the majority was comprised of case reports. When searched via PubMed, a total of 16 articles and 2 articles returned for glossopharyngeal neuralgia and Eagle's syndrome, respectively. After criteria selection and cross-referencing, a total of seven articles were found with respect to pediatric glossopharyngeal neuralgia. CONCLUSIONS: While they are rare conditions, there are multiple etiologies that lead to the debilitating symptoms of GN and Eagle's syndrome. The clinical anatomy proved notable as multiple causes of GN and Eagle's syndrome are due to variation in the anatomy of the neurovascular structures surrounding the glossopharyngeal nerve, an elongated styloid process, a calcified stylohyoid ligament as well as a calcified stylomandibular ligament. Due to the success of different treatment modalities, the treatment of choice is dependent on clinical judgment.

Suprasellar Epidermoid Cyst Originating from the Infundibulum: Case Report and Literature Review.

Epidermoid cysts account for a small fraction of intracranial brain tumors, most commonly found in the cerebellopontine angle and parasellar cisterns. Here we present a rare case of an epidermoid cyst located in the suprasellar region, specifically originating from the infundibulum. Only one additional case with an epidermoid cyst originating within the pituitary stalk has been previously reported in the literature. The patient in this case presented with headaches, diplopia and blurred vision without any endocrinopathy. The patient's pre-operative evaluation was significant for pseudotumor cerebri, hyponatremia, obesity, and a history of smoking; post-operative course was significant for neurogenic diabetes insipidus.

A Median Artery of the Corpus Callosum.

The anterior communicating artery is one of the main components of the vascular network that delivers blood to the brain. Therefore, a good understanding of the normal anatomy and its variations is important to neurologists, neurosurgeons, and other health care providers dealing with the central nervous system. Here, we present a case of a median artery of the corpus callosum found in a cadaver, with consideration of cerebral hemodynamics implications.

Variations of the Transverse Sinus: Review with an Unusual Case Report.

The dural venous sinuses are venous channels in the cranium that drain blood and cerebrospinal fluid circulating from the brain into the vascular system via the internal jugular veins. The transverse sinus is a dural venous sinus present in the posterior aspect of the cranium. We report an unusual variant of this sinus with the presence of a fenestration at its proximal segment. We will review and discuss the background and the potential clinical relevance of this anatomical variation.

An Unusual Back Muscle Identified Bilaterally: Case Report.

Most muscular structures in the human body are named based on their function, origin/insertion, or shape. During routine dissection of the back, an unusual muscle was found deep to the rhomboid muscles. The details of this case and a review of the extant literature are provided.

Innervation of Orbicularis Oculi by Trochlear Nerve: Word of Caution.

BACKGROUND: Neurosurgeons who operate in and around the pathway of the ocular nerves should have good knowledge of not only their normal anatomy but also their variations. CASE DESCRIPTION: During routine dissection of the orbits in an adult cadaver, an aberrant branch of the right trochlear nerve continued on to innervate the orbicularis oculi muscle. In this case, the trochlear nerve also provided a branch to the supratrochlear nerve. CONCLUSIONS: Surgeons who operate along the pathway of the trochlear nerve such as the cavernous sinus should be aware of such an anatomic variant in order to avoid unwanted complications such as weakness of the orbicularis oculi muscle.

Endoscopic Transnasal Transclival Approach to a Pontine Cavernoma with Associated Developmental Venous Anomaly.

BACKGROUND: Brainstem cavernous malformations represent around 8%-22% of all intracranial cavernous malformations but exhibit a higher annual incidence of hemorrhage (2%-3%) compared with other cavernous angiomas and tend to be more symptomatic given their proximity to critical nuclei and fiber tracts. Recently, endoscopic endonasal techniques have been used for the removal of ventral skull base lesions, with significant improvement in operative morbidity and mortality compared with open approaches. Here we demonstrate the utility and feasibility of the endoscopic transclival approach for ventrally located pontine cavernomas in carefully selected patients. CASE DESCRIPTION: Consent was provided by the patient before the writing of this report. Institutional review board approval was not necessary because there was no other patient data accessed. A 21-year-old man presented to the emergency department with right-sided hemiparesis. Magnetic resonance imaging demonstrated evidence of hemorrhage from a ventrally located pontine cavernoma. Given the ventral location of the lesion and the desire for early control of an associated developmental venous anomaly (DVA), an endoscopic endonasal transclival approach was chosen. Gross total resection was achieved, and the patient did well postoperatively with no new neurologic deficits or cerebrospinal fluid leak. He is currently routinely followed and is neurologically well. CONCLUSIONS: This approach provided direct visualization of the lesion and the associated DVA allowing for a gross total resection without injury to the DVA. The transclival approach may be considered as an alternative to open lateral and dorsolateral neurosurgical approaches for ventral brainstem cavernomas in carefully selected patients.

A case series of atypical features of patients with biopsy-proven isolated IgG4-related hypophysitis and normal serum IgG4 levels.

BACKGROUND: IgG4-related hypophysitis is a rare clinical entity that forms part of an emerging group of multi-organ IgG4-related fibrosclerotic systemic diseases. The rare prevalence of the disease, presenting features that overlap with other sellar pathologies, and variable imaging features can make preoperative identification challenging. PURPOSE AND METHODS: We report three cases of isolated IgG4-related hypophysitis with atypical clinical and imaging features that mimicked those of pituitary apoplexy and other sellar lesions. Additionally, we review the literature of IgG4-related hypophysitis to provide context for individual patient data described herein. RESULTS: All patients presented with symptoms that mimicked those of pituitary apoplexy and visual disturbance, and MRI findings suggestive of pituitary macroadenoma, Rathke's cleft cyst and craniopharyngioma. The clinical presentation warranted surgical decompression, resulting in rapid symptomatic improvement. Preoperative high-dose followed by postoperative low-dose glucocorticoid replacement therapy was administered in all cases. Histopathology showed dense infiltrate of IgG4 cells. Post-operative follow-up monitoring for 12-26 months revealed normal serum IgG4 levels with no other organ involvement, while endocrinological testing revealed persistent pituitary hormone deficiencies. CONCLUSIONS: Our cases highlight the importance of considering IgG4-related hypophysitis in the differential diagnosis of solid and cystic sellar lesions presenting acutely with pituitary apoplexy symptoms. Existing diagnostic criteria may not be sufficiently precise to permit rapid and reliable identification, or avoidance of surgery in the acute setting. In contrast to other reports of the natural history of this condition, despite the severity of presenting features, the disease in our cases was pituitary-restricted with normal serum IgG4 levels.