Clinicopathologic characteristics of Nocardia brain abscesses: Necrotic and non-necrotic foci of various stages.

Nocardia brain abscesses are rare bacterial infections associated with a high mortality rate, and their preoperative diagnosis can be difficult for various reasons including a nonspecific clinical presentation. While late-stage nocardial brain abscesses may be radiologically characteristic, early-stage lesions are nonspecific and indistinguishable from another inflammatory/infectious process and other mimics. Despite the paucity of previous histopathological descriptions, histopathological examination is critical for the identification of the pathogen, lesion stage(s), and possible coexisting pathology. In this study, we examined the clinical, radiological and histopathological features of 10 patients with brain nocardiosis. Microscopic findings were analysed in correlation with clinical and radiological features in 9 patients, which revealed that brain nocardiosis was characterized by numerous necrotic and non-necrotic foci of various stages (I-IV) along with Nocardia identification, as well as the leptomeningeal involvement in most cases, and co-infection of brain nocardiosis with toxoplasmosis in 2 patients. The imaging features were characteristic with a multilobulated/bilobed ring-enhancing appearance in 8 patients including 2 patients with multiple lobulated and non-lobulated lesions and 1 patient showing the progression from a non-lobulated to lobulated lesion. These findings suggest that nocardial brain abscesses particularly at late-stages share common characteristics. Nevertheless, given the complex pathologic features, including possible co-infection by other pathogens, nocardial brain abscesses remain a therapeutic challenge.

Early-onset juvenile nasopharyngeal angiofibroma (JNA): a systematic review.

BACKGROUND: Juvenile Nasopharyngeal Angiofibroma (JNA) is a fibrovascular tumor of the nasopharynx that classically presents in adolescent males. The reported mean age of onset is between 13 and 22 years old [1-6]. Significant androgen stimulation is hypothesized to explain the strong predisposition for JNA to present in young adolescent males. However, considerable variability in age at diagnosis exists with rare involvement of very young patients incongruent with typical male pubertal growth patterns. OBJECTIVE: The purpose of this systematic review is to identify cases of early-onset JNA (EOJNA), (defined as age < 10 years) in the literature and to examine the disease characteristics and treatments used in this patient group. A case of a 7 year old boy with EOJNA at our institution is also described and presented. METHODS: We searched Embase, Cochrane database and MEDLINE from 1996 to February 2021 for studies that reported cases of EOJNA. Relevant clinico-demographic data, disease severity and treatment outcomes were recorded and analyzed using descriptive statistics. We compared our findings with reported means for JNA in all ages. RESULTS: We identified 29 studies containing a total of 34 cases of EOJNA. The vast majority (31/34) of patients were males and the mean age of diagnosis was 8.15 years old. The most common presenting symptoms were nasal obstruction (65.2%) and epistaxis (60.9%). Patients were most commonly Radkowski stage II (39.4%) and III (39.4%). Primary treatment modalities included open surgery (66.7%), endoscopic surgery (24.2%), and radiotherapy (9.1%). Recurrence was evident in 30%. Radkowski stage and type of treatment did not differ significantly within the EOJNA group (p = 0.440 and p = 0.659, respectively). CONCLUSION: This systematic review suggests that rare cases of EOJNA have distinct disease characteristics. Patients in this cohort appeared to have more advanced disease and higher recurrence rates when compared with reported averages. We hope that this review prompts increased clinical awareness of this potentially more aggressive subtype of JNA. As more cases of EOJNA are reported, a more powered statistical analysis of this cohort would be feasible.

Risk Factors Related to Transient Diabetes Insipidus Development Following Transsphenoidal Pituitary Adenoma Resection: A Multicentric Study.

OBJECTIVE: To analyze and find risk factors associated with developing transient diabetes insipidus (DI) using a multicenter case series after trans-sphenoidal surgery. METHODS: Medical records of patients who underwent trans-sphenoidal surgery for pituitary adenoma resection between 2010 and 2021 at 3 different neurosurgical centers by 4 experienced neurosurgeons were retrospectively analyzed. The patients were divided into 2 groups (DI group or control group). Logistic regression analysis was conducted to identify risk factors associated with postoperative DI. Univariate logistic regression was performed to identify variables of interest. Covariates with a P value <0.05 were incorporated into multivariate logistic regression models to identify independently associated risk factors for DI. All statistical tests were conducted using RStudio. RESULTS: A total of 344 patients were included; 68% were women, the mean age was 46.5 years, and nonfunctioning adenomas were the most frequent (171, 49.7%). The mean tumor size was 20.3 mm. Covariates associated with postoperative DI were age, female gender, and gross total resection. The multivariable model showed that age (odds ratio [OR] 0.97, CI 0.95-0.99, P = 0.017) and female gender (OR 2.92, CI 1.50-6.03, P = 0.002) remained significant predictors of DI development. Gross total resection was no longer a significant predictor of DI in the multivariable model (OR 1.86, CI 0.99-3.71, P = 0.063), suggesting that this variable may be confounded by other factors. CONCLUSIONS: The independent risk factors for the development of transient DI were female and young patients.

Diagnosis and management of intraparenchymal rhabdomyosarcoma.

BACKGROUND: Intracranial rhabdomyosarcomas represent a rare condition, posing a diagnostic challenge to physicians. Brain intraparenchymal rhabdomyosarcomas are exceptionally rare with poorly understood pathogenesis. METHODS: Here we report the first adult case of intraparenchymal rhabdomyosarcoma (RMS) with brainstem and cranial nerve involvement. We conducted a literature search using Embase, MEDLINE, and PubMed for published cases of patients with rhabdomyosarcoma of the brain. The keywords used were 'rhabdomyosarcoma' combined with 'intraparenchymal', 'parenchymal', 'cerebral' or 'brain' for title/abstract. Included cases were adult patients (>18 years of age). RESULTS: A 59-year-old man presents with multiple cranial nerve palsies. MRI revealed a solitary pontine lesion that was not responsive to steroids. No systemic lesions were identified with an extensive imaging workup. A wide range of serum and cerebrospinal fluid tests were non-diagnostic during a ten-month workup until, ultimately, the patient died as a result of aspiration pneumonia. At autopsy, pathological examination on whole-brain autopsy revealed RMS, centred in the left side of pons with extension to the left side of the midbrain and the right side of pons with multiple cranial nerve involvement. There are only 20 adult cases of primary intraparenchymal RMS reported in the literature. Our present case is the first reported adult RMS in this location, with novel molecular information, providing some insight into the pathogenesis of this rare diagnosis. CONCLUSIONS: Intraparenchymal rhabdomyosarcoma without evidence of systemic primary disease is extremely rare, resulting in delayed diagnosis in some cases, particularly those not amenable to biopsy. The diagnostic challenge posed by this complementary case highlights the importance of maintaining a differential of neoplasm in the face of non-diagnostic investigations to the contrary.

Incidental multifocal calcifying pseudoneoplasm of the neuraxis: case report and literature review.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is thought to be a rare tumefactive lesion with unknown pathogenesis. Its prevalence is questionable with few previously reported cases of incidental CAPNON, and likely underdiagnosis. We report a unique case of incidental multifocal CAPNON. A 64-year-old female was admitted with loss of consciousness due to a ruptured right middle cerebral artery aneurysm with subarachnoid and intraventricular hemorrhage. She has a craniotomy and clipping. At time of operation, numerous small dural-based nodules were found, and one was excised for biopsy and was diagnosed as CAPNON. Retrospective review of her CT images identified nodules that were all ipsilateral to the ruptured aneurysm. A literature review revealed that incidental and/or multifocal CAPNONs are rare but likely underreported. Our case suggests a reactive process in the pathogenesis of CAPNON.

A Canadian National Survey of the Neurosurgical Management of Intracranial Abscesses.

OBJECTIVE: Intracerebral abscess is a life-threatening condition for which there are no current, widely accepted neurosurgical management guidelines. The purpose of this study was to investigate Canadian practice patterns for the medical and surgical management of primary, recurrent, and multiple intracerebral abscesses. METHODS: A self-administered, cross-sectional, electronic survey was distributed to active staff and resident members of the Canadian Neurosurgical Society and Canadian Neurosurgery Research Collaborative. Responses between subgroups were analyzed using the Chi-square test. RESULTS: In total, 101 respondents (57.7%) completed the survey. The majority (60.0%) were staff neurosurgeons working in an academic, adult care setting (80%). We identified a consensus that abscesses >2.5 cm in diameter should be considered for surgical intervention. The majority of respondents were in favor of excising an intracerebral abscess over performing aspiration if located superficially in non-eloquent cortex (60.4%), located in the posterior fossa (65.4%), or causing mass effect leading to herniation (75.3%). The majority of respondents were in favor of reoperation for recurrent abscesses if measuring greater than 2.5 cm, associated with progressive neurological deterioration, the index operation was an aspiration and did not include resection of the abscess capsule, and if the recurrence occurred despite prior surgery combined with maximal antibiotic therapy. There was no consensus on the use of topical intraoperative antibiotics. CONCLUSION: This survey demonstrated heterogeneity in the medical and surgical management of primary, recurrent, and multiple brain abscesses among Canadian neurosurgery attending staff and residents.

Randomized controlled trials in neurosurgery.

Randomized controlled trials (RCTs) have become the standard method of evaluating new interventions (whether medical or surgical), and the best evidence used to inform the development of new practice guidelines. When we review the history of medical versus surgical trials, surgical RCTs usually face more challenges and difficulties when conducted. These challenges can be in blinding, recruiting, funding, and even in certain ethical issues. Moreover, to add to the complexity, the field of neurosurgery has its own unique challenges when it comes to conducting an RCT. This paper aims to provide a comprehensive review of the history of neurosurgical RCTs, focusing on some of the most critical challenges and obstacles that face investigators. The main domains this review will address are: (1) Trial design: equipoise, blinding, sham surgery, expertise-based trials, reporting of outcomes, and pilot trials, (2) trial implementation: funding, recruitment, and retention, and (3) trial analysis: intention-to-treat versus as-treated and learning curve effect.

Reoperation in adult patients with recurrent glioblastoma: A matched cohort analysis.

Background: Despite maximal safe cytoreductive surgery and postoperative adjuvant therapies, glioblastoma (GBM) inevitably recurs and leads to deterioration of neurological status and eventual death. There is no consensus regarding the benefit of repeat resection for enhancing survival or quality of life in patients with recurrent GBM. We aimed to examine if reoperation for GBM recurrence incurs a survival benefit as well as examine its complication profile. Methods: We performed a single-center retrospective chart review on all adult patients who underwent resection of supratentorial GBM between January 1, 2008 and December 1, 2013 at our center. Patients with repeat resection were manually matched for age, sex, tumor location, and Karnofsky Performance Status (KPS) with patients who underwent single resection to compare overall survival (OS), and postoperative morbidity. Results: Of 237 patients operated with GBM, 204 underwent single resection and 33 were selected for repeat surgical resections. In a matched analysis there was no difference in the OS between groups (17.8 ± 17.6 months vs 17 ± 13.5 months, P = .221). In addition, repeat surgical resection had a higher rate of postoperative neurological complications compared to the initial surgery. Conclusions: When compared with matched patients who underwent a single surgical resection, patients undergoing repeat surgical resection did not show significant increase in OS and may have incurred more neurological complications related to the repeat resection. Further studies are required to assess which patients would benefit from repeat surgical resection and optimize timing of the repeat resection in selected patients.

Retrospective Review of the Clinical Outcomes of Surgically Managed Patients with Intracranial Abscesses: A Single-Center Review.

OBJECTIVE: This study analyzed patient, radiologic, and clinical factors associated with operative brain abscesses and patients' functional outcomes. METHODS: A retrospective analysis was conducted of neurosurgical cases of brain abscesses from 2009 to 2019 at a Canadian center. Functional outcome was recorded as Modified Rankin Scale score and Extended Glasgow Outcome Scale score. Multivariate analysis was conducted to identify relevant prognostic factors. RESULTS: We identified 139 patients managed surgically for brain abscesses. Resection alone was performed in 64% of patients, whereas 26.6% underwent aspiration alone. Most were adults (93.2%) and male (68.3%). Immunocompromise risk factors included diabetes (24.5%), cancer (23.7%), and immunosuppressive therapy (11.5%). Likely sources were postoperative (17.3%), systemic spread (16.5%), and poor dentition (12.9%). Microorganisms cultured from abscess samples were mixed growth (28%), Streptococcus anginosus (24.5%), and Staphylococcus aureus (7.9%). Disposition was home (42.4%) or repatriation to a home hospital (50.4%). By Extended Glasgow Outcome Scale, 25.2% had an unfavorable outcome including a mortality of 11.5%. Factors on multivariate analysis associated with poor outcome included diabetes (odds ratio, 2.8; 95% confidence interval [CI], 1.2-5.0) and ventricular rupture (odds ratio, 5.0; 95% CI, 1.7-13.5; hazard ratio, 12; 95% CI, 3.9-37.0). Supratentorial superficial eloquently located abscess was also associated with poor outcome (hazard ratio, 5.5; 95% CI, 1.8-16.7). Outcomes were similar with surgical excision and aspiration. CONCLUSIONS: Ventricular rupture and diabetes are significant risk factors for poor outcomes in intraparenchymal brain abscesses. No clear difference in outcomes was found between surgical excision or aspiration in our retrospective cohort.

Craniocerebral gunshot injury bullet migration to the cardiac right ventricle.

BACKGROUND: Missile embolism is the process of slow velocity projectiles penetrating into vascular spaces followed by arterial, venous, or paradoxical embolism of the fragments. This is a rare complication in craniocerebral gunshot injuries (CGI), with only five other cases previously published demonstrating pulmonary or arterial emboli from these injuries. There is a high rate of mortality from these injuries. CASE DESCRIPTION: A patient presented with a CGI from an occipital trajectory, causing penetrating fragments into the venous sinus system. The weapon was a Glock Model 17M 9 mm with a hollow-point bullet, fired close range. Initial chest X-ray demonstrated only atelectasis. After stabilization, 18 min from the initial chest X-ray, subsequent computed tomography (CT) imaging demonstrated extensive intracranial injuries and fragmentation of the bullet with the expected devastating intracranial injuries. Unexpectedly, chest CT revealed metallic fragments in the right cardiac ventricle which was redemonstrated on follow-up chest X-ray. Unfortunately, his extensive intracranial injuries and poor clinical status were nonsurvivable, and thus the family elected to discontinue supportive measures. CONCLUSION: This case demonstrates radiographic imaging of a metallic intravascular fragment from CGI through presumed transvenous mechanisms. The imaging provides a consistent timeline demonstrating migration can occur in the acute phase. This study additionally supports the presumed mechanism for pulmonary of migration through the right heart. Fragment embolization should be considered in cases of acute deterioration in this patient population.

Safety of Early Mobilization in Patients With Intraoperative Cerebrospinal Fluid Leak in Minimally Invasive Spine Surgery: A Case Series.

BACKGROUND: Cerebrospinal fluid (CSF) leak is a common complication in spine surgery. Repairing durotomy is more difficult in the setting of minimally invasive spine surgery (MISS). Efficacy of postoperative bed rest in case of dural tear in MISS is not clear. OBJECTIVE: To assess the safety and efficacy of our protocol of dura closure without changing access, early mobilization, and discharge in cases of intraoperative CSF leak in MISS. METHODS: A retrospective review from 2006 to 2018 of patients who underwent MISS for degenerative and neoplastic diseases with documented accidental or intentional durotomy was conducted. The primary outcome of interest was readmission rate for repair of persistent CSF leak. Secondary outcomes captured included development of pseudomeningocele, positional headache, and subdural hematoma. RESULTS: A total of 80 patients were identified out of 527 patients. Of these, intentional durotomy was performed in 28 patients and unintentional durotomy occurred in 52 patients. Mean follow-up period was 80.6 mo. Most of the patients were discharged on postoperative day 0 (within 4 h of surgery) without activity restrictions. A total of 2 (2.5%) patients required readmission and dural repair for continuous CSF leak and 3 patients (3.75%) developed pseudomeningocele. No lumbar drain insertion, meningitis, or subdural hematoma was reported. CONCLUSION: Early mobilization and discharge in cases of intraoperative CSF leak in MISS appear to be safe and not associated with higher rate of complications than that of reported literature.

Calcifying Pseudoneoplasm of the Neuraxis: From Pathogenesis to Diagnostic and Therapeutic Considerations.

Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumefactive lesion that can develop anywhere within the neuraxis. The incidence is likely underreported, given its nonspecific imaging features and because CAPNON has often been overwhelmed by the presence of comorbid disease. CAPNON is typically diagnosed by the histopathological examination findings. However, the histopathological diagnosis is often challenging owing to the existence of similar calcifying pathological entities. Although the pathogenesis of CAPNON has remained elusive, emerging evidence supports a reactive proliferative and immune-mediated process involving the aggregation of neurofilament light chain protein and the infiltration of immune cells. The management of CAPNON is largely dependent on the symptoms, which are mainly related to the location and associated mass effects. Maximal surgical resection will result in excellent patient outcomes with rare recurrence, especially in patients presenting with epilepsy. The discovery of neurofilament light chain protein within CAPNON suggests that neurofilament might be implicated in the pathogenesis of CAPNON, serve as an immunohistochemical marker to improve the diagnostic accuracy of CAPNON, and hold therapeutic potential for the treatment of CAPNON.

Immunohistochemical Markers in the Diagnosis of Calcifying Pseudoneoplasm of the Neuraxis.

BACKGROUND: Calcifying pseudoneoplasm of the neuraxis (CAPNON) is a rare tumor-like lesion with unknown pathogenesis. It is likely under-reported due to diagnostic challenges including the nonspecific radiographic features, lack of diagnostic markers, and often asymptomatic nature of the lesions. METHODS: We performed detailed examination of 11 CAPNON specimens diagnosed by histopathology, with the help of electron microscopy and immunohistochemistry. RESULTS: Electron microscopy revealed the presence of fibrillary materials consistent with neurofilaments. In addition to some entrapped axons at the periphery of CAPNONs, we discovered that all specimens stained positive for neurofilament-light (NF-L) within the granular amorphous cores, but not neurofilament-phosphorylated (NF-p). CAPNONs also showed variable infiltration of CD8+ T-cells and a decreased ratio of CD4/CD8+ T-cells, suggesting an immune-mediated process in the pathogenesis of CAPNON. CONCLUSION: NF-L and CD4/CD8 immunostains may serve as diagnostic markers for CAPNON and shed light on its pathogenesis.

Mini-Tubular Access Surgery: A Single Surgeon's 12 Years in the Corridors of the Neuroaxis.

BACKGROUND: Tubular approach surgery now includes complex spinal and cranial procedures. Aided by modified instrumentation and frameless stereotaxy, minimal access surgery is being offered for a growing array of neurosurgical conditions. METHODS: This article explores the flexibility and adaptability of the tubular retractor system for multiple indications by highlighting the 12-year experience of the primary surgeon using a tubular retractor system reported for the entire neuroaxis including intracranial, foramen magnum, and the craniocaudal extent of the spine for intra- and extradural pathologies. For this article we have not analyzed our experience with degenerative spinal disease. Patient characteristics, pathology, resection results, length of hospital stay, and complications are discussed. RESULTS: From August 2005 through March 2017, 538 patients underwent neurosurgical procedures with mini-tubular access. Of these, the 127 patients who underwent mini-tubular access operations for nontraditional indications are discussed here. There were 65 women and 61 men with an average age of 53.5 years. The cases by anatomical location are as follows: 27 cranial cases, 11 foramen magnum decompressions, and 89 for spinal indications. The cranial pathologies included primary and metastatic tumors. The spinal pathologies included intra- and extradural spinal tumors, spina bifida occulta, syringomyelia, and other cystic lesions in the spine. In the vast majority of the patients where gross total resection was the goal, it was achieved. The mean length of stay was 2.94 days. CONCLUSIONS: This report demonstrates that mini-tubular access surgery can be adapted to pathologies in the entire neuroaxis with outcomes that are comparable with open techniques. Limited tissue dissection, smaller incisions, and limited bone resection make the mini-tubular access approach a desirable option when feasible. Greater experience with all of these techniques is needed before the definitive status of these procedures in the neurosurgical armamentarium can be demonstrated.

Genetics of Colloid Cyst in Monozygotic Twins: Case Report and Review of Literature.

BACKGROUND: Colloid cysts are rare developmental lesions, accounting for approximately 1% of intracranial tumors. Often, these benign lesions are asymptomatic, but they are associated with significant mortality as a result of acute hydrocephalus. This mortality in patients with vague or no symptoms dictates a need for better understanding of the etiology of colloid cysts to expedite diagnosis and management. We present a case of monozygotic twins with colloid cysts to propose a genetic etiology for colloid cyst. CASE DESCRIPTION: Previously healthy male monozygotic twins presented 4 years apart with headache secondary to hydrocephalus as a result of colloid cysts. Both patients underwent multiple surgeries and were doing well at last follow-up. CONCLUSIONS: The present case adds to a body of literature of familial colloid cysts, suggesting higher concordance in monozygotic compared with dizygotic twins. This may be due to high genetic load, shared intrauterine environment, epigenetic changes, or genetic mutation. This literature review suggests that given high morbidity and mortality of colloid cysts, screening may be beneficial. Even in the absence of a single, definitive genetic etiology, we recommend consideration of genetic screening or, at a minimum, screening with neuroimaging for monozygotic twins in cases where 1 twin is diagnosed with colloid cyst.

Modern Brain Retractors and Surgical Brain Injury: A Review.

Surgical brain injury caused by brain retraction is a well-known consequence of intracranial surgery. Modern retractor designs, particularly since the 1980s, have significantly improved ease of use, improved visibility for surgeons, and minimized retraction-induced injuries, though not yet been entirely eliminated. Today, brain retractors come in a broad range of styles, each with its own pros and cons regarding operational utility and patient safety. Which type is chosen for use depends on the surgical approach, lesion size and depth, cost, and surgeon preference. Traditionally, self-retaining brain retractors with moveable arms and 1 or more attachable blades made from malleable stainless steel or silicone rubber have been the tool of choice; however, recently tubular retraction systems that only require fixation to the head frame and cause less focal pressure damage than older retractors have gained in popularity for some cases. This review aims to address the history of brain retraction and discuss each of the commonly used brain retractor types, as well as some newer and less common varieties especially in terms of the extent of tissue damage typically caused as well as the types of injuries reported by the users.

Visual Outcomes After Endoscopic Endonasal Resection of Orbital Lesions.

BACKGROUND: The endoscopic endonasal approach (EEA) has been increasing in popularity as an alternative to traditional transcranial and transorbital approaches in the treatment of orbital pathological entities. The purpose of the present study was to examine the outcomes of patients who had undergone EEA resection of orbital lesions at our center. METHODS: We performed a retrospective medical record review of patients who had undergone the EEA for resection of orbital lesions and orbital apex decompression from January 1, 2006 to December 1, 2019. For all the patients, the demographic data, presenting symptoms, symptom duration, imaging data, operative details, and postoperative outcomes were collected and reviewed. RESULTS: Nine patients underwent endoscopic endonasal resection of orbital lesions and orbital apex decompression at our center, including 6 male patients and 3 female patients. The mean age was 49.4 years, and the mean follow-up period was 3.8 years (range, 1-13.5 years). The orbital pathological lesions that were treated included nasopharyngeal carcinoma, hemangioma, fibrous dysplasia, IgG4 pseudotumor, inverted papilloma, angioleiomyoma, adenocarcinoma, and neuroendocrine paraganglioma metastasis. All the patients presented with exophthalmos of the affected orbit. Of the 9 patients, 5 presented with decreased visual acuity on examination. Postoperatively, 1 of these 5 patients had improved to baseline visual acuity, 3 had stable vision, and 1 had brief improvement before experiencing progressive visual decline 1 month postoperatively. Two patients presented with diplopia, and both improved postoperatively. Three patients experienced new, transient, and self-limiting postoperative diplopia. CONCLUSIONS: For patients with orbital lesions causing compressive optic neuropathy, the endoscopic endonasal approach can be used as an alternative strategy in appropriately selected patients.