La Crosse virus encephalitis in children.

PURPOSE OF REVIEW: La Crosse virus encephalitis (LACV-E) is among the most common neuroinvasive arthropod-borne viral infections of childhood in North America. Children are uniquely predisposed to symptomatic disease, whereas symptomatic adult infections remain uncommon. Infection results frequently in neurologic symptomatology including headaches, seizures, and altered mentation, often necessitating hospitalization and significant diagnostic evaluation. The purpose of this review is to provide a contemporary assessment of clinical, laboratory, and neurobehavioral outcomes of children with LACV-E. RECENT FINDINGS: Common clinical manifestations at presentation, specifically seizure activity and altered mental status, are independent predictors of disease severity. Epileptiform discharges on electroencephalogram (EEG) during hospitalization may predict long-term epilepsy diagnosis. Lastly, long-term neurologic sequelae from acute infection is persistent and likely under-recognized among children with LACV-E. SUMMARY: As climate change alters the geographic distribution of mosquito borne illnesses, a possibility of regional expansion of La Crosse virus (LACV) endemicity exists. The above data highlight readily identifiable features and testing modalities for clinicians who may encounter this viral infection. Importantly, an emphasis on long term neurobehavioral follow up is necessary to better identify and provide support of affected individuals. Future research in identifying host immune responses to LACV infection, as well as therapeutic options, are needed.

Clinical characteristics and outcomes of COVID-19-associated encephalopathy in children.

Apart from the typical respiratory symptoms, coronavirus disease 2019 (COVID-19) also affects the central nervous system, leading to central disorders such as encephalopathy and encephalitis. However, knowledge of pediatric COVID-19-associated encephalopathy is limited, particularly regarding specific subtypes of encephalopathy. This study aimed to assess the features of COVID-19-associated encephalopathy/encephalitis in children. We retrospectively analyzed a single cohort of 13 hospitalized children with COVID-19-associated encephalopathy. The primary outcome was the descriptive analysis of the clinical characteristics, magnetic resonance imaging and electroencephalography findings, treatment progression, and outcomes. Thirteen children among a total of 275 (5%) children with confirmed COVID-19 developed associated encephalopathy/encephalitis (median age, 35 months; range, 3-138 months). Autoimmune encephalitis was present in six patients, acute necrotizing encephalopathy in three, epilepsy in three, and central nervous system small-vessel vasculitis in one patient. Eight (62%) children presented with seizures. Six (46%) children exhibited elevated blood inflammatory indicators, cerebrospinal fluid inflammatory indicators, or both. Two (15%) critically ill children presented with multi-organ damage. The magnetic resonance imaging findings varied according to the type of encephalopathy/encephalitis. Electroencephalography revealed a slow background rhythm in all 13 children, often accompanied by epileptic discharges. Three (23%) children with acute necrotizing encephalopathy had poor prognoses despite immunotherapy and other treatments. Ten (77%) children demonstrated good functional recovery without relapse. This study highlights COVID-19 as a new trigger of encephalopathy/encephalitis in children. Autoimmune encephalitis is common, while acute necrotizing encephalopathy can induce poor outcomes. These findings provide valuable insights into the impact of COVID-19 on children's brains.

Detection of SARS-coronavirus-2 in the central nervous system of patients with severe acute respiratory syndrome and seizures.

This study was designed to evaluate whether severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) can directly target the central nervous system (CNS). We present four patients suffering from the loss of consciousness and seizure during the clinical course of COVID-19 infection. In addition to positive nasopharyngeal swab tests, SARS-CoV-2 has been detected in their cerebrospinal fluid. This report indicates the neuroinvasive potential of SARS-CoV-2, suggesting the ability of this virus to spread from the respiratory tract to the CNS.

Neurological, neuropsychiatric and neurodevelopmental complications of COVID-19.

Although COVID-19 is predominantly a respiratory disease, it is known to affect multiple organ systems. In this article, we highlight the impact of SARS-CoV-2 (the coronavirus causing COVID-19) on the central nervous system as there is an urgent need to understand the longitudinal impacts of COVID-19 on brain function, behaviour and cognition. Furthermore, we address the possibility of intergenerational impacts of COVID-19 on the brain, potentially via both maternal and paternal routes. Evidence from preclinical models of earlier coronaviruses has shown direct viral infiltration across the blood-brain barrier and indirect secondary effects due to other organ pathology and inflammation. In the most severely ill patients with pneumonia requiring intensive care, there appears to be additional severe inflammatory response and associated thrombophilia with widespread organ damage, including the brain. Maternal viral (and other) infections during pregnancy can affect the offspring, with greater incidence of neurodevelopmental disorders, such as autism, schizophrenia and epilepsy. Available reports suggest possible vertical transmission of SARS-CoV-2, although longitudinal cohort studies of such offspring are needed. The impact of paternal infection on the offspring and intergenerational effects should also be considered. Research targeted at mechanistic insights into all aspects of pathogenesis, including neurological, neuropsychiatric and haematological systems alongside pulmonary pathology, will be critical in informing future therapeutic approaches. With these future challenges in mind, we highlight the importance of national and international collaborative efforts to gather the required clinical and preclinical data to effectively address the possible long-term sequelae of this global pandemic, particularly with respect to the brain and mental health.

Chemokine receptors CCR2 and CX3CR1 regulate viral encephalitis-induced hippocampal damage but not seizures.

Viral encephalitis is a major risk factor for the development of seizures, epilepsy, and hippocampal damage with associated cognitive impairment, markedly reducing quality of life in survivors. The mechanisms underlying seizures and hippocampal neurodegeneration developing during and after viral encephalitis are only incompletely understood, hampering the development of preventive treatments. Recent findings suggest that brain invasion of blood-born monocytes may be critically involved in both seizures and brain damage in response to encephalitis, whereas the relative role of microglia, the brain's resident immune cells, in these processes is not clear. CCR2 and CX3CR1 are two chemokine receptors that regulate the responses of myeloid cells, such as monocytes and microglia, during inflammation. We used Ccr2-KO and Cx3cr1-KO mice to understand the role of these receptors in viral encephalitis-associated seizures and neurodegeneration, using the Theiler's virus model of encephalitis in C57BL/6 mice. Our results show that CCR2 as well as CX3CR1 plays a key role in the accumulation of myeloid cells in the CNS and activation of hippocampal myeloid cells upon infection. Furthermore, by using Cx3cr1-creER+/-tdTomatoSt/Wt reporter mice, we show that, with regard to CD45 and CD11b expression, some microglia become indistinguishable from monocytes during CNS infection. Interestingly, the lack of CCR2 or CX3CR1 receptors was associated with almost complete prevention of hippocampal damage but did not prevent seizure development after viral CNS infection. These data are compatible with the hypothesis that CNS inflammatory mechanism(s) other than the infiltrating myeloid cells trigger the development of seizures during viral encephalitis.

[Neurology and COVID-19: Case Series of Neurological Complications in 96 patients Admitted at a University Hospital]. / Neurología hospitalaria y COVID-19: serie de 96 pacientes evaluados en un hospital universitario.

BACKGROUND: There are multisystemic consequences secondary to SARS- CoV-2 infection. AIM: To characterize neurological complications in patients admitted due to SARS-CoV-2 infection. METHODS: Review of medical records of patients aged over 15 years with COVID-19 evaluated by the neurology team between April and August 2020 at a university hospital. Severity of the infection, referral reasons, neurological diagnoses and laboratory results were registered. The diagnoses were defined by consensus among the members of the hospital neurology group. Cerebrovascular and inflammatory diseases of the central and peripheral nervous system were defined as "probably associated" or "possibly associated" to COVID-19. RESULTS: Ninety-six patients had at least 1 new neu- rological complication. 74% were admitted due to pneumonia and 20% due to a neurological disease. The most common reasons for neurological referral were impaired consciousness (39%), focal neurological deficit (24%), headache (9%) and seizures (5%). The most relevant neurological diagnoses were delirium in 48 patients, stroke in 24, critical illness polyneuropathy and myopathy in 17, seizures in 14, brachial plexopathy in 3, compressive neuropathies in 5, encephalitis in 1, possible vasculitis in 1 and Guillain-Barré syndrome in 1. Stroke and epilepsy were associated with increased length of hospital stay, but without differences in mortality. CONCLUSIONS: The spectrum of neurological complications of COVID-19 is wide. There are clinical entities typical of critically ill patients and also diseases associated directly and indirectly with the SARS-CoV2 infection.

Central nervous system involvement by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2).

Neurologic sequelae can be devastating complications of respiratory viral infections. We report the presence of virus in neural and capillary endothelial cells in frontal lobe tissue obtained at postmortem examination from a patient infected with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). Our observations of virus in neural tissue, in conjunction with clinical correlates of worsening neurologic symptoms, pave the way to a closer understanding of the pathogenic mechanisms underlying central nervous system involvement by SARS-CoV-2.

Neurological manifestations of COVID-19: available evidences and a new paradigm.

The recent pandemic outbreak of coronavirus is pathogenic and a highly transmittable viral infection caused by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV2). In this time of ongoing pandemic, many emerging reports suggested that the SARS-CoV-2 has inimical effects on neurological functions, and even causes serious neurological damage. The neurological symptoms associated with COVID-19 include headache, dizziness, depression, anosmia, encephalitis, stroke, epileptic seizures, and Guillain-Barre syndrome along with many others. The involvement of the CNS may be related with poor prognosis and disease worsening. Here, we review the evidence of nervous system involvement and currently known neurological manifestations in COVID-19 infections caused by SARS-CoV-2. We prioritize the 332 human targets of SARS-CoV-2 according to their association with brain-related disease and identified 73 candidate genes. We prioritize these 73 genes according to their spatio-temporal expression in the different regions of brain and also through evolutionary intolerance analysis. The prioritized genes could be considered potential indicators of COVID-19-associated neurological symptoms and thus act as a possible therapeutic target for the prevention and treatment of CNS manifestations associated with COVID-19 patients.

COVID-19 and seizures: Is there a link?

The rapid spread of the SARS-CoV-2 pandemic poses particular challenges to the management of persons with chronic disease. Reports of a possible neuroinvasiveness of SARS-CoV-2 as well as pathophysiological mechanisms and indirect consequences in severe COVID-19 cases raise the question of whether the infection can be associated with an increased risk of seizure recurrence or the development of new onset and acute symptomatic seizures. Although the literature does not provide relevant evidence for seizure worsening in persons with epilepsy during the course of a SARS-CoV-2 infection, there are theoretical risks, for example, seizures triggered by fever. Moreover, a severe disease course and advanced disease stages can, for instance, result in hypoxic encephalopathy, cerebrovascular events, and cytokine storm, which may trigger the development of acute seizures. This is further confirmed by reports of occasional seizures in COVID-19 patients. Although the low number of reports so far suggests that the risk may be relatively low, the reports indicate that an early neurological manifestation with seizures should not be ruled out. In the context of these cases, we discuss possible pathophysiological mechanisms that may trigger ictogenesis in patients with SARS-CoV-2 infection.

Seizure in patients with COVID-19.

OBJECTIVE: The purpose of the current study was to collect the data on the occurrence of seizures in patients with COVID-19 and to clarify the circumstances of the occurrence of seizures in these patients. METHODS: All consecutive patients who referred to healthcare facilities anywhere in Fars province (located in South Iran with a population of 4.851 million people) from February 19 until June 2, 2020, and had confirmed COVID-19 by positive result on polymerase chain reaction testing and seizure were included. RESULTS: During the study period, 6,147 people had confirmed COVID-19 in Fars province, Iran; 110 people died from the illness (case fatality rate 1.79%). During this time period, five people had seizures (seizure rate 0.08%). In four patients, seizure was one of the presenting manifestations, and in one person, it happened during the course of hospital admission. Two patients had status epilepticus. All patients experienced hypoxemia and four of them needed respirator. Two patients had related metabolic derangements and one had cerebrospinal fluid (CSF) lymphocytic pleocytosis. Brain imaging was abnormal in three patients. Four patients died. CONCLUSION: New-onset seizures in critically ill patients with COVID-19 should be considered as acute symptomatic seizures and the treating physician should try to determine the etiology of the seizure and manage the cause immediately and appropriately. Detailed clinical, neurological, imaging, and electrophysiological investigations and attempts to isolate SARS-CoV-2 from CSF may clarify the role played by this virus in causing seizures in these patients.

The changes of the epidemiology and clinical characteristics of rotavirus gastroenteritis-associated convulsion after the introduction of rotavirus vaccine.

Rotavirus (RV) vaccine contributed to the reduction of the hospitalization for gastroenteritis (GE)-associated convulsion whereas there were few studies investigating the vaccination rate and the reduction of the disease simultaneously. The aim of this study is to investigate the alterations of the epidemiology and clinical characteristics of RVGE-associated convulsion after the introduction of RV vaccines and evaluate the reduction of the disease in the context of the vaccination rate. This retrospective study included hospitalized patients with GE and GE-associated convulsion from 2009 to 2015. The proportion of patients with RVGE and RVGE-associated convulsion and the clinical characteristics of RVGE-associated convulsion were compared between the pre- (2009-2011) and post-vaccination periods (2013-2015). The presumptive RV vaccination rate in the subject area was also investigated. During the pre- and post-vaccination periods, 47 and 49 patients with GE-associated convulsion, and 319 and 330 with GE were enrolled, respectively. Proportions of both hospitalized patients with RVGE-associated convulsion and those with RVGE during the post-vaccination period were significantly lower than those during the pre-vaccination periods (P = 0.042 and P = 0.003). Serum sodium level was significantly lower in hospitalized patients with RVGE-associated convulsion during the post-vaccination period (P = 0.021). The presumptive RV vaccination rates were 35.9%, 45.8% and 52.6% in 2013, 2014 and 2015, respectively. The proportions of hospitalized patients with RVGE-associated convulsion as well as those with RVGE decreased after the introduction of RV vaccine. RV vaccination would be also effective for the prevention of extra-intestinal complications of the virus.

Parechovirus-A3 encephalitis presenting with focal seizure mimicking herpes simplex virus infection.

BACKGROUND: Febrile neonates and young infants presenting with seizure require immediate evaluation and treatment. Herein we experienced two young infants with parechovirus-A3 (PeV-A3) encephalitis, initially presented with focal seizure suspecting herpes simplex virus (HSV) encephalitis. CASES: We have experienced 2 infantile cases, initially presented with focal seizure. At presentation, HSV encephalitis was strongly suspected and empiric acyclovir therapy was started; however, serum and/or cerebrospinal fluid (CSF) PCR for HSV were negative. Instead, serum and/or CSF PCR for parechovirus-A was positive. PeV-A3 infection was confirmed by genetic sequence analyses. Both cases required multiple anticonvulsant therapy and intensive care for intractable seizure. Diffusion-weighted imaging of brain magnetic resonance imaging (MRI) showed distinct findings; high-intensity lesions in the gray matter of parietal and occipital lobes in Case 1, and bilateral decreased diffusion of the deep white matter and corpus callosum in Case 2. We have followed two cases more than four years; Case 1 developed epilepsy, has been on an anticonvulsant to control her seizure. Case 2 has significant neurodevelopmental delay, unable to stand or communicate with language. CONCLUSIONS: PeV-A3 encephalitis needs to be in differential diagnosis when neonates and young infants present with focal seizure, mimicking HSV encephalitis. Special attention may be necessary in patients with PeV-A3 encephalitis given it could present with intractable seizure with high morbidity in a long-term.

Neurological manifestations of COVID-19.

Coronavirus disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) has turned out to be a formidable pandemic. Upcoming evidence from confirmed cases of COVID-19 suggests an anticipated incursion of patients with neurological manifestations in the weeks to come. An expression of the angiotensin-converting enzyme 2 (ACE 2), the cellular receptor for SARS-CoV-2 over the glial cells and neurons have made the brain a potential target. Neurotoxicity may occur as a result of direct, indirect and post-infectious complications. Attention to neurological deficits in COVID-19 is fundamental to ensure appropriate, timely, beneficial management of the affected patients. Most common neurological manifestations seen include dizziness, headache, impaired consciousness, acute cerebrovascular disease, ataxia, and seizures. Anosmia and ageusia have recently been hinted as significant early symptoms in COVID-19. As cases with neurological deficits in COVID-19 emerge, the overall prognosis is yet unknown.

Indoleamine 2,3-dioxygenase 1 deletion promotes Theiler's virus-induced seizures in C57BL/6J mice.

OBJECTIVE: Viral encephalitis increases the risk for developing seizures and epilepsy. Indoleamine 2,3-dioxygenase 1 (Ido1) is induced by inflammatory cytokines and functions to metabolize tryptophan to kynurenine. Kynurenine can be further metabolized to produce kynurenic acid and the N-methyl-d-aspartate receptor agonist quinolinic acid (QuinA). In the present study, we sought to determine the role of Ido1 in promoting seizures in an animal model of viral encephalitis. METHODS: C57BL/6J and Ido1 knockout mice (Ido1-KO) were infected with Theiler's murine encephalomyelitis virus (TMEV). Quantitative real-time polymerase chain reaction was used to evaluate hippocampal expression of proinflammatory cytokines, Ido1, and viral RNA. Body weights and seizure scores were recorded daily. Elevated zero maze was used to assess differences in behavior, and hippocampal pathology was determined by immunohistochemistry. RESULTS: Infected C57BL/6J mice up-regulated proinflammatory cytokines, Ido1, and genes encoding the enzymatic cascade responsible for QuinA production in the kynurenine pathway prior to the onset of seizures. Seizure incidence was elevated in Ido1-KO compared to C57BL/6J mice. Infection increased locomotor activity in Ido1-KO compared to C57BL/6J mice. Furthermore, the occurrence of seizures was associated with hyperexcitability. Neither expression of proinflammatory cytokines nor viral RNA was altered as a result of genotype. Immunohistochemical analysis revealed increased hippocampal pathology in Ido1-KO mice. SIGNIFICANCE: Our findings suggest that Ido1 deletion promotes seizures and neuropathogenesis during acute TMEV encephalitis.

Human herpesvirus 6 associated post-transplant acute limbic encephalitis: Clinical observations of biomarkers for risk of seizure in a pediatric population.

BACKGROUND: Human herpesvirus 6 (HHV6) is a cause of post-transplant acute limbic encephalitis (PALE). Seizures are associated with this disorder yet no predictive biomarkers have been identified. The objective of this study was to evaluate lab and neurodiagnostic biomarkers in patients with HHV6 associated PALE. METHODS: A retrospective chart review was performed at our institutions between 2000 and 2017. Patients were identified through a clinical database. Inclusion criteria included: age less than 18 years, HHV6 (quantitative real-time PCR or meningoencephalitis panel) tested in CSF and serum. Biomarkers of serum and CSF viral load, EEG, and MRI were reviewed along with clinical data. RESULTS: In total, 11 patients met inclusion criteria. All patients had undergone hematopoietic stem cell transplantation. Five of 11 patients had seizures as part of their clinical course, all being controlled with antiepileptic monotherapy. Seizure semiology was focal-onset in three cases and generalized in two. Neuroimaging was normal in all patients within seven days but six patients developed T2 signal intensities in the temporal lobes on repeat imaging between 14-28 days. The median CSF HHV6 viral load for all patients was 47 300 copies/mL although the median viral load was 2586 copies/mL in patients who had seizure compared to 473 969 copies/mL in those who had not (P = 0.02). Those with seizures tended to be younger (median 6.5 years compared to 11 years, P = 0.27). All patients with seizures had an EEG with 80% demonstrating abnormalities. CONCLUSION: In patients with post-hematopoietic stem cell transplant HHV6 associated PALE, lower CSF viral load may be associated with a higher likelihood to have seizures. This may indicate a primary infection as opposed to secondary reactivation phenomenon.

Prevalence and incidence of new-onset seizures and epilepsy in patients with human immunodeficiency virus (HIV): Systematic review and meta-analysis.

BACKGROUND: The prevalence and incidence of seizures are substantially higher in patients with human immunodeficiency virus (HIV) compared with the general population and is associated with higher mortality rates. Despite this, the condition remains poorly understood, and there is variation in reported epidemiological studies. The aim of this systematic review and meta-analysis was to investigate the risk factors associated with seizures in the population with HIV, explore the source of variations, and describe management plans that can aid clinicians in the acute and long-term treatment of these patients. METHODS: A structured electronic database search of MEDLINE, EMBASE, and Cochrane Library was conducted. Studies were included if they described clinical details of patients with HIV with seizures or epilepsy. We extracted select variables from each included study, and we estimated pooled estimates of the incidence and prevalence of seizures using random-effects meta-analysis of proportions. RESULTS: Information on 6639 cases of patients with HIV was extracted from 9 included studies. These comprised of 2 studies from the United States of America (USA), 3 from Europe, 3 from Asia, and 1 from Africa. The pooled prevalence and incidence rate of seizures in HIV were 62 per 1000 population and 60 per 1000 population respectively. Among those who presented with new-onset seizures, 63% had seizure recurrence. At the time of first seizure, 82.3% had acquired immunodeficiency syndrome (AIDS). Factors that appeared to be linked to seizures in HIV included advanced HIV disease, opportunistic infections particularly toxoplasmosis, and metabolic derangement. Most seizures were effectively controlled by common antiepileptic drugs (AEDs). CONCLUSIONS: The prevalence and incidence of seizures and epilepsy in the population with HIV are substantially higher than the general population. Our results suggest that advanced HIV and opportunistic infections are associated with the majority of the seizures. Early initiation of highly active antiretroviral therapy (HAART), prophylactic use of cotrimoxazole (trimethoprim-sulfamethoxazole) and routine electroencephalogram (EEG) in patients with HIV may reduce seizure incidence and frequency and help in early diagnosis of nonconvulsive seizures in this population. We recommend long-term seizure management with AED, and for patients on HAART, enzyme-inducing AED should be avoided when possible.

Rotavirus Vaccination Is Associated With Reduced Seizure Hospitalization Risk Among Commercially Insured US Children.

Rotavirus commonly causes diarrhea but can also cause seizures. Analysis of insurance claims for 1773295 US children with 2950 recorded seizures found that, compared to rotavirus-unvaccinated children, seizure hospitalization risk was reduced by 24% (95% confidence interval [CI], 13%-33%) and 14% (95% CI, 0%-26%) among fully and partially rotavirus-vaccinated children, respectively.

The immune response to picornavirus infection and the effect of immune manipulation on acute seizures.

Viral infection of the central nervous system can result in encephalitis. About 20% of individuals who develop viral encephalitis go on to develop epilepsy. We have established an experimental model where virus infection of mice with Theiler's murine encephalomyelitis virus (TMEV) leads to acute seizures, followed by a latent period (no seizures/epileptogenesis phase) and then spontaneous recurrent seizures-epilepsy. Infiltrating macrophages (CD11b+CD45hi) present in the brain at day 3 post-infection are an important source of interleukin-6, which contributes to the development of acute seizures in the TMEV-induced seizure model. Time course analysis of viral infection and inflammatory [CD11b+CD45hiLy-6Chi] and patrolling [CD11b+CD45hiLy-6Clow] monocyte and T cell infiltration into the brains of TMEV-infected C57BL/6J mice over the entire course of the acute viral infection was performed to elucidate the role of virus and the immune response to virus in seizures and viral clearance. The infiltrating inflammatory macrophages were present early following infection but declined over the course of acute viral infection, supporting a role in seizure development, while the lymphocyte infiltration increased rapidly and plateaued, advocating that they play a role in viral clearance. In addition, we showed for the first time that, while TMEV infection of RAG1-/- mice did not alter the number of mice experiencing acute seizures, TMEV infection of C57BL/6J mice depleted of macrophages resulted in a significant decrease in the number of mice experiencing seizures, again supporting a role for infiltrating macrophages in the development of acute seizures in the TMEV-induced seizure model.

Zika virus-induced acute myelitis and motor deficits in adult interferon αß/γ receptor knockout mice.

Zika virus (ZIKV) has received widespread attention because of its effect on the developing fetus. It is becoming apparent, however, that severe neurological sequelae, such as Guillian-Barrë syndrome (GBS), myelitis, encephalitis, and seizures can occur after infection of adults. This study demonstrates that a contemporary strain of ZIKV can widely infect astrocytes and neurons in the brain and spinal cord of adult, interferon α/ß receptor knockout mice (AG129 strain) and cause progressive hindlimb paralysis, as well as severe seizure-like activity during the acute phase of disease. The severity of hindlimb motor deficits correlated with increased numbers of ZIKV-infected lumbosacral spinal motor neurons and decreased numbers of spinal motor neurons. Electrophysiological compound muscle action potential (CMAP) amplitudes in response to stimulation of the lumbosacral spinal cord were reduced when obvious motor deficits were present. ZIKV immunoreactivity was high, intense, and obvious in tissue sections of the brain and spinal cord. Infection in the brain and spinal cord was also associated with astrogliosis as well as T cell and neutrophil infiltration. CMAP and histological analysis indicated that peripheral nerve and muscle functions were intact. Consequently, motor deficits in these circumstances appear to be primarily due to myelitis and possibly encephalitis as opposed to a peripheral neuropathy or a GBS-like syndrome. Thus, acute ZIKV infection of adult AG129 mice may be a useful model for ZIKV-induced myelitis, encephalitis, and seizure activity.

Parechovirus: an important emerging infection in young infants.

Epidemics of human parechovirus (HPeV) causing disease in young children have occurred every 2 years in Australia since 2013. HPeV genotype 3 caused the epidemic from late 2017 to early 2018. Most HPeV infections cause no or mild symptoms including gastroenteritis or influenza-like illness. Characteristically, young infants present with fever, irritability and on occasions a diffuse rash ("red, hot and angry" babies). Severe disease can manifest as meningoencephalitis, seizures or sepsis-like presentations (including septic shock), or less common presentations including signs of surgical abdomen. Testing for HPeV by specific molecular tests is indicated in children younger than 6 months of age with characteristic presentations without another confirmed diagnosis including febrile illnesses with other suggestive features (eg, rash, seizures), sepsis syndromes (including shock), and suspected meningoencephalitis (which may be detected by magnetic resonance imaging only). There are no effective antiviral therapies. Treatment is primarily supportive, including management of complications. Some infants with severe HPeV infection may have adverse neurodevelopment. Follow-up by a paediatrician is recommended.