Spinal extramedullary hematopoiesis mimicking an epidural tumor in a patient with high-risk polycythemia vera: illustrative case.

BACKGROUND: Here the authors present the case of a 43-year-old male with a history of T-cell lymphoma, which was treated with azacitidine plus cyclophosphamide, doxorubicin, vincristine, and prednisone and autologous hematopoietic cell transplant, and high-risk polycythemia vera (PCV) presenting with severe lower-back pain radiating to the bilateral legs with associated lower-extremity weakness and splenomegaly. OBSERVATIONS: T2-weighted magnetic resonance imaging revealed multilevel epidural lesions involving T1-10 and S1-2. Because of severe spinal canal stenosis, the patient underwent surgical decompression of T5-7, with immediate postoperative alleviation of the lower-extremity pain and complete resolution of the lower-leg weakness. Biopsy results revealed extramedullary hematopoiesis (EMH) mimicking a spinal epidural tumor. EMH is radiosensitive and displays a rapid response to low dosages, so the patient was further treated with palliative radiation therapy for residual tumors and symptom alleviation, as well as hydroxyurea and corticosteroids as indicated for cytoreduction. LESSONS: EMH associated with PCV or myeloproliferative conditions occurring within the spine is a rare phenomenon without a standard treatment approach. https://thejns.org/doi/10.3171/CASE23659.

Reducing implicit bias in the neurosurgery application and interview process: a single-institution experience.

OBJECTIVE: The neurosurgical match is a challenging process for applicants and programs alike. Programs must narrow a wide field of applicants to interview and then determine how to rank them after limited interaction. To streamline this, programs commonly screen applicants using United States Medical Licensing Examination (USMLE) Step scores. However, this approach removes nuance from a consequential decision and exacerbates existing biases. The primary objective of this study was to demonstrate the feasibility of effecting minor modifications to the residency application process, as the authors have done at their institution, specifically by reducing the prominence of USMLE board scores and Alpha Omega Alpha (AΩA) status, both of which have been identified as bearing racial biases. METHODS: At the authors' institution, residents and attendings holistically reviewed applications with intentional redundancy so that every file was reviewed by two individuals. Reviewers were blinded to applicants' photographs and test scores. On interview day, the applicant was evaluated for their strength in three domains: knowledge, commitment to neurosurgery, and integrity. For rank discussions, applicants were reviewed in the order of their domain scores, and USMLE scores were unblinded. A regression analysis of the authors' rank list was made by regressing the rank list by AΩA status, Step 1 score, Step 2 score, subinternship, and total interview score. RESULTS: No variables had a significant effect on the rank list except total interview score, for which a single-point increase corresponded to a 15-position increase in rank list when holding all other variables constant (p < 0.05). CONCLUSIONS: The goal of this holistic review and domain-based interview process is to mitigate bias by shifting the focus to selected core qualities in lieu of traditional metrics. Since implementation, the authors' final rank lists have closely reflected the total interview score but were not significantly affected by board scores or AΩA status. This system allows for the removal of known sources of bias early in the process, with the aim of reducing potential downstream effects and ultimately promoting a final list that is more reflective of stated values.

Multiple craniotomies for the resection of symptomatic multifocal intracranial metastatic cardiac myxoma: A case report.

Background: Myxomas, rare benign mesenchymal lesions, are the most common cardiac tumors. Patients may rarely develop hematogenous metastasis to the brain, which can present as new-onset neurological deficits that correlate with multifocal hemorrhagic lesions on imaging. Limited guidelines presently exist for the treatment of such lesions. This report outlines a unique case involving three craniotomies and failed radiation therapy in the treatment of metastatic cardiac myxoma. Case Description: A 63-year-old woman presented with a right middle cerebral artery embolic stroke secondary to a left atrial myxoma and multifocal hemorrhagic lesions consistent with intracranial metastasis. She had a right frontal craniotomy for tumor resection, followed by stereotactic radiosurgery, though this did not arrest disease progression. She later had a left occipital craniotomy for a symptomatic lesion. More than two years after her initial presentation, she returned with acute-onset symptoms correlating to growth in a left frontal lesion requiring another resection. Following this third craniotomy, imaging has not revealed the progression of metastatic intracranial disease. She is pursuing further treatment through primary cardiac tumor resection. Conclusion: Although rare, hematogenous seeding with subsequent formation of hemorrhagic metastasis is a possible complication of atrial myxoma. While surgical resection, radiation therapy, and chemotherapy have historically been used, no standard of care currently exists. This case demonstrates repeat tumor resection as effective for managing symptomatic intracranial metastatic myxoma in a patient with poor response to radiation therapy and multiple recurrences, with follow-up showing improvement in neurological symptoms and mass effect and absence of recurrence on imaging.

Aneurysm presence at the anterior communicating artery bifurcation is associated with caliber tapering of the A1 segment.

OBJECTIVE: Vessel tapering results in blood flow acceleration at downstream bifurcations (firehose nozzle effect), induces hemodynamics predisposing to aneurysm initiation, and has been associated with middle cerebral artery (MCA) aneurysm presence and rupture status. The authors sought to determine if vessel caliber tapering is a generalizable predisposing factor by evaluating upstream A1 segment profiles in association with aneurysm presence in the anterior communicating artery (ACoA) complex, the most prevalent cerebral aneurysm location associated with a high rupture risk. METHODS: Three-dimensional rotational angiographic studies were analyzed for 68 patients with ACoA aneurysms, 37 nonaneurysmal contralaterals, and 53 healthy bilateral controls (211 samples total). A1 segments were determined to be dominant, codominant, or nondominant based on flow and size. Equidistant cross-sectional orthogonal cuts were generated along the A1 centerline, and cross-sectional area (CSA) was evaluated proximally and distally, using intensity-invariant edge detection filtering. The relative tapering of the A1 segment was evaluated as the tapering ratio (distal/proximal CSA). Computational fluid dynamics was simulated on ACoA parametric models with and without tapering. RESULTS: Aneurysms occurred predominantly on dominant (79%) and codominant (17%) A1 segments. A1 segments leading to unruptured ACoA aneurysms had significantly greater tapering compared to nonaneurysmal contralaterals (0.69 ± 0.13 vs 0.80 ± 0.17, p = 0.001) and healthy controls (0.69 ± 0.13 vs 0.83 ± 0.16, p < 0.001), regardless of dominance labeling. There was no statistically significant difference in tapering values between contralateral A1 and healthy A1 controls (0.80 ± 0.17 vs 0.83 ± 0.16, p = 0.56). Hemodynamically, A1 segment tapering induces high focal pressure, high wall shear stress, and high velocity at the ACoA bifurcation. CONCLUSIONS: Aneurysmal, but not contralateral or healthy control, A1 segments demonstrated significant progressive vascular tapering, which is associated with aneurysmogenic hemodynamic conditions at the ACoA complex. Demonstration of the upstream tapering effect in the communicating ACoA segment is consistent with its prior detection in the noncommunicating MCA bifurcation, which together form more than 50% of intracranial aneurysms. The mechanistic characterization of this upstream vascular tapering phenomenon is warranted to understand its clinical relevance and devise potential therapeutic strategies.

Spinal anesthesia in contemporary and complex lumbar spine surgery: experience with 343 cases.

OBJECTIVE: Spinal anesthesia (SA) is an alternative to general anesthesia (GA) for lumbar spine surgery, including complex instrumented fusion, although there are relatively few outcome data available. The authors discuss their experience using SA in a modern complex lumbar spine surgery practice to describe its utility and implementation. METHODS: Data from patients receiving SA for lumbar spine surgery by one surgeon from March 2017 to December 2020 were collected via a retrospective chart review. Cases were divided into nonfusion and fusion procedure categories and analyzed for demographics and baseline medical status; pre-, intra-, and postoperative events; hospital course, including Acute Pain Service (APS) consults; and follow-up visit outcome data. RESULTS: A total of 345 consecutive lumbar spine procedures were found, with 343 records complete for analysis, including 181 fusion and 162 nonfusion procedures and spinal levels from T11 through S1. The fusion group was significantly older (mean age 65.9 ± 12.4 vs 59.5 ± 15.4 years, p < 0.001) and had a significantly higher proportion of patients with American Society of Anesthesiologists (ASA) Physical Status Classification class III (p = 0.009) than the nonfusion group. There were no intraoperative conversions to GA, with infrequent need for a second dose of SA preoperatively (2.9%, 10/343) and rare preoperative conversion to GA (0.6%, 2/343) across fusion and nonfusion groups. Rates of complications during hospitalization were comparable to those seen in the literature. The APS was consulted for 2.9% (10/343) of procedures. An algorithm for the integration of SA into a lumbar spine surgery practice, from surgical and anesthetic perspectives, is also offered. CONCLUSIONS: SA is a viable, safe, and effective option for lumbar spine surgery across a wide range of age and health statuses, particularly in older patients and those who want to avoid GA. The authors' protocol, based in part on the largest set of data currently available describing complex instrumented fusion surgeries of the lumbar spine completed under SA, presents guidance and best practices to integrate SA into contemporary lumbar spine practices.

Lumbar ligamentum flavum burden: Evaluating the role of ATTRwt amyloid deposition in ligamentum flavum thickness at all lumbar levels.

BACKGROUND: Wild-type transthyretin (ATTRwt) amyloid deposition has been found in the ligamentum flavum (LF) of patients undergoing spinal stenosis surgery. Our group previously reported that ATTRwt amyloid is associated with an increased lumbar ligamentum flavum thickness at symptomatic levels that required surgery. A comprehensive evaluation of LF thickness at asymptomatic levels in addition to symptomatic, treated levels has never been performed in ATTRwt patients. In this study, we compare the total LF thickness of all lumbar levels (lumbar LF burden) in ATTRwt and non-ATTRwt patients. METHODS: We retrospectively identified 177 patients who underwent lumbar spine surgery. Ligamentum flavum thickness of 885 lumbar levels was measured on T2-weighted axial MRI. Amyloid presence was confirmed through Congo red staining of specimens, and subtype of ATTRwt was confirmed using mass-spectrometry and gene sequencing. RESULTS: Of the 177 patients, 30 (16.9%) were found to have ATTRwt in the ligamentum flavum. One hundred and fifty ATTRwt levels and 735 non-ATTRwt levels were measured by four different reviewers, with an intraclass coefficient (ICC) of 0.79. Mean ligamentum flavum thickness was 4.64 (±1.31) mm in the ATTRwt group and 3.99 (±1.45) mm in the non-ATTRwt group (p < 0.001). The lumbar LF burden (sum of ligamentum flavum thickness at all lumbar levels) for ATTRwt patients was 23.22 (±4.48) mm, and for non-ATTRwt patients was 19.96 (±5.49) mm (p = 0.003) CONCLUSION: The lumbar LF burden is greater in patients with ATTRwt amyloid compared to non-ATTRwt patients. This supports prior evidence that ATTRwt amyloid deposition might be associated with increased LF thickness and lumbar stenosis. This potential association requires more research and could be an important finding, as medications have recently become available that can treat patients with ATTRwt amyloid deposition.

Diagnosis of a chronic spinal cord injury via televisit in a patient from an underserved community.

A 42-year-old woman from a medically underserved community in rural New England was referred by her primary care provider (PCP) for televisit during the coronavirus disease 2019 (COVID-19) pandemic following 2 years of chronic neck pain and numbness in her left hand that was initially concerning for demyelinating disease. Upon further evaluation, it was revealed that she had experienced a traumatic fall with a concussion and symptoms consistent with central cord syndrome but had refused magnetic resonance imaging (MRI) at her initial medical evaluation. On MRI conducted 1 month prior to neurosurgical evaluation she was found to have a disc bulge and 4-mm T2-hyperintense lesion at the C4-C5 level that was consistent with a chronic spinal cord injury secondary to spinal trauma with associated vertebrogenic injury. This televisit confirmed the diagnosis of chronic spinal cord injury for this patient and allowed for discussion of future interventions, avoided further unnecessary referrals, and increased access to care.

Increased thickness of lumbar spine ligamentum flavum in wild-type transthyretin amyloidosis.

BACKGROUND: Wild-type transthyretin (ATTRwt) amyloid deposits have been found in the ligamentum flavum of patients undergoing surgery for spinal stenosis. The relationship between ATTRwt and ligamentum flavum thickness is unclear. We used pre-operative magnetic resonance imaging (MRI) to analyze ligamentum flavum thickness in lumbar spinal stenosis patients with and without ATTRwt amyloid. METHODS: We retrospectively identified 178 patients who underwent lumbar spine surgery. Ligamentum flavum thickness of 253 specimens was measured on T2-weighted axial MRI. Amyloid presence was confirmed through Congo red staining of specimens, and ATTRwt was confirmed using mass-spectrometry and gene sequencing. RESULTS: Twenty four of the 178 patients (13.5%) were found to have ATTRwt in the ligamentum flavum. Forty ATTRwt specimens and 213 non-ATTRwt specimens were measured. Mean ligamentum flavum thickness was 4.92 (±1.27) mm in the ATTRwt group and 4.00 (±1.21) mm in the non-ATTRwt group (p < 0.01). The ligamentum flavum was thickest at L4-L5, with a thickness of 5.15 (±1.27) mm and 4.23 (±1.29) mm in the ATTRwt and non-ATTRwt group, respectively (p = 0.007). There was a significant difference in ligamentum flavum thickness between ATTRwt and non-ATTRwt case for both patients younger than 70 years (p = 0.016) and those older than 70 years (p = 0.004). ATTRwt patients had greater ligamentum flavum thickness by 0.83 mm (95% confidence interval (CI): 0.41-1.25 mm, p < 0.001) when controlled for age and lumbar level. CONCLUSION: Patients with ATTRwt had thicker ligamentum flavum compared to patients without ATTRwt. Further studies are needed to investigate the pathophysiology of ATTRwt in ligamentum flavum thickening.

Clinical and histopathological principles for the diagnosis of a recurrent paraganglioma of the jugular foramen initially diagnosed as a middle ear adenoma: illustrative case.

BACKGROUND: Paragangliomas (PGLs) are rare neoplasms that may be associated with hereditary PGL syndromes and variable risk of metastasis. Middle ear adenomas are extremely rare tumors with no known hereditary predisposition and extremely low risk of metastasis. Although often easily differentiated, they may share clinical and pathological features that misdirect and confuse the diagnosis. OBSERVATIONS: The authors discussed a 35-year-old woman with left-sided hearing loss and bleeding from the external ear canal who presented to an outside hospital. She underwent resection of a middle ear and mastoid mass, initially diagnosed as a middle ear adenoma with neuroendocrine features, with later mastoidectomy and ligation of the sigmoid sinus with microsurgical excision of persistent tumor in the jugular foramen and temporal bone. Histopathologically, her tumor was vascular, composed of benign-appearing epithelioid cells with "salt and pepper" neuroendocrine chromatin arranged in vague nests. Lesional cells were GATA3-immunopositive, glucagon-negative, and succinate dehydrogenase-immunonegative, consistent with PGL rather than middle ear adenoma, and required further workup for hereditary PGL syndromes. LESSONS: This case demonstrates potential challenges in differentiating a PGL from a middle ear adenoma. The authors offer clinical, histopathological, and imaging principles to aid in diagnosis and workup.

Increased focal internal carotid artery angulation in patients with posterior communicating artery aneurysms.

BACKGROUND: Aneurysms at the posterior communicating artery (PCOM) origin represent the most common location on the internal carotid artery (ICA), and are associated with greater recurrence following endovascular treatment. We evaluate the association between ICA angulation in three-dimensional (3D) space and PCOM aneurysmal development, using high-resolution 3D rotational angiography (3DRA) studies. METHODS: 3DRA datasets were evaluated in 70 patients with PCOM aneurysms, 31 non-aneurysmal contralateral, and 86 healthy controls (187 total). The local angle formed by upstream and downstream ICA segments at the PCOM origin, αICA@PCOM, was measured using 3DRA multiplanar reconstruction. Computational fluid dynamics (CFD) analysis was performed on parametric and patient-based models. RESULTS: αICA@PCOM was significantly larger in aneurysm-bearing ICA segments (68.14±11.91°) compared with non-aneurysmal contralateral (57.17±10.76°, p<0.001) and healthy controls (48.13±13.68°, p<0.001). A discriminant threshold αICA@PCOM value of 61° (87% specificity, 80% sensitivity) was established (area under the curve (AUC)=0.88). Ruptured PCOM aneurysms had a significantly larger αICA@PCOM compared to unruptured (72.65±15.16° vs 66.35±9.94°, p=0.04). In parametric and patient-based CFD analysis, a large αICA@PCOM induces high focal pressure at the PCOM origin, relatively low wall shear stress (WSS), and high proximal WSS spatial gradients (WSSG). CONCLUSION: ICA angulation at PCOM origin is significantly higher in vessels harboring PCOM aneurysms compared with contralateral and healthy ICAs. This sharper bend in the ICA leads to high focal pressure at the aneurysm neck, low focal WSS and high proximal WSSG. These findings underline the importance of morphological ICA variations and the likelihood of PCOM aneurysm, an association which can inform clinical decisions and may serve in predictive analytics.

The use of decompressive segmental sublaminoplasty to treat myelopathy caused by lumbar stenosis in tethered cord syndrome.

A 79-year-old woman presented with acute-onset right leg pain in the setting of 3 months of progressive gait deterioration and bilateral leg weakness. On exam she had right lower extremity hyperreflexia and weakness. Lumbar spine magnetic resonance imaging demonstrated L3-L5 central canal stenosis with L4-L5 spondylolisthesis and a previously undiagnosed tethered cord. She underwent minimally invasive left segmental sublaminoplasty at L3-L4 and L4-L5 for spinal cord decompression with onlay arthrodesis resulting in resolution of her radicular pain and improved strength. This is a unique case of lumbar spinal stenosis presenting with myelopathy in the context of a previously asymptomatic and undiagnosed tethered cord.