Urothelial cell carcinoma presenting with rapid visual deterioration, a case of rare brain metastases with unique clinical presentation.

BACKGROUND: Urothelial cell carcinoma (UCC), the most common cancer of the urinary system, rarely metastasizes to the brain. 1-3 More rare still is the subset of patients with urothelial carcinoma brain metastases whose UCC primary is first diagnosed at the same time as their CNS metastatic disease, with oncologic workup prompted by CNS clinical manifestations.4 Paraneoplastic optic neuropathy (PON) is likewise a rare clinical entity, which has not yet been described in association with UCC brain metastases. CASE DESCRIPTION: Herein, we present the sentinel case of UCC believed to be of endometrial origin in an 81 year old woman initially presenting with symptoms of fatigue, nausea, vertigo, and rapidly deteriorating vision over the course of 1 month. Visual deterioration prompted neuro imaging remarkable for multiple supratentorial and infratentorial metastases as well as likely neoplastic inflammatory involvement of the bilateral optic nerves. The patient underwent a right temporal open brain biopsy, with pathology findings consistent with UCC. Subsequent PET scanning demonstrated a heavy burden of disease including an FDG-avid uterine mass with local and distal extension of disease including bilateral hydroureteronephrosis with obstruction of the distal ureters. The patient and her family elected to pursue home hospice without further workup or intervention. CONCLUSIONS: While this is the first such case presented, it is possible that UCC of the uterine wall represents a particularly aggressive form of the disease more prone to presenting with CNS metastases and PON.

Severe hypokalemia in a patient with subarachnoid hemorrhage.

Hypokalemia is a common electrolyte disorder in the intensive care unit. Its cause often is complex, involving both potassium losses from the body and shifts of potassium into cells. We present a case of severe hypokalemia of sudden onset in a patient being treated for subarachnoid hemorrhage in the surgical intensive care unit in order to illustrate the diagnosis and management of severe hypokalemia of unclear cause. Our patient received agents that promote renal potassium losses and treatments associated with a shift of potassium into cells. We outline the steps in diagnosis and management, focusing on the factors regulating the transcellular distribution of potassium in the body.

Sentinel report of uniquely paired collision tumors: glioblastoma multiforme and coexistent intraventricular subependymoma. Illustrative case.

BACKGROUND: The presence of intracranial collision tumors, histologically distinct tumors occurring in anatomical proximity, is quite rare. Herein, the authors describe the sentinel case of a contiguous collision tumor combination consisting of glioblastoma multiforme and intraventricular subependymoma. OBSERVATIONS: A 67-year-old male presented with several months of progressive fatigue superimposed on more recently noted word-finding difficulty, slight left-sided weakness, and episodic confusion. He was found to have a large right frontal mass abutting the right lateral ventricle with an additional nodular focus of enhancement within the right frontal horn. The patient underwent an awake right frontal craniotomy for gross-total resection of the tumor, noted to be of two distinct histological identities. LESSONS: Although exceptionally rare, primary glial neoplasms of various histologies can be encountered simultaneously during resection, as in this case of co-occurring glioblastoma of the right frontal lobe and right frontal horn intraventricular subependymoma. Close attention to tumoral locations and the gross appearance of specimens during resection can prime the operative neurosurgeon for success in contributing to accurate diagnoses through sending separate pathological specimens for histological analysis when qualitatively different tissue is suspected.

Great Hospitals: The History of Neurosurgery at the University of Vermont Medical Center-A Macroscopic Examination of Microscope-Savvy Pioneers.

The University of Vermont's (UVM) Division of Neurosurgery is enshrined in a rich history of innovation and academic prowess, which have significantly contributed to making neurosurgery the field it is today. From humble beginnings, the department was started by one Raymond Madiford Peardon "Pete" Donaghy on a parenthetically watertight research budget amounting to $25 and shared space in a Quonset hut. Passion and commitment to progress, as well as an innate openness to collaboration, propelled Pete Donaghy, his colleagues, pupils, and successors to establish an exemplary center for treatment of neurosurgical disease, with multiple revolutionary accomplishments along the way. These accomplishments include the birth and promotion of microneurosurgery, the performance of the first extracranial to intracranial bypass, and the education of other neurosurgical giants. The New England Skull Base Course, held annually in UVM's "R.M. Peardon Donaghy Microvascular and Skull Base Laboratory," is a 3-day cadaver-based teaching course for neurosurgery and ear nose and throat residents throughout New England. The course bears testament to Donaghy's everlasting influence on the UVM Division of Neurosurgery and continues to positively affect the education of countless trainees. The purpose of this historical perspective is to outline the events and accomplishments that define the UVM Division of Neurosurgery's many contributions to the field at large and the ongoing efforts to honor Donaghy's example through maintaining a culture of humility, hard work, and commitment to neurosurgical innovation and education.

Intratumoral abscess complicating a postradiation-induced World Health Organization grade II meningioma: illustrative case.

BACKGROUND: Cerebral meningiomas and brain abscesses are common independently, but intrameningioma abscesses rarely occur, with only 15 cases in the literature. These abscesses most frequently develop in patients with a known source of bacteremia; only one case of intrameningioma abscess without a known source of infection has been reported previously. OBSERVATIONS: This is the second reported case of an intrameningioma abscess without a clear source of infection, occurring in a 70-year-old female with a history of transsphenoidal craniopharyngioma resection and radiation many years prior. She presented with severe fatigue and altered mental status initially ascribed to adrenal insufficiency, and magnetic resonance imaging showed a new heterogeneously enhancing left temporal mass with surrounding edema. After urgent tumor resection, pathology demonstrated a World Health Organization grade II meningioma (radiation induced). After a course of steroids and intravenous nafcillin, the patient recovered without neurological deficits. LESSONS: The natural history of intrameningioma abscesses is not fully understood. These uncommon lesions can form secondary to hematogenous spread facilitated by meningiomas' robust vascularization, typically in patients with bacteremia. Even when no significant source of infection is identified, the differential diagnosis of intrameningioma abscess should be considered because this pathology can be rapidly progressive, even fatal, but is treatable if recognized promptly.

Contralateral interhemispheric transfalcine approach to precuneal glioblastoma: fluorescein guided microsurgical resection and endoscopic microinspection tool.

Maximum safe resection remains a primary goal in the treatment of glioblastoma, with gross-total resection conveying additional survival benefit. Multiple intraoperative visualization techniques have been developed to improve the extent of resection. Herein, the authors describe the use of fluorescein and endoscopic assistance with a novel microinspection device in achieving a gross-total resection of a deep seated precuneal glioblastoma. An interhemispheric transfalcine approach was utilized and microsurgical resection was completed with fluorescein guidance. A 45° endoscope was then used to inspect the resection bed, and remaining areas of concern were then resected under endoscopic visualization. The video can be found here: https://stream.cadmore.media/r10.3171/2021.10.FOCVID21195.

Surgical removal of a compressive thoracic epidural vascular malformation in a patient with Klippel-Trénaunay syndrome: illustrative case.

BACKGROUND: Klippel-Trénaunay syndrome (KTS) is a combined capillary-lymphatic-venous malformation disorder traditionally associated with high surgical morbidity. Although rare, pathologic involvement of the spinal cord has been reported in the literature. However, the safety of surgical intervention remains unclear. We report a case of successful decompression of a thoracic epidural lesion in an individual with KTS who presented with spastic paraparesis. OBSERVATIONS: The patient is a 38-year-old male, diagnosed with KTS as an infant, who presented with spastic paraparesis secondary to a thoracic epidural lesion. He underwent laminectomies and resection of the lesion with subsequent improvement of his symptoms and without significant postoperative morbidity. Histopathology confirmed the lesion to be a benign vascular malformation. LESSONS: Currently, the literature regarding management of symptomatic vascular lesions in individuals with KTS supports nonoperative management, due to the increased risk of operative morbidity associated with this syndrome. This case presents evidence for safe and appropriate surgical management of a thoracic epidural vascular malformation in a patient with KTS in the setting of progressive neurological decline, establishing a role for neurosurgical intervention in this high-risk population when no conservative management portends further neurological deterioration.

Clinical Reasoning: A 67-Year-Old Woman With Abdominal Pain, Constipation, and Urinary Retention.

Meningeal melanocytomas are an extremely rare, pigmented tumors of the central nervous system (CNS). They generally carry a favorable prognosis, although recurrence and transformation into the more aggressive malignant melanoma has been reported. We present a case of a patient who reported constipation and abdominal pain around the umbilicus, which progressed into cord compression with lower extremity weakness and gait instability. Spinal magnetic resonance imaging (MRI) revealed a tumor at the level of T11, and she underwent gross total resection of the mass. Pathology demonstrated a meningeal melanocytoma with intermediate features. She received post-operative radiation therapy and had stable disease for three years, at which time she developed new weakness and drop metastases. This case represents a rare presentation of a rare disease, in which a spinal cord tumor presented with constipation and abdominal distress. Intradural-extramedullary tumors of the thoracic spine are most commonly nerve sheath tumors or meningiomas, but rare entities such as melanocytomas can present in this location; even more rarely, these tumors can have an aggressive course with delayed recurrence.

Anal cancer with cerebral metastasis: a case report.

Carcinoma of the anal canal is a relatively rare cancer with a low propensity for metastasis. A literature review identifies two cases of brain metastases from anal cancer. The authors present the case of a 63-year-old female with poorly differentiated squamous cell carcinoma of the anal canal who presented with a solitary dural-based enhancing lesion of the right parietal area. The patient underwent craniectomy and tumor resection. Histopathology confirmed the cerebral lesion to be a poorly differentiated squamous cell carcinoma, consistent with the known primary tumor of the anal canal. Although exceptionally rare, the presence of a cerebral lesion in a patient with carcinoma of the anal canal should raise the possibility of metastatic disease. Treatment decisions in patients with newly diagnosed dural-based enhancing lesions and known anal cancer should bear in mind the possibility of metastatic disease.

Chiari malformation and spinal interdural cyst: A proposed association and review of the literature.

Background: Interdural cysts are rare meningeal cysts with an unclear etiology. They are often mistaken for other mass lesions, including arachnoid cysts and tumors. Correctly identifying and classifying these cysts, as well as how they have formed in individual patients, are crucial to providing effective treatment options for patients. Case Description: We report a case of a patient with shunted idiopathic intracranial hypertension who developed a symptomatic Chiari malformation and was subsequently discovered to have a spinal interdural cyst. The Chiari malformation was likely due to intracranial hypotension secondary to lumbar cerebrospinal fluid (CSF) diversion. Once the shunt was removed, a spinal interdural cyst became clinically and radiographically evident, and the Chiari resolved, suggesting that both entities were effects of shared CSF flow dynamics. Conclusion: This cyst likely originated due to the trauma from remote repeated lumbar punctures and lumboperitoneal shunt placement, allowing CSF to enter the interdural space after the catheter was removed.

Endoscopic supracerebellar infratentorial approach to pineal region epidermoid tumor.

Epidermoid cysts of the pineal region are a rare entity. Herein, the authors describe the endoscopic resection of a recurrent pineal region epidermoid by way of a supracerebellar infratentorial approach. The patient was positioned in the semiseated upright position with head tilted to the right and slightly flexed, maximizing gravity-based cerebellar retraction, and a paramedian craniotomy was performed owing to the gradual flattening of the tentorium from medial to lateral. This setup, in tandem with the enlarged viewing window achieved by use of 0°, 30°, and 70° endoscopes, afforded the necessary access to achieve a satisfactory resection through this anatomical corridor. The video can be found here: https://stream.cadmore.media/r10.3171/2021.4.FOCVID2131.

Disseminated Rosette-Forming Glioneuronal Tumor with Spinal Drop Metastasis, a Uniquely Aggressive Presentation of Rare Tumor.

BACKGROUND: The rosette-forming glioneuronal tumor (RGNT) is a rare World Health Organization grade I tumor, most often originating in the fourth ventricle and characterized by a predominant glial component, as well as a neurocytic component. Despite its benign grading, there are a few documented cases of RGNT displaying more aggressive behavior with malignant characteristics. CASE DESCRIPTION: Herein, we describe a uniquely aggressive presentation of RGNT in a 49-year-old man initially presenting with obstructive hydrocephalus with lesions in the right frontal lobe, fourth ventricle, and left lateral ventricle. The patient was found to have 2 distinct intracranial entities: a right frontal meningioma and disseminated intraventricular RGNT. He underwent an anatomically limited resection of the fourth ventricular lesion with fourth ventricle-to-subarachnoid space shunting. His disease progressed thereafter, with diffuse intracranial dissemination and drop metastases in the lumbar spine. He was treated with craniospinal radiation and remains on palliative care 5 months after completion of radiotherapy. CONCLUSIONS: This case supplements and complements the handful of published cases available documenting the evolution of a particularly aggressive case of disseminated RGNT.

Differential Patterns of Referral to Neurosurgery: A Comparison of Allopathic Physicians, Osteopathic Physicians, Nurse Practitioners, Physician Assistants, and Chiropractors.

BACKGROUND: Rising cost and limited resources remain major challenges to U.S. health care and neurosurgery in particular. To ensure an efficient and cost-effective health care system, it is important that referrals to neurosurgery clinics are appropriate, and that referred patients have a reasonably high probability of requiring surgical intervention or, at a minimum, ongoing neurosurgical follow-up. This retrospective study tests the null hypothesis that the probability of a referred patient requiring surgery is independent of referring provider credentials and referring service specialty. METHODS: A database of all patients referred to the neurosurgery clinic from 2015 through 2018 (n = 5677) was reviewed; the database included referring provider, referring provider specialty, number of subsequent clinic visits, and outcome of surgery or no surgery. Associations between categorical variables were tested using a χ2 analysis with post hoc relative risk (RR) calculations and binary logistical regression. RESULTS: Compared with patients referred by allopathic physicians, patients referred by osteopathic physicians (RR, 0.63; 95% confidence interval [CI], 0.48-0.84) and those referred by nurse practitioners (RR, 0.66; 95% CI, 0.51-0.86) were significantly less likely to require surgery. Probability of surgical intervention also varied by referrer specialty. Patients referred by neurologists required surgery 35% of the time, whereas patients referred by family practitioners required surgery 19% of the time, and patients referred by pediatricians required surgery only 7% of the time (P < 0.01). Binary logistic regression revealed that referrals from nurse practitioners and osteopathic physicians were independently associated with a decreased probability of surgical intervention. CONCLUSIONS: Our data strengthen the concept of having interdisciplinary teams led by physicians at the primary care level to ensure appropriate referrals. Training and adherence to guidelines must continually be reinforced to ensure proper referrals.

Oxyhemoglobin-induced expression of R-type Ca2+ channels in cerebral arteries.

BACKGROUND AND PURPOSE: Cerebral vasospasm after subarachnoid hemorrhage (SAH) is a major contributor to mortality and morbidity after aneurysm rupture. Recently, R-type voltage-dependent Ca(2+) channel (VDCC) expression has been associated with increased cerebral artery constriction in a rabbit model of SAH. The goal of the present study was to examine whether the blood component oxyhemoglobin (oxyHb) can mimic the ability of SAH to cause R-type VDCC expression in the cerebral vasculature. METHODS: Rabbit cerebral arteries were organ cultured in serum-free media for up to 5 days in the presence or absence of purified oxyHb (10 micromol/L). Diameter changes in response to diltiazem, (L-type VDCC antagonist) and SNX-482 (R-type VDCC antagonist) were recorded at day 1, 3, or 5 in arteries constricted by elevated extracellular potassium. RT-PCR was performed on RNA extracted from arteries cultured for 5 days (+/-oxyHb) to assess VDCC expression. RESULTS: After 5 days, oxyHb-treated arteries were less sensitive and partially resistant to diltiazem compared to similar arteries organ cultured in the absence of oxyHb. Further, SNX-482 dilated arteries organ cultured for 5 days in the presence, but not in the absence, of oxyHb. RT-PCR revealed that oxyHb treated arteries expressed R-type VDCCs (Ca(V) 2.3) in addition to L-type VDCCs (Ca(V) 1.2), whereas untreated arteries expressed only Ca(V) 1.2. CONCLUSIONS: These results demonstrate that oxyhemoglobin exposure for 5 days induces the expression of Ca(V) 2.3 in cerebral arteries. We propose that oxyhemoglobin contributes to enhanced cerebral artery constriction after SAH via the emergence of R-type VDCCs.

Oxyhemoglobin-induced suppression of voltage-dependent K+ channels in cerebral arteries by enhanced tyrosine kinase activity.

Cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) has devastating consequences. Oxyhemoglobin (oxyhb) has been implicated in SAH-induced cerebral vasospasm as it causes cerebral artery constriction and increases tyrosine kinase activity. Voltage-dependent, Ca(2+)-selective and K(+)-selective ion channels play an important role in the regulation of cerebral artery diameter and represent potential targets of oxyhb. Here we provide novel evidence that oxyhb selectively decreases 4-aminopyridine sensitive, voltage-dependent K(+) channel (K(v)) currents by approximately 30% in myocytes isolated from rabbit cerebral arteries but did not directly alter the activity of voltage-dependent Ca(2+) channels or large conductance Ca(2+)-activated (BK) channels. A combination of tyrosine kinase inhibitors (tyrphostin AG1478, tyrphostin A23, tyrphostin A25, genistein) abolished both oxyhb-induced suppression of K(v) channel currents and oxyhb-induced constriction of isolated cerebral arteries. The K(v) channel blocker 4-aminopyridine also inhibited oxyhb-induced cerebral artery constriction. The observed oxyhb-induced decrease in K(v) channel activity could represent either channel block, or a decrease in K(v) channel density on the plasma membrane. To explore whether oxyhb altered trafficking of K(v) channels to the plasma membrane, we used an antibody generated against an extracellular epitope of K(v)1.5 channels. In the presence of oxyhb, staining of K(v)1.5 on the plasma membrane surface was markedly reduced. Furthermore, oxyhb caused a loss of spatial distinction between staining with K(v)1.5 and the general anti-phosphotyrosine antibody PY-102. We propose that oxyhb-induced suppression of K(v) currents occurs via a mechanism involving enhanced tyrosine kinase activity and channel endocytosis. This novel mechanism may contribute to oxyhb-induced cerebral artery constriction following SAH.

Subclavian artery stenosis causing transient bilateral brachial diplegia: an unusual cause of anterior spinal artery syndrome.

The author report a case of a 74-year-old man who had presented with transient bilateral brachial diplegia. Investigations led to the diagnosis and treatment of subclavian artery stenosis. There are no known published cases of subclavian artery stenosis associated with transient bilateral arm weakness, and the authors believe that a steal phenomenon leading to vertebrobasilar artery insufficiency and subsequent anterior spinal artery insufficiency may have caused these symptoms, which resolved after correction of the patient's stenosis.

Tenosynovial Giant Cell Tumor of the Clinoid: Rare Condition.

BACKGROUND: A tenosynovial giant cell tumor (TGCT) is a rare type of tumor that primarily arises from the tendon sheath, synovium, and bursae. In rare cases, these tumors can affect joints of the head and neck such as the temporomandibular joint. This is the only case to our knowledge of an intracranial TGCT tumor of the clinoid. CASE DESCRIPTION: We present the case of a 25-year-old female with a 2-year history of progressively blurred vision in her left eye without visual field defects. She denied any headaches or symptoms referable to the left eye region. Past medical history was significant for meningitis at 10 months of age. Family history was noncontributory with no history of brain tumors. CONCLUSIONS: A tumor originating from the left anterior clinoid was found intraoperatively and confirmed by histology to be a TGCT.

Emergence of a R-type Ca2+ channel (CaV 2.3) contributes to cerebral artery constriction after subarachnoid hemorrhage.

Cerebral aneurysm rupture and subarachnoid hemorrhage (SAH) inflict disability and death on thousands of individuals each year. In addition to vasospasm in large diameter arteries, enhanced constriction of resistance arteries within the cerebral vasculature may contribute to decreased cerebral blood flow and the development of delayed neurological deficits after SAH. In this study, we provide novel evidence that SAH leads to enhanced Ca2+ entry in myocytes of small diameter cerebral arteries through the emergence of R-type voltage-dependent Ca2+ channels (VDCCs) encoded by the gene CaV 2.3. Using in vitro diameter measurements and patch clamp electrophysiology, we have found that L-type VDCC antagonists abolish cerebral artery constriction and block VDCC currents in cerebral artery myocytes from healthy animals. However, 5 days after the intracisternal injection of blood into rabbits to mimic SAH, cerebral artery constriction and VDCC currents were enhanced and partially resistant to L-type VDCC blockers. Further, SNX-482, a blocker of R-type Ca2+ channels, reduced constriction and membrane currents in cerebral arteries from SAH animals, but was without effect on cerebral arteries of healthy animals. Consistent with our biophysical and functional data, cerebral arteries from healthy animals were found to express only L-type VDCCs (CaV 1.2), whereas after SAH, cerebral arteries were found to express both CaV 1.2 and CaV 2.3. We propose that R-type VDCCs may contribute to enhanced cerebral artery constriction after SAH and may represent a novel therapeutic target in the treatment of neurological deficits after SAH.

A modeling study of idiopathic intracranial hypertension: etiology and diagnosis.

OBJECTIVE: To investigate the relationship between idiopathic intracranial hypertension (IIH) and transverse sinus stenosis through experiments performed on a validated mathematical model. METHODS: A mathematical model of intracranial pressure (ICP) dynamics has been extended to accommodate venous sinus compression through the introduction of a Starling-like resistor between the sagittal and transverse sinuses. RESULTS: In the absence of this type of resistor, the sinuses are rigid, and the model has only a unique, stable steady state with normal pressures. With resistance a function of the external pressure on the sinus, a second stable steady state may exist. This state is characterized by elevated ICP concurrent with a compressed transverse sinus. Simulations predict that a temporary perturbation that causes a transient elevation of ICP can induce a permanent transition from the normal to the higher steady state. Comparisons to clinical data from IIH patients provide supporting evidence for the validity of the model's predictions. Simulations suggest a possible clinical diagnostic technique to determine if an individual has a compressible transverse sinus and is at risk for developing IIH. CONCLUSIONS: Results of the model experiments suggest that the primary cause of IIH may be a compressible, as opposed to rigid, transverse sinus, and that the observed stenosis is a necessary characteristic of the elevated pressure state.

Metastatic Cardiac Angiosarcoma to the Lung, Spine, and Brain: A Case Report and Review of the Literature.

BACKGROUND: Metastatic angiosarcoma to the brain is a rare entity without an established management protocol. CASE DESCRIPTION: A man with primary cardiac angiosarcoma presented with a rare brain metastasis. The patient underwent successful resection of the brain metastasis and was initiated on chemotherapy only for his systemic disease. The patient did not develop local recurrence. A review of primary and metastatic central nervous system angiosarcoma, its pathologic features, clinical disease course, treatment strategies, and genomics is also provided. CONCLUSIONS: Angiosarcomas are rare tumors that are difficult to treat. Gross total resection of a central nervous system metastasis is recommended before initiation of adjuvant chemotherapy or radiation therapy. Close follow-up is still required given the propensity for continued metastasis of these tumors. Future treatments may be developed based on the genomics of angiosarcomas.