Diagnosis and Treatment of Isolated Cerebral Mucormycosis: Patient-Level Data Meta-Analysis and Mayo Clinic Experience

Diagnosis, Prognosticators, and Management of Acute Invasive Fungal Rhinosinusitis: Multidisciplinary Consensus Statement and Evidence-Based Review with Recommendations

BACKGROUND

Acute invasive fungal sinusitis (AIFS) is an aggressive disease that requires prompt diagnosis and multidisciplinary treatment given its rapid progression. However, there is currently no consensus on diagnosis, prognosis, and management strategies for AIFS, with multiple modalities routinely employed. The purpose of this multi-institutional and multidisciplinary evidence-based review with recommendations (EBRR) is to thoroughly review the literature on AIFS, summarize the existing evidence, and provide recommendations on the management of AIFS.

METHODS

The PubMed, EMBASE, and Cochrane databases were systematically reviewed from inception through January 2022. Studies evaluating management for orbital, non-sinonasal head and neck, and intracranial manifestations of AIFS were included. An iterative review process was utilized in accordance with EBRR guidelines. Levels of evidence and recommendations on management principles for AIFS were generated.

RESULTS

A review and evaluation of published literature was performed on 12 topics surrounding AIFS (signs and symptoms, laboratory and microbiology diagnostics, endoscopy, imaging, pathology, surgery, medical therapy, management of extrasinus extension, reversing immunosuppression, and outcomes and survival). The aggregate quality of evidence was varied across reviewed domains.

CONCLUSION

Based on the currently available evidence, judicious utilization of a combination of history and physical examination, laboratory and histopathologic techniques, and endoscopy provide the cornerstone for accurate diagnosis of AIFS. In addition, AIFS is optimally managed by a multidisciplinary team via a combination of surgery (including resection whenever possible), antifungal therapy, and correcting sources of immunosuppression. Higher quality (i.e., prospective) studies are needed to better define the roles of each modality and determine diagnosis and treatment algorithms.

Isolated cerebral mucormycosis: A case discussion

We report a case of a 32-year-old male with a history of type 1 diabetes, inhaled drug use, and alcohol use disorder, who presented with encephalopathy, holocranial headaches, neck pain, confusion, and generalized tonic-clonic seizures. The patient initially presented at a rural community hospital with a fever and was found to be in diabetic ketoacidosis (DKA). He was also hemodynamically stable but stuporous, prompting intubation to protect his airway. Despite initial treatment measures, his neurological condition worsened and he remained ventilator-dependent. Key findings include a high glucose level, presence of ketones, and evidence of drug use. Blood cultures showed no growth, but his febrile state persisted. Cerebrospinal fluid (CSF) analysis revealed mild pleocytosis, hyperglycorrhachia but normal protein, with no growth. Neuroimaging showed right hemispheric slowing on EEG and diffusion restriction in the right frontal lobe on MRI. The patient's neurological status worsened on the second day of admission, manifesting as sluggish pupillary reflexes, right third nerve palsy, and decerebrate posturing. Emergent MRI suggested cerebral edema, leading to initiation of hypertonic saline. This case highlights the diagnostic challenges and critical management considerations in a patient with multiple comorbidities presenting with unexplained neurological deterioration, emphasizing the importance of a comprehensive and timely approach to diagnosis and treatment.

Isolated cerebral mucormycosis that looks like stroke and brain abscess: A case report and review of the literature

BACKGROUND

Cerebral mucormycosis is an infectious disease of the brain caused by fungi of the order Mucorales. These infections are rarely encountered in clinical practice and are often misdiagnosed as cerebral infarction or brain abscess. Increased mortality due to cerebral mucormycosis is closely related to delayed diagnosis and treatment, both of which present unique challenges for clinicians.

CASE SUMMARY

Cerebral mucormycosis is generally secondary to sinus disease or other disseminated disease. However, in this retrospective study, we report and analyze a case of isolated cerebral mucormycosis.

CONCLUSION

The constellation of symptoms including headaches, fever, hemiplegia, and changes in mental status taken together with clinical findings of cerebral infarction and brain abscess should raise the possibility of a brain fungal infection. Early diagnosis and prompt initiation of antifungal therapy along with surgery can improve patient survival.

Let's talk about Sex Characteristics - as a Risk Factor for Invasive Fungal Diseases

Biological sex, which comprises differences in host sex hormone homeostasis and immune responses, can have a substantial impact on the epidemiology of infectious diseases. Comprehensive data on sex distributions in invasive fungal diseases (IFDs) is lacking. In this review we performed a literature search of in vitro/animal studies, clinical studies, systematic reviews, and meta-analyses of invasive fungal infections. Females represented 51.2% of invasive candidiasis cases, mostly matching the proportions of females among the general population in the United States and Europe (>51%). In contrast, other IFDs were overrepresented in males, including invasive aspergillosis (51% males), mucormycosis (60%), cryptococcosis (74%), coccidioidomycosis (70%), histoplasmosis (61%), and blastomycosis (66%). Behavioral variations, as well as differences related to biological sex, may only in part explain these findings. Further investigations concerning the association between biological sex/gender and the pathogenesis of IFDs is warranted.

Isolated Cerebral Mucormycosis Caused by Lichtheimia Species in a Polytrauma Patient

Isolated post-traumatic cerebral mucormycosis represents an extremely rare and severe disease. A case of isolated cerebral mucormycosis infection caused by Lichtheimia spp. in a 21-year-old multi-trauma patient is presented. The patient was hospitalized in the intensive care unit and underwent craniotomy due to brain injuries. Two weeks following the initial procedure, pus drained from the surgical wound was microscopically examined and cultured, yielding Lichtheimia spp. Imaging showed parietal, temporal and frontal abscesses at the right side. The patient was commenced on amphotericin B and underwent surgical debridement, while histopathological examination of the affected tissue demonstrated broad, aseptate hyphae, findings typical for mucormycetes. The patient passed away due to heavy traumatic injuries after 2 months. It is speculated that direct inoculation was the portal of entry for infection, and that high steroid use for 2 weeks following inoculation contributed to the severity of infection that developed. Isolated cerebral mucormycosis in immunocompetent hosts is an extremely rare, but severe disease. Diagnosis is established through direct microscopy, histopathology and/or cultures. PCR-based techniques are useful either to detect mucormycetes in tissues, especially when cultures are negative, or to accurately identify the fungi grown in cultures at the species level. A high suspicion index, especially in the necrotic lesions of traumas, is of the utmost importance for early diagnosis. Appropriate surgical debridement, as well as antifungal therapy, including amphotericin B, represents the treatment of choice.

Case Report: Metagenomics Next-Generation Sequencing for Diagnosing Cerebral Infarction and Infection Caused by Hematogenous Disseminated Mucormycosis in a Patient With Acute Lymphoblastic Leukemia

Disseminated mucormycosis, a serious complication, is associated with high mortality in patients with acute leukemia after chemotherapy. Blood cultures are always negative because of recurrent empirical antifungal treatments. The identification of pathogens is important for diagnosis and therapy. In this case report, we diagnosed culture-negative disseminated mucormycosis with Rhizomucor miehei infection leading to cerebral infarction in a patient with leukemia using metagenomics next-generation sequencing (mNGS) form peripheral blood, cerebral spinal fluid, and bronchoalveolar lavage fluid. mNGS technology can be applied to precisely diagnose culture-negative disseminated mucormycosis.

Isolated cerebral mucormycosis masquerading as a tumor in an immunocompetent patient

Mucormycosis is an opportunistic fungal disease that commonly presents as cutaneous or rhinocerebral infections associated with immunocompromised states. It may exceptionally present as isolated involvement of the brain with a varied clinical presentation, which may be difficult to diagnose early, leading to increased mortality. Herein, we report the case of a 42-year-old immunocompetent female with left-sided limb weakness and a history of recurrent vomiting and headache for the last two years. Clinically, glioma was suspected, but histopathological examination revealed a few broad aseptate fungal hyphae. As no other organ was involved, the diagnosis of isolated cerebral mucormycosis was rendered. Reporting this case, we show an unusual presentation of a central nervous system mucormycosis masquerading a tumor in an immunocompetent patient. The case also highlights the importance of a careful histopathological examination to avoid missing the presence of occasional fungal hyphae. Ideally, recognition of fungal hyphae in the brain, during intraoperative consultation, can prompt brain tissue culture for definitive diagnosis and early empirical antifungal therapy, which may prove life-saving.

Isolated Cerebral Mucormycosis in Immunocompetent Adults who Inject Drugs: Case Reports and Systematic Review of the Literature

Background

Mucormycosis involves life-threatening rapidly progressive angioinvasion with infiltration across tissue planes, resulting in necrosis and thrombosis, most commonly seen in the setting of immunocompromised states. We describe 2 cases of isolated cerebral mucormycosis in immunocompetent adults and describe this syndrome in detail in the context of a systemic literature review.

Methods

Using the criteria (1) isolated cerebral disease, (2) mucormycosis (by polymerase chain reaction, culture, or pathology), and (3) affected an immunocompetent individual, we identified 53 additional cases from 1969 to 2020.

Results

Of these 55 cases, ~60% occurred in men, >70% were in patients under age 35, 92% were associated with intravenous drug use, and >85% had infection centered in the basal ganglia. Many presented with cranial nerve deficits, headache, focal weakness, or altered mental status.

Conclusions

No patient survived without amphotericin, and steroid administration was associated with worse outcomes. Given the current opioid crisis, this syndrome may be seen more frequently.

Epidemiology and Diagnosis of Mucormycosis: An Update

Mucormycosis is an angioinvasive fungal infection, due to fungi of the order Mucorales. Its incidence cannot be measured exactly, since there are few population-based studies, but multiple studies have shown that it is increasing. The prevalence of mucormycosis in India is about 80 times the prevalence in developed countries, being approximately 0.14 cases per 1000 population. Diabetes mellitus is the main underlying disease globally, especially in low and middle-income countries. In developed countries the most common underlying diseases are hematological malignancies and transplantation. Τhe epidemiology of mucormycosis is evolving as new immunomodulating agents are used in the treatment of cancer and autoimmune diseases, and as the modern diagnostic tools lead to the identification of previously uncommon genera/species such as Apophysomyces or Saksenaea complex. In addition, new risk factors are reported from Asia, including post-pulmonary tuberculosis and chronic kidney disease. New emerging species include Rhizopus homothallicus, Thamnostylum lucknowense, Mucor irregularis and Saksenaea erythrospora. Diagnosis of mucormycosis remains challenging. Clinical approach to diagnosis has a low sensitivity and specificity, it helps however in raising suspicion and prompting the initiation of laboratory testing. Histopathology, direct examination and culture remain essential tools, although the molecular methods are improving. The internal transcribed spacer (ITS) region is the most widely sequenced DNA region for fungi and it is recommended as a first-line method for species identification of Mucorales. New molecular platforms are being investigated and new fungal genetic targets are being explored. Molecular-based methods have gained acceptance for confirmation of the infection when applied on tissues. Methods on the detection of Mucorales DNA in blood have shown promising results for earlier and rapid diagnosis and could be used as screening tests in high-risk patients, but have to be validated in clinical studies. More, much needed, rapid methods that do not require invasive procedures, such as serology-based point-of-care, or metabolomics-based breath tests, are being developed and hopefully will be evaluated in the near future.

Isolated cerebral mucormycosis associated with intravenous drug use

We present an uncommon case of isolated basal ganglia mucormycosis in a patient without any known cause of immunosuppression, but with a history of drug injection. The patient presented a good clinical and radiological response to antifungal treatment without aggressive surgical debridement (liposomal amphotericin B combined with isavuconazole for 4 weeks followed by isavuconazole as maintenance therapy for 10 months).

Fatal and Rapid Progressive Isolated Cerebral Mucormycosis Involving the Bilateral Basal Ganglia: A Case Report

Isolated cerebral mucormycosis is a clinical type of mucormycosis that is estimated to account for 8% of all mucormycosis cases. The clinical symptoms of isolated cerebral mucormycosis are elusive, and thus conventional techniques often lake sensitivity and specificity. Moreover, cultures are often negative, even when direct microscopy examination is positive. Although histopathology will probably remain the gold standard for the diagnosis of mucormycosis, obtaining a biopsy specimen is not always feasible in most vulnerable populations. Thus, molecular approaches are currently used as an advantageous assistant examination method to improve the early identification of the causative agent and subsequently guide therapy to improve the prognosis of patients. Here, we report a case of isolated cerebral mucormycosis caused by Rhizopus microspores in a healthy young adult that was identified using next-generation sequencing technology.

Mucormycosis of the Central Nervous System

Mucormycosis involves the central nervous system by direct extension from infected paranasal sinuses or hematogenous dissemination from the lungs. Incidence rates of this rare disease seem to be rising, with a shift from the rhino-orbital-cerebral syndrome typical of patients with diabetes mellitus and ketoacidosis, to disseminated disease in patients with hematological malignancies. We present our current understanding of the pathobiology, clinical features, and diagnostic and treatment strategies of cerebral mucormycosis. Despite advances in imaging and the availability of novel drugs, cerebral mucormycosis continues to be associated with high rates of death and disability. Emerging molecular diagnostics, advances in experimental systems and the establishment of large patient registries are key components of ongoing efforts to provide a timely diagnosis and effective treatment to patients with cerebral mucormycosis.

Disease Entities in Mucormycosis

Mucormycosis is an emerging life-threatening fungal infection caused by Mucorales. This infection occurs mainly in immunocompromised patients, especially with hematological malignancy, transplantation, or diabetes mellitus. Rhino-orbito-cerebral and pulmonary mucormycosis are the predominant forms. Interestingly, location is associated with the underlying disease as pulmonary mucormycosis is more frequent in hematological malignancy patients whereas rhino-orbito-cerebral mucormycosis is associated with diabetes. Cutaneous mucormycosis results from direct inoculation, mainly after trauma or surgery. Gastro-intestinal mucormycosis occurs after ingestion of contaminated food or with contaminated device and involves the stomach or colon. Disseminated disease is the most severe form and is associated with profound immunosuppression. Uncommon presentations with endocarditis, osteoarticluar or isolated cerebral infections are also described. Finally, health-care associated mucormycosis is a matter of concern in premature newborns and burn units. Clinical symptoms and CT scan findings are not specific, only the early reversed halo sign is associated with pulmonary mucormycosis. Circulating Mucorales DNA detection is a recent promising diagnostic tool that may lead to improving the diagnosis and prompting therapeutic initiation that should include antifungal treatment, correction of the underlying disease and surgery when feasible.