Infectious disease-associated encephalopathies.

Infectious diseases may affect brain function and cause encephalopathy even when the pathogen does not directly infect the central nervous system, known as infectious disease-associated encephalopathy. The systemic inflammatory process may result in neuroinflammation, with glial cell activation and increased levels of cytokines, reduced neurotrophic factors, blood-brain barrier dysfunction, neurotransmitter metabolism imbalances, and neurotoxicity, and behavioral and cognitive impairments often occur in the late course. Even though infectious disease-associated encephalopathies may cause devastating neurologic and cognitive deficits, the concept of infectious disease-associated encephalopathies is still under-investigated; knowledge of the underlying mechanisms, which may be distinct from those of encephalopathies of non-infectious cause, is still limited. In this review, we focus on the pathophysiology of encephalopathies associated with peripheral (sepsis, malaria, influenza, and COVID-19), emerging therapeutic strategies, and the role of neuroinflammation.

Clinical, cerebrospinal fluid, and neuroimaging findings in COVID-19 encephalopathy: a case series.

OBJECTIVE: To describe the clinical, neurological, neuroimaging, and cerebrospinal fluid (CSF) findings associated with encephalopathy in patients admitted to a COVID-19 tertiary reference center. METHODS: We retrospectively reviewed records of consecutive patients with COVID-19 evaluated by a consulting neurology team from March 30, 2020 through May 15, 2020. RESULTS: Fifty-five patients with confirmed SARS-CoV-2 were included, 43 of whom showed encephalopathy, and were further divided into mild, moderate, and severe encephalopathy groups. Nineteen patients (44%) had undergone mechanical ventilation and received intravenous sedatives. Eleven (26%) patients were on dialysis. Laboratory markers of COVID-19 severity were very common in encephalopathy patients, but did not correlate with the severity of encephalopathy. Thirty-nine patients underwent neuroimaging studies, which showed mostly non-specific changes. One patient showed lesions possibly related to CNS demyelination. Four had suffered an acute stroke. SARS-CoV-2 was detected by RT-PCR in only one of 21 CSF samples. Two CSF samples showed elevated white blood cell count and all were negative for oligoclonal bands. In our case series, the severity of encephalopathy correlated with higher probability of death during hospitalization (OR = 5.5 for each increment in the degree of encephalopathy, from absent (0) to mild (1), moderate (2), or severe (3), p < 0.001). CONCLUSION: In our consecutive series with 43 encephalopathy cases, neuroimaging and CSF analysis did not support the role of direct viral CNS invasion or CNS inflammation as the cause of encephalopathy.

Multiple tuberculomas in an immunocompetent patient and their diagnostic challenge in a high prevalence country: Case report and literature review.

CONTEXT: Intracranial tuberculomas are rare yet lethal forms of tuberculosis. Diagnosis is often difficult because of its nonspecific symptoms and radiological findings. AIM: This study aims to perform a literature review of multiple tuberculomas to improve disease recognition and management in immunocompetent patients along with presenting a case report on the topic. DATA SOURCES: Scopus, LILACS, Ovid MEDLINE and EMBASE. STUDY SELECTION: Case reports and case series up to December 2018 in English, Spanish, and Portuguese focusing on intracranial tuberculomas in adult and pediatric immunocompetent patients. Data on presentation, diagnostic workup, and treatment was analyzed. DATA EXTRACTION: Cochrane Collaboration/Cochrane Handbook and PRISMA guidelines. RESULTS: Twenty reports involving 21 patients were included. Most patients were male (57.14%). The average age at diagnosis was 26.9 ± 14.9 years. Headache was the most common presenting symptom (52.4%; 11/21), followed by motor weakness (47.6%; 10/21) and vomiting (23.8%; 5/21). MRI was the most used image technique (17/21). Most lesions occurring in the cerebral hemispheres (16/21); we found five or more lesions in 66.6% (14/21) of the patients. The majority treated with anti-tuberculous drugs resulted in a favorable outcome. CONCLUSIONS: Immunocompetent patients living in TB endemic areas whose clinical evaluation and neuroimaging findings are compatible with tuberculoma should undergo anti-tubercular treatment despite a lack of bacteriological confirmation.

Ageusia and anosmia, a common sign of COVID-19? A case series from four countries.

Over the course of the pandemic due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), multiple new clinical manifestations, as the consequence of the tropism of the virus, have been recognized. That includes now the neurological manifestations and conditions, such as headache, encephalitis, as well as olfactory and taste disorders. We present a series of ten cases of RT-PCR-confirmed SARS-CoV-2-infected patients diagnosed with viral-associated olfactory and taste loss from four different countries.

Neurologic manifestations of antiphospholipid syndrome.

Neurological involvement in antiphospholipid antibody syndrome (APS) is common, and its occurrence increases morbidity and mortality. Patients may present variable neurological involvement, such as cerebrovascular disease, cognitive dysfunction, headache, seizures, movement disorders, multiple sclerosis-like syndrome, transverse myelitis and ocular symptoms. Most neurological manifestations are associated with thrombosis of the microcirculation or of large vessels; nonetheless, there is compelling evidence suggesting that, in some cases, symptoms are secondary to an immune-mediated pathogenesis, with direct binding of aPL on neurons and glia. Herein we describe clinical characteristics and management of neurological APS manifestations.

Aspergilosis cerebral como causa de lesión cerebral focal asociada SIDA: a propósito de un caso y revisión de la literatura / Focal brain lesion due to cerebral aspergillosis in a patient with AIDS: case report and literature review

Resumen La aspergilosis cerebral es una patología infrecuente, pero de elevada mortalidad en pacientes con SIDA. Es importante considerarla entre los diagnósticos diferenciales ante una lesión expansiva cerebral. Se requiere un alto grado de sospecha para poder realizar un diagnóstico precoz. Se presenta el caso de un paciente con infección por VIH con un cuadro neurológico rápidamente progresivo por Aspergillus sección flavi. Se realiza una revisión de 40 casos publicados de aspergilosis cerebral en pacientes con SIDA.

Cerebral aspergillosis is a rare disease with high mortality rates in AIDS patients. It is important to take this into account in the differential diagnosis of a brain expansive lesion. A high level of suspicion is required to make an early diagnosis. We present a case of an HIV-infected patient with progresive neurological disease caused by Aspergillus flavi. We review 40 previously published cases of central nervous system aspergillosis in patients with AIDS.

[Focal brain lesion due to cerebral aspergillosis in a patient with AIDS. Case report and literature review]. / Aspergilosis cerebral como causa de lesión cerebral focal asociada SIDA. A propósito de un caso y revisión de la literatura.

Cerebral aspergillosis is a rare disease with high mortality rates in AIDS patients. It is important to take this into account in the differential diagnosis of a brain expansive lesion. A high level of suspicion is required to make an early diagnosis. We present a case of an HIV-infected patient with progresive neurological disease caused by Aspergillus flavi. We review 40 previously published cases of central nervous system aspergillosis in patients with AIDS.

Post-treatment vascular leakage and inflammatory responses around brain cysts in porcine neurocysticercosis.

Cysticidal treatment of neurocysticercosis, an infection of humans and pig brains with Taenia solium, results in an early inflammatory response directed to cysts causing seizures and focal neurological manifestations. Treatment-induced pericystic inflammation and its association with blood brain barrier (BBB) dysfunction, as determined by Evans blue (EB) extravasation, was studied in infected untreated and anthelmintic-treated pigs. We compared the magnitude and extent of the pericystic inflammation, presence of EB-stained capsules, the level of damage to the parasite, expression of genes for proinflammatory and regulatory cytokines, chemokines, and tissue remodeling by quantitative PCR assays between treated and untreated infected pigs and between EB-stained (blue) and non stained (clear) cysts. Inflammatory scores were higher in pericystic tissues from EB-stained cysts compared to clear cysts from untreated pigs and also from anthelmintic-treated pigs 48 hr and 120 hr after treatment. The degree of inflammation correlated with the severity of cyst wall damage and both increased significantly at 120 hours. Expression levels of the proinflammatory genes for IL-6, IFN-γ, TNF-α were higher in EB-stained cysts compared to clear cysts and unaffected brain tissues, and were generally highest at 120 hr. Additionally, expression of some markers of immunoregulatory activity (IL-10, IL-2Rα) were decreased in EB-stained capsules. An increase in other markers for regulatory T cells (CTLA4, FoxP3) was found, as well as significant increases in expression of two metalloproteases, MMP1 and MMP2 at 48 hr and 120 hr post-treatment. We conclude that the increase in severity of the inflammation caused by treatment is accompanied by both a proinflammatory and a complex regulatory response, largely limited to pericystic tissues with compromised vascular integrity. Because treatment induced inflammation occurs in porcine NCC similar to that in human cases, this model can be used to investigate mechanisms involved in host damaging inflammatory responses and agents or modalities that may control damaging post treatment inflammation.

Neuropeptides in sepsis: from brain pathology to systemic inflammation.

Septic encephalopathy is frequently diagnosed in critically ill patients and in up to 70% of patients with severe systemic infection [19]. The syndrome is defined by diffuse cerebral dysfunction or structural abnormalities attributed to the effects of systemic infection, rather than a direct central nervous system cause. The clinical characteristics can range from mild delirium to deep coma, but patients are often medically sedated making the diagnosis difficult. Any manifestation, however, is specific and markers of disease are lacking [43]. Sepsis survivors present long term cognitive impairment, including alterations of memory, attention and concentration [10,54]. Here, we propose that neuropeptides may play a key role in septic encephalopathy, leading to a vicious circle characterized by brain disease and systemic inflammation.

Novel brain lesions caused by Edwardsiella tarda in a red tilapia (Oreochromis spp.).

The histological lesions caused by Edwardsiella tarda in a variety of fish species, including tilapia, have been well characterized. There are apparent differences in the type of inflammatory response manifested by these different species, which may be due to the fish species itself, the phase of infection, or the virulence factors produced by different strains of E. tarda. In catfish, systemic abscesses involving muscles of the flank or caudal peduncle are the most common lesions. By contrast, infection in tilapia and red sea bream is more likely to be associated with granulomatous inflammation. Necrotic meningitis, encephalitis, and vasculitis with fibrinoid necrosis of the blood vessels walls, as well as the formation of a plaque-like structure in the brain, are described in the current study. The presence of E. tarda was confirmed by microbiological isolation and a positive nested polymerase chain reaction in paraffin wax-embedded tilapia tissues.

NMO in pediatric patients: brain involvement and clinical expression.

OBJECTIVE: To analyze the clinical, neuroimaging characteristics and positivity of the acquaporin water channel (NMO-IgG) in pediatric patients with neuromyelitis optica (NMO). This disorder could have a variable clinical expression. To address such variability, the term NMO spectrum has been suggested. METHOD: We evaluated six pediatric patients, with a median age of 11 years at the time of the study, with the diagnosis of NMO by the Wingerchuck criteria. RESULTS: All the cases exhibited bilateral optic neuritis (ON). Four patients had abnormalities on brain MRI from the onset,although only three of them developed symptoms correlated to those lesions during the course of their disorder. NMO-IgG was positive in 80%. CONCLUSION: Optic neuropathy is the most impaired feature in NMO patients. Brain MRI lesions are not compatible with multiple sclerosis and positivity of the NMO-IgG are also present in NMO pediatric patients, confirming the heterogeneity in the expression of this disorder.

NMO in pediatric patients: brain involvement and clinical expression / NMO en pacientes pediátricos: afectación del cerebro y expresión clínica

OBJECTIVE: To analyze the clinical, neuroimaging characteristics and positivity of the acquaporin water channel (NMO-IgG) in pediatric patients with neuromyelitis optica (NMO). This disorder could have a variable clinical expression. To address such variability, the term NMO spectrum has been suggested. METHOD: We evaluated six pediatric patients, with a median age of 11 years at the time of the study, with the diagnosis of NMO by the Wingerchuck criteria. RESULTS: All the cases exhibited bilateral optic neuritis (ON). Four patients had abnormalities on brain MRI from the onset,although only three of them developed symptoms correlated to those lesions during the course of their disorder. NMO-IgG was positive in 80 percent. CONCLUSION: Optic neuropathy is the most impaired feature in NMO patients. Brain MRI lesions are not compatible with multiple sclerosis and positivity of the NMO-IgG are also present in NMO pediatric patients, confirming the heterogeneity in the expression of this disorder.

OBJETIVO: Analizar las características clínicas y de neuroimagen, y la positividad del canal de agua acuaporin (NMO-IgG) en pacientes pediátricos con neuromielitis óptica (NMO). Este trastorno puede tener una expresión clínica variable. El término espectro de NMO ha sido propuesto para poder incluir la variabilidad. METODO: Evaluamos seis pacientes pediátricos, con una mediana de edad de 11 años al momento del estudio, con el diagnóstico de NMO de acuerdo a los criterios de Wingerchuck. RESULTADOS: Todos los casos exhibían neuritis óptica bilateral (ON). Cuatro pacientes tuvieron anormalidades en la RM cerebral desde el inicio, aunque solo tres de ellos desarrollaron síntomas relacionados con las lesiones durante el curso de la enfermedad. NMO-IgG fue positiva en el 80 por ciento. CONCLUSIÓN: Neuropatía óptica es la característica mayormente observada en los pacientes con NMO. Lesiones cerebrales en la RM cerebral no compatibles con esclerosis multiple y positividad de la NMO-IgG están también presentes en los pacientes pediátricos con NMO; lo cual confirma la heterogeneidad en la expresión clínica de este trastorno.

Boosting controlled autoimmunity: a new therapeutic target for CNS disorders.

In most tissues, the immune system plays an essential role in protection, repair and healing. Although immunologically privileged, the CNS remains subject to a highly regulated form of immunosurveillance that is of increasing interest. There is evolving evidence that repair mechanisms within the CNS may be enhanced by exploiting an innate process of protective immunity. Understanding the regulation of protective autoimmunity within the CNS is likely to lead to novel therapeutic approaches to neuroinflammatory and neurodegenerative diseases.

Short report: limited and short-lasting humoral response in Taenia solium: seropositive households compared with patients with neurocysticercosis.

Epidemiologic data suggest that 30-40% of Taenia solium-seropositive people become spontaneously negative without acquiring cysticercosis. To compare the responses of these individuals with those of patients with neurocysticercosis, we screened seropositive persons among family members of 16 patients. We searched for specific antibodies in patients and their 118 households by an enzyme-linked immunoelectrotransfer blot assay using specific glycoproteins of T. solium metacestodes. We found six seropositive individuals without neurocysticercosis among members of four families. The matching patients were young, harbored viable cysts, and had short evolution of disease. The baseline response of healthy seropositive individuals was scarce and showed a low frequency of antibodies against glycoproteins GP39-42 and GP24, which are immunodominant in patients with neurocysticercosis. Moreover, they became spontaneously negative in few months. The response of patients was heterogeneous as shown in other studies. The results of this work support a highly dynamic host-parasite immunologic interaction and suggest individual susceptibility or level of exposure among family members.

Effect of Trypanosoma lewisi (Kinetoplastida: Trypanosomatidae) on the infection of white rats with Toxoplasma gondii (Eucoccidia: Sarcocystidae) oocysts.

White rats were inoculated with 10(6) trypomastigotes of Trypanosoma lewisi, simultaneously or two days before and after inoculation with 10(5) oocysts of T. gondii. A greater number of cysts was found in the brain of the animals having concomitant inoculations, as compared with rats inoculated with either one of the two parasites. An apparent immunosuppressive effect is likely. Since both organisms can be found in rats, it is possible that infections with T. lewisi, could make this rodent another intermediate host for Toxoplasma infections.

Antigens from Taenia crassiceps cysticerci used in complement fixation, enzyme-linked immunosorbent assay, and western blot (immunoblot) for diagnosis of neurocysticercosis.

Antigens from Taenia solium cysticerci for the immunodiagnosis of cysticercosis are scarce and difficult to obtain. We studied the reliability of antigens from Taenia crassiceps cysticerci as a substitute for those from T. solium in three diagnostic tests: complement fixation, enzyme-linked immunosorbent assay, and Western blot (immunoblot). Precision rates of the three tests of 93, 99, and 96%, respectively, were found. Cysticerci from T. crassiceps can be easily obtained in large quantities and can be effectively used for the diagnosis of human neurocysticercosis.

Neurocysticercosis in Brazilian children: report of 10 cases.

In a 6-year period, ten cases of neurocysticercosis were diagnosed in children with ages ranging from 4 to 13 years, in a Brazilian teaching hospital. Most of the children presented epilepsy and/or raised intracranial pressure, but meningoencephalitis and psychotic reactions were also observed. The cerebrospinal fluid (CSF) cell count ranged from 1 to 52 cells per mm3, with pleocytosis in 6 cases, mostly by lymphocytes and eosinophils. Antibodies to Cysticercus cellulosae were detected in the CSF in all cases. A cranial radiograph was abnormal in 5 out of 6 cases, and a computed tomographic (CT) scan in 4 out of 8 cases. Stool examination was positive for ova and/or proglottids of Taenia sp in 4 out of the 10 cases. Seven patients were treated with either praziquantel or albendazole plus dexamethasone; there were no important side effects, and surgical treatment was required in no case. Neurocysticercosis must be included in the differential diagnosis of seizures, raised intracranial pressure, meningitis and psychotic reactions in children living in or having travelled to the tropics. The diagnosis can be suspected by the presence of eosinophils in the CSF, and confirmed by imaging methods such as CT scans and by immunological tests in the CSF.

Pertussis whole cell vaccine: relation between intracerebral protection in mice and antibody response to pertussis toxin, filamentous hemagglutinin and adenylate cyclase.

N:NIH mice were vaccinated according to the WHO recommendations for the potency test with the Second International Standard for Pertussis Vaccine (ISPV). Blood for serological investigation was taken from the animals on day 14 post immunization before intracerebral challenge with Bordetella pertussis 18323 was done. The relationship between anti-pertussis toxin, anti-filamentous hemagglutinin and anti-adenylate cyclase antibody levels as measured by ELISA and protection from intracerebral challenge was studied. The proportion of surviving mice increased in correlation with increasing anti-PT titres; a protective level of 4 ELISA units/ml was found. Such relationship between protection against intracerebral challenge and antibody titres was not found for anti-FHA nor for anti-AC antibodies, thus suggesting that these antibodies do not play an important role in protection in this model. The excellent correlation between anti-PT antibody titres and protection suggests that the measure of anti-PT response could be a useful tool for estimating the potency of whole-cell vaccines. The development of an alternative method for testing the potency of pertussis whole-cell vaccines based on the anti-PT response should be considered.

Deteccion de antigeno del polisacarido capsular de Cryptococcus neoformans en pacientes con SIDA y neurocriptococosis en Sao Paulo, Brasil / Detection of capsular polysaccharide antigen of Cryptococcus neoformans in patients with AIDS and neurocryptococcosis in Sao Paulo, Brazil

Antigeno del polisacarido capsular (AgPC) de Cryptococcus neoformans fue detectado por la tecnica de aglutinacion de latex (AL) en LCR y suero de pacientes con Sindrome de Inmunodeficiencia Adquirida (SIDA) y primer episodio de neurocriptococosis, usando como patron el examen micologico (examen directo y cultivo) de LCR. Se obtuvo una sensibilidad de 100 por ciento de AL para detectar AgPC de C. neoformans, el cual por su rapidez permite tratamiento especifico precoz. Titulos iniciales de AgPC de la levadura en esos pacientes pueden ser>1.000.000, pareciendo que cuando esos titulos estan presentes en suero, se relacionan con mortalidad durante el tratamiento. En los pacientes que sobrevivieron se observo que el examen micologico directo y AgPC de C. neoformans, en LCR y suero, permanecen positivos aun despues de tratamiento y mejoria clinica del paciente.