Acute COVID-19 Infection Associated With Necrotizing Disseminated Acute Leukoencephalopathy and Brain Microhemorrhages in a Pediatric Patient.

We present a case of a 14-year-old, previously healthy female, admitted with acute coronavirus disease 2019 infection and new-onset seizures secondary to virus-associated necrotizing disseminated acute leukoencephalopathy. Her symptoms resolved completely with intravenous immunoglobulin and steroids. Pathophysiology and prognosis of neurologic manifestations of coronavirus disease 2019 remain unclear.

COVID-19 leukoencephalopathy with subacute magnetic resonance imaging findings of vasculitis and demyelination.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) commonly results in a respiratory illness in symptomatic patients; however, those critically ill can develop a leukoencephalopathy. We describe two patients who had novel subacute MRI findings in the context of coronavirus disease 2019 (COVID-19) leukoencephalopathy, which we hypothesize could implicate a potent small-vessel vasculitis, ischemic demyelination and the presence of prolonged ischemia. Recent evidence of the direct neuroinvasiness of SARS-CoV-2 leading to ischemia and vascular damage supports this hypothesis.

Delayed post-hypoxic leukoencephalopathy in an adult with COVID-19.

As the novel coronavirus, SARS-CoV-2, has enveloped the world in a pandemic, it has become clear that the symptoms extend far beyond the respiratory system and have particularly caused a wide range of neurologic CNS complications, including diffuse leukoencephalopathy. Here, we describe a case of a 59-year-old male with severe COVID-19 infection who developed severe encephalopathy, which persisted well after his acute infection had subsided and had begun to improve from his respiratory dysfunction. He was found to have diffuse leukoencephalopathy with concomitant diffusion restriction on MR imaging. This case represents a delayed onset of leukoencephalopathy secondary to hypoxia in a small but growing cohort of COVID-related leukoencephalopathy due to similarities in imaging features and lack of superior alternate diagnosis. Patient's clinical improvement suggests reversibility with likely pathology being demyelination rather than infarction.

Neonatal Rotavirus-Associated Leukoencephalopathy Is One of the Main Causes of Fifth-Day Fits.

Our province recently experienced an outbreak of neonatal rotavirus-associated leukoencephalopathy. This study aimed to verify whether rotavirus-associated leukoencephalopathy constituted fifth-day fits, which prevailed in Europe and Australia between the 1970s and mid-1980s. Of 118 full-term neonates who were admitted between 2008 and 2017 due to seizures, those who fulfilled the following criteria for fifth-day fits were included: healthy full-term neonates prior to seizures; absence of perinatal asphyxia; seizure onset during 4-6 days of age; and no known cause of neonatal seizures. Overall, 54 patients (45.8%) met the criteria for fifth-day fits. Of them, 44 patients (81.5%) also had rotavirus-associated leukoencephalopathy. The mean annual incidence of fifth-day fits was 5.4 cases, which peaked in 2012-2013 (13 cases) and became zero in 2017. Fifth-day fits with rotavirus-associated leukoencephalopathy accounted for 37.2% of neonatal seizures, which peaked at 70.6% in 2012, and gradually reduced to zero in 2017. Concordance of clinical features between rotavirus-associated leukoencephalopathy and fifth-day fits and their epidemic-like features suggest that rotavirus-associated leukoencephalopathy is one of the main causes of fifth-day fits.

Unusual Brain MRI Pattern in 2 Patients with COVID-19 Acute Respiratory Distress Syndrome.

We report the cases of 2 patients hospitalized in our intensive care unit with confirmed coronavirus disease 2019 infection in whom brain MR imaging showed an unusual DWI pattern with nodular and ring-shaped lesions involving the periventricular and deep white matter. We discuss the possible reasons for these findings and their relationship to the infection.

COVID-19-associated Diffuse Leukoencephalopathy and Microhemorrhages.

Diffuse leukoencephalopathy and juxtacortical and/or callosal microhemorrhages were brain imaging features in critically ill patients with coronavirus disease 2019. Coronavirus disease 2019 (COVID-19) has been reported in association with a variety of brain imaging findings such as ischemic infarct, hemorrhage, and acute hemorrhagic necrotizing encephalopathy. Herein, the authors report brain imaging features in 11 critically ill patients with COVID-19 with persistently diminished mental status who underwent MRI between April 5 and April 25, 2020. These imaging features include (a) confluent T2 hyperintensity and mild restricted diffusion in bilateral supratentorial deep and subcortical white matter (in 10 of 11 patients) and (b) multiple punctate microhemorrhages in juxtacortical and callosal white matter (in seven of 11 patients). The authors also discuss potential pathogeneses.

Monocyte Chemoattractant Protein (MCP)-1 in Rotavirus-Associated White Matter Injury in Newborns.

Recent reports have suggested an association between rotavirus infection and a distinctive pattern of white matter injury (WMI) in neonates with seizures; however, the connection between the two is not fully understood. To evaluate the underlying mechanism, we profiled and compared eight cytokines (IL [interleukin]-1ß, IL-6, IL-8, IL-10, IFN-γ [interferon-γ ], MCP-1 [monocyte chemoattractant protein-1], MIP-1ß [macrophage inflammatory protein-1ß], and TNF-α [tumor necrosis factor-α]) in the cerebrospinal fluid (CSF) of 33 neonates with seizures who had no other well-known causes of seizures and 13 control patients (rotavirus-induced gastroenteritis but without seizures). Among the 33 neonates with seizures, 9 showed WMI and all were infected with rotavirus (R + W + ). Among the 24 patients without WMI, 11 were infected with rotavirus (R + W - ) and 13 were not (R - W - ).Only MCP-1 and MIP-1ß were different between the groups. MCP-1 was increased in R+ W+ compared with R + W- (p < 0.01), R - W- (p < 0.01), and control (p = 0.03) patients. MIP-1ß was decreased in R + W+ compared with R - W- (p < 0.01) and control (p < 0.01), but not R + W- (p = 0.23) patients. MCP-1 and MIP-1ß are C-C chemokines that recruit immune cells to the site of inflammation. Our pilot study suggests MCP-1-mediated monocyte recruitment may be linked with this complication caused by rotavirus.

Human immunodeficiency virus-related cerebral white matter disease in children.

The human immunodeficiency virus (HIV) epidemic seems largely controlled by anti-retroviral treatment with resultant large numbers of children growing up with the disease on long-term treatment, placing them at higher risk to develop HIV-related brain injury, ongoing cognitive impairment and treatment-related neurological complications. Cerebral white matter involvement is a common radiologic finding in HIV infection and the causes of this have overlapping appearances, ranging from diffuse widespread involvement to focal lesions. The varied pathophysiology is broadly grouped into primary effects of HIV, opportunistic infection, vascular disease and neoplasms. White matter changes in children can be different from those in adults. This review provides guidance to radiologists with the diagnostic dilemma of nonspecific cerebral white matter lesions in children with HIV. The authors discuss common causes of HIV-related cerebral white matter disease as well as the role of neuroimaging in the management of these children.

Human pegivirus-1 associated leukoencephalitis: Clinical and molecular features.

Etiologic diagnosis is uncertain in 35% to 50% of patients with encephalitis, despite its substantial global prevalence and disease burden. We report on 2 adult female patients with fatal leukoencephalitis associated with human pegivirus-1 (HPgV-1) brain infection. Neuroimaging showed inflammatory changes in cerebral white matter. Brain-derived HPgV-1 RNA sequences clustered phylogenetically with other pegiviruses despite an 87-nucleotide deletion in the viral nonstructural (NS)2 gene. Neuropathology disclosed lymphocyte infiltration and gliosis predominantly in brain white matter. HPgV-1 NS5A antigen was detected in lymphocytes as well as in astrocytes and oligodendrocytes. HPgV-1 neuroadaptation should be considered in the differential diagnosis of progressive leukoencephalitis in humans. Ann Neurol 2018;84:789-795.

Neurodevelopmental outcomes in newborns with neonatal seizures caused by rotavirus-associated leukoencephalopathy.

PURPOSE: Rotavirus infection has recently been reported to be associated with seizures accompanied by leukoencephalopathy in newborns. We aimed to determine long-term outcomes and prognostic factors in newborns with neonatal seizures caused by rotavirus-associated leukoencephalopathy. METHODS: We retrospectively reviewed the records and brain magnetic resonance (MR) images of 32 patients who fulfilled the following criteria: (1) neonatal seizures, (2) distinctive symmetric cerebral white matter lesions on diffusion-weighted MR images (DWI), (3) rotavirus infection, (4) absence of a specific etiology of seizures, except for the aforementioned DWI lesions, and (5) Korean Bayley Scales of Infant Development II (K-BSID-II) assessment after 12 months of age. RESULTS: The mean age at seizure onset was 4.7 ±â€¯0.8 days. The median age of the patients at the time of K-BSID-II assessment was 22 months. Fourteen patients (43.8%) showed normal or accelerated performance in the mental and motor scales, while 18 patients (56.2%) had delayed performance in the mental and/or motor scales. Seven patients (21.9%) had significantly delayed performances on the mental and/or motor scales. The percentage of volume of diffusion-restricted lesions based on total brain volume was significantly negatively correlated with the mental developmental index (MDI) score (r = -0.507, p = .003), but not with the psychomotor developmental index (PDI) score (r = -0.324, p = .071). CONCLUSIONS: Rotavirus-associated leukoencephalopathy in newborns around 5 days of age can cause adverse neurodevelopmental outcomes with a wide range of severity. The extent of white matter lesion on initial DWI can predict neurocognitive outcome.

Type I interferon and proinflammatory cytokine levels in cerebrospinal fluid of newborns with rotavirus-associated leukoencephalopathy.

OBJECTIVE: The purpose of this study was to identify whether there is an increase in type I interferon and proinflammatory cytokine levels in the cerebrospinal fluid of newborns with rotavirus-associated leukoencephalopathy. METHODS: Levels of type I interferons (interferon-alpha and interferon-beta) and proinflammatory cytokines (interleukin-6 and interferon-gamma) were measured in the cerebrospinal fluid of 23 newborns with rotavirus-associated leukoencephalopathy (patient group) and 39 infants under 90 days-of-age (control group). RESULTS: Cerebrospinal fluid pleocytosis was not observed in either group. Cerebrospinal fluid interleukin-6 levels were significantly higher in the patient group (7.02 ±â€¯5.88 pg/mL) than in the control group (1.14 ±â€¯1.90 pg/mL) (p < .0001). The mean cerebrospinal fluid interferon-gamma levels of the patient group (24.43 ±â€¯40.16 pg/mL) were also significantly higher than those of the controls group (0.0 ±â€¯0.0 pg/mL) (p < .0001). Cerebrospinal fluid interferon-alpha was not detected in any patient (0%) from the patient group, but was detected in four (10.3%) of the controls. Interferon-beta was detected in only two patients (8.7%) from the patient group and in one (2.6%) of the controls. Cerebrospinal fluid interleukin-6 levels correlated positively with the extent of white matter lesions on diffusion-weighted magnetic resonance imaging (r = 0.607, p = .002). CONCLUSIONS: Significant increases in proinflammatory cytokine levels accompanied by very low detection rates of type I interferon in cerebrospinal fluid indicate that rotavirus-associated leukoencephalopathy in newborns can be correlated with central nervous system inflammatory processes without direct virus invasion into the central nervous system.

Diffusion Basis Spectral Imaging Detects Ongoing Brain Inflammation in Virologically Well-Controlled HIV+ Patients.

Inflammation occurs after HIV infection and persists, despite highly active antiretroviral therapy (HAART). Diffusion tensor imaging (DTI) measures HIV-associated white matter changes, but can be confounded by inflammation. Currently, the influence of inflammation on white matter integrity in well-controlled HIV+ patients remains unknown. We used diffusion basis spectral imaging (DBSI)-derived cellularity to isolate restricted water diffusion associated with inflammation separated from the anisotropic diffusion associated with axonal integrity. Ninety-two virologically suppressed HIV+ patients on HAART and 66 HIV uninfected (HIV-) controls underwent neuropsychological performance (NP) testing and neuroimaging. NP tests assessed multiple domains (memory, psychomotor speed, and executive functioning). DTI- and DBSI-derived fractional anisotropy (FA) maps were processed with tract-based spatial statistics for comparison between both groups. Cellularity was assessed regarding age, HIV status, and NP. Within the HIV+ cohort, cellularity was compared with clinical (HAART duration) and laboratory measures of disease (eg, CD4 cell current and nadir). NP was similar for both groups. DTI-derived FA was lower in HIV+ compared with HIV- individuals. By contrast, DBSI-derived FA was similar for both groups. Instead, diffuse increases in cellularity were present in HIV+ individuals. Observed changes in cellularity were significantly associated with age, but not NP, in HIV+ individuals. A trend level association was seen between cellularity and HAART duration. Elevated inflammation, measured by cellularity, persists in virologically well-controlled HIV+ individuals. Widespread cellularity changes occur in younger HIV+ individuals and diminish with aging and duration of HAART.

Immunohistochemical and transcriptome analyses indicate complex breakdown of axonal transport mechanisms in canine distemper leukoencephalitis.

INTRODUCTION: CDV-DL (Canine distemper virus-induced demyelinating leukoencephalitis) represents a spontaneously occurring animal model for demyelinating disorders. Axonopathy represents a key pathomechanism in this disease; however, its underlying pathogenesis has not been addressed in detail so far. This study aimed at the characterization of axonal cytoskeletal, transport, and potential regenerative changes with a parallel focus upon Schwann cell remyelination. METHODS: Immunohistochemistry of canine cerebellar tissue as well as a comparative analysis of genes from an independent microarray study were performed. RESULTS: Increased axonal immunoreactivity for nonphosphorylated neurofilament was followed by loss of cytoskeletal and motor proteins. Interestingly, a subset of genes encoding for neurofilament subunits and motor proteins was up-regulated in the chronic stage compared to dogs with subacute CDV-DL. However, immunohistochemically, hints for axonal regeneration were restricted to up-regulated axonal positivity of hypoxia-inducible factor 1 alpha, while growth-associated protein 43, erythropoietin and its receptor were not or even down-regulated. Periaxin-positive structures, indicative of Schwann cell remyelination, were only detected within few advanced lesions. CONCLUSIONS: The present findings demonstrate a complex sequence of axonal cytoskeletal breakdown mechanisms. Moreover, though sparse, this is the first report of Schwann cell remyelination in CDV-DL. Facilitation of these very limited endogenous regenerative responses represents an important topic for future research.

Human Parechovirus 3 Meningitis and Fatal Leukoencephalopathy.

Human parechovirus 3 (HPeV3) is a picornavirus associated with neurologic disease in neonates. Human parechovirus 3 infection of preterm and term infants is associated with seizures and destructive periventricular white matter lesions. Despite unremarkable cerebrospinal fluid (CSF), HPeV3 RNA can be amplified from CSF and nasopharyngeal and rectal swabs. We report pathologic findings in 2 autopsy cases of infants with active HPeV3 infection. Both children were born approximately 1 month premature and were neurologically intact but, after a few weeks, developed seizures and radiologic evidence of white matter lesions. Neuropathologic examination demonstrated classic severe periventricular leukomalacia in the absence of an immune response. Human parechovirus 3 sequences were identified in RNA extracted from CSF, sera, and tissues. Human parechovirus 3 in situ hybridization detection of infected cells was limited to meninges and associated blood vessels in addition to smooth muscle of pulmonary vessels. Ultrastructural evaluation of meninges demonstrated dense core structures compatible with picornavirus virions. These findings suggest that encephalopathic changes are secondary to infection of meninges and potential compromise of vascular perfusion. Thus, parechovirus infection of vascular smooth muscle may be a more general pathogenic process.

Evolutive leukoencephalopathy in congenital cytomegalovirus infection.

Congenital cytomegalovirus infection is the most common infectious cause of congenital brain injury. Type and severity of congenital cytomegalovirus infection-related brain abnormalities depend on the developmental stage of the central nervous system at the time of fetal infection. The aim of this study was to follow the course of leukoencephalopathy in a patient with congenital cytomegalovirus infection. We describe brain magnetic resonance imaging (MRI) findings of a boy with symptomatic congenital cytomegalovirus infection performed at the age of 3 weeks, 13 months, and 4 and 7 years. Neonatal brain MRI showed most of characteristic findings in congenital cytomegalovirus infection with most prominent white matter abnormalities and cortical dysplasia. MRI follow-up images showed that cortical dysgenesis remained unchanged and static, whereas white matter abnormalities evolved over the years. We propose that leukoencephalopathy in congenital cytomegalovirus infection is not only nonprogressive or static but even evolutive and suggests both underlying disruption and delay of myelination.

Apathy is associated with white matter abnormalities in anterior, medial brain regions in persons with HIV infection.

Apathy is a relatively common psychiatric syndrome in HIV infection, but little is known about its neural correlates. In the present study, we examined the associations between apathy and diffusion tensor imaging (DTI) indices in key frontal white matter regions in the thalamocorticostriatal circuit, which has been implicated in the expression of apathy. Nineteen participants with HIV infection and 19 demographically comparable seronegative comparison subjects completed the Apathy subscale of the Frontal Systems Behavioral Scale as a part of a comprehensive neuropsychiatric research evaluation. When compared to the seronegative participants, the HIV+ group had significantly more frontal white matter abnormalities. Within HIV+ persons, and as predicted, higher ratings of apathy were associated with greater white matter alterations in the anterior corona radiata, genu, and orbital medial prefrontal cortex. The associations between white matter alterations and apathy were independent of depression and were stronger among participants with lower current cluster of differentiation 4 (CD4) counts. All told, these findings indicate that apathy is independently associated with white matter abnormalities in anterior, medial brain regions in persons infected with HIV, particularly in the setting of lower current immune functioning, which may have implications for antiretroviral therapy.

New aspects of the pathogenesis of canine distemper leukoencephalitis.

Canine distemper virus (CDV) is a member of the genus morbillivirus, which is known to cause a variety of disorders in dogs including demyelinating leukoencephalitis (CDV-DL). In recent years, substantial progress in understanding the pathogenetic mechanisms of CDV-DL has been made. In vivo and in vitro investigations provided new insights into its pathogenesis with special emphasis on axon-myelin-glia interaction, potential endogenous mechanisms of regeneration, and astroglial plasticity. CDV-DL is characterized by lesions with a variable degree of demyelination and mononuclear inflammation accompanied by a dysregulated orchestration of cytokines as well as matrix metalloproteinases and their inhibitors. Despite decades of research, several new aspects of the neuropathogenesis of CDV-DL have been described only recently. Early axonal damage seems to represent an initial and progressive lesion in CDV-DL, which interestingly precedes demyelination. Axonopathy may, thus, function as a potential trigger for subsequent disturbed axon-myelin-glia interactions. In particular, the detection of early axonal damage suggests that demyelination is at least in part a secondary event in CDV-DL, thus challenging the dogma of CDV as a purely primary demyelinating disease. Another unexpected finding refers to the appearance of p75 neurotrophin (NTR)-positive bipolar cells during CDV-DL. As p75NTR is a prototype marker for immature Schwann cells, this finding suggests that Schwann cell remyelination might represent a so far underestimated endogenous mechanism of regeneration, though this hypothesis still remains to be proven. Although it is well known that astrocytes represent the major target of CDV infection in CDV-DL, the detection of infected vimentin-positive astrocytes in chronic lesions indicates a crucial role of this cell population in nervous distemper. While glial fibrillary acidic protein represents the characteristic intermediate filament of mature astrocytes, expression of vimentin is generally restricted to immature or reactive astrocytes. Thus, vimentin-positive astrocytes might constitute an important cell population for CDV persistence and spread, as well as lesion progression. In vitro models, such as dissociated glial cell cultures, as well as organotypic brain slice cultures have contributed to a better insight into mechanisms of infection and certain morphological and molecular aspects of CDV-DL. Summarized, recent in vivo and in vitro studies revealed remarkable new aspects of nervous distemper. These new perceptions substantially improved our understanding of the pathogenesis of CDV-DL and might represent new starting points to develop novel treatment strategies.

White matter signal abnormalities in children with suspected HIV-related neurologic disease on early combination antiretroviral therapy.

BACKGROUND: The natural history and manifestation of HIV-related neurologic disease have been ameliorated by combination antiretroviral therapy (ART). We describe the characteristics of white matter signal abnormalities (WMSA) on magnetic resonance imaging in children with HIV-related neurologic disease. METHODS: We reviewed magnetic resonance imaging scans of children with suspected HIV-related neurologic disease despite early ART and correlated with clinical, neurodevelopmental data, virologic markers and time on ART. These children were also on the Children with HIV Early Antiretroviral (CHER) trial. RESULTS: Magnetic resonance imaging scans were performed at a mean age 31.9 months (range 8-54) on 44 children: 10 on deferred and 34 on early treatment arms, commencing ART at mean age of 18.5 and 8 weeks, respectively. Multiple high signal intensity lesions on T2/fluid attenuated inversion recovery were documented in 22 patients (50%), predominantly in frontal (91%) and parietal (82%) white matter. No differences in neurodevelopmental scores comparing children with and without WMSA were found. Neither lesion load nor distribution showed significant correlation with neurodevelopmental scores or neurologic examination. Normal head growth was more common in the WMSA group (P = 0.01). There was a trend for association of WMSA and longer time on ART (P = 0.13) and nadir CD4% (P = 0.08). CONCLUSIONS: Half of children referred with HIV-related brain disease had WMSA on T2/fluid attenuated inversion recovery. Our findings of the association with normal head growth and duration of ART require further study. We suspect that WMSA can occur early and that initiating ART by 8 weeks of life may be too late to prevent HIV from entering the central nervous system.