Aspergillosis of the central nervous system in a previously healthy patient that simulated Creutzfeldt-Jakob disease

ASPERGILLOSIS OF THE BRAIN, DIAGNOSTIC DIFFICULTIES: CASE REPORT

Background. Neuroaspergillosis has nonspecific clinical manifestations and severe course. Cases of CNS aspergillosis are becoming more frequent. Its lifetime diagnosis is very difficult. At the same time, timely diagnosis makes it possible to conduct adequate specific therapy and save the patient's life. Clinical Case Description. The case reports demonstrate the possibility of lethal damage to the brain by filamentous fungi in a patient who does not have risk factors described in the literature - AIDS, neutropenia, organ and tissue transplantation, long therapy with immunosuppressive drugs or corticosteroids. Conclusion. It is necessary to take into account the possibility of the presence of this pathology in patients even in the absence of fever and immunodeficiency conditions. A specific study of biological fluids for the content of galactomannan antigen will allow you to establish the correct diagnosis in time and conduct adequate treatment.

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.

Neuroinfections caused by fungi

BACKGROUND

Fungal infections of the central nervous system (FIs-CNS) have become significantly more common over the past 2 decades. Invasion of the CNS largely depends on the immune status of the host and the virulence of the fungal strain. Infections with fungi cause a significant morbidity in immunocompromised hosts, and the involvement of the CNS may lead to fatal consequences.

METHODS

One hundred and thirty-five articles on fungal neuroinfection in PubMed, Google Scholar, and Cochrane databases were selected for review using the following search words: "fungi and CNS mycoses", CNS fungal infections", "fungal brain infections", " fungal cerebritis", fungal meningitis", "diagnostics of fungal infections", and "treatment of CNS fungal infections". All were published in English with the majority in the period 2000-2018. This review focuses on the current knowledge of the epidemiology, clinical presentations, diagnosis, and treatment of selected FIs-CNS.

RESULTS

The FIs-CNS can have various clinical presentations, mainly meningitis, encephalitis, hydrocephalus, cerebral abscesses, and stroke syndromes. The etiologic factors of neuroinfections are yeasts (Cryptococcus neoformans, Candida spp., Trichosporon spp.), moniliaceous moulds (Aspergillus spp., Fusarium spp.), Mucoromycetes (Mucor spp., Rhizopus spp.), dimorphic fungi (Blastomyces dermatitidis, Coccidioides spp., Histoplasma capsulatum), and dematiaceous fungi (Cladophialophora bantiana, Exophiala dermatitidis). Their common route of transmission is inhalation or inoculation from trauma or surgery, with subsequent hematogenous or contiguous spread. As the manifestations of FIs-CNS are often non-specific, their diagnosis is very difficult. A fast identification of the etiological factor of neuroinfection and the application of appropriate therapy are crucial in preventing an often fatal outcome. The choice of effective drug depends on its extent of CNS penetration and spectrum of activity. Pharmaceutical formulations of amphotericin B (AmB) (among others, deoxycholate-AmBd and liposomal L-AmB) have relatively limited distribution in the cerebrospinal fluid (CSF); however, their detectable therapeutic concentrations in the CNS makes them recommended drugs for the treatment of cryptococcal meningoencephalitis (AmBd with flucytosine) and CNS candidiasis (L-AmB) and mucormycosis (L-AmB). Voriconazole, a moderately lipophilic molecule with good CNS penetration, is recommended in the first-line therapy of CNS aspergillosis. Other triazoles, such as posaconazole and itraconazole, with negligible concentrations in the CSF are not considered effective drugs for therapy of CNS fungal neuroinfections. In contrast, clinical data have shown that a novel triazole, isavuconazole, achieved considerable efficacy for the treatment of some fungal neuroinfections. Echinocandins with relatively low or undetectable concentrations in the CSF do not play meaningful role in the treatment of FIs-CNS.

CONCLUSION

Although the number of fungal species causing CNS mycosis is increasing, only some possess well-defined treatment standards (e.g., cryptococcal meningitis and CNS aspergillosis). The early diagnosis of fungal infection, accompanied by identification of the etiological factor, is needed to allow the selection of effective therapy in patients with FIs-CNS and limit their high mortality.