Magnetic resonance imaging findings in central nervous system cryptococcosis: comparison between immunocompetent and immunocompromised patients

Quantitative MRI of a Cerebral Cryptococcoma Mouse Model for In Vivo Distinction between Different Cryptococcal Molecular Types

The controversially discussed taxonomy of the Cryptococcus neoformans/Cryptococcus gattii species complex encompasses at least eight major molecular types. Cerebral cryptococcomas are a common manifestation of cryptococcal neurological disease. In this study, we compared neurotypical symptoms and differential neurovirulence induced by one representative isolate for each of the eight molecular types studied. We compared single focal lesions caused by the different isolates and evaluated the potential relationships between the fungal burden and properties obtained with quantitative magnetic resonance imaging (qMRI) techniques such as diffusion MRI, T2 relaxometry and magnetic resonance spectroscopy (MRS). We observed an inverse correlation between parametric data and lesion density, and we were able to monitor longitudinally biophysical properties of cryptococcomas induced by different molecular types. Because the MRI/MRS techniques are also clinically available, the same approach could be used to assess image-based biophysical properties that correlate with fungal cell density in lesions in patients to determine personalized treatments.

Association between neuroimaging and clinical outcomes in individuals with central nervous system cryptococcosis

BACKGROUND

The radiological manifestations of central nervous system (CNS) cryptococcosis are diverse and often subtle. There is heterogeneity on how different neuroimaging patterns impact prognosis. This study aims to assess the association between the neuroimaging and clinical outcomes of CNS cryptococcosis.

METHODS

All patients with CNS cryptococcosis between July 2017 and April 2023 who underwent brain magnetic resonance imaging (MRI) were included. The primary outcome was mortality during hospitalisation. Secondary outcomes were readmission, ventricular shunting, duration of hospitalisation and time to the first negative cerebrospinal fluid culture. We compared the outcomes for each of the five main radiological findings on the brain MRI scan.

RESULTS

We included 46 proven CNS cryptococcosis cases. The two main comorbidity groups were HIV infection (20, 43%) and solid organ transplantation (10, 22%), respectively. Thirty-nine patients exhibited at least one radiological abnormality (85%), with the most common being meningeal enhancement (34, 74%). The mortality rates occurred at 11% (5/46) during hospitalisation. We found no significant disparities in mortality related to distinct radiological patterns. The presence of pseudocysts was significantly associated with the need for readmission (p = .027). The ventricular shunting was significantly associated with the presence of pseudocysts (p = .005) and hydrocephalus (p = .044).

CONCLUSION

In this study, there is no association between brain MRI findings and mortality. Larger studies are needed to evaluate this important issue.

Infectious Diseases of the Brain and Spine: Fungal Diseases

Advances in treatments of autoimmune diseases, acquired immunodeficiency syndrome, organ transplantation, and the use of long-term devices have increased the rates of atypical infections due to prolonged immune suppression. There is a significant overlap in imaging findings of various fungal infections affecting the central nervous system (CNS), often mimicking those seen in neoplastic and noninfectious inflammatory conditions. Nonetheless, there are imaging characteristics that can aid in distinguishing certain atypical infections. Hence, familiarity with a wide range of infectious agents is an important part of diagnostic neuroradiology. In this article, an in-depth review of fungal diseases of the CNS is provided.

Overview of the Current Knowledge and Conventional MRI Characteristics of Peri- and Para-Vascular Spaces

Brain spaces around (perivascular spaces) and alongside (paravascular or Virchow-Robin spaces) vessels have gained significant attention in recent years due to the advancements of in vivo imaging tools and to their crucial role in maintaining brain health, contributing to the anatomic foundation of the glymphatic system. In fact, it is widely accepted that peri- and para-vascular spaces function as waste clearance pathways for the brain for materials such as ß-amyloid by allowing exchange between cerebrospinal fluid and interstitial fluid. Visible brain spaces on magnetic resonance imaging are often a normal finding, but they have also been associated with a wide range of neurological and systemic conditions, suggesting their potential as early indicators of intracranial pressure and neurofluid imbalance. Nonetheless, several aspects of these spaces are still controversial. This article offers an overview of the current knowledge and magnetic resonance imaging characteristics of peri- and para-vascular spaces, which can help in daily clinical practice image description and interpretation. This paper is organized into different sections, including the microscopic anatomy of peri- and para-vascular spaces, their associations with pathological and physiological events, and their differential diagnosis.

Cryptococcosis in kidney transplant recipients: Current understanding and practices

Cryptococcosis is the third most commonly occurring invasive fungal disease in solid organ transplant recipients (SOT). It is caused by encapsulated yeast, Cryptococcus species, predominantly Cryptococcus neoformans and Cryptococcus gattii. Though kidney transplant recipients are at the lowest risk of cryptococcosis when compared to other solid organ transplant recipients such as lung, liver or heart, still this opportunistic infection causes significant morbidity and mortality in this subset of patients. Mortality rates with cryptococcosis range from 10%-25%, while it can be as high as 50% in SOT recipients with central nervous system involvement. The main aim of diagnosis is to find out if there is any involvement of the central nervous system in disseminated disease or whether there is only localized pulmonary involvement as it has implications for both prognostication and treatment. Detection of cryptococcal antigen (CrAg) in cerebrospinal fluid or plasma is a highly recommended test as it is more sensitive and specific than India ink and fungal cultures. The CrAg lateral flow assay is the single point of care test that can rapidly detect cryptococcal polysaccharide capsule. Treatment of cryptococcosis is challenging in kidney transplant recipients. Apart from the reduction or optimization of immunosuppression, lipid formulations of amphotericin B are preferred as induction antifungal agents. Consolidation and maintenance are done with fluconazole; carefully monitoring its interactions with calcineurin inhibitors. This review further discusses in depth the evolving developments in the epidemiology, pathogenesis, diagnostic assays, and management approach of cryptococcosis in kidney transplant recipients.

Insights into Magnetic Resonance Imaging Findings in Central Nervous System Paracoccidioidomycosis: A Comprehensive Review

Paracoccidioidomycosis (PCM) is a infection caused by the thermodimorphic fungus Paracoccidioides spp. (P. lutzii and, mainly, P. brasiliensis). This infection predominantly affects rural male workers aged between 30 and 50 years old who deal with soil on daily activities. Clinically, the disease is classified as acute/subacute phase, which evolves rapidly, secondary to dissemination of the fungus through to the phagocytic-mononuclear system, leading to fever, weight loss, and anorexia, associated with hepatosplenomegaly and lymphadenopathy, which can be complicated with suppuration and fistulization; and chronic phase, which corresponds to 74% to 95% of symptomatic cases, with a common pulmonary involvement. Central nervous system involvement is almost always a characteristic of the chronic form. Inhalation is the most common route of primary infection, usually affecting the lungs, forming the primary complex. From the primary complex, hematogenic dissemination can occur to any organ, including the brain and spinal cord. Although PCM of the central nervous system diagnosis is usually based on histopathological analysis and the imaging features are not specific for PCM, computed tomography and magnetic resonance imaging can demonstrate evidences of granuloma, abscess, meningitis, or a combination of these lesions, contributing to a preoperative diagnosis, especially when considered in conjunction with epidemiology. In this article, we review the pathophysiology, clinical manifestations and imaging aspects of neuro-PCM.

Dural and Leptomeningeal Diseases: Anatomy, Causes, and Neuroimaging Findings

Meningeal lesions can be caused by various conditions and pose diagnostic challenges. The authors review the anatomy of the meninges in the brain and spinal cord to provide a better understanding of the localization and extension of these diseases and summarize the clinical and imaging features of various conditions that cause dural and/or leptomeningeal enhancing lesions. These conditions include infectious meningitis (bacterial, tuberculous, viral, and fungal), autoimmune diseases (vasculitis, connective tissue diseases, autoimmune meningoencephalitis, Vogt-Koyanagi-Harada disease, neuro-Behçet syndrome, Susac syndrome, and sarcoidosis), primary and secondary tumors (meningioma, diffuse leptomeningeal glioneuronal tumor, melanocytic tumors, and lymphoma), tumorlike diseases (histiocytosis and immunoglobulin G4-related diseases), medication-induced diseases (immune-related adverse effects and posterior reversible encephalopathy syndrome), and other conditions (spontaneous intracranial hypotension, amyloidosis, and moyamoya disease). Although meningeal lesions may manifest with nonspecific imaging findings, correct diagnosis is important because the treatment strategy varies among these diseases. ©RSNA, 2023 Online supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article. Quiz questions for this article are available through the Online Learning Center.

In vivo assessment of differences in fungal cell density in cerebral cryptococcomas of mice infected with Cryptococcus neoformans or Cryptococcus gattii

In cerebral cryptococcomas caused by Cryptococcus neoformans or Cryptococcus gattii, the density of fungal cells within lesions can contribute to the overall brain fungal burden. In cultures, cell density is inversely related to the size of the cryptococcal capsule, a dynamic polysaccharide layer surrounding the cell. Methods to investigate cell density or related capsule size within fungal lesions of a living host are currently unavailable, precluding in vivo studies on longitudinal changes. Here, we assessed whether intravital microscopy and quantitative magnetic resonance imaging techniques (diffusion MRI and MR relaxometry) would enable non-invasive investigation of fungal cell density in cerebral cryptococcomas in mice. We compared lesions caused by type strains C. neoformans H99 and C. gattii R265 and evaluated potential relations between observed imaging properties, fungal cell density, total cell and capsule size. The observed inverse correlation between apparent diffusion coefficient and cell density permitted longitudinal investigation of cell density changes. Using these imaging methods, we were able to study the multicellular organization and cell density within brain cryptococcomas in the intact host environment of living mice. Since the MRI techniques are also clinically available, the same approach could be used to assess fungal cell density in brain lesions of patients.

Systematic review of neuroparacoccidioidomycosis: The contribution of neuroimaging

BACKGROUND

Advanced neuroimaging demonstrated that neurological involvement occurs in up to 30% of paracoccidioidomycosis (PCM) cases. Current knowledge of neuroparacoccidioidomycosis (NPCM) is based on a 2009 systematic review. However, in the last decade, several new cases have been published, with modern neuroimaging techniques.

OBJECTIVES

We believe a new systematic review is needed to summarise these advances.

METHODS

We searched PubMed/MEDLINE, Embase and LILACS for studies from January 2010 to May 2022. Case series and case reports of NPCM were included. We performed a metaproportion to estimate a summary proportion with 95% confidence intervals (CI).

RESULTS

Thirty-four studies including 104 patients were evaluated. We combined our data with the results from the previous review that included 257 cases, totalling 361 patients. We found no new important demographic, clinical or laboratory characteristics. On magnetic resonance imaging (MRI), we found that 72% (95%CI: 38-91) had hyperintensity on T1-weighted image; 84% (95%CI: 71%-92%) had hypointensity on T2-weighted image; 80% (95%CI: 66-89) had contrast enhancement with the classical ring-enhancing pattern. All 8 patients undergoing spectroscopy presented lipid peaks. We found a 16% mortality, lower than in the previous review (44%).

CONCLUSION

NPCM presents a characteristic pattern on MRI that may help to differentiate it from other causes of single or multiple brain lesions. Albeit there is a frequent pattern, it is not specific, as other granulomatous diseases may show similar findings. Advances in neuroimaging with early diagnosis and appropriate management of the disease may have contributed to reducing its mortality.

Cryptococcal Meningitis in a Mexican Neurological Center

BACKGROUND

Cryptococcal meningitis, one of the most severe infections affecting the central nervous system, often involves severe neurological sequels and high mortality.

METHODS

A retrospective review was performed, including 76 cases admitted in a 10-year period at a neurological referral center in Mexico City. From 68 isolates, 52 fungal specimens were identified as part of the Cryptococcus neoformans var. neoformans complex, 15 as C. neoformans var gattii complex, and one as Cryptococcus non-neoformans/gattii.

RESULTS

Higher cryptococcal meningitis incidence and severity were found in HIV-infected men; other risk factors frequently observed were diabetes mellitus and labor exposure to poultry. The main clinical manifestations were subacute headache, cognitive alterations, and photophobia (exclusively in HIV patients). MRI was highly sensitive for pathologic findings such as meningeal enhancements and cryptococcomas, most of them associated to C. neoformans complex. Eleven patients developed severe brain vasculitis, as observed by transcranial Doppler. Hydrocephalus with intracranial hypertension was the most frequent complication.

CONCLUSIONS

One-half of the population died, and the rest had neurological sequels, mainly neuropsychiatric manifestations and secondary headaches. These patients developed severe functional limitations in performing daily activities in an independent manner.

What's New in Cryptococcus gattii: From Bench to Bedside and Beyond

Cryptococcus species are a major cause of life-threatening infections in immunocompromised and immunocompetent hosts. While most disease is caused by Cryptococcus neoformans, Cryptococcus gattii, a genotypically and phenotypically distinct species, is responsible for 11-33% of global cases of cryptococcosis. Despite best treatment, C. gattii infections are associated with early mortality rates of 10-25%. The World Health Organization's recently released Fungal Priority Pathogen List classified C. gattii as a medium-priority pathogen due to the lack of effective therapies and robust clinical and epidemiological data. This narrative review summarizes the latest research on the taxonomy, epidemiology, pathogenesis, laboratory testing, and management of C. gattii infections.

Cerebral cryptococcoma successfully treated by isavuconazole in an immunocompetent patient: A case report

Cryptococcosis has been recognized as an increasing cause of severe systemic mycosis in immunocompetent patients in the last few years. Cerebral cryptococcomas are a more uncommon manifestation of cryptococcal meningitis, which are not usually included in the differential of brain masses. We report a case of a young, immunocompetent woman that rapidly developed severe neurological deficits. She was ultimately diagnosed with cerebral cryptococcoma caused by both Cryptococcus neoformans and Cryptococcus gattii, and was treated with amphotericin B and isavuconazole. After several complications during hospitalization, including hydrocephalus and cerebellitis, she was discharged home on isavuconazole. On follow-up, she only complained of anosmia. We review the clinical and radiological findings of similar cases. It is the first time that this form of cryptococcal meningitis is favorably treated with isavuconazole and is caused by 2 species of Cryptococcus. We emphasize that cerebral cryptococcomas should be suspected in immunocompetent patients that present with brain masses.

Treatment recommendations for non-HIV associated cryptococcal meningoencephalitis including management of post-infectious inflammatory response syndrome

Cryptococcal meningoencephalitis (CM) continues to cause major morbidity and mortality in a range of patients such as those immunosuppressed from HIV and with biologic immunosuppressants, including treatments of autoimmunity, malignancies, and conditioning regimens for transplantation. It is currently the most common cause of non-viral meningitis in the United States. Infections in previously healthy patients also develop with autoantibodies to granulocyte-macrophage colony stimulating factor or with monogenetic defects. In all populations, mortality and significant long-term morbidity occur in 30-50% despite therapy, and immune reconstitution and post-infectious inflammatory response syndromes complicate management. To help with these difficult cases, we present here a practical tutorial of the care of a range of patients with CM in the absence of HIV/AIDS.

Common and uncommon neuroimaging manifestations of ataxia: an illustrated guide for the trainee radiologist. Part 1 – acquired diseases

Abstract Ataxia is defined as a lack of coordination of voluntary movement, caused by a variety of factors. Ataxia can be classified by the age at onset and type (chronic or acute). The causative lesions involve the cerebellum and cerebellar connections. The correct, appropriate use of neuroimaging, particularly magnetic resonance imaging, can make the diagnosis relatively accurate and facilitate implementation of the appropriate clinical management. The purpose of this pictorial essay is to describe the imaging findings of ataxia, based on cases obtained from the archives of a tertiary care hospital, with a review of the most important findings. We also review and discuss the imaging aspects of infectious, toxic, vascular, and inflammatory diseases.

Case Report: Cryptococcal Meningitis

BACKGROUND: Cryptococcal meningitis is one of the most common opportunistic infections in immunocompromised patients. Mostly it manifests as subacute/chronic meningitis, although pathological findings suggest extensive tissue invasion of the brain parenchyma and meninges. This disease has a very high mortality rate, even with the administration of an antifungal combination. CASE REPORT: Male, 53 years old, with clinical symptoms of headache, was experienced by the patient from 1 month before admission and worsening within 1 week. The headache describe throbbing throughout the head, with severe intensity, and does not go away with pain medications. The frequency of headaches is persistent and does not go away with pain medications. A history of weight loss was found, about 10 kg in 3 months. A history of free sex was found. History of HIV known since 1 day before admission to hospital and has not undergone antiretroviral treatment. The patient was diagnosed with cryptococcal meningitis on the basis of the finding of yeas t-like cells on the Indian ink test, and the patient was also a stage IV HIV patient with a decreased CD4 count. The patients treated with tapering off dexamethasone injection, 1× 960 mg Cotrimoxazole, 400 mg/24 h injection of fluconazole, and 3 × 1 folic acid, and received 1 × 1 fixed dose combination antiretrovirals therapy. CONCLUSION: Cryptococcal meningitis is a disease caused by cryptococcal fungi and its incidence increases with the increase in diseases associated with immune system disorders such as HIV.

Fungal CNS Infections in Africa: The Neuroimmunology of Cryptococcal Meningitis

Cryptococcal meningitis (CM) is the leading cause of central nervous system (CNS) fungal infections in humans, with the majority of cases reported from the African continent. This is partly due to the high burden of HIV infection in the region and reduced access to standard-of-care including optimal sterilising antifungal drug treatments. As such, CM is responsible for 10-15% of all HIV-related mortality, with a large proportion being preventable. Immunity to the causative agent of CM, Cryptococcus neoformans, is only partially understood. IFNγ producing CD4⁺ T-cells are required for the activation of myeloid cells, especially macrophages, to enable fungal killing and clearance. However, macrophages may also act as a reservoir of the fungal yeast cells, shielding them from host immune detection thus promoting latent infection or persistent chronic inflammation. In this chapter, we review the epidemiology and pathogenesis of CNS fungal infections in Africa, with a major focus on CM, and the antifungal immune pathways operating to protect against C. neoformans infection. We also highlight the areas of research and policy that require prioritisation to help reduce the burden of CNS fungal diseases in Africa.

Cryptococcosis Presenting as Cerebrovascular Disease

Infection plays a complex role in cerebrovascular disease and is believed to have both direct and indirect mechanisms on stroke pathogenesis. if not diagnosed and treated promptly, this may have devastating consequences. Management of infection-related strokes focuses on the treatment of the underlying infection with appropriate antimicrobial drugs and the prevention of medical complications. This can lead to devastating neurological deficits. We present two cases of cryptococcal meningoencephalitis that presented with an atypical cerebral infarction. A 55-year-old male with a history of unknown autoimmune disease presented with acute onset cognitive changes and no stroke-like symptoms. A 35-year-old male with no history of autoimmune disease or other existing immunodeficiency presented with breakthrough seizure a long with stroke-like symptoms. Both patients developed multiple cerebral infarcts in multiple vascular territories, with histologic and radiologic findings consistent with a central nervous system cryptococcosis. They were subsequently diagnosed with cryptococcal meningoencephalitis and started on the appropriate anti-fungal regimen with amphotericin B and flucytosine. Prior to discharge to an inpatient rehabilitation facility, both patients were notably improved and near their neurologic baseline. It is important to understand the pathogenesis of cryptococcal infection in the central nervous system because it produces a wide variety of clinico-radiographic features that can be overlooked. Clinicians should keep infection-mediated cerebral infarcts in mind, regardless of risk factors, in order to expedite antimicrobial therapy and minimize adverse events.

Neurologic Complications of Human Immunodeficiency Virus

PURPOSE OF REVIEW

This article reviews the neurologic complications associated with human immunodeficiency virus (HIV) infection.

RECENT FINDINGS

Neurologic complications of HIV may be caused by direct virally mediated pathology, immune-mediated phenomena in response to viral infection, or opportunistic infections secondary to depletion of lymphocytes. These neurologic disorders may be influenced by the degree of immunosuppression (ie, CD4+ T-cell lymphocyte count) and stage of infection (early versus late), as well as use of antiretroviral therapy, and may manifest as a variety of central and peripheral neurologic syndromes, including the more commonly encountered HIV-associated cognitive disorders and length-dependent sensorimotor polyneuropathy, respectively. Immune dysregulation underlies the majority of these neurologic phenomena, as well as other HIV-associated conditions including immune reconstitution inflammatory syndrome (IRIS), CD8 lymphocytosis, and potentially the development of compartmentalized infection within the CSF, also referred to as CSF escape.

SUMMARY

This article reviews a spectrum of clinical syndromes and related neuropathologic states associated with HIV infection.

A Tale of Two Organ Systems: Imaging review of diseases affecting the thoracic and neurological systems. Part 1

In an era of rapidly expanding knowledge and sub-specialization, it is becoming increasingly common to focus on one organ system. However, the human body is intimately linked, and disease processes affecting one region of the body not uncommonly affect the other organ systems as well. Understanding diseases from a macroscopic perspective, rather than a narrow vantage point, enables efficient and accurate diagnosis. This tenet holds true for diseases affecting both the thoracic and neurological systems; in isolation, the radiologic appearance of disease in one organ system may be nonspecific, but viewing the pathophysiologic process in both organ systems may markedly narrow the differential considerations, and potentially lead to a definitive diagnosis. In this article, we discuss a variety of disease entities known to affect both the thoracic and neurological systems, either manifesting simultaneously or at different periods of time. Some of these conditions may show neither thoracic nor neurological manifestations. These diseases have been systematically classified into infectious, immune-mediated / inflammatory, vascular, syndromic / hereditary and neoplastic disorders. The underlying pathophysiological mechanisms linking both regions and radiologic appearances in both organ systems are discussed. When appropriate, brief clinical and diagnostic information is provided. Ultimately, accurate diagnosis will lead to expedited triage and prompt institution of potentially life-saving treatment for these groups of complex disorders.

Multiple intracranial cryptococcomas in an immunocompetent patient with pulmonary involvement

Opportunistic infections affecting central nervous system (CNS) have high prevalence in developing countries and cryptococcosis is one of them. It is associated with myriad of signs symptoms and clinical behavior. Though commonly associated with AIDS/HIV infection, it has been reported to be pathogenic in immunocompetent patients. Leptomeningitis is most common presentation in CNS, but unusual tumor like mass lesions have been reported. Lungs are primary site of infection, but it can affect different organs with varied clinical presentations. Therefore, correct diagnosis and proper management is essential in such cases excluding the differentials as fatality rate can be quite high. We report such an unusual case of multiple cryptococcal mass lesions in brain in a healthy immune competent individual with bilateral pulmonary involvement.

Initial diagnosis of HIV/AIDS in patients presenting to the emergency department: Imaging and clinical findings at a single institution

PURPOSE

To evaluate the clinical, laboratory, and imaging findings along with treatment and outcomes associated with patients presenting to the emergency department (ED) who were subsequently diagnosed with HIV/AIDS.

METHODS

591 patients with HIV and available imaging studies presenting to our hospital's ED between 2004 and 2019 were identified in the medical record. Following initial review, we identified 19 patients who were diagnosed with HIV within one week after an initial ED visit and also had received CT imaging during the ED visit. Demographic, clinical, treatment, imaging, and outcome data were reviewed and recorded for each patient.

RESULTS

Among this 19-patient cohort, the most common indication for HIV testing was oral/esophageal candidiasis (n = 8, 42%). 12 patients presented with an AIDS-defining illness upon initial diagnosis; the most common were esophageal candidiasis (4) and Pneumocystis jiroveci pneumonia (PJP) (3). 10 patients (59%) presented with CD4+ counts <200 cells/L. The most common imaging findings were liver abnormalities (n = 9, 47%). Five of the 19 patients were confirmed deceased at the time of this study, with the median time from diagnosis to death of 5.6 months (range 8 days-14 months).

CONCLUSION

Our series demonstrates the breadth of potential imaging findings and clinical presentations of late-stage HIV in the emergency setting, including common AIDS-defining illnesses such as PJP and PML. Although the incidence of these conditions is decreasing, maintaining awareness of their clinical and imaging findings, as well as the potential for multi-organ involvement, is essential due to the possibility of rapid decline in these patients.

Comparison of patterns of infarction in TB and cryptococcal meningitis

BACKGROUND

To compare the frequency and patterns of stroke, the specificity of tubercular zone (TBZ) infarction and its effect on outcomes in TB (TBM) and cryptococcal meningitis (CM).

METHODS

This retrospective study was conducted at two tertiary centres in India from May 2018 to July 2020. Sixty-one patients with TBM and 22 with CM were included. The primary outcome was the proportions of TBM and CM patients with infarction. Secondary outcomes included the anatomical locations of infarction and in-hospital mortality.

RESULTS

Infarction was noted in 52.5% of patients with TBM and in 54.5% of those with CM (p=0.87), with caudate head infarcts in 9.4% vs 41.7% (p=0.01), cerebellar in 9.4% vs 33.3% (p=0.05), thalamic in 25% vs 0% and lobar in 28.1% vs 0%, respectively. In TBM, the infarcts were located in the TBZ in 3 (9.4%), in the ischaemic zone in 23 (71.9%), while 6 (18.8%) patients showed infarcts in both, while in CM, the infarcts were in 0 (0%), 6 (50%) and 6 (50%) patients, respectively. Infarcts were not associated with in-hospital mortality, either in TBM or CM.

CONCLUSION

Caudate head and cerebellar infarction was more common in CM, while thalamic and lobar infarcts were more frequent in TBM. TBZ infarcts were not specific to TBM.

Cerebellar amelanotic melanoma can mimic cerebellar abscess in a pediatric case of neurocutaneous melanosis

Neurocutaneous melanosis (NCM) is a rare phakomatosis that may be associated with intracerebral masses. The differential diagnosis of intracerebral masses in NCM is often challenging and should include pigmented and nonpigmented lesions.

Diagnostic value of real-time PCR of brain mass lesion in HIV-associated toxoplasmic encephalitis: a case series

BACKGROUND

Toxoplasmic encephalitis (TE) is a leading cause of brain mass lesions (BML) in human immunodeficiency viruses (HIV)-infected patients. Yet, so far, no accurate diagnostic approach for TE has been developed. Herein, we presented a case series (9 HIV-infected patients with TG confirmed by RT-PCR of BML) to assess the diagnostic value of reverse transcription-polymerase chain reaction (RT-PCR) on TE.

METHODS

A total of 9 HIV-infected patients with TE confirmed by RT-PCR of BML were included in this study. Clinical data, including clinical symptoms, blood and CSF analysis, neuroimaging features, histopathological characteristics, treatment, and prognosis, were assessed in all patients. According to the results of RT-PCR of BML, all the patients received oral administration of trimethoprim-sulfamethoxazole combined with antiretroviral therapy (ART). Patients were followed up by telephone or outpatient service.

RESULTS

There were 8 male and 1 female patients; their age ranged from 26 to 56 years-old. The main symptom was intracranial hypertension (6/9). Six patients presented multiple brain lesions, which were mainly located in the supratentorial area (7/9). CD₄⁺ count ranged from 11 to 159 cells/μl (median 92 cells/μl), and serological HIV viral load 0-989190 copies/ml (median 192836 copies/ml). IgG and IgM against serum TG were positive in 7 and 1 patients, respectively. Moreover, regarding CSF, IgG against TG was positive in 3 patients, while all patients were negative for IgM. The neuroimaging features on MRI showed no specificity. Four patients were diagnosed with TE by histopathological findings. After receiving anti-Toxoplasma therapy, 8 (8/9) patients improved clinically to a considerable extent.

CONCLUSIONS

The application of RT-PCR of BML, together with conventional methods, may significantly improve the diagnostic efficiency of TE.

Haemorrhagic encephalitis in the garb of scrub typhus

A 19-year-old girl presented with fever, headache, vomiting and drowsiness. She had grade 1 papilloedema and neck rigidity but no focal deficits or seizures. Cerebrospinal fluid analysis revealed lymphocytic pleocytosis, slightly elevated protein and normal glucose. MRI of the brain showed a hyperintense lesion in left ganglio-capsular region on the fluid attenuation inversion recovery sequence with perilesional oedema and mild midline shift. Haemorrhage was seen in the region on susceptibility weighted imaging . The patient was thoroughly investigated for known causes of meningoencephalitis, but the diagnosis of scrub typhus was delayed till the 10th day of illness. She was treated with doxycycline for 2 weeks and had marked improvement, both clinically and radiologically. Literature review has revealed that although meningoencephalitis in scrub typhus is not uncommon, such atypical lesions on brain MRI are a rarity. Serial imaging was performed to document the disease progression and resolution on treatment.

Cerebral toxoplasmosis in HIV-infected patients over 2015-2018 (a case study of Russia)

Cerebral toxoplasmosis is a leading cause of the central nervous system disorders in acquired immune deficiency syndrome. This study aimed to investigate the clinical course of cerebral toxoplasmosis in human immunodeficiency virus (HIV)-infected individuals. The study included 90 HIV-infected patients with cerebral toxoplasmosis, who underwent inpatient treatment. In case of positive enzyme immunoassay, HIV infection was confirmed with the immunoblot test. The HIV-1 ribonucleic acid level was determined using the polymerase chain reaction method. The flow cytometry was used for counting CD4 (cluster of differentiation 4 cells). Pathomorphological examination included the autopsy, gross and microscopic examination of internal organs, histological and other methods. The incidence of cerebral toxoplasmosis significantly increases at the CD4 count below 100 cells/μl, P < 0.001, and at the HIV viral load above 50 copies/ml, P < 0.05. The clinical picture of cerebral toxoplasmosis included focal symptoms, cognitive impairment, toxic syndrome, mild cerebral symptoms and a meningeal symptom. Given the absence of a specific clinical picture and the absence of abnormal laboratory and instrumental findings, the cerebral toxoplasmosis needs to be diagnosed with a number diagnostic methods combined: clinical examination, laboratory testing, immunological examination, molecular genetic testing and neuroradiological imaging.

Brain miliary enhancement

PURPOSE

Miliary enhancement refers to the presence of multiple small, monomorphic, enhancing foci on T1-weighted post-contrast MRI images. In the absence of a clear clinical presentation, a broad differential diagnosis may result in invasive procedures and possibly brain biopsy for diagnostic purposes.

METHODS

An extensive review of the literature is provided for diseases that may present with miliary enhancement on T1-weighted brain MR images. Additional disease-specific findings, both clinical and radiological, are summarized and categorized by the presence or absence of perivascular space involvement.

RESULTS

Miliary pattern of enhancement may be due to a variety of underlying causes, including inflammatory, infectious, nutritional or neoplastic processes. The recognition of disease spread along the perivascular spaces in addition to the detection or exclusion of disease-specific features on MRI images, such as leptomeningeal enhancement, presence of haemorrhagic lesions, spinal cord involvement and specific localisation or systemic involvement, allows to narrow the potential differential diagnoses.

CONCLUSION

A systematic approach to disease-specific findings from both clinical and radiological perspectives might facilitate diagnostic work-up, and recognition of disease spread along the perivascular spaces may help narrowing down differential diagnoses and may help to minimize the use of invasive diagnostic procedures.

CNS Infections in Immunoincompetent Patients : Neuroradiological and Clinical Features

In patients with immunodeficiency the pathogen spectrum of central nervous system (CNS) infections is broader and different from that of immunocompetent patients. Numerous opportunistic infections are characterized by a high prevalence of viral, bacterial and parasitic pathogens, and depend on the type of impaired immune defense, for example impaired T‑cell or monocyte function, monoclonal antibody treatment, and impaired granulocyte function. Neuroradiological features as well as laboratory findings are often different and versatile in comparison to immunocompetent individuals and pathognomonic imaging findings do not exist; however, knowledge of possible pathways of pathogens in the CNS and preferred tissue affection may help in narrowing down differential diagnoses. Therefore, knowledge of the type of patient and the performed immunomodulatory therapy is essential for the neuroradiological assessment and the differential diagnostic considerations. Moreover, parenchymal reactions in the sense of an immune reconstitution inflammatory syndrome (IRIS) can occur when immunocompetence is restored. This review focus on the most common pathologies in immunocompromised patients, and an overview of imaging features but also of pathology and clinical aspects is given. The synopsis of anamnestic information, clinical findings and structured analysis of the lesion pattern, its spread and short-term follow-up may increase the correct diagnostic classification; however, the gold standard is still determination of the pathogen in the cerebrospinal fluid (CSF), blood cultures or biopsies.

Central Nervous System Cryptococcal Infections in Non-HIV Infected Patients

Central nervous system (CNS) cryptococcosis in non-HIV infected patients affects solid organ transplant (SOT) recipients, patients with malignancy, rheumatic disorders, other immunosuppressive conditions and immunocompetent hosts. More recently described risks include the use of newer biologicals and recreational intravenous drug use. Disease is caused by Cryptococcus neoformans and Cryptococcus gattii species complex; C. gattii is endemic in several geographic regions and has caused outbreaks in North America. Major virulence determinants are the polysaccharide capsule, melanin and several ‘invasins’. Cryptococcal plb1, laccase and urease are essential for dissemination from lung to CNS and crossing the blood–brain barrier. Meningo-encephalitis is common but intracerebral infection or hydrocephalus also occur, and are relatively frequent in C. gattii infection. Complications include neurologic deficits, raised intracranial pressure (ICP) and disseminated disease. Diagnosis relies on culture, phenotypic identification methods, and cryptococcal antigen detection. Molecular methods can assist. Preferred induction antifungal therapy is a lipid amphotericin B formulation (amphotericin B deoxycholate may be used in non-transplant patients) plus 5-flucytosine for 2–6 weeks depending on host type followed by consolidation/maintenance therapy with fluconazole for 12 months or longer. Control of raised ICP is essential. Clinicians should be vigilant for immune reconstitution inflammatory syndrome.

The Diagnostic Challenge of an Infrequent Spectrum of Cryptococcus Infection

Cryptococcal infection results from inhalation of fungal spores and usually is confined to the lungs, but may disseminate systemically. Radiologically, cryptococcal infection has multiple forms of presentation. The diagnosis is usually based on fungal isolation from cultured clinical specimens. Long term antifungal therapy is recommended, but surgical procedures may eventually be necessary when large thoracic symptomatic masses are present. We report a case of a 41-year-old male, immunocompetent, investigating a palpable mass in the left supraclavicular region associated with unintentional weight loss over the last three months. He also reported chest pain in this period. Chest X-ray, ultrasonography, and computed tomography were performed, which diagnosed a mediastinal and left supraclavicular mass, interpreted as lymph node conglomerates of unknown etiology. He also underwent a biopsy of the left supraclavicular mass for etiological determination by histopathology, which confirmed cryptococcosis infection. Although very infrequent, mediastinal cryptococcal infection (simulating masses) is a challenging but important differential diagnosis of benign and malignant lesions, since its treatment is usually clinical.

Fungal infections in pediatric neurosurgery

INTRODUCTION

Invasive mycosis of the central nervous system represent a diverse group of diseases that have gradually emerged as not only opportunistic infections in patients with immune susceptibility due to congenital and acquired deficiency, immunomodulation, solid organ and stem cell transplantation, hematological malignancies, and chronic steroid use but also in selected risk populations such as low weight preterm infants, patients with shunted hydrocephalus and external ventricular drainages, skull base surgery, and head injury.

OBJECTIVES

The purpose of this review is to familiarize the pediatric neurosurgeon with the most common mycosis and their clinical scenarios which can be encountered in the clinical practice, with special emphasis on clinical, radiological, and laboratory diagnosis beyond classical microorganism cultures as well as options in medical and surgical treatment given the high incidence of morbidity and mortality associated with these challenging entities.

METHODS

We conducted an online database review (Ovid, PubMed) gathering relevant English language literature published in the last 20 years with special emphasis on recent breakthroughs in the diagnosis and treatment of invasive mycosis of the CNS as well as reported cases within the pediatric neurosurgical literature and their surgical management.

RESULTS

Fungal agents capable of invading the CNS can behave as aggressive entities with rapid progression manifesting as overwhelming meningoencephalitis with vascular compromise or can lead to space-occupying lesions with abscess formation which require prompt diagnosis by either laboratory identification of the components of these biological agents and their host response or by obtaining tissue specimens for microbiological identification which may not be straightforward due to prolonged culture time.

CONCLUSION

Following a high degree of suspicion with prompt initiation of antifungal agents and reversal of potential immunosuppressant therapies along with neurosurgical evacuation of intracranial collections or removal of infected hardware (CSF shunts) can lead to more optimistic outcomes of these complex clinical scenarios.

The prognostic factors of HIV-negative adult cryptococcal meningitis with a focus on cranial MRI-based neuroimaging findings

The prognostic significance of clinical characteristics and neuroimaging features, especially cranial magnetic resonance imaging (MRI)-based neuroimaging features, in patients with human immunodeficiency virus (HIV)-negative cryptococcal meningitis (CM) has rarely been examined in the literature. We analyzed the clinical characteristics and MRI findings of 65 HIV-negative patients (43 men, 22 women, age 19-86 years) collected during a study period of 15 years (January 2001-December 2015). Their underlying conditions included diabetes mellitus, liver cirrhosis, hematologic disorders, autoimmune disorders, malignancy, chronic obstructive pulmonary disease, adrenal insufficiency and organ transplantation, and their clinical presentations included headache, altered consciousness, fever, seizure, visual disturbance and hearing impairment. The main cranial MRI findings were basal meningeal enhancement (44.6%, 29/65), dilated Virchow-Robin space/pseudocyst (43.1%, 28/65), "dirty" cerebrospinal fluid sign (38.5%, 25/65), hydrocephalus (36.9%, 21/65), acute/subacute cerebral infarct (ASCI, 21.5%, 14/65), cryptococcoma (9.2%, 6/65), and hazy brain base (1.5%, 1/65). The therapeutic results of the 65 patients were evaluated using the Glasgow Outcome Scale (GOS). A comparison of the good outcome group (GOS score = 4-5, n = 37) and poor outcome group (GOS score = 1-3, n = 28) revealed that both the presence of seizures and ASCI were significantly associated with the prognosis. A comparison of the groups with ASCI (n = 14) and without ASCI (n = 51) revealed that the presence of basal meningeal enhancement was a significant factor for the development of ASCI, and that this correlation may be associated with intense basal meningeal inflammation in adjacent small vessels.