Aspergillus meningitis: a rare clinical manifestation of central nervous system aspergillosis. Case report and review of 92 cases

Solid organ transplant-related central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections in solid organ transplant (SOT) recipients may present atypical or nonspecific symptoms. Due to a wider range of infectious agents compared with immunocompetent hosts, diagnosis is challenging. This review categorizes CNS infections in SOT recipients by cause.

RECENT FINDINGS

New studies have reported new data on the epidemiology and the risk factors associated with each specific pathogen described in this review. Additionally, we included the treatment recommendations.

SUMMARY

The latest findings give us an insight into the different pathogens causing infectious neurologic complications in SOT recipients.

Aspergillus fumigatus Epidural Abscess and Postsurgical Wound Infection in an Immunocompetent Host

In this case, we present an immunocompetent patient who had a wound infection secondary to Aspergillus fumigatus after undergoing a neurosurgical procedure that was complicated by an epidural abscess. The patient was treated with voriconazole and responded favorably. We highlight the need for awareness of the possibility of an Aspergillus infection in people without any obvious immunocompromise and advocate for the inclusion of this opportunistic fungus in the workup of postneurosurgical infections and dura-based collections. A brief review of relevant literature is also included.

Diagnostic performance of noncultural methods for central nervous system aspergillosis

BACKGROUND

Central nervous system (CNS) aspergillosis is an uncommon but fatal disease, the diagnosis of which is still difficult.

OBJECTIVES

We aim to explore the diagnositic performance of noncultural methods for CNS aspergillosis.

METHODS

In this retrospective study, all pathologically confirmed rhinosinusitis patients in whom cerebrospinal fluid (CSF) galactomannan (GM) test and metagenomic next-generation sequencing (mNGS) had been performed were included. We evaluated the diagnostic performances of CSF GM optical density indexes (ODI) at different cut-off values and compared performance with mNGS in patients with and without CNS aspergillosis, as well as in patients with different manifestations of CNS aspergillosis.

RESULTS

Of the 21 proven and probable cases, one had positive culture result, five had positive mNGS results and 10 had a CSF GM ODI of >0.7. Sample concordance between mNGS and GM test was poor, but best diagnostic performance was achieved by combination of GM test (ODI of >0.7) and mNGS, which generated a sensitivity of 61.9% and specificity of 82.6%. Further investigation of combination diagnostic performances in different kind of CNS aspergillosis was also conducted. Lowest sensitivity (42.9%) was identified in abscess group, while increased sensitivity (60.0%) was achieved in abscess with encephalitis groups. Combination test exhibited the best performance for encephalitis patients who had only CSF abnormalities, in whom the sensitivity and specificity were 77.8% and 82.6%, respectively.

CONCLUSIONS

In conclusion, combination of these two tests might be useful for diagnosis of CNS aspergillosis associated with fungal rhinosinusitis, especially in encephalitis patients.

Mycoviruses in Fungi: Carcinogenesis of Fungal Agents May Not Always Be Mycotoxin Related

Certain viruses have been found to induce diverse biological pathways to carcinogenesis, evidenced by the presence of viral gene products in some tumors. Despite the fact that many fungal agents contain mycoviruses, until recently, their possible direct effects on human health, including carcinogenesis and leukemogenesis, had not been explored. In this regard, most studies of fungal agents have rightly concentrated on their mycotoxin formation and effects. Recently, the direct role of yeasts and fungi in the etiology of cancers, including leukemia, have been investigated. While greater attention has been placed on the carcinogenic effects of Candida, the role of filamentous fungi in carcinogenesis has also been explored. Recent findings from studies using the enzyme-linked immunosorbent assay (ELISA) technique indicate that the plasma of patients with acute lymphoblastic leukemia (ALL) uniformly contains antibodies for a certain mycovirus-containing Aspergillus flavus, while controls are negative. The exposure of mononuclear leukocytes from patients with ALL in full remission, and long-term survivors, to the product of this organism was reported to result in the re-development of typical genetics and cell surface phenotypes characteristic of active ALL. Mycoviruses are known to be able to significantly alter the biological characteristics and functions of their host. The possible carcinogenic and leukemogenic role of mycoviruses, with and without their host, needs to be further investigated.

Invasive Cerebral Aspergillosis in Non-Neutropenic Patients: A Case Series from Western India

PURPOSE

Invasive cerebral aspergillosis (ICA) is a rare but fatal infection affecting neutropenic immunocompromised patients. Recently cases have been reported in non-neutropenic settings also. We hereby present a series of ICA cases in non-neutropenic patients diagnosed at our tertiary care centre in Western India between March to October 2021.

METHODS

All patients with clinico-radiological suspicion of CNS infections were analysed. Data regarding Clinico-radiological features, diagnosis, treatment and outcome were collected. After ruling out bacterial, viral and mycobacterial causes, appropriate samples were sent for KOH (potassium hydroxide) wet mount, fungal culture, histopathology and serum/CSF galactomannan.

RESULTS

A total of four patients were diagnosed with ICA with a mean age of 43.5 years. Three patients had significant comorbidities; Diabetes mellitus, chronic liver disease and COVID-19 pneumonia treated with dexamethasone, respectively. One patient had no known predisposing factor. Radiologically, one patient presented with a frontal brain abscess and two patients had multiple subcortical hyperintensities. Three patients were diagnosed based on CSF galactomannan (Platelia™ Aspergillus antigen, Bio-Rad, France) with OD >1 and one patient had high serum galactomannan (OD >2). CSF culture grew Aspergillus species in two patients. All patients were treated with Voriconazole. One patient recovered, and the remaining three succumbed due to delayed presentation and extensive cerebral involvement.

CONCLUSION

Even in non-neutropenic patients, a high index of suspicion is warranted for cerebral aspergillosis. CSF galactomannan can be considered a reliable marker for diagnosing ICA in non-neutropenic settings. Early diagnosis allows timely antifungal therapy, which could be a key to improving the outcomes.

Cerebral aspergillosis after heart-lung transplantation in a child: Case report with 3-year follow-up and literature review

There are limited cases of heart-lung transplantation (HLT) in children worldwide owing to lack of donors, demanding surgical teamwork, and arduous post-operative management. Post-transplant management difficulties stem from the possible development of several post-operative complications, with infection being a common complication. Intracranial fungal infections are difficult to diagnose and prone to treatment delays because of their relatively insidious onset and atypical clinical presentation. Here, we present a case of a cerebral infection developed 3 months after HLT in a 10-year-old child, showing no positive results on conventional imaging or cerebrospinal fluid (CSF) examination and culture. On metagenomic next-generation sequencing of the cerebrospinal fluid, the causative organism was finally determined as Aspergillus. After administering 1-year anti-Aspergillus treatment, no recurrence of intracranial fungal infection was noted during the 3-year follow-up. This case illustrates the multifaceted diagnostic techniques for cerebral aspergillosis after HLT and shows the significance of dynamic monitoring of symptoms, such as headache, and of metagenomic sequencing results, trends in intracranial pressure and (1-3)-β-D-glucan levels for guiding diagnosis and treatment.

Aspergillus fumigatus cerebral abscess following hemodialysis: A case report

Background and Purpose

Cerebral aspergillosis is a notorious disease that causes rapid clinical deterioration and carries a poor prognosis. Therefore, it requires timely diagnosis and prompt management.

Case Report

This study reports a case of fungal cerebral abscess in a 26years old man following hemodialysis,2 months afterdengue-induced acute kidney disease. Aspergillus fumigatus was recovered from a brain abscess specimen that was subjected to a parietal craniotomy. The patient was successfully treated with oral Voriconazole 400mg BD for 2 days, followed by 200 mg BD for 3months.

Conclusion

Hemodialysis patients are at high risk offungal infections due to the frequent use of catheters or the insertion of needles to access the bloodstream. Therefore, a high index of suspicion of fungal infection is required in patients with hemodialysis by the clinician for early diagnosis and treatment.

Host immune responses in the central nervous system during fungal infections

Fungal infections in the central nervous system (CNS) cause high morbidity and mortality. The frequency of CNS mycosis has increased over the last two decades as more individuals go through immunocompromised conditions for various reasons. Nevertheless, options for clinical interventions for CNS mycoses are still limited. Thus, there is an urgent need to understand the host-pathogen interaction mechanisms in CNS mycoses for developing novel treatments. Although the CNS has been regarded as an immune-privileged site, recent studies demonstrate the critical involvement of immune responses elicited by CNS-resident and CNS-infiltrated cells during fungal infections. In this review, we discuss mechanisms of fungal invasion in the CNS, fungal pathogen detection by CNS-resident cells (microglia, astrocytes, oligodendrocytes, neurons), roles of CNS-infiltrated leukocytes, and host immune responses. We consider that understanding host immune responses in the CNS is crucial for endeavors to develop treatments for CNS mycosis.

The leptomeninges as a critical organ for normal CNS development and function: First patient and public involved systematic review of arachnoiditis (chronic meningitis)

BACKGROUND & IMPORTANCE

This patient and public-involved systematic review originally focused on arachnoiditis, a supposedly rare "iatrogenic chronic meningitis" causing permanent neurologic damage and intractable pain. We sought to prove disease existence, causation, symptoms, and inform future directions. After 63 terms for the same pathology were found, the study was renamed Diseases of the Leptomeninges (DLMs). We present results that nullify traditional clinical thinking about DLMs, answer study questions, and create a unified path forward.

METHODS

The prospective PRISMA protocol is published at Arcsology.org. We used four platforms, 10 sources, extraction software, and critical review with ≥2 researchers at each phase. All human sources to 12/6/2020 were eligible for qualitative synthesis utilizing R. Weekly updates since cutoff strengthen conclusions.

RESULTS

Included were 887/14286 sources containing 12721 DLMs patients. Pathology involves the subarachnoid space (SAS) and pia. DLMs occurred in all countries as a contributor to the top 10 causes of disability-adjusted life years lost, with communicable diseases (CDs) predominating. In the USA, the ratio of CDs to iatrogenic causes is 2.4:1, contradicting arachnoiditis literature. Spinal fusion surgery comprised 54.7% of the iatrogenic category, with rhBMP-2 resulting in 2.4x more DLMs than no use (p<0.0001). Spinal injections and neuraxial anesthesia procedures cause 1.1%, and 0.2% permanent DLMs, respectively. Syringomyelia, hydrocephalus, and arachnoid cysts are complications caused by blocked CSF flow. CNS neuron death occurs due to insufficient arterial supply from compromised vasculature and nerves traversing the SAS. Contrast MRI is currently the diagnostic test of choice. Lack of radiologist recognition is problematic.

DISCUSSION & CONCLUSION

DLMs are common. The LM clinically functions as an organ with critical CNS-sustaining roles involving the SAS-pia structure, enclosed cells, lymphatics, and biologic pathways. Cases involve all specialties. Causes are numerous, symptoms predictable, and outcomes dependent on time to treatment and extent of residual SAS damage. An international disease classification and possible treatment trials are proposed.

Central nervous system aspergillosis misdiagnosed as Toxoplasma gondii encephalitis in a patient with AIDS: a case report

Background

Patients with acquired immunodeficiency syndrome (AIDS) tend to suffer from several central nervous system (CNS) infections due to hypoimmunity. However, CNS aspergillosis (CNSAG) is extremely rare and difficult to diagnose. Thus, it is easily misdiagnosed.

Case presentation

We reported a 47-year-old male AIDS patient with ghosting vision and anhidrosis on the left head and face. He was accordingly diagnosed with Toxoplasma gondii encephalitis (TE) at other hospitals, for which he received regular anti-Toxoplasma gondii and anti-human immunodeficiency virus (anti-HIV) treatment. Then, the patient was transferred to our hospital due to a lack of any improvement with the prescribed treatment. The patient's neurological examination revealed no abnormalities at admission, only a slight change in the cerebrospinal fluid. His cranial magnetic resonance imaging (MRI) revealed multiple abnormal signals in the brain parenchyma, and his blood was positive for Toxoplasma gondii IgG antibody. The initial diagnosis at our hospital was also TE. Considering the poor efficacy of anti-TE treatment, cerebrospinal fluid metagenomics next-generation sequencing (mNGS) was performed, but no pathogenic bacteria were detected. However, Aspergillus fumigatus was detected in the cerebrospinal fluid via targeted next-generation sequencing (tNGS) and bronchoalveolar alveolar lavage fluid via mNGS. The diagnosis was accordingly revised to CNSAG combined with his other clinical manifestations. After administering voriconazole antifungal therapy, the patient’s symptoms were relieved, with improved absorption of the intracranial lesions.

Conclusions

The present case experience indicates the need for clinicians to strengthen their understanding of CNSAG. Moreover, for patients with diagnostic difficulties, early mNGS and tNGS (using biological samples with only a few pathogens) are helpful for early diagnosis and treatment, potentially allowing patients to achieve favorable outcomes.

Promising effects of corticosteroid treatment in combination with antifungal agents in a patient with Aspergillus meningitis

Although Aspergillus meningitis is poorly responsive to current guidelines for treatment, we describe a dramatic response of Aspergillus meningitis in a patient to treatment using a combination of corticosteroids with guideline’s suggested antifungal agents. Administration of corticosteroids in patients with Aspergillus meningitis is rarely reported in previous studies.

Isavuconazole Treatment of Spinal Cord Invasive Aspergillosis Guided by Cerebrospinal Fluid (1,3)-β-d-Glucan Levels in a Patient with Low Interferon-Gamma and Ulcerative Colitis

This case highlights the use of (1,3)-beta-d glucan to direct treatment of a cervical spinal cord Aspergillus fumigatus infection in a 22-year-old woman immunocompromised due to steroid and anti-TNF therapy in the context of ulcerative colitis and interferon gamma deficiency. A 4-year treatment course requiring neurosurgical intervention on four occasions and prolonged antifungal therapy, including isavuconazole, resulted in clinical cure with a corresponding decrease in CSF beta-d-glucan to <30 pg/mL. Serum and CSF galactomannan levels were not elevated at any point during the clinical course.

Evaluation of Vitreous Galactomannan and (1, 3) β-D-Glucan Levels in the Diagnosis of Fungal Endophthalmitis in Southern India

PURPOSE

To evaluate vitreous Galactomannan(GM) and 1,3 β-D-Glucan (BDG) levels in the diagnosis of fungal endophthalmitis, with emphasis on culture-negative cases.

METHODS

Vitreous from 31 clinically suspected fungal endophthalmitis patients and 11 controls were evaluated for GM and BDG using ELISA Kits. The Receiver Operating Characteristic (ROC) curves and diagnostic significance was calculated.

RESULTS

The median vitreous GM in culture-positive (60.83pg/ml) and culture-negative (59.9pg/ml) samples were higher than the (51.2pg/ml) control group. The median vitreous BDG in culture-positive (1.47pg/ml) and culture-negative (1.52pg/ml) samples were also similar, and higher than the control group (1.18pg/ml). ROC analysis showed that at a cut-off of 51.35pg/ml, the sensitivity and specificity for GM were 0.88 and 0.73.Similarly, for BDG at a cut-off of 1.18pg/ml, the sensitivity and specificity were 0.94 and 0.82 respectively.

CONCLUSION

Vitreous GM and BDG above the indicated threshold level could suggest a fungal infection, even when cultures are negative.

Surgical treatment of ruptured right middle cerebral artery mycotic aneurysm and central nervous system aspergillosis: Clinical case and literature review

Background:

Central nervous system (CNS) aspergillosis is more often met in patients with expressed immune suppression. Still, in 50% of cases of meningitis caused by Aspergillus spp., it is observed in patients without expressed immune suppression. The prognosis of CNS aspergillosis is unfavorable with the general rate of lethality around 70%.

Case Description:

Clinical case of a 58-year-old man who developed an Aspergillus abscess in the chiasmosellar region and an associated mycotic aneurysm of the right middle cerebral artery (MCA) and intracerebral hemorrhage. Microsurgical clipping of the fusiform-ectatic aneurysm of the right MCA in the conditions of rupture was performed. An extra-intracranial micro anastomosis was formed on the right. An open biopsy of the neoplasm in the chiasmosellar region was made. The neoplasm was yellow and destroyed the bone plate of the skull base. Biopsy results: Mycotic lesion (aspergillosis). The analysis of surgical treatment for mycotic aneurysms in the acute period of hemorrhage in patients with aspergillosis revealed a high rate of lethality. The issue of the feasibility and effectiveness of complicated revascularization interventions in the patients with hemorrhage and aspergillosis remains unsolved.

Conclusion:

The lack of generally accepted tactics of the treatment of this pathology requires further studies and systemic analysis. A high risk of the lethal outcome in patients with invasive mycotic infection and rupture of mycotic aneurysm highlight the importance of timely diagnostics and the beginning of antimycotic therapy. WThe issue of the evaluation of the revascularization methods effectiveness in patients after surgical treatment of a mycotic aneurysm associated with cerebral aspergillosis remains poor.

Cerebral aspergillosis in the era of new antifungals: The CEREALS national cohort study Nationwide CEREbral Aspergillosis Lesional study (CEREALS)

BACKGROUND

Cerebral aspergillosis (CA) is a life-threatening disease for which diagnosis and management remain challenging. Detailed analyses from large cohorts are lacking.

METHODS

We included 119 cases of proven (n = 54) or probable (n = 65) CA diagnosed between 2006 and 2018 at 20 French hospitals. Data were collected at baseline and during follow-up. Cerebral imaging was reviewed centrally by two neuroradiologists.

RESULTS

The most frequent underlying conditions were hematological malignancy (40%) and solid organ transplantation (29%). Galactomannan was detected in the serum of 64% of patients. In 75% of cases, at least one of galactomannan, Aspergillus PCR, and β-d-glucan was positive in the cerebrospinal fluid. Six-week mortality was 45%. Two distinct patterns of disease were identified according to presumed route of dissemination. Presumed haematogenous dissemination (n = 88) was associated with a higher frequency of impaired consciousness (64%), shorter time to diagnosis, the presence of multiple abscesses (70%), microangiopathy (52%), detection of serum galactomannan (69%) and Aspergillus PCR (68%), and higher six-week mortality (54%). By contrast, contiguous dissemination from the paranasal sinuses (n = 31) was associated with a higher frequency of cranial nerve palsy (65%), evidence of meningitis on cerebral imaging (83%), macrovascular lesions (61%), delayed diagnosis, and lower six-week mortality (30%). In multivariate analysis and in a risk prediction model, haematogenous dissemination, hematological malignancy and the detection of serum galactomannan were associated with higher six-week mortality.

CONCLUSION

Distinguishing between hematogenous and contiguous dissemination patterns appears to be critical in the workup for CA, as they are associated with significant differences in clinical presentation and outcome.

Challenges with Utilizing the 1,3-Beta-d-Glucan and Galactomannan Assays To Diagnose Invasive Mold Infections in Immunocompromised Children

Establishing the diagnosis of invasive mold infections (IMI) in immunocompromised children is challenging due to nonspecific clinical presentations and the limited sensitivity of traditional culture-based methods. Rapid non-culture-based diagnostics such as the 1,3-beta-d-glucan and galactomannan assays have emerged as promising adjuncts to conventional diagnostic tests in adults. Available data suggest that 1,3-beta-d-glucan has limited accuracy in the pediatric population and is not recommended to be used for the diagnosis of IMI in children. On the other hand, the diagnostic performance of the serum and bronchoalveolar lavage galactomannan in immunocompromised children is comparable to results observed in adults and can be used as a screening tool in children at high risk of developing invasive aspergillosis (IA) who are not receiving mold-active antifungal prophylaxis and as a diagnostic tool in symptomatic children suspected of having IA. Herein, we summarize the available evidence for the use of these rapid non-culture-based diagnostics in immunocompromised children. We also summarize potential causes of false positivity for the 1,3-beta-d-glucan and galactomannan assays.

Clinical manifestations, diagnosis, and treatment outcome of CNS aspergillosis: A systematic review of 235 cases

Aspergillus is a ubiquitous ascomycete that can cause a variety of clinical presentations depending on immune status. Central nervous system aspergillosis is a fatal disease with non-specific clinical features. The aim of this systematic review was to evaluate the epidemiology, clinical features, diagnosis and therapeutic interventions in CNS aspergillosis patients. We also aimed to examine the possible predictors of mortality in neuroaspergillosis. Literature search was performed in Medline, PubMed, and Google scholar and all patients≥18 years with proven CNS aspergillosis were included. A total of 175 articles (235 patients) were included in the final analysis. Their mean age was 51 years and the majority were male (57.4%). Overall case-fatality was 45.1%. Aspergillus fumigatus was the most common species (70.8%) followed by A. flavus (18.6%). Corticosteroids (22.6%), malignancy (19.1%) and diabetes mellitus (14%) were the most common risk factors. Neuroimaging findings included cerebral abscess (70.2%), meningitis (14%), infarction (13.2%) and mycotic aneurysm (8.9%). Disseminated disease (29.2% vs 17.8%, p 0.03), CSF hypoglycorrhachia (48.1% vs 22.2%, P: 0.001) and heightened CSF galactomannan (3.62 vs 2.0ng/ml, p 0.05), were the factors associated with poor outcome in neuroaspergillosis. Persons infected with Aspergillus flavus (13.1% vs 3.1%, P: 0.01), and having been treated with Voriconazole (51.9% vs 29.2%, P: 0.004) were more likely to survive. Our review will provide insight into the different spectrums of CNS aspergillosis. Notwithstanding the promising role of Voriconazole, future work is required to ascertain the role of combination antifungal therapy.

Defining Galactomannan Positivity in the Updated EORTC/MSGERC Consensus Definitions of Invasive Fungal Diseases

The consensus definitions of invasive fungal diseases from the EORTC/MSGERC were recently revised and updated. They now include consensus cutoff values for the galactomannan test that support the diagnosis of probable invasive aspergillosis. In this supplement article, we provide a rationale for these proposed thresholds based on the test's characteristics and performance in different patient populations and in different specimen types.

Aspergillus flavus endocarditis and meningitis in a child with marfan syndrome

Background and Purpose:

Aspergillus species are implicated as the etiology of approximately 26% of endocarditis cases. Central nervous system aspergillosis is a life-threatening condition that has a mortality rate of 80%.

Case report:

Herein, we report a four– year- old female who was admitted to the pediatric infectious ward due to a fever of unknown origin in January 2020. She was a known case of Marfan syndrome with a family history of this syndrome in her mother. The species was identified using (PCR) and the antifungal susceptibility test was performed using four antifungal agents based on the Clinical and Laboratory Standards Institute M38 3rd edition. Fluconazole-resistant Aspergillus flavus was identified to be responsible for endocarditis and meningitis as well as fever of unknown origin.

Conclusion:

The clinicians should be aware and consider fungal endocarditis in blood culture-negative endocarditis even in patients with no significant risk factor when antibiotic therapy fails.

A clinical approach to hypertrophic pachymeningitis

IMPORTANCE

Hypertrophic pachymeningitis (HP) is a non-usual manifestation of rheumatologic, infectious, and neoplastic diseases. Etiological diagnosis is a challenge, but when made promptly it creates a window of opportunity for treatment, with the possibility of a total reversal of symptoms.

OBSERVATIONS

HP is an inflammatory process of the dura mater that can occur as a manifestation of sarcoidosis, granulomatosis with polyangiitis, and IgG4-related disease. The HP case evaluation is extensive and includes central nervous system imaging, cerebrospinal fluid analysis, serology, rheumatologic tests, and systemic survey for other manifestations sites. After systemic investigation, meningeal biopsy might be necessary. Etiology guides HP treatment, and autoimmune disorders are treated with corticosteroids alone or associated with an immunosuppressor.

CONCLUSION

HP is a manifestation of several diseases, and a precise etiological diagnosis is crucial because of the difference among treatments. An extensive investigation of patients with HP helps early diagnosis and correct treatment.

A Case of Invasive Aspergillus Rhinosinusitis Presenting with Unilateral Visual Loss and Subsequently Associated with Meningitis, Subarachnoid Hemorrhage, and Cerebral Infarction

Visual impairment can occur because of several mechanisms, including optic nerve disease and occasionally fungal sinusitis. An 87-year-old man presented with the loss of right visual acuity; he was diagnosed with optic neuritis. Steroid pulse therapy was not effective. One month later, he became unconscious because of meningitis, following which treatment with ceftriaxone and acyclovir was initiated. However, his consciousness deteriorated because of a subarachnoid hemorrhage caused by a ruptured aneurysm. Meningitis and vascular invasion caused by fungal rhinosinusitis were suspected, and the sinus mucosa was biopsied. He was pathologically diagnosed with invasive Aspergillus rhinosinusitis. Despite continuous liposomal amphotericin B administration, he died of cerebral infarction, following a right internal carotid artery occlusion. It is important to consider the possibility of Aspergillus as an etiological agent, especially when cerebrovascular events are associated with visual impairment.

Aspergillosis infection over 20 years: a case report of probable vascular invasion in central nervous system

Background

Aspergillosis infection of central nervous system (CNS) is rare and fatal. Diagnosis of invasive aspergillosis remains difficult. Aspergillosis of CNS can be an acute, subacute, or chronic onset, and the longest course of the disease was currently reported to be 4 years. Here, we report a case with recurrent headache over 20 years.

Case presentation

A 54-year-old man was admitted to our neurological disease ward due to intermittent throbbing headache lasting for more than 20 years that had grown notably worse over the past week. The headache was localized to the side of his head blown by a cold wind. He also experienced nausea and vomiting when the headache became severe. The headache usually lasted for 3–4 h after he was blown by the cold wind, though he had no fever. The neurological examination was normal. Magnetic resonance imaging (MRI) of the brain was negative for parenchymal and meningeal lesions. However, the case had increased intracranial pressure (ICP), and elevated protein level in the cerebrospinal fluid (CSF). Aspergillus fumigatus was found in CSF by nanopore targeted sequencing (NTS) and in blood by enzyme-linked immunosorbent assay (ELISA). Aspergillus fumigatus-specific antibody IgG was 104.62 AU/mL, aspergillus galactomannan (GM) antigen was 3.27 μg/L, D-dimer was 3.25 mg/L and fibrinogen degradation product was 11.50 mg/L, which were markedly higher than the normal levels. The patient was prescribed by voriconazole. After the treatment of 14 days, the ICP, CSF protein level, Aspergillus fumigatus-specific antibody IgG, GM antigen, D-dimer and fibrinogen degradation product returned normal. Aspergillus was disappeared by NTS test of CSF. His headache has never occurred again after blowing by a cold wind.

Conclusions

This report reveals that aspergillosis infection of CNS can last for more than 20 years and the major symptom is only intermittent throbbing headache in an immunocompetent patient. Vascular invasion is probably the mechanism of headache in our case with CNS aspergillosis infection. Performing high-throughput gene sequencing technology in CSF is important when the pathogen is not determined for the patients with suspected CNS infection.

Diphtheric aspergillosis tracheitis with gastrointestinal dissemination secondary to viral infections in a dairy calf

Diphtheric aspergillosis tracheitis is an uncommon syndrome described in human pathology, usually associated with immunosuppression in the affected individuals. Interestingly, no comparative/equivalent cases were found in domestic animals. This report describes the pathological and mycological findings associated with diphtheric aspergillosis tracheitis in an immunocompromised calf. The main pathological findings were diphtheric tracheitis and rhinitis, and necrotizing ruminitis associated with intralesional septate, acute branching fungal hyphae consistent with Aspergillus spp. Mycological culture and isolation confirmed the fungal hyphae as A. fumigatus due to characteristic features. Immunohistochemistry (IHC) assays identified intralesional antigens of bovine viral diarrhea virus (BVDV) and malignant catarrhal fever virus (MCFV) at the trachea and small intestine; IHC detected intralesional antigens of bovine alphaherpesvirus 1 (BoHV-1) only at the trachea. These findings confirmed the simultaneous occurrence of A. fumigatus with concomitant infections due to BVDV, MCFV, and BoHV-1 in this calf. Since ovine gammaherpesvirus-2 (OvHV-2) is the cause of MCF in Brail, it is likely that the intralesional MCFV antigens identified were those of OvHV-2. In this case, disseminated aspergillosis was probably associated with the undeveloped immunological status of the calf that was further impaired due to the combined immunodepressive effects of BVDV and BoHV-1 infections. Although BVDV and BoHV-1 are infectious disease pathogens frequently associated with the development of bovine respiratory disease (BRD) in feedlot and dairy cattle, the identification of intralesional OvHV-2-like antigens in several parts of the lungs suggest that this MCFV also played a role in the BRD-associated lesions identified in this calf.

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An unusual presentation of fungal diphtheric tracheitis associated with Aspergillus fumigatus is described in a dairy calf.

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A Malignant Catarrhal Fever Virus, most likely, OvHV-2, was associated with the development of pneumonia in this calf.

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Simultaneous infections in dairy calves may be more frequent than previously reported.

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OvHV-2 should be considered as a possible disease pathogen associated with the development of bovine respiratory disease.

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The immunodepressive effects of BVDV and BoHV-1 were fundamental for the development of the fungal disease observed in this calf.

Methods for rapid diagnosis of meningitis etiology in adults

Infectious meningitis can be caused by viral, bacterial or fungal pathogens. Despite widely available treatments, many types of infectious meningitis are still associated with significant morbidity and mortality. Delay in diagnosis contributes to poor outcomes. Cerebrospinal fluid cultures have been used traditionally but are time intensive and sensitivity is decreased by empiric treatment prior to culture. More rapid techniques such as the cryptococcal lateral flow assay (IMMY), GeneXpert MTB/Rif Ultra (Cepheid) and FilmArray multiplex-PCR (Biofire) are three examples that have drastically changed meningitis diagnostics. This review will discuss a holistic approach to diagnosing bacterial, mycobacterial, viral and fungal meningitis.

Successful surgical management of an Escherichia coli epidural-subdural abscess secondary to sino-rhinotomy

OBJECTIVE

To describe a case of successful management of epidural-subdural abscess and severe meningitis with secondary brain herniation in a dog.

CASE SUMMARY

A rhino-sinusotomy was performed in a 3-year-old mixed-breed dog for management of refractory sinonasal aspergillosis. Initial recovery was good, but the dog became acutely stuporous 36 hours after surgery. Evidence of increased intracranial pressure with brain herniation and midline shift secondary to an epidural abscess was observed on magnetic resonance imaging. Decompressive craniectomy and drainage of the abscess was performed. Intensive nursing care and physiologic support was performed with consciousness returning 7 days after initial stupor. The dog was discharged 14 days after craniectomy and was ambulatory with support.

NEW/UNIQUE INFORMATION PROVIDED

Intracranial abscesses are rarely described in dogs and few had a successful outcome reported. All previous reports have been of brain abscesses or empyema, rather than a combination of epidural and subdural abscessation. Additionally, the process of sino-rhinotomy for management of aspergillosis has not been previously linked to intracranial abscess formation. To the authors' knowledge, this is the first report of successful management of an epidural-subdural abscess and suggests that even with cases with low modified Glasgow Coma Scale scores outcome may be positive.

Chronic Meningitis

PURPOSE OF REVIEW

This article describes the clinical presentation, diagnostic approach (including the use of novel diagnostic platforms), and treatment of select infectious and noninfectious etiologies of chronic meningitis.

RECENT FINDINGS

Identification of the etiology of chronic meningitis remains challenging, with no cause identified in at least one-third of cases. Often, several serologic, CSF, and neuroimaging studies are indicated, although novel diagnostic platforms including metagenomic deep sequencing may hold promise for identifying organisms. Infectious etiologies are more common in those at risk for disseminated disease, specifically those who are immunocompromised because of human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS), transplantation, or immunosuppressant medications. An important step in identifying the etiology of chronic meningitis is assembling a multidisciplinary team of individuals, including those with specialized expertise in ophthalmology, dermatology, rheumatology, and infectious diseases, to provide guidance regarding diagnostic procedures.

SUMMARY

Chronic meningitis is defined as inflammation involving the meninges that lasts at least 4 weeks and is associated with a CSF pleocytosis. Chronic meningitis has numerous possible infectious and noninfectious etiologies, making it challenging to definitively diagnose patients. Therefore, a multifaceted approach that combines history, physical examination, neuroimaging, and laboratory analysis, including novel diagnostic platforms, is needed. This article focuses on key aspects of the evaluation of and approach to patients with chronic meningitis. Specific infectious etiologies and differential diagnoses of subacute and chronic meningitis, including noninfectious etiologies, are addressed.

Intracranial aspergillosis amongst immunocompetent patients: An experience with combined surgical and medical management of 18 patients

OBJECTIVE

Fungal infections of central nervous system (CNS) commonly affect immunocompromised patients, however, recently such cases have been reported even amongst immunocompetent patients.

PATIENTS & METHODS

In this study, we retrospectively analyzed outcome of 18 immunocompetent patients with histopathologically proven intracranial Aspergillosis undergoing combined surgical and medical management.

RESULTS

The age of patients ranged from 5-65 years. Fourteen out of 18 patients had well defined lesions while 4 had diffuse disease. Paranasal sinuses were involved in 8 & cavernous sinus in 3 patients. Six patients had hydrocephalus. Four patients developed infarcts during their clinical course. Surgical interventions included gross (n = 4) or subtotal excision (n = 8), decompressive craniectomy & biopsy of lesion (n = 4), biopsy only (n = 2) and ventriculoperitoneal shunt placement (n = 6). All patients received postoperative antifungal therapy. The duration of follow up ranged from 10-60 months. Overall mortality was 44.4%. Mortality amongst patients undergoing gross total and subtotal excision was 25% & 50% respectively. Patients undergoing DC had a mortality of 25%. Both patients undergoing only biopsy died. Hydrocephalus was associated with a very high mortality (83.3%). Amongst surviving patients (n = 10), 6 patients became disease free & rest 4 had stable disease at last follow up.

CONCLUSIONS

Intracranial aspergillosis is associated with high morbidity & mortality even amongst immunocompetent patients. An aggressive multidisciplinary management is thus needed to improve outcome. Our study shows that a combination of surgical excision or decompressive craniectomy and antifungal therapy can be helpful in improving prognosis of these patients.

Special scenarios in the management of central nervous system aspergillosis: a case series and review of literature

Aspergillus is a rare but important opportunistic pathogen to invade the central nervous system (CNS). It is a significant pathogen of not only immunocompromised but also immunocompetent patients. Its manifestations are pleiotropic, reflecting multiple mechanisms of pathogenesis and host interactions. Despite significant advances in diagnostic methods and therapeutic options, the mortality remains high. Several advances have been made in medications and surgical management, yet, current treatment practices lack uniformity. Patient woes are further heightened by the high costs of treatment and prolonged duration of therapy. In view of the challenging aspects of this disease, we present a short review of four challenging cases touching on the varied aspects of management of CNS aspergillosis covering pathogenesis, diagnostic pitfalls, surgical and medical options and evidence-based guidelines for the management of the same.

An Autopsy Case with Cerebral Hemorrhaging due to disseminated Aspergillosis During Glucocorticoid Therapy for Overlap Syndrome of Systemic Lupus Erythematosus and Systemic Sclerosis

We encountered a 60-year-old female patient who died of cerebral hemorrhage caused by disseminated aspergillosis during massive steroid therapy for overlap syndrome of systemic lupus erythematosus (SLE) and systemic sclerosis (SSc) and performed autopsy. Histologically, necrotizing vasculitis accompanied by Aspergillus hyphae was noted in the arterial wall of the region with cerebral hemorrhage and an abscess containing Aspergillus clumps was present in the lung, therefor we considered the cerebral hemorrhage caused by disseminated aspergillosis. For immunocompromised patients, it is desirable to perform treatment taking the possibility of deep mycosis into consideration, and when it is suspected, early therapeutic intervention may be useful.

Histopathology

During the last 30 years, advances in intensive and critical care units, organ transplantation, concomitant use of immunosuppressive drugs, and increasing prevalence of chronic diseases, malnutrition, and other debilitating conditions, as well as the human immunodeficiency virus pandemic, have increased the incidence of systemic mycotic diseases, the most serious form of fungal diseases are the ones that comprise the central nervous system, representing the most dangerous clinical situations. In those cases, starting an adequate therapy through a rapid and assertive diagnosis is absolutely necessary. Considering the fastidious microbiological nature of some fungi (longtime requirement, specific culture conditions, and biohazard issues), as well as the lack of alternative testing availability, a rapid diagnosis is always challenging. When a tissue or liquid specimen is available, its pathological analysis constitutes a rapid and cost-effective way to provide a presumptive or definitive diagnosis of an invasive fungal infection; however, microbiologists, pathologists, and clinicians need to be aware of the limitations of microscopical diagnosis. In this chapter, we review the usual histological presentation of the most frequent central nervous system fungal infections.

Central nervous system infections in immunocompromised patients

PURPOSE OF REVIEW

Although rare, central nervous system (CNS) infections are increasingly being recognized in immunocompromised patients. The goal of the present review is to provide a practical diagnostic approach for the intensivist, and to briefly discuss some of the most prevalent conditions.

RECENT FINDINGS

Immunocompromised patients presenting with new neurological symptoms should always be suspected of a CNS infection. These infections carry a poor prognosis, especially if intracranial hypertension, severely altered mental status or seizures are present. Clinical examination and serum blood tests should be followed by brain imaging, and when no contra-indications are present, a lumbar puncture including cerebrospinal fluid PCR to identify causative organisms. Empirical therapy depends on the type of immunodeficiency. In HIV-infected patients, the most common CNS infection is cerebral toxoplasmosis, whereas in other immunocompromised patients, aspergillosis, cryptococcal meningitis and tuberculous meningitis are more prevalent. Multiple pathogens can be detected in up to 15% of patients. The diagnostic value of fast multiplex PCR has yet to be evaluated in this setting.

SUMMARY

CNS infections represent a rare but severe complication in immunocompromised patients. A systematic approach including early diagnosis, appropriate antimicrobial treatment, early ICU admission and aggressive measures to reduce intracranial pressure may improve outcome.

Central Nervous System Aspergillosis: An Unexpected Complication following Neurosurgery

Post-surgical aspergillosis is an uncommon complication that carries a high mortality rate in affected patients. The diagnosis is challenging given the lack of highly sensitive methods to isolate Aspergillus from surgical sites. Here, we present a case of post-surgical aspergillosis that occurred after the resection of acoustic neuroma in an immunocompetent patient. Imaging revealed leptomeningeal enhancement and a cerebellar extra-axial fluid collection adjacent to the right retrosigmoid craniotomy. The patient was taken to the operating room for debridement, where purulent fluid was obtained from subdural space. The diagnosis was achieved by histopathology and polymerase chain reaction (PCR) in brain tissue. Appropriate investigations failed to detect contamination in the operating room. The patient was successfully treated with 3 months of voriconazole. We highlight the importance of recognizing this uncommon complication and advocate for the use of molecular techniques to improve the diagnostic yield in central nervous system aspergillosis.

Advances in the diagnosis and treatment of fungal infections of the CNS

Fungal infections of the CNS are challenging to treat and their optimal management requires knowledge of their epidemiology, host characteristics, diagnostic criteria, and therapeutic options. Aspergillus and Cryptococcus species predominate among fungal infections of the CNS. Most of these fungi are ubiquitous, but some have restricted geographical distribution. Fungal infections of the CNS usually originate from primary sites outside the CNS (eg, fungal pneumonia) or occur after inoculation (eg, invasive procedures). Most patients with these infections have immunodeficiencies, but immunocompetent individuals can also be infected through heavy exposure. The infecting fungi can be grouped into moulds, yeasts, and dimorphic fungi. Substantial progress has been made with new diagnostic approaches and the introduction of novel antifungal drugs, but fungal infections of the CNS are frequently lethal because of diagnostic delays, impaired drug penetration, resistance to antifungal treatments, and inadequate restoration of immune function. To improve outcomes, future research should advance diagnostic methods (eg, molecular detection and fungus identification), develop antifungal compounds with enhanced CNS-directed efficacy, and further investigate crucial host defence mechanisms.

Fatal Mycotic Aneurysm of the Basilar Artery Caused by Aspergillus fumigatus in a Patient with Pituitary Adenoma and Meningitis

Fungal infections of the central nervous system (CNS) frequently occur in immunosuppressed patients. Here, we describe the case of an immunocompetent 64-year-old man who presented with diplopia, right-sided hemiparesis, and a mild headache after cleaning and replacing nesting boxes of wild birds during the preceding months. Lumbar puncture revealed pleocytosis, elevated protein, and lactate levels in the cerebrospinal fluid (CSF). Initial imaging showed ischemia in the left thalamus and an enlargement of the sellar region. Antibiotic treatment and corticosteroids led to an initial improvement but was followed by rapid deterioration. Antibiotic treatment was modified and antifungal therapy was added. Eighteen days after admission, the patient died from a subarachnoid hemorrhage resulting from the rupture of a fusiform aneurysm of the basilar artery. Microbiological culture of CSF was negative, but a positive galactomannan assay suggested fungal infection which was corroborated by detection of Aspergillus fumigatus DNA in pan-fungal PCR and sequencing. The presence of septated hyphae in the wall of the basilar artery confirmed the diagnosis of a mycotic aneurysm caused by hyphomycetal infection. In addition, brain autopsy revealed the presence of an invasive adrenocorticotrophic hormone-producing pituitary adenoma with arrosion of the sellar bone. This process and its invasiveness likely facilitated the spread of the fungal pathogen from the sphenoid sinus to the dura mater and finally led to cerebral angioinvasion. Our case demonstrates the challenge to timely diagnose and effectively treat aspergillosis as a cause of CNS infection also in apparently immunocompetent patients. The potential of assays detecting fungal antigens and of PCR to facilitate a timely diagnosis is discussed.

Translational Development and Application of (1→3)-β-d-Glucan for Diagnosis and Therapeutic Monitoring of Invasive Mycoses

Early diagnosis and prompt initiation of appropriate antimicrobial therapy are crucial steps in the management of patients with invasive fungal infections. However, the diagnosis of invasive mycoses remains a major challenge in clinical practice, because presenting symptoms may be subtle and non-invasive diagnostic assays often lack sensitivity and specificity. Diagnosis is often expressed on a scale of probability (proven, probable and possible) based on a constellation of imaging findings, microbiological tools and histopathology, as there is no stand-alone assay for diagnosis. Recent data suggest that the carbohydrate biomarker (1→3)-β-d-glucan may be useful in both the diagnosis and therapeutic monitoring of invasive fungal infections due to some yeasts, molds, and dimorphic fungi. In this paper, we review recent advances in the use of (1→3)-β-d-glucan to monitor clinical response to antifungal therapy and explore how this assay may be used in the future.

Successful treatment of Aspergillus ventriculitis through voriconazole adaptive pharmacotherapy, immunomodulation, and therapeutic monitoring of cerebrospinal fluid (1→3)-β-D-glucan

Aspergillus ventriculitis is an uncommon but often fatal form of invasive aspergillosis of the central nervous system (CNS). As little is known about the diagnosis, treatment, and outcome of this potentially lethal infection, we report the strategies used to successfully treat Aspergillus ventriculitis complicating a pineal and pituitary germinoma with emphasis on the critical role of adaptive pharmacotherapy of voriconazole and serial monitoring of (1→3)-β-D-glucan in cerebrospinal fluid. We describe several rationally based therapeutic modalities, including adaptive pharmacotherapy, combination therapy, sargramostim-based immunomodulation, and biomarker-based therapeutic monitoring of the CNS compartment. Through these strategies, our patient remains in remission from both his germinoma and Aspergillus ventriculitis making him one of the few survivors of Aspergillus ventriculitis.

CNS infections in patients with hematological disorders (including allogeneic stem-cell transplantation)-Guidelines of the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO)

Diagnosis of CNS infections remains a great challenge in patients with hematological disorders since symptoms might both be masked and be mimicked by other conditions such as metabolic disturbances or consequences from antineoplastic treatment. Thus, awareness of this complication is crucial and any suspicion of a CNS infection should lead to timely and adequate diagnostics and treatment to improve the outcome in this population.

Infections of the central nervous system (CNS) are infrequently diagnosed in immunocompetent patients, but they do occur in a significant proportion of patients with hematological disorders. In particular, patients undergoing allogeneic hematopoietic stem-cell transplantation carry a high risk for CNS infections of up to 15%. Fungi and Toxoplasma gondii are the predominant causative agents. The diagnosis of CNS infections is based on neuroimaging, cerebrospinal fluid examination and biopsy of suspicious lesions in selected patients. However, identification of CNS infections in immunocompromised patients could represent a major challenge since metabolic disturbances, side-effects of antineoplastic or immunosuppressive drugs and CNS involvement of the underlying hematological disorder may mimic symptoms of a CNS infection. The prognosis of CNS infections is generally poor in these patients, albeit the introduction of novel substances (e.g. voriconazole) has improved the outcome in distinct patient subgroups. This guideline has been developed by the Infectious Diseases Working Party (AGIHO) of the German Society of Hematology and Medical Oncology (DGHO) with the contribution of a panel of 14 experts certified in internal medicine, hematology/oncology, infectious diseases, intensive care, neurology and neuroradiology. Grades of recommendation and levels of evidence were categorized by using novel criteria, as recently published by the European Society of Clinical Microbiology and Infectious Diseases.

Diagnostic Performance of Galactomannan Antigen Testing in Cerebrospinal Fluid

Testing cerebrospinal fluid (CSF) for the presence of galactomannan (GM) antigen may help in diagnosing cerebral aspergillosis (CA). However, the use of the CSF GM test as a diagnostic test has been little studied. We evaluated its diagnostic performance by comparing the CSF GM optical density indexes (ODI) at different cutoffs in patients with probable and proven CA to those in patients without CA. Patients from 2 tertiary referral hospitals with suspected CA between 2004 and 2014 and in whom CSF GM ODI had been determined were selected. European Organization for Research and Treatment of Cancer/Invasive Infectious Diseases Study Mycoses Group (EORTC/MSG) definitions of invasive aspergillosis and CA were used, but with the exclusion of the test to be validated (i.e., the CSF GM test) as a microbiological EORTC/MSG criterion. The study population consisted of 44 patients (4 with proven CA, 13 with probable CA, and 27 with no CA). Of the 17 patients with CA, 15 had a CSF GM ODI of ≥2.0. Of 27 patients without CA, 26 had a CSF GM ODI of <0.5 and 1 had a CSF GM ODI of 8.2. When a GM CSF ODI cutoff of 1.0 was used, the sensitivity, specificity, and positive and negative predictive values were 88.2%, 96.3%, 93.8%, and 92.9%, respectively. The same results were found when a CSF GM ODI cutoff of 0.5 or 2.0 was used. Testing GM in CSF has a high diagnostic performance for diagnosing CA and may be useful to diagnose or virtually rule out the infection without the need for a cerebral biopsy.

Aspergillus terreus Meningitis in Immunocompetent Patient: A Case Report

We present a description of a rare but dangerous case of fungal meningitis caused by Aspergillus terreus in an immunocompetent patient with a history of sinus disease.

Consensus guidelines for the treatment of invasive mould infections in haematological malignancy and haemopoietic stem cell transplantation, 2014

Mould species represent the pathogens most commonly associated with invasive fungal disease in patients with haematological malignancies and patients of haemopoietic stem cell transplants. Invasive mould infections in these patient populations, particularly in the setting of neutropenia, are associated with high morbidity and mortality, and significantly increase the complexity of management. While Aspergillus species remain the most prevalent cause of invasive mould infections, Scedosporium and Fusarium species and the Mucormycetes continue to place a significant burden on the immunocompromised host. Evidence also suggests that infections caused by rare and emerging pathogens are increasing within the setting of broad-spectrum antifungal prophylaxis and improved survival times placing immunosuppressed patients at risk for longer. These guidelines present evidence-based recommendations for the antifungal management of common, rare and emerging mould infections in both adult and paediatric populations. Where relevant, the role of surgery, adjunctive therapy and immunotherapy is also discussed.