Granulomatous meningoencephalitis and blindness associated with Mycobacterium tuberculosis complex infection in a senile female chimpanzee (Pan troglodytes).

A 40-year old female chimpanzee (Pan troglodytes) developed hyporexia, weight loss, followed by progressive and complete blindness. Tomography demonstrated an intracranial mass in the rostroventral brain involving the optic chiasm, with a presumptive diagnosis of neoplasm. However, histopathology revealed a granulomatous meningoencephalitis, and tissue samples tested positive for Mycobacterium tuberculosis.

Utility of Film Array Meningoencephalitis Panel in Children With Acute Encephalitis Syndrome: A Single Centre Experience from South India.

OBJECTIVE: To describe the utility of film array meningoencephalitis (FAME) panel in the management of children with acute encephalitis syndrome (AES). METHODS: A retrospective audit was conducted between January 2017 to July 2022. We included children aged < 18 years with a diagnosis of AES for whom a CSF analysis study including FAME panel testing performed within 48 hours of admission was available. Electronic medical records were reviewed for details including demographic profile, clinical presentation, investigations and outcome. RESULTS: Out of 157 CSF samples sent for FAME panel testing, 49 were positive (31.4%.) Viral pathogens were identified in 42 (Enterovirus: 31, Human herpes virus 6: 9, Varicella zoster virus: 1, and Cytomegalovirus: 1) Bacterial pathogens were identified in 6 (Streptococcus pneumoniae: 2, Streptococcus agalactiae: 2, Hemophilus influenzae: 1, and Escherischia coli: 1). Fungal etiology (Cryptococcus neoformans) was detected in one child. Antibiotics could be stopped within 72 hours of initiation in 42 children in whom a viral etiology was established. Acyclovir could be stopped in 21 out of 32 children within 72 hours after the FAME panel testing. FAME panel was presumed to be false positive in 4 children. CONCLUSION: Etiology of AES could be established in nearly a third of children with AES using the rapid diagnostic FAME panel testing in CSF and it was found to be effective in reducing empirical antibiotic/antiviral therapy.

Early Neonatal Presentation and Neuroimaging of Parechovirus Meningoencephalitis in a Preterm Baby: A Case Report.

Neonatal meningoencephalitis caused by human parechovirus infection is being increasingly recognized in recent literature. While most cases are postnatally acquired, intrauterine infection is rare, presents early and has a more severe impact on brain health and development. We discuss here an infant born preterm at 34 weeks gestational age, with neonatal course remarkable for severe encephalopathy presenting on day 2 of life due to human parechovirus meningoencephalitis transmitted in utero. Early magnetic resonance brain imaging detected extensive white matter injury and subsequently evolved into multicystic leukoencephalopathy. Posthospital discharge, infant was noted to have early neurodevelopmental impairment at 4 months corrected age.

Persistent hypernatremia secondary to adipsic central diabetes insipidus in a patient with herpes-induced meningoencephalitis and COVID-19 infection: a case report.

Central diabetes insipidus (CDI) typically manifests as a polyuria-polydipsia syndrome, in which normonatremia is generally maintained through the polydipsia. A 53-year-old woman presented with diabetic ketosis and hyperosmolar hyperglycemic syndrome. Her medical history included herpes meningoencephalitis, which was associated with confusion and amnesia. On physical examination, she was apyretic, confused, and had signs of extracellular dehydration. Her capillary glucose concentration was high and her urine was positive for ketones. Laboratory investigations revealed severe hyperglycemia, hypernatremia (plasma hyperosmolarity of 393.6 mOsm/L), and mild acute renal failure. In addition, she had a paucisymptomatic COVID-19 infection. Intravenous rehydration with isotonic saline solution and insulin therapy were effective at controlling the ketosis and ameliorating the hyperglycemia, but failed to normalize the hypernatremia and hyperosmolarity. She was not thirsty and had a urine output of 1 L/day, with urinary hypotonicity. Desmopressin administration reduced the hypernatremia and hyperosmolarity to within their normal ranges, and the patient's urinary osmolarity increased to 743 mOsm/L. Therefore, adipsic CDI was diagnosed. Endocrine investigations revealed isolated central hypothyroidism. The results of pituitary magnetic resonance imaging were normal. Thus, patients with impaired thirst may have an atypical presentation of CDI. In addition, the diagnosis of adipsic CDI is particularly challenging.

[Listeria meningoencephalitis resulting in complete bilateral ophtalmoplegia and locked-in syndrome]. / Listerioznyi meningoentsefalit s razvitiem polnoi dvustoronnei oftal'moplegii i sindroma «zapertogo cheloveka¼.

This is a description of the case of quite severe neurolisteriosis in an adult man resulting in the rare combination of neurological symptoms such as complete bilateral ophtalmoplegia and locked-in syndrome. The case illustrates clinical features that are special for this disorder and also highlights management of such patients.

Borna disease in an adult free-ranging Eurasian beaver (Castor fiber albicus).

Borna disease (BD) associated with a peracute bacterial septicaemia with Escherichia coli was diagnosed in an adult female, naturally infected, free-ranging Eurasian beaver of the subspecies Castor fiber albicus, clinically characterized by weight loss, depression, weakness and gurgled peristaltic sounds. The beaver was euthanized humanely. Necropsy and light microscopy revealed a non-purulent meningoencephalitis with typical mononuclear perivascular cuffs and parenchymal infiltrates. The diagnosis of BD was confirmed by detection of viral antigen and RNA by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR). The PCR product was sequenced and cluster analysis revealed a close relationship between endemic clusters in Saxony-Anhalt. This is the first report of naturally occurring BD in a free-ranging Eurasian beaver.

Causes and prognosis of adults experiencing a first seizure in adulthood: A pilot cohort study conducted in five countries in Latin America.

There are limited data on first seizure (FS) among adults in low and middle-income countries. We describe findings from a prospective cohort study involving 180 adults presenting with seizures in emergency departments in five Latin American countries. Overall, 102 participants (56.7%) had acute symptomatic seizures (ASyS) while 78 (43.3%) had unprovoked seizures (UPS). Among patients with ASyS, 55 (53.9%) had structural causes, with stroke (n = 24, 23.5%), tumor (n = 10, 9.8%), and trauma (n = 3, 3%) being the most frequent. Nineteen patients (18.6%) had infectious causes, including four (4%) with meningoencephalitis, three (3%) neurocysticercosis, and two (2%) bacterial meningoencephalitis. Twenty patients (19.6%) had metabolic/toxic evidence, including four (4%) with uremic encephalopathy, two (2%) hyponatremia, and three (3%) acute alcohol intoxication. Immune dysfunction was present in seven (7%) patients and neurodegenerative in two (2%). Among participants with UPS, 45 (57.7%) had unknown etiology, 24 (30.7%) had evidence of structural disorders (remote symptomatic), four (5%) were related to infectious etiology (>7 days before the seizure), and five (6.4%) had genetic causes. During the 3- and 6-month follow-up, 29.8% and 14% of patients with UPS, respectively, experienced seizure recurrence, while 23.9% and 24.5% of patients with ASyS had seizure recurrence. Longer follow-up is necessary to assess seizure recurrence for patients with ASyS after the acute cause is resolved and to determine the 10-year risk of recurrence, which is part of the definition of epilepsy. PLAIN LANGUAGE SUMMARY: We monitored 180 adults who presented with their first seizure in emergency departments across five Latin American countries. Among these patients, 57% had acute symptomatic seizures, with structural causes such as stroke (23%), infection (17%), or tumor (10%) being more prevalent. Among the 43% with unprovoked seizures, 58% showed no identifiable acute cause, while 6.4% were due to genetics. Within 3 months after their initial seizure, 26.6% of individuals experienced a second seizure, with 11.9% continuing to have seizures in Months 3-6. Between Months 3 and 6, an additional 20% of patients encountered a second seizure. Research is needed to better understand the cause and prognosis of these patients to improve outcomes.

Epileptiform electroencephalogram discharges increase seizure recurrence risk in patients with acute symptomatic seizure due to a structural brain lesion.

OBJECTIVE: The risk factors for seizure recurrence after acute symptomatic seizure due to a structural brain lesion are not well established. The aim of this study was to analyze possible associations between demographic, clinical, and electroencephalographic variables and epilepsy development in patients with acute symptomatic seizure due to an acute structural brain lesion. METHODS: We designed an observational prospective study of patients with acute symptomatic seizure due to an acute structural brain lesion (hemorrhagic stroke, ischemic stroke, traumatic brain injury, or meningoencephalitis) who underwent EEG during their initial admission between January 2015 and January 2020. We analyzed prospectively recorded demographic, clinical, electroencephalographic (EEG), and treatment-related variables. All variables were compared between patients with and without seizure recurrence during 2 years of follow up. RESULTS: We included 194 patients (41.2 % women; mean [SD] age, 57.3 [15.8] years) with acute symptomatic seizure due to an acute structural brain lesion. They all underwent EEG during admission and were followed for at least 2 years. The identifiable causes were hemorrhagic stroke (44.8 %), ischemic stroke (19.5 %), traumatic brain injury (18.5 %), and meningoencephalitis (17 %). Fifty-six patients (29 %) experienced a second seizure during follow-up. Seizure recurrence was associated with epileptiform discharges on EEG (52% vs 32 %; OR 2.3 [95 % CI, 1.2-4.3], p = 0.008) and onset with status epilepticus (17% vs 0.05 %, OR 4.03 [95 % CI 1.45-11.2], p = 0.009). CONCLUSIONS: Epileptiform discharges on EEG and status epilepticus in patients with acute symptomatic seizure due to an acute structural brain lesion are associated with a higher risk of epilepsy development.

Batf3-dependent orchestration of the robust Th1 responses and fungal control during cryptococcal infection, the role of cDC1.

While type I conventional dendritic cells (cDC1s) are vital for generating adaptive immunity against intracellular pathogens and tumors, their role in defense against fungal pathogen Cryptococcus neoformans remains unclear. We investigated the role of the cDC1 subset in a fungus-restricting mouse model of cryptococcal infection. The cDC1 subset displayed a unique transcriptional signature with highly upregulated T-cell recruitment, polarization, and activation pathways compared to other DC subsets. Using Batf3-/- mice, which lack the cDC1 population, our results support that Batf3-dependent cDC1s are pivotal for the development of the effective immune response against cryptococcal infection, particularly within the lung and brain. Deficiency in Batf3 cDC1 led to diminished CD4 accumulation and decreased IFNγ production across multiple organs, supporting that cDC1s are a major driver of potent Th1 responses during cryptococcal infection. Consistently, mice lacking Batf3-cDC1 demonstrated markedly diminished fungicidal activity and weaker containment of the fungal pathogen. In conclusion, Batf3-dependent cDC1 can function as a linchpin in mounting Th1 response, ensuring effective fungal control during cryptococcal infection. Harnessing cDC1 pathways may present a promising strategy for interventions against this pathogen.IMPORTANCECryptococcus neoformans causes severe meningoencephalitis, accounting for an estimated 200,000 deaths each year. Central to mounting an effective defense against these infections is T-cell-mediated immunity, which is orchestrated by dendritic cells (DCs). The knowledge about the role of specific DC subsets in shaping anti-cryptococcal immunity is limited. Here, we demonstrate that Batf3 cDC1s are important drivers of protective Th1 CD4 T-cell responses required for clearance of cryptococcal infection. Deficiency of Batf3 cDC1 in the infected mice leads to significantly reduced Th1 response and exacerbated fungal growth to the point where depleting the remaining CD4 T cells no longer affects fungal burden. Unveiling this pivotal role of cDC1 in antifungal defense is likely to be important for the development of vaccines and therapies against life-threatening fungal pathogens.

New insights into neuropathology and pathogenesis of autoimmune glial fibrillary acidic protein meningoencephalomyelitis.

Anti-glial fibrillary acidic protein (GFAP) meningoencephalomyelitis (autoimmune GFAP astrocytopathy) is a new autoimmune central nervous system (CNS) disease diagnosable by the presence of anti-GFAP autoantibodies in the cerebrospinal fluid and presents as meningoencephalomyelitis in the majority of patients. Only few neuropathological reports are available and little is known about the pathogenic mechanisms. We performed a histopathological study of two autopsies and nine CNS biopsies of patients with anti-GFAP autoantibodies and found predominantly a lymphocytic and in one autopsy case a granulomatous inflammatory phenotype. Inflammatory infiltrates were composed of B and T cells, including tissue-resident memory T cells. Although obvious astrocytic damage was absent in the GFAP-staining, we found cytotoxic T cell-mediated reactions reflected by the presence of CD8+/perforin+/granzyme A/B+ cells, polarized towards astrocytes. MHC-class-I was upregulated in reactive astrocytes of all biopsies and two autopsies but not in healthy controls. Importantly, we observed a prominent immunoreactivity of astrocytes with the complement factor C4d. Finally, we provided insight into an early phase of GFAP autoimmunity in an autopsy of a pug dog encephalitis that was characterized by marked meningoencephalitis with selective astrocytic damage with loss of GFAP and AQP4 in the lesions.Our histopathological findings indicate that a cytotoxic T cell-mediated immune reaction is present in GFAP autoimmunity. Complement C4d deposition on astrocytes could either represent the cause or consequence of astrocytic reactivity. Selective astrocytic damage is prominent in the early phase of GFAP autoimmunity in a canine autopsy case, but mild or absent in subacute and chronic stages in human disease, probably due to the high regeneration potential of astrocytes. The lymphocytic and granulomatous phenotypes might reflect different stages of lesion development or patient-specific modifications of the immune response. Future studies will be necessary to investigate possible implications of pathological subtypes for clinical disease course and therapeutic strategies.

[Clinical features and pathogenesis of Glial fibrillary acidic protein (GFAP) antibody-associated disorders].

Glial fibrillary acidic protein (GFAP) antibody-associated disorders (AD) were recently proposed to be immune-mediated neurological disorders. The pathogenesis of GFAP antibody-AD is poorly understood. Pathologically, there is a marked infiltration of large numbers of lymphocytes, including CD8+ and CD4+ T cells, into the meningeal and brain parenchyma, especially around the perivascular areas. GFAP-specific cytotoxic T cells are considered to be the effector cells of GFAP antibody-AD. The common phenotype of GFAP antibody-AD includes meningoencephalitis with or without myelitis. During the clinical disease course, patients present with consciousness disturbances, urinary dysfunction, movement disorders, meningeal irritation, and cognitive dysfunction. The detection of GFAP antibodies in the cerebrospinal fluid (CSF) by cell-based assay is essential for a diagnosis of GFAP antibody-AD. The CSF can be examined for lymphocyte-predominant pleocytosis and elevated protein levels. Brain linear perivascular radial enhancement patterns are observed in about half of GFAP antibody-AD patients. Spinal cord magnetic resonance imaging is used to detect longitudinal extensive spinal cord lesions. Although corticosteroid therapy is generally effective, some patients have a poor prognosis and relapse.

C-reactive protein concentration has limited value in the diagnosis of meningoencephalitis of unknown origin in dogs.

OBJECTIVES: To evaluate blood and cerebrospinal fluid (CSF) concentrations of C-reactive protein (CRP) in dogs with meningoencephalitis of unknown origin (MUO); to evaluate whether blood CRP concentration is associated with epidemiological, clinicopathologic, and MRI findings; and to investigate blood CRP predictive power in survival. ANIMALS: 30 client-owned dogs with MUO, 15 client-owned dogs with steroid-responsive meningitis arteritis (SRMA; positive control group), and 15 healthy dogs (negative control group). METHODS: Blood CRP concentration was measured in each group, while it was performed in CSF only in the MUO and SRMA groups. The analysis of epidemiological data included breed, age, sex, duration of clinical signs, and history of seizures. Blinded analysis of MRI was performed based on a classification grid, and traditional CSF analysis parameters were assessed. The predictive power of blood CRP concentration regarding survival at 6 months was investigated. RESULTS: Of the 30 dogs with MUO, 9 (30%) had an increased CRP concentration in blood, and 3 (10%) showed a measurable CRP in CSF. Median blood CRP concentration in dogs with MUO was 0.1 mg/L (range, 0.1 to 102 mg/L), which was not statistically different from the healthy dog group but significantly lower than the SRMA control group. Only the duration of clinical signs was positively associated with an increased blood CRP level. Blood CRP concentration was not associated with survival at 6 months. CLINICAL RELEVANCE: Blood CRP concentration is of limited value for the diagnosis and prognosis of dogs with MUO. Chronicity of the disease may be associated with an increased concentration of blood CRP.

Case Report: A Series of Three Meningoencephalitis Cases Caused by Acanthamoeba spp. from Eastern India.

Acanthamoeba spp. are rare etiological agents of meningoencephalitis with high mortality. We present three cases of Acanthamoeba meningoencephalitis in immunocompetent individuals from Eastern India. The first patient presented with fever and headache; the second with headache, visual disturbance, and squint; and the third presented in a drowsy state. The cases presented on March 3, 18, and 21, 2023 respectively. The first two patients had concomitant tubercular meningitis for which they received antitubercular therapy and steroid. Their cerebrospinal fluid showed slight lymphocytic pleocytosis and increased protein. The diagnosis was done by microscopy, culture, and polymerase chain reaction. They received a combination therapy comprising rifampicin, fluconazole, and trimethoprim-sulfamethoxazole. The first patient additionally received miltefosine. She responded well to therapy and survived, but the other two patients died despite intensive care. Detection of three cases within a period of 1 month from Eastern India is unusual. It is imperative to sensitize healthcare providers about Acanthamoeba meningoencephalitis to facilitate timely diagnosis and treatment of the disease.

Spinal cord infarction: a rare but serious complication of pneumococcal meningoencephalitis.

Here, we report the case of a woman in her 40s who came with pyogenic meningitis and infarcts in the brain. While on treatment with antibiotics, she developed new-onset weakness involving bilateral lower limbs and one upper limb 2 weeks into the course of illness. MRI of the spine showed an infarct in the spinal cord. Spinal cord infarction as a complication of pyogenic meningitis is not well recognised unlike tuberculosis meningitis. Unlike ischaemic strokes where thrombolysis is done, for stroke related to infections, there are no definite strategies. Our patient was treated with physiotherapy, continued on antibiotics and slowly recovered over months and at 18-month follow-up, she was walking with a walker. The exact mechanism of thrombosis is not known but may be due to inflammation of the arterial wall and activation of the procoagulant cascade by infection-triggered inflammation. Spinal cord infarction can occur at any phase of the infection and may occur despite appropriate response to antibiotic treatments.

Disseminated cryptococcosis in a patient with idiopathic CD4 + T lymphocytopenia presenting as prostate and adrenal nodules: diagnosis from pathology and mNGS, a case report.

Disseminated Cryptococcosis infection typically occurs in immunocompromised patients, often manifested as pneumonia or meningoencephalitis. Cases with involvement of either prostate or adrenal glands are less frequent. We describe a case of an immunocompromised 62-year-old man with new-found Idiopathic CD4 + T lymphocytopenia who presented with urinary irritation symptoms followed by headache. The patient was finally diagnosed as disseminated cryptococcosis of prostate, adrenal gland involvement with the help of combining histopathology of formalin-fixed, paraffin-embedded tissue with metagenomic next-generation sequencing technique to identify C neoformans sensu stricto in prostate, adrenal gland tissues. Clinicians should be aware of atypical presentations of cryptococcal disease. In this case of cryptococcosis in immunocompromised patients, we find that cryptococcosis can affect varied organs simultaneously and should be considered in the differential of infectious diseases. And mNGS technology helps to confirm the diagnosis.

Monkeypox virus-associated meningoencephalitis diagnosed by detection of intrathecal antibody production.

BACKGROUND: In the 2022 mpox-outbreak most patients presented with mild symptoms. Central nervous system (CNS) involvement has previously been described as a rare and severe complication of mpox; however, diagnostic findings in cerebrospinal fluid (CSF) analysis and neuroimaging studies have only been reported in one case previously. CASE PRESENTATION: We report a previously healthy 37-year-old man with mpox complicated by encephalitis. He first presented with painful skin lesions and genital ulcers; polymerase chain reaction (PCR) from the lesions was positive for mpox. Twelve days later he was admitted with fever and confusion. Neuroimaging and CSF analysis indicated encephalitis. The CSF was PCR-negative for monkeypox virus but intrathecal antibody production was detected. He spontaneously improved over a few days course and recovered fully. CONCLUSIONS: This case of mpox-associated encephalitis shows that CNS involvement in mpox infection may have a relatively mild clinical course, and that detection of intrathecal antibody production can be used to establish the diagnosis if CSF monkeypox virus-PCR is negative.

Host-microbe interactions at the blood-brain barrier through the lens of induced pluripotent stem cell-derived brain-like endothelial cells.

Microbe-induced meningoencephalitis/meningitis is a life-threatening infection of the central nervous system (CNS) that occurs when pathogens are able to cross the blood-brain barrier (BBB) and gain access to the CNS. The BBB consists of highly specialized brain endothelial cells that exhibit specific properties to allow tight regulation of CNS homeostasis and prevent pathogen crossing. However, during meningoencephalitis/meningitis, the BBB fails to protect the CNS. Modeling the BBB remains a challenge due to the specialized characteristics of these cells. In this review, we cover the induced pluripotent stem cell-derived, brain-like endothelial cell model during host-pathogen interaction, highlighting the strengths and recent work on various pathogens known to interact with the BBB. As stem cell technologies are becoming more prominent, the stem cell-derived, brain-like endothelial cell model has been able to reveal new insights in vitro, which remain challenging with other in vitro cell-based models consisting of primary human brain endothelial cells and immortalized human brain endothelial cell lines.