Concentric structure of thalamic lesions in acute necrotizing encephalopathy

Identification of neurological complications in childhood influenza: a random forest model

BACKGROUND

Among the neurological complications of influenza in children, the most severe is acute necrotizing encephalopathy (ANE), with a high mortality rate and neurological sequelae. ANE is characterized by rapid progression to death within 1-2 days from onset. However, the knowledge about the early diagnosis of ANE is limited, which is often misdiagnosed as simple seizures/convulsions or mild acute influenza-associated encephalopathy (IAE).

OBJECTIVE

To develop and validate an early prediction model to discriminate the ANE from two common neurological complications, seizures/convulsions and mild IAE in children with influenza.

METHODS

This retrospective case-control study included patients with ANE (median age 3.8 (2.3,5.4) years), seizures/convulsions alone (median age 2.6 (1.7,4.3) years), or mild IAE (median age 2.8 (1.5,6.1) years) at a tertiary pediatric medical center in China between November 2012 to January 2020. The random forest algorithm was used to screen the characteristics and construct a prediction model.

RESULTS

Of the 433 patients, 278 (64.2%) had seizures/convulsions alone, 106 (24.5%) had mild IAE, and 49 (11.3%) had ANE. The discrimination performance of the model was satisfactory, with an accuracy above 0.80 from both model development (84.2%) and internal validation (88.2%). Seizures/convulsions were less likely to be wrongly classified (3.7%, 2/54), but mild IAE (22.7%, 5/22) was prone to be misdiagnosed as seizures/convulsions, and a small proportion (4.5%, 1/22) of them was prone to be misdiagnosed as ANE. Of the children with ANE, 22.2% (2/9) were misdiagnosed as mild IAE, and none were misdiagnosed as seizures/convulsions.

CONCLUSION

This model can distinguish the ANE from seizures/convulsions with high accuracy and from mild IAE close to 80% accuracy, providing valuable information for the early management of children with influenza.

MRI Findings of COVID-19 Associated Acute Necrotizing Encephalopathy in Two Pediatric Patients: Case Report and Literature Review

Acute necrotizing encephalopathy (ANE) is a rare immune-mediated complication of a viral infection commonly involving the bilateral thalamus and has been reported mainly in children. Here, we describe the MRI findings of coronavirus disease 2019 (COVID-19)-associated ANE in two pediatric patients, including a 7-year-old girl with fever and mental change, and a 6-year-old girl with fever and generalized seizures. Brain MRI revealed symmetrical T2 fluid attenuated inversion recovery high-signal intensity lesions in the bilateral thalamus with central hemorrhage. In one patient, the thalamic lesions showed a trilaminar pattern on the apparent diffusion coefficient map. This report emphasizes the importance of creating awareness regarding these findings in patients with COVID-19, particularly in children with severe neurological symptoms. Furthermore, it provides a literature review of several documented cases of COVID-19 presenting with bilateral thalamic hemorrhagic necrosis, suggesting a diagnosis of ANE.

Clinical characteristics and prognostic analysis of acute necrotizing encephalopathy of childhood: a retrospective study at a single center in China over 3 years

Objective

Acute Necrotizing Encephalopathy of Childhood (ANEC) is a rare, fulminant neurological disease in children with unknown mechanisms and etiology. This study summarized the clinical characteristics, treatment, and prognosis of ANEC through a retrospective analysis, providing insights into the ANEC early diagnosis and prognosis assessment.

Methods

Clinical data of children diagnosed with ANEC at the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University from July 1, 2020, to June 30, 2023, were retrospectively analyzed.

Results

There were 25 cases, 14 males and 11 females, with a median age of 3 years. Hospital admissions were mainly in the winter (14/25, 56%) and spring (9/25, 36%). All patients presented with varying degrees of fever and altered consciousness, with 92% (23/25) experiencing high body temperatures (>39.1°C) and 88% (22/25) having a Glasgow coma scale (GCS) score of ≤8. Seizures were observed in 88% (22/25) of patients. Laboratory findings indicated 100% B lymphocyte activation (14/14), and 78% (14/18) of patients showed cytokine storm (interleukin (IL)-6, IL-8, IL-10, interferon (IFN)-α). Neuroimaging showed symmetrical thalamus involvement, commonly involving basal ganglia and brainstem regions. Viral infection (23/24, 96%) was the predominant etiological finding, with 42% (10/24) of cases due to SARS-CoV-2 infection and 42% (10/24) to influenza A virus infection. Multi-organ dysfunction occurred in 68% (17/25) of patients, and 52% (13/25) died. Correlation analysis revealed the death group exhibited higher proportion of male, lower GCS scores, higher IL-6 level and a greater likelihood of associated brainstem impairment (p < 0.05).

Conclusion

ANEC is more prevalent in the winter and spring, and its etiology may be associated with B lymphocyte activation and cytokine storm following viral infections. Clinical manifestations lack specific features, with fever, consciousness disturbances, and seizures being the main presentations, particularly in cases of high fever and hyperpyrexia. ANEC progresses rapidly and has a high mortality rate. The child's gender, GCS score, IL-6 levels, and the presence of brainstem involvement can serve as important risk factors for assessing the risk of mortality.

Coronavirus or Cholangitis? An Acute Necrotizing Encephalopathy Caused by COVID-19

A 63-year-old Japanese woman presented to the emergency room with a fever and altered mental status. She was diagnosed as acute cholangitis and coronavirus disease 2019 (COVID-19). On the second day, her consciousness level deteriorated. The patient was finally diagnosed with acute necrotizing encephalopathy (ANE). This case illustrated ANE caused by COVID-19 that co-occurred with acute cholangitis. ANE is a subtype of acute encephalitis/encephalopathy, sometimes related to COVID-19. ANE shares some clinical features with acute cholangitis. COVID-19 and bacterial infections may coexist, thus complicating an accurate diagnosis. Physicians should avoid overlooking life-threatening febrile conditions even if the diagnosis of COVID-19 is confirmed.

Human Herpesvirus-6 Encephalitis Associated With Acute Necrotizing Encephalopathy in an Immunocompetent Child: A Case Report and Literature Review

Human herpesvirus type 6 (HHV-6) is a DNA virus considered a member of the Herpesviridae family. HHV-6 is acquired early in life, when it may cause roseola infantum and nonspecific febrile illnesses which is usually a self-limiting disease before the age of two. Primary HHV-6 encephalitis and acute necrotizing encephalopathy (ANE) are rare diseases to occur in immunocompetent children. We describe an unusual case of HHV-6 encephalitis with mixed features of acute necrotizing encephalopathy and acute disseminated encephalomyelitis and contextualize it with a review of the literature on HHV-6 encephalitis in immunocompetent children. Although the incidence of primary HHV-6 encephalitis is rare in immunocompetent children, HHV-6 encephalitis associated with acute necrotizing encephalopathy is a devastating disease, highly fatal and neurologically damaging disease. Therefore, early testing and diagnosis are crucial as well as effective management of encephalitis with antiviral therapy is highly recommended.

Genetic and environmental risk factors of acute infection-triggered encephalopathy

Acute encephalopathy is a constellation of syndromes in which immune response, metabolism and neuronal excitation are affected in a variable fashion. Most of the syndromes are complex disorders, caused or aggravated by multiple, genetic and environmental risk factors. Environmental factors include pathogenic microorganisms of the antecedent infection such as influenza virus, human herpesvirus-6 and enterohemorrhagic Escherichia coli, and drugs such as non-steroidal anti-inflammatory drugs, valproate and theophylline. Genetic factors include mutations such as rare variants of the SCN1A and RANBP2 genes, and polymorphisms such as thermolabile CPT2 variants and HLA genotypes. By altering immune response, metabolism or neuronal excitation, these factors complicate the pathologic process. On the other hand, some of them could provide promising targets to prevent or treat acute encephalopathy.

COVID-19 and Parkinsonism: A Critical Appraisal

A few cases of parkinsonism linked to COVID-19 infection have been reported so far, raising the possibility of a post-viral parkinsonian syndrome. The objective of this review is to summarize the clinical, biological, and neuroimaging features of published cases describing COVID-19-related parkinsonism and to discuss the possible pathophysiological mechanisms. A comprehensive literature search was performed using NCBI’s PubMed database and standardized search terms. Thirteen cases of COVID-19-related parkinsonism were included (7 males; mean age: 51 years ± 14.51, range 31–73). Patients were classified based on the possible mechanisms of post-COVID-19 parkinsonism: extensive inflammation or hypoxic brain injury within the context of encephalopathy (n = 5); unmasking of underlying still non-symptomatic Parkinson’s Disease (PD) (n = 5), and structural and functional basal ganglia damage (n = 3). The various clinical scenarios show different outcomes and responses to dopaminergic treatment. Different mechanisms may play a role, including vascular damage, neuroinflammation, SARS-CoV-2 neuroinvasive potential, and the impact of SARS-CoV-2 on α-synuclein. Our results confirm that the appearance of parkinsonism during or immediately after COVID-19 infection represents a very rare event. Future long-term observational studies are needed to evaluate the possible role of SARS-CoV-2 infection as a trigger for the development of PD in the long term.

Influenza A H3N2-Associated Meningoencephalitis in an Older Adult With Viral RNA in Cerebrospinal Fluid: Case Report

Influenza-associated encephalopathy (IAE) is most frequently observed in young children, but less reported in adults. Diagnosis of IAE is difficult, as clinical presentations vary significantly and the influenza virus is rarely detected in cerebrospinal fluid (CSF). Herein, we described the case of an older adult presenting with acute meningoencephalitis due to an influenza A (H3N2) infection and the influenza A (H3N2) RNA is detected in cerebrospinal fluid. To the best of our knowledge, this is infrequently reported in the literature. We emphasize that, in adults presenting with acute viral encephalitis, clinicians should consider an influenza infection as part of the differential diagnosis and that metagenomic next-generation sequencing of CSF for IAE may help establish an accurate diagnosis. It must be emphasized that the administration of steroids in a timely manner following the onset of symptoms may yield a better outcome in patients.

Parameters Indicating Development of Influenza-Associated Acute Necrotizing Encephalopathy: Experiences from a Single Center

Background

Influenza-associated acute necrotizing encephalopathy (IANE) can be lethal and disabling and have a sudden onset and deteriorate rapidly but lacks early diagnostic indicators. We aimed to examine the early clinical diagnostic indicators in children with IANE.

Material/Methods

Acute influenza patients were grouped according to their clinical manifestations: flu alone (FA), flu with febrile seizure (FS), influenza-associated encephalopathy (IAE), and IANE. The clinical features, biomarkers, neuroelectrophysiological results, and neuroimaging examination results were compared.

Results

A total of 31 patients were included (FA (n=4), FS (n=8), IAE (n=14), and IANE (n=5)). The IANE group, whose mean age was 3.7 years, was more likely to show rapid-onset seizure, acute disturbance of consciousness (ADOC), Babinski’s sign, and death/sequela. More patients in the IANE group required tracheal intubation mechanical ventilation and received intravenous immunoglobulins (IVIG) and glucocorticoids. The alanine aminotransferase (ALT), aspartate transaminase (AST), and lactate dehydrogenase (LDH) levels in the IANE group were significantly higher than in the FS and IAE groups. The aquaporin-4 (AQP-4) antibody and malondialdehyde (MDA) levels in the serum and cerebrospinal fluid (CSF) were notably higher in IANE patients in the acute stage compared with FS and IAE patients. All patients in the IANE group had positive neuroimaging findings.

Conclusions

Early clinical warning factors for IANE include rapid-onset seizures in patients under 4 years of age, ADOC, and pathological signs. Increased AQP-4 antibodies and MDA levels in CSF might contribute to early diagnosis. Early magnetic resonance venography (MRV) and susceptibility-weighted imaging (SWI) sequences, or thrombelastography to identify deep vein thrombosis, might indicate clinical deterioration.

Fulminant Course of Acute Necrotizing Encephalopathy Followed by Serial MRI: A Case Report

Acute necrotizing encephalopathy (ANE) is a rare but distinctive type of influenza-associated encephalopathy characterized by symmetric multiple lesions with an invariable thalamic involvement. Although the exact pathogenesis of ANE remains unclear, the most prevalent hypothesis is the “cytokine storm,” which results in blood-brain-barrier breakdown. We present the case of a 10-year-old boy with fulminant ANE confirmed with serial MRI studies, including diffusion-weighted imaging and susceptibility-weighted imaging. A comparison of these serial images demonstrated detailed and longitudinal changes in MRI findings during the clinical course corresponding to pathophysiological changes. Our case clarifies the pathogenesis of ANE brain lesions using serial imaging studies and suggests that early immunomodulatory therapy reduces brain damage.

Guidelines for the diagnosis and treatment of acute encephalopathy in childhood

The cardinal symptom of acute encephalopathy is impairment of consciousness of acute onset during the course of an infectious disease, with duration and severity meeting defined criteria. Acute encephalopathy consists of multiple syndromes such as acute necrotizing encephalopathy, acute encephalopathy with biphasic seizures and late reduced diffusion and clinically mild encephalitis/encephalopathy with reversible splenial lesion. Among these syndromes, there are both similarities and differences. In 2016, the Japanese Society of Child Neurology published 'Guidelines for the Diagnosis and Treatment of Acute Encephalopathy in Childhood', which made recommendations and comments on the general aspects of acute encephalopathy in the first half, and on individual syndromes in the latter half. Since the guidelines were written in Japanese, this review article describes extracts from the recommendations and comments in English, in order to introduce the essence of the guidelines to international clinicians and researchers.

Acute necrotizing encephalopathy in an adult as a complication of H1N1 infection

Acute necrotizing encephalitis is one of the recognized influenza-associated encephalopathies which has a characteristic multifocal symmetric involvement of the thalami bilaterally with only very few cases were reported in adults. We present a case of a young adult female who was presented with post-H1N1 Acute Necrotizing Encephalopathy with full neurological recovery after proper clinicoradiological diagnosis and rapid treatment with steroids and intravenous immunoglobulins.

Developing a mouse model of acute encephalopathy using low-dose lipopolysaccharide injection and hyperthermia treatment

IMPACT STATEMENT

Acute encephalopathy (AE), mainly reported in East Asia, is classified into four categories based on clinical and neuropathological findings. Among them, AE caused by cytokine storm is known as the severest clinical entity that causes cerebral edema with poor prognosis. Because suitable and convenient model animal of AE had not been developed, the treatment of patients with AE is not established. In the present study, we established a simple and convenient protocol to mimic AE due to cytokine storm. Our model animal should be useful to elucidate the pathogenesis of AE.

Elderly-onset acute necrotizing encephalopathy mimicking severe heat stroke: a case report and review of the literature

Background

Acute necrotizing encephalopathy (ANE), known as influenza-associated encephalitis, typically affects children.

Case presentation

A 70-year-old woman was admitted to the hospital with altered consciousness, a high temperature, and severe hypotension. Computed tomography (CT) of the head showed no abnormalities; thus, a diagnosis of suspected severe heat stroke was made. On day 2, repeated head CT revealed bilateral symmetrical lesions to the thalamus, and a rapid influenza antigen test was positive. Based on the CT findings and the medical history of influenza, a differential diagnosis of ANE was made. Subsequently, brain edema spread across the whole brain, and the patient died on day 21.

Conclusion

In elderly patients, differentiating ANE from severe heat stroke in a high-temperature environment is difficult because of the similarities in clinical symptoms due to multiple organ failure.

Deep cerebral venous thrombosis mimicking influenza-associated acute necrotizing encephalopathy: a case report

Background

Acute necrotizing encephalopathy is one of the most devastating neurological complications of influenza virus infection. Acute necrotizing encephalopathy preferentially affects the thalamus bilaterally, as does deep cerebral venous thrombosis, which can lead to misdiagnosis.

Case presentation

A 52-year-old Japanese woman infected with seasonal influenza B virus presented to the emergency care unit in our hospital with progressive alteration of her level of consciousness. Bilateral thalamic lesions were demonstrated by magnetic resonance imaging, leading to a tentative diagnosis of acute necrotizing encephalopathy. However, she had deep cerebral venous thrombosis, and the presence of diminished signal and enlargement of deep cerebral veins on T2*-weighted imaging contributed to a revised diagnosis of deep cerebral venous thrombosis. Anticoagulant therapy was initiated, leading to her gradual recovery, with recanalization of the deep venous system and straight sinus.

Conclusions

To the best of our knowledge, these results represent the first report of deep cerebral venous thrombosis associated with influenza infection. It is clinically important to recognize that deep cerebral venous thrombosis, although rare, might be one of the neurological complications of influenza infection. In the presence of bilateral thalamic lesions in patients with influenza infection, deep cerebral venous thrombosis should be considered in addition to acute necrotizing encephalopathy. Delays in diagnosis and commencement of anticoagulant therapy can lead to unfavorable outcomes.

Acute necrotizing encephalopathy in an adult

Acute necrotizing encephalopathy (ANE) is a rapidly progressing neurologic disorder that occurs in children after common viral infections of the respiratory or gastrointestinal systems. This disease is commonly seen in East Asia. Normal healthy infants and children can get affected. The condition carries a poor prognosis with high morbidity and mortality rates. We report here a case of a 23-year-old female with ANE and describe its neuroimaging findings. Magnetic resonance imaging examination performed showed symmetric lesions involving the thalami, brainstem, and cerebellum.

Acute necrotizing encephalopathy: an underrecognized clinicoradiologic disorder

Acute necrotizing encephalopathy (ANE) is a rare but distinctive type of acute encephalopathy with global distribution. Occurrence of ANE is usually preceded by a virus-associated febrile illness and ensued by rapid deterioration. However, the causal relationship between viral infections and ANE and the exact pathogenesis of ANE remain unclear; both environmental and host factors might be involved. Most cases of ANE are sporadic and nonrecurrent, namely, isolated or sporadic ANE; however, few cases are recurrent and with familial episodes. The recurrent and familial forms of ANE were found to be incompletely autosomal-dominant. Further the missense mutations in the gene encoding the nuclear pore protein Ran Binding Protein 2 (RANBP2) were identified. Although the clinical course and the prognosis of ANE are diverse, the hallmark of neuroradiologic manifestation of ANE is multifocal symmetric brain lesions which are demonstrated by computed tomography (CT) or magnetic resonance imaging (MRI). The treatment of ANE is still under investigation. We summarize the up-to-date knowledge on ANE, with emphasis on prompt diagnosis and better treatment of this rare but fatal disease.

Hypoxic-ischemic encephalopathy mimicking acute necrotizing encephalopathy

BACKGROUND

Acute necrotizing encephalopathy is a rare childhood syndrome associated with distinct and unifying neuroimaging features that are often used for the diagnosis of this entity.

PATIENT

We describe a previously healthy 9-month-old girl who presented with upper respiratory symptoms, suspected seizures, and positive nasopharyngeal rapid antigen test for influenza A virus. Magnetic resonance imaging revealed signal abnormality in both thalami, bilateral caudate nuclei, brainstem tegmentum, subcortical white matter, and cerebellar hemispheres, suggestive of acute necrotizing encephalopathy. She subsequently had a cardiac arrest, was placed on extracorporeal membrane oxygenation, and treated with methylprednisone, intravenous immunoglobulin, and plasmapheresis without apparent clinical response. On autopsy, neuropathology showed evidence of hypoxic-ischemic injury but lacked evidence of hemorrhagic necrosis, which is typically associated with acute necrotizing encephalopathy.

CONCLUSION

Combined clinical and neuroimaging features may be suggestive but not sufficient for the diagnosis of acute necrotizing encephalopathy.

Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea

Purpose

Acute necrotizing encephalopathy (ANE) is a fulminant disease of the brain characterized by bilateral thalamic lesions, and is prevalent among children in East Asia. The prognosis of ANE is usually poor with a high mortality rate and neurological sequelae. This study aimed to delineate the clinical characteristics and prognostic factors of ANE.

Methods

We retrospectively analyzed clinical data of 399 pediatric patients with encephalitis who were admitted to Samsung Medical Center from December 1998 to March 2011. We enrolled ten patients (11 cases) with ANE and analyzed their demographic, clinical, and neuroimaging data. The location and extent of the brain regions were checked based on fluid-attenuated inversion recovery, T1-, and T2-weighted imaging findings; the presence of contrast enhancement, restricted diffusion, and hemorrhage.

Results

Ten patients were identified, including one patient with two episodes. The median age of onset was 1.5 years (0.4-8.4 years). The mortality rate was 40%, and only 30% of patients survived without neurological sequelae. The definite involvement of the brainstem on brain magnetic resonance imaging was significantly correlated with mortality (P=0.04).

Conclusion

Broad and extensive brainstem involvement suggested the fulminant course of ANE. Early diagnosis of ANE before brainstem involvement, through careful identification of symptoms of brain dysfunction, may be the best way to achieve better neurological outcomes.

MRI gadolinium enhancement precedes neuroradiological findings in acute necrotizing encephalopathy

We report a 2-year-old Japanese boy with acute necrotizing encephalopathy (ANE) triggered by human herpes virus-6, who presented insightful magnetic resonance imaging (MRI) findings. He was admitted due to impaired consciousness and a convulsion, 2 days after the onset of an upper respiratory infection. At admission, cranial MRI showed marked gadolinium enhancement at the bilateral thalami, brainstem and periventricular white matter without abnormal findings in noncontrast MRI sequences. On the following day, noncontrast computed tomography demonstrated homogeneous low-density lesions in the bilateral thalami and severe diffuse brain edema. The patient progressively deteriorated and died on the 18th day of admission. The pathogenesis of ANE remains mostly unknown, but it has been suggested that hypercytokinemia may play a major role. Overproduced cytokines cause vascular endothelial damage and alter the permeability of the vessel wall in the multiple organs, including the brain. The MRI findings in our case demonstrate that blood-brain barrier permeability was altered prior to the appearance of typical neuroradiological findings. This suggests that alteration of blood-brain barrier permeability is the first step in the development of the brain lesions in ANE, and supports the proposed mechanism whereby hypercytokinemia causes necrotic brain lesions. This is the first report demonstrating MRI gadolinium enhancement antecedent to typical neuroradiological findings in ANE.

Clinical and MRI features of neurological complications after influenza A (H1N1) infection in critically ill children

BACKGROUND

Influenza A (H1N1) can cause severe neurological complications.

OBJECTIVE

The purpose of this study was to analyze clinical and MRI features of neurological complications after H1N1 infection in critically ill children.

MATERIALS AND METHODS

We retrospectively analyzed clinical and neuroimaging findings in 17 children who were hospitalized in an intensive care unit with severe neurological complications after H1N1 infection in South China between September 2009 and December 2011. All children underwent pre- and post-contrast-enhanced brain MRI. Postmortem studies were performed in two children.

RESULTS

Six children died, five because of acute necrotizing encephalopathy (ANE) and one because of intracranial fungal infection. Eleven recovered; their manifestations of H1N1 were meningitis (3), encephalitis (1) and influenza encephalopathy (7). MRI features of ANE included multiple symmetrical brain lesions demonstrating prolonged T1 and T2 signal in the thalami, internal capsule, lenticular nucleus and pontine tegmentum. Postmortem MRI in two children with acute necrotizing encephalopathy showed diffuse prolonged T1 and T2 signal in the bilateral thalami, brainstem deformation and tonsillar herniation.

CONCLUSION

Fatal neurological complications in children after H1N1 infection include ANE and opportunistic fungal infection. MRI is essential for identification of neurological complications and for clinical evaluation.

Acute necrotizing encephalopathy associated with enterovirus infection

Acute necrotizing encephalopathy is a rare, clinically distinct entity of acute encephalopathy triggered by acute febrile diseases, mostly viral infections. It is postulated to arise from uncontrolled cytokine release during a febrile illness, and is most often seen in East Asia. We describe a rare Saudi patient of acute necrotizing encephalopathy attributable to enterovirus in a 4 years and 6 months old girl. A work-up revealed elevations in serum and cerebrospinal fluid interleukin-6 and tumor necrosis factor-α. The outcome on intravenous pulse methylprednisolone was good. This case is the first, to the best of our knowledge, of acute necrotizing encephalopathy reported from Saudi Arabia with a good outcome despite severe magnetic resonance imaging findings and delay in the steroid treatment.

Acute necrotizing encephalopathy (ANE1): rare autosomal-dominant disorder presenting as acute transverse myelitis

The term "acute transverse myelitis (ATM)" comprises various non-traumatic disorders that eventually can be associated with a focal myelopathy. Patients characteristically present with an acutely occurring paraparesis/plegia and require a comprehensive and timely diagnostic work up for the initiation of an appropriate treatment. We present a case of a 36-year-old female patient with a rare genetic disorder (ANE1: Acute Necrotizing Encephalopathy due to a RANBP2 mutation) who presented with an acute quadriplegia. Following an acute pulmonal infection, she rapidly (< 24 h) developed a severe quadriplegia (total motor score 38) with some facial sensory symptoms (perioral hypoesthesia). Magnetic resonance imaging (MRI) revealed a combination of longitudinal extensive transverse myelitis and symmetrical thalamic lesions. A work-up for infectious and systemic diseases was negative; specifically, no findings related to multiple sclerosis, neuromyelitis optica or vascular disorders. After empirical high dose steroid treatment and rehabilitation therapy, the patient gained almost normal gait and upper limb function. She was found to carry an autosomal-dominant missense mutation in the RANBP2 gene predisposing for ANE. Gene segregation was confirmed in other family members that had been affected by other episodes of acute steroid-responsive encephalopathies. We propose that a redefined diagnostic workup of ATM might include ANE1, as the frequency of this rare disorder might be underestimated.

Recurrent acute necrotizing encephalopathy in a Korean child: the first non-Caucasian case

Acute necrotizing encephalopathy is characterized by fever, seizures, acute encephalopathy, and rapid progression to coma. It is usually associated with viral illness and shows characteristic brain magnetic resonance imaging features, including symmetrical involvement of bilateral thalami, brain stem, white matter, and cerebellum. After the first report of recurrent or familial cases in 2003, similar cases were found exclusively in American and European regions. The association with Ran-binding protein 2 gene was identified in 75% of familial or recurrent cases. This report describes a previous healthy 22-month-old boy who recurrently manifested typical clinical and radiological characteristics of acute necrotizing encephalopathy. His neurological outcome worsened with repeated episodes. There was no family history of acute necrotizing encephalopathy and no mutation in the coding region of Ran-binding protein 2 (RANBP2) gene. This is the first reported case of recurrent acute necrotizing encephalopathy in a non-Caucasian family.

The interplay of infection and genetics in acute necrotizing encephalopathy

PURPOSE OF REVIEW

Acute necrotizing encephalopathy (ANE) presents with fulminant encephalopathy and characteristic brain lesions following viral infection. The rarity and unpredictability of the disorder have significantly impaired its study. Growing recognition of ANE and the discovery of causative missense mutations in the nuclear pore gene RANBP2 give promising steps toward unraveling this disease. This review summarizes recent advances of clinical and scientific understanding of ANE.

RECENT FINDINGS

Inflammatory factors participate in the pathogenesis of ANE, but the lack of difference between influenza and noninfluenza ANE focuses attention on the abnormal host response as causative. Early treatment with steroids provides the best outcome for patients who do not have brainstem lesions. Missense mutations in RANBP2 cause the majority of familial and recurrent ANE cases, but other single-gene causes of ANE are possible for familial, recurrent, and sporadic cases.

SUMMARY

Early recognition and systematic evaluation of ANE are necessary. Modeling ANE as a genetic disorder may provide the most immediate gains in the understanding and treatment of ANE and related disorders.

Acute necrotizing encephalopathy of childhood with spinal cord involvement: a case report

Acute necrotizing encephalopathy of childhood is a rare acute encephalopathy occurring after febrile illness with subsequent rapid deterioration of consciousness and convulsions. Typical brain magnetic resonance imaging (MRI) findings are symmetric involvement of the bilateral thalami, brainstem, and cerebral periventricular white matter or the cerebellum. Spinal cord involvement has never been reported. This report describes a healthy 2-year-old girl, who displayed typical clinical manifestations of acute necrotizing encephalopathy. Brain MRI demonstrated symmetrical lesions over the bilateral thalami and periventricular white matter. The clinical features and radiologic images suggested spinal cord involvement. This is the first reported case of acute necrotizing encephalopathy with spinal cord involvement. Spinal cord lesions are, therefore, possible in cases of acute necrotizing encephalopathy of childhood, and these require special attention.

Radiographic study of severe Influenza-A (H1N1) disease in children

OBJECTIVE

To characterize the radiographic findings of pediatric patients with severe Influenza-A (H1N1) disease.

METHODS

A retrospective study of data from chest X-ray, CT and MRI exam of 29 pediatric patients treated in intensive care unit for severe Influenza-A (H1N1) disease.

RESULTS

Disease developed quickly at early stage. Here are four types of radiographic findings. The disease continued to progress for 2-3 days and X-ray showed that all 29 patients had increased solid lesions with the existence of interstitial lesions. Four days later, all lung lesions showed absorption to certain degree. Fifteen days later, X-ray and CT showed complete or significant absorption in 19 cases (85.5%); delayed recovery was identified in 8 cases (27.6%), pulmonary fibrosis was found in 3 cases (10.3%), and 3 patients (10.3%) died. But the latter identified more lesions. Cranial CT and MRI were performed for 8 patients who had neurological symptoms. Of them, 3 cases (10.3%) were abnormal, showed symmetrical long T1 and T2 signal shadow in bilateral thalamus and longer T1 and T2 signals in the between. 3 cases had autopsy completed.

CONCLUSION

The severe Influenza-A (H1N1) among children progression was generally rapid in the first 3 days. The overall radiographic findings are similar to acute respiratory distress syndrome (ARDS). A small portion of the patients occurred acute necrotizing encephalopathy and plastic bronchitis.

Acute necrotizing encephalopathy secondary to diphtheria, tetanus toxoid and whole-cell pertussis vaccination: diffusion-weighted imaging and proton MR spectroscopy findings

We present a previously healthy 6-month-old boy who was admitted to our hospital with lethargy, hypotonia and focal clonic seizures 6 days following diptheria, tetanus toxoid and whole-cell pertussis vaccination. A diagnosis of acute necrotising encephalopathy was made with the aid of MRI, including diffusion-weighted imaging and proton MR spectroscopy.

Acute necrotizing encephalopathy in 3 brothers

Acute necrotizing encephalopathy (ANE) is a devastating and rapidly progressive neurologic disorder that occurs in healthy children after common viral infections. Typically, ANE is sporadic and does not recur. However, familial (ANE1) and recurrent cases have been reported and were recently linked to mutations in RANBP2 (RAN-binding protein 2). We report here a multiply affected kindred with recurrent familial ANE. These affected male siblings (a set of twins and their older brother) all presented with prodromal fever and upper respiratory tract infection that progressed within 72 hours to seizures, coma, and ultimately death, a course that is typical of ANE. It should be noted that 1 brother was treated with early aggressive management, including corticosteroids, and he survived for an additional 5 years. This represents the second reported case of familial ANE in the United States and the only case of male siblings with consanguineous parents. We hope that early recognition and growing awareness can lead to more effective treatment and better outcomes in the future.

Acute necrotizing encephalopathy

Acute necrotizing encephalopathy (ANEC) is a rare disease well recognized in Japan but has not yet been reported from Indian subcontinent. We describe here a case of ANEC with the neuroimaging findings. P. vivax infection was detected as an associated finding and the treatment given.

Outcome of acute necrotizing encephalopathy in relation to treatment with corticosteroids and gammaglobulin

OBJECTIVE

To examine the relation between outcome and treatment with steroids and gammaglobulin in children with acute necrotizing encephalopathy.

METHODS

We retrospectively evaluated the clinical course and outcome of 34 children with acute necrotizing encephalopathy. They were divided into two groups; 17 patients with brainstem lesion and 17 patients without brainstem lesion. Early steroid use was defined as when steroids were administered within 24h after the onset. The outcome was judged as good when a patient had no or mild cognitive impairment and poor when a patient had more severe sequelae, or died.

RESULTS

Among patients without brainstem lesions, the outcome was good in 7 of 12 with early steroid, whereas it was poor in all 5 patients without early steroid. There was no significant difference in sex, age, and laboratory data between patients with and without early steroid. The outcome was not correlated with gammaglobulin treatment. As to patients without brainstem lesions, the outcome was not correlated with early steroid or gammaglobulin treatment.

CONCLUSIONS

Steroid within 24 h after the onset was related to better outcome of children with acute necrotizing encephalopathy without brainstem lesions. Early steroid treatment will be an important option of the treatment for acute necrotizing encephalopathy.

Acute Necrotizing Encephalopathy in an Infant: Observations by CT, Contrast-Enhanced MRI and Diffusion MRI. A Case Report

Acute necrotizing encephalopathy is characterized by bilateral necrotic, hemorrhagic lesions which occur symmetrically in the thalami, dorsal brainstem and dentate nuclei. Development of an extensive breakdown of the blood-brain barrier in the prominent lesions of acute necrotizing encephalopathy was demonstrated in a seven-month-old boy with the disorder, within 14 h after hospitalization by an initially negative post-contrast CT scan, and subsequently positive post-contrast T1-weighted MRI. Diffusion MRI demonstrated concomitant cytotoxic and vasogenic edema in the lesions. By the fortieth day, the lesions apparently regressed with remaining hemorrhagic material in the thalami.

Neuroimaging of viral infections in infants and young children

Many viral infections can involve the central nervous systems (CNS) of fetuses, neonates, infants, and children. The pathogenesis, patterns of CNS involvement, and species of viral infection may differ in the developing fetus, infant and neonate, and early childhood. Familiarity with the clinical course and imaging appearances of the variable CNS diseases is helpful in making correct differential diagnoses and in prompting timely treatment. This article reviews the clinical courses, pathologic findings, and imaging features of the most common viral infections that may involve the CNS of neonates and infants, including congenital and neonatal CNS viral infections, common CNS viral infections, and parainfectious encephalomyelitis.

[Acute necrotizing encephalopathy: patient with a relapsing and lethal evolution]

Acute necrotizing encephalopathy was initially reported in Japanese children. The rapid evolution and symmetrical brain lesions seen in the brainstem, cerebellum and specially in the thalamus characterize the disease. We studied a 7-month-old-girl, who presented with two episodes of rapid loss of consciousness and paresis without metabolic disturbances. At the first time she had a rapid improvement, but at the second episode the course was fulminant and in two days she lapsed into a clinical state of brain death. The magnetic resonance studies showed symmetrical lesions in the thalamus and additional lesions involving the brainstem and the cerebellum.

Acute necrotizing encephalopathy of childhood: report of a Spanish case

Acute necrotizing encephalopathy of childhood is a rare disease with a broad clinical, radiologic, and biochemical spectrum. In the few postmortem studies published to date, the neuropathologic findings involved symmetric, necrotic brain lesions as the hallmark. Here we report on the clinical and neuropathologic findings of a Spanish child with the most severe form of the disease.

Acute encephalopathy associated with influenza and other viral infections

Acute encephalopathy is the most serious complication of pediatric viral infections, such as influenza and exanthem subitum. It occurs worldwide, but is most prevalent in East Asia, and every year several hundreds of Japanese children are affected by influenza-associated encephalopathy. Mortality has recently declined, but is still high. Many survivors are left with motor and intellectual disabilities, and some with epilepsy. This article reviews various syndromes of acute encephalopathy by classifying them into three major categories. The first group caused by metabolic derangement consists of various inherited metabolic disorders and the classical Reye syndrome. Salicylate is a risk factor of the latter condition. The second group, characterized by a systemic cytokine storm and vasogenic brain edema, includes Reye-like syndrome, hemorrhagic shock and encephalopathy syndrome, and acute necrotizing encephalopathy. Non-steroidal anti-inflammatory drugs, such as diclofenac sodium and mephenamic acid, may aggravate these syndromes. Severe cases are complicated by multiple organ failure and disseminated intravascular coagulation. Mortality is high, although methylprednisolone pulse therapy may be beneficial in some cases. The third group, characterized by localized edema of the cerebral cortex, has recently been termed acute encephalopathy with febrile convulsive status epilepticus, and includes hemiconvulsion-hemiplegia syndrome and acute infantile encephalopathy predominantly affecting the frontal lobes. Theophylline is a risk factor of these syndromes. The pathogenesis is yet to be clarified, but an increasing body of evidence points to excitotoxicity and delayed neuronal death.