Vascular complications of fungal meningitis attributed to injections of contaminated methylprednisolone acetate

Cerebrovascular Complications Associated With Iatrogenic Fungal Meningitis Following Surgical Procedures in Mexico

BACKGROUND

The current fungal meningitis outbreak caused by contaminated epidural anesthesia with Fusarium solani among patients who underwent surgical procedures in Matamoros, Mexico remains a cause of concern. Its association with an increased susceptibility for cerebrovascular complications (CVC) has not been reported. This single-center study describes 3 patients with a unique pattern of CVC attributed to fungal meningitis.

METHODS

A retrospective case series of patients diagnosed with fungal meningitis following surgical procedures under contaminated epidural anesthesia who developed a unique pattern of CVC during their hospitalization.

RESULTS

Three female patients (mean age, 35 years) with CVC due to iatrogenic fungal meningitis were included. Positive Fungitell β-D-glucan assay in cerebrospinal fluid was documented in all cases, and F. solani was confirmed by polymerase chain reaction in case 3. All cases were complicated by severe vertebrobasilar circulation vasculopathy and arterial dissections with resultant subarachnoid hemorrhage and intraventricular hemorrhage, ultimately leading to patients' death.

CONCLUSIONS

The death toll from the ongoing fungal meningitis outbreak keeps rising, underscoring the need for early recognition and aggressive treatment. We highlight the risk for vertebrobasilar circulation CVC among these patients. The angioinvasive nature of F. solani is yet to be clarified; however, a clear pattern has been observed. Public health awareness should be raised and a strong response should be pursued.

Management and long-term comorbidities of patients with necrotizing otitis externa

PURPOSE

We aimed to present the management of the patients with necrotizing otitis externa (NOE) and its comorbidities in early and long-term follow-up.

METHODS

Between 2011 and 2022, 30 patients with the diagnose of NEO, who had cortical bone erosion or trabecular demineralization in temporal bone computed tomography and administered at least 6-week antimicrobial therapy were included in the study. Clinical, laboratory and imaging findings of patients, and comorbidities during follow-up were analysed. NOE extending further from the petro-occipital fissure on magnetic resonance imaging was accepted as medial skull base (MSB) involvement.

RESULTS

30 patients, (8 women, 22 men, mean age 66.2 ± 1.7), with NOE were followed 36.4 ± 29.6 months. The mortality rate was 23.33% and the mean survival time was 12.37 ± 11.35 months. Repeated cultures reveal a new or second pathogen in 5 patients (20%). Severe and profound sensorineural hearing loss (SNHL) were observed in 4 and 12 patients, respectively. Labyrinthitis ossificans emerged in 3 of 6 surviving patients with profound SNHL during follow-up. Chronic disease anemia (CDA) (66.66%), cerebrovascular disease (CVD) (43.33%), chronic renal failure (CRF) (30%), and retinopathy (26.66%) were the most frequent comorbidities in patients with NOE. Cranial nerve paralysis (CNP) (P < 0.001), SNHL (P < 0.04), CDA (P < 0.005), and mortality (P < 0.022) were significantly associated with the presence of MSB involvement.

CONCLUSIONS

NOE is a disease that requires long-term follow-up, causes severe morbidity, and has a high mortality rate. MSB involvement is associated with CNP, SNHL and labyrinthitis ossificans. Moreover, CDA, CVD, CRF and retinopathy are the most common comorbitidies needed to be managed.

Blood vessel occlusion by Cryptococcus neoformans is a mechanism for haemorrhagic dissemination of infection

Meningitis caused by infectious pathogens is associated with vessel damage and infarct formation, however the physiological cause is often unknown. Cryptococcus neoformans is a human fungal pathogen and causative agent of cryptococcal meningitis, where vascular events are observed in up to 30% of patients, predominantly in severe infection. Therefore, we aimed to investigate how infection may lead to vessel damage and associated pathogen dissemination using a zebrafish model that permitted noninvasive in vivo imaging. We find that cryptococcal cells become trapped within the vasculature (dependent on their size) and proliferate there resulting in vasodilation. Localised cryptococcal growth, originating from a small number of cryptococcal cells in the vasculature was associated with sites of dissemination and simultaneously with loss of blood vessel integrity. Using a cell-cell junction tension reporter we identified dissemination from intact blood vessels and where vessel rupture occurred. Finally, we manipulated blood vessel tension via cell junctions and found increased tension resulted in increased dissemination. Our data suggest that global vascular vasodilation occurs following infection, resulting in increased vessel tension which subsequently increases dissemination events, representing a positive feedback loop. Thus, we identify a mechanism for blood vessel damage during cryptococcal infection that may represent a cause of vascular damage and cortical infarction during cryptococcal meningitis.

Meningitis is a life threatening form of infection in the brain that is difficult to treat. How infection spreads from the blood to cause meningitis is not well understood. Here we have shown how infection with the fungus Cryptococcus neoformans can be spread from the blood by blocking and bursting blood vessels. Using zebrafish larvae, we were able to follow the same infections over a period of days to understand how this infection behaves in blood vessels. We found that fungal cells become stuck within blood vessels depending on their size. These cells grow within blood vessels, resulting in the blood vessels becoming wider. We measured increased tension in blood vessels suggesting that, with the bloackage and widening of vessels, there was increased local blood pressure. We found that vessel blockage was associated with their rupture and spreading of fungus into the surround tissue. Finally, by increasing the tension in vessels we could increase the number of blood bursting events supporting our conclusion that blood vessel blockage leads to the spread of the infection outside of blood vessels.

The Regulation of Cerebral Spinal Fluid Flow and Its Relevance to the Glymphatic System

PURPOSE OF REVIEW

The glymphatic system is a relatively new concept that has been associated with regulation of cerebrospinal fluid (CSF), as well as brain waste clearance. Novel techniques to study glymphatic dysfunction have in turn prompted a reassessment of brain physiology and underlying elements of neurological disease. This review incorporates a contemporary imaging perspective focused on understanding the regulation of CSF flow, thus expanding the putative clinical relevance of this system and the relationships between CSF flow and glymphatic function.

RECENT FINDINGS

MR imaging studies, especially those that employ intrathecal gadolinium contrast, have identified potentially new pathways regulating CSF production, absorption, and clearance. These studies, when viewed in the context of more historical anatomic descriptors of CSF production and absorption, provide a more robust description of CSF physiology and waste clearance. CSF production and resorption are under-investigated and could be related to various pathophysiologic processes in neurodegeneration. Anatomically based clinical exemplars of CSF clearance are discussed. Future studies should focus on linking glymphatic functionality with neurological disease.

True mycotic aneurysm in a patient with gonadotropinoma after trans-sphenoidal surgery

Background:

Immunosuppressive therapy, prolonged antibiotic use, and intrathecal injections are known risk factors for the development of invasive aspergillosis. Central nervous system (CNS) aspergillosis can manifest in many forms, including mycotic aneurysm formation. The majority of the mycotic aneurysms presents with subarachnoid hemorrhage after rupture and are associated with high mortality. Only 3 cases of true mycotic aneurysms have been reported following trans-sphenoidal surgery.

Case Description:

A 38-year-old man was admitted with nonfunctioning pituitary adenoma for which he underwent trans-sphenoidal surgery. Three weeks later, he presented with cerebrospinal fluid (CSF) rhinorrhea and meningitis. He was treated with intrathecal and intravenous antibiotics, stress dose of glucocorticoids, and lumbar drain. The defect in the sphenoid bone was closed endoscopically. After 3 weeks of therapy, he suddenly became unresponsive, and computed tomography of the head showed subarachnoid hemorrhage. He succumbed to illness on the next day, and a limited autopsy of the brain was performed. The autopsy revealed extensive subarachnoid hemorrhage and aneurysmal dilatation, thrombosis of the basilar artery (BA), multiple hemorrhagic infarcts in the midbrain, and pons. Histopathology of the BA revealed the loss of internal elastic lamina and septate hyphae with an acute angle branching on Grocott's methenamine silver stain, conforming to the morphology of Aspergillus.

Conclusion:

The possibility of intracranial fungal infection should be strongly considered in any patient receiving intrathecal antibiotics who fails to improve in 1–2 weeks, and frequent CSF culture for fungi should be performed to confirm the diagnosis. Since CSF culture has poor sensitivity in the diagnosis of fungal infections of CNS; empirical institution of antifungal therapy may be considered in this scenario.

Analysis of a food-borne fungal pathogen outbreak: virulence and genome of a Mucor circinelloides isolate from yogurt

Food-borne pathogens are ongoing problems, and new pathogens are emerging. The impact of fungi, however, is largely underestimated. Recently, commercial yogurts contaminated with Mucor circinelloides were sold, and >200 consumers became ill with nausea, vomiting, and diarrhea. Mucoralean fungi cause the fatal fungal infection mucormycosis, whose incidence has been continuously increasing. In this study, we isolated an M. circinelloides strain from a yogurt container, and multilocus sequence typing identified the strain as Mucor circinelloides f. circinelloides. M. circinelloides f. circinelloides is the most virulent M. circinelloides subspecies and is commonly associated with human infections, whereas M. circinelloides f. lusitanicus and M. circinelloides f. griseocyanus are less common causes of infection. Whole-genome analysis of the yogurt isolate confirmed it as being close to the M. circinelloides f. circinelloides subgroup, with a higher percentage of divergence with the M. circinelloides f. lusitanicus subgroup. In mating assays, the yogurt isolate formed sexual zygospores with the (−) M. circinelloides f. circinelloides tester strain, which is congruent with its sex locus encoding SexP, the (+) mating type sex determinant. The yogurt isolate was virulent in murine and wax moth larva host systems. In a murine gastromucormycosis model, Mucor was recovered from fecal samples of infected mice for up to 10 days, indicating that Mucor can survive transit through the GI tract. In interactions with human immune cells, M. circinelloides f. lusitanicus induced proinflammatory cytokines but M. circinelloides f. circinelloides did not, which may explain the different levels of virulence in mammalian hosts. This study demonstrates that M. circinelloides can spoil food products and cause gastrointestinal illness in consumers and may pose a particular risk to immunocompromised patients.

The U.S. FDA reported that yogurt products were contaminated with M. circinelloides, a mucoralean fungal pathogen, and >200 consumers complained of symptoms, including vomiting, nausea, and diarrhea. The manufacturer voluntarily withdrew the affected yogurt products from the market. Compared to other food-borne pathogens, including bacteria, viruses, and parasites, less focus has been placed on the risk of fungal pathogens. This study evaluates the potential risk from the food-borne fungal pathogen M. circinelloides that was isolated from the contaminated commercial yogurt. We successfully cultured an M. circinelloides isolate and found that the isolate belongs to the species M. circinelloides f. circinelloides, which is often associated with human infections. In murine and insect host models, the isolate was virulent. While information disseminated in the popular press would suggest this fungal contaminant poses little or no risk to consumers, our results show instead that it is capable of causing significant infections in animals.

Resolution of a fungal mycotic aneurysm after a contaminated steroid injection: a case report

BACKGROUND

In the past ten years there have been three separate outbreaks of fungal contaminated steroid injections from compounding pharmacies. The 2012 outbreak of central nervous system fungal infections associated with contaminated methylprednisolone produced by a United States compounding pharmacy has led to 750 infections (151 with meningitis and paraspinal infections and 325 cases with paraspinal infections without meningitis) and 64 deaths as of October 23, 2013. Exserohilum rostratum has been the predominant pathogen identified by culture, polymerase chain reaction or antibody tests. According to previous reports, cerebral involvement with phaeohyphomycosis has a high risk of morbidity and mortality.

CASE PRESENTATION

We report a 41 year-old Caucasian woman who received a lumbar methylprednisolone injection from a contaminated lot in August 2012. She was diagnosed with fungal meningitis by cerebrospinal fluid pleocytosis and positive (1, 3) beta-D-glucan after cultures and polymerase chain reaction were negative. Two weeks after onset of therapy, she developed a 4.1 mm superior cerebellar artery mycotic aneurysm associated with new stroke symptoms, which resolved with thirty-two weeks of antifungal treatment.

CONCLUSIONS

This is the rare case report of successful medical management of a cerebral mycotic aneurysm with stroke symptoms related to a presumed phaeohyphomycosis in an immunocompetent individual. Further studies are needed to determine the utility of cerebrospinal fluid (1, 3) beta-D-glucan in diagnosing and monitoring patients with meningitis thought to be related to fungal infection.

Fungal central nervous system infections: prevalence and diagnosis

Fungal infections of the central nervous system (CNS) are rare but they pose a significant challenge. Their prevalence spans a wide array of hosts including immunosuppressed and immunocompetent individuals, patients undergoing neurosurgical procedures and those carrying implantable CNS devices. Cryptococcus neoformans and Aspergillus spp. remain the most common pathogens. Magnetic resonance imaging can help localize the lesions, but diagnosis is challenging since invasive procedures may be needed for the retrieval of tissue, especially in cases of fungal abscesses. Antigen and antibody tests are available and approved for use in the cerebrospinal fluid (CSF). PCR-based techniques are promising but they are not validated for use in the CSF. This review provides an overview on the differential diagnosis of the fungal CNS disease based on the host and the clinical syndrome and suggests the optimal use of diagnostic techniques. It also summarizes the emergence of Cryptococcus gatti and an unanticipated outbreak caused by Exserohilum rostratum.