Mild Encephalopathy With A Reversible Splenial Lesion Research Articles

Underlying Disorders in Children With Infection-Related Acute Encephalopathy

BackgroundVarious factors contribute to the development of infection-related acute encephalopathy (AE) in children, such as infectious agents and chronic underlying disorders. We studied underlying disorders in children with AE to identify predisposing factors of AE. MethodsWe investigated underlying disorders or past histories in patients with two types of AE from the database in the Tokai area of Japan between 2009 and 2022: 204 patients with AE with reduced subcortical diffusion (AED) and 137 with clinically mild encephalopathy with a reversible splenial lesion (MERS). We compared them with 89 patients with acute disseminated encephalomyelitis (ADEM) to clarify the specific disorders in the two AE types. ResultsThe prevalence of underlying disorders in AED (34%, 70 patients) was significantly higher than that in ADEM (12%, 11 patients) (P < 0.01). The prevalence of underlying disorders in MERS was 23% (32 patients). The underlying disorders included seizure disorders, premature birth, genetic/congenital disorders, and endocrine/renal diseases. In patients with seizure disorders in AED, five patients (18%) had Dravet syndrome and four (15%) had West syndrome, whereas none with MERS had these syndromes. Twenty-five (12%) of 204 patients with AED, three (2%) with MERS, and one (1%) with ADEM were preterm or low birth weight. ConclusionsThe high prevalence of seizure disorders suggests that seizure susceptibility is an important predisposing factor in AED. Premature birth also has an impact on the development of AED. Caution is required regarding the development of AE in patients with chronic seizure disorders or premature birth.

Mild Encephalopathy with Reversible Splenium Lesion Associated with SARS-CoV-2 Infection (P14-4.007)

<h3>Objective:</h3> NA <h3>Background:</h3> Encephalopathy secondary to SARS-CoV-2 infection has been previously reported, although neuroimaging in many of these patients is typically unremarkable. There are only a few reported cases of patients with SARS-CoV-2 infection associated with mild encephalopathy with a reversible splenial lesion (MERS) on imaging. MERS has a monophasic course of encephalopathy, marginal pleocytosis in the cerebrospinal fluid, and a characteristic MRI finding of a reversible lesion in the splenium of the corpus callosum. <h3>Design/Methods:</h3> NA <h3>Results:</h3> A 68-year-old woman presented to the hospital with altered mental status. The patient was found unresponsive during a welfare check at home. Initial neurological evaluation revealed that the patient was awake, alert, and oriented to name and age but not date and time. Speech was fluent with intact naming, repetition, and comprehension. Polymerase chain reaction for SARS-CoV-2 was positive, and history revealed that patient was not vaccinated. CT of the head was unrevealing. MRI of the brain revealed increased signal in the corpus callosum on FLAIR with low diffusivity on diffusion-weighted imaging. The patient was given tocilizumab, dexamethasone, remdesivir, and ceftriaxone to treat superimposed bacterial pneumonia. Encephalopathy improved gradually throughout the hospital course, and the patient was transitioned to an inpatient rehabilitation facility. Repeat brain MRI five weeks from initial imaging showed resolution of the hyperintensity and focus of low diffusivity in the splenium. <h3>Conclusions:</h3> This is a rare case of MERS triggered by SARS-CoV-2 in a patient who presented with encephalopathy. This case expands the clinical spectrum of neurological manifestations associated with SARS-CoV-2 and adds to the already existing literature. Further investigation is imperative for a better understanding of the pathophysiology and management of this entity to avoid unnecessary invasive diagnostic and therapeutic interventions. <b>Disclosure:</b> Dr. Kokash has nothing to disclose. Dr. Reyes has nothing to disclose. Dr. Yacoub has nothing to disclose.

Mild encephalopathy with reversible extensive white matter lesions in a child with acute adenoviral infection and a literature review

Mild encephalopathy with a reversible splenial lesion (MERS) is a known clinical-radiological description. However, MERS with extensive lesions (MERS type-2) is rarely associated with adenovirus. There are only three published cases of MERS type-2 associated with adenovirus infection. We present a 10-year-old previously healthy girl who presented with speech difficulty and mild encephalopathy after three days of prodromal illness. The magnetic resonance imaging (MRI) revealed bilateral diffusion restriction in the parietal white matter, splenium and genu of the corpus callosum without mass effect and slight thickening at the splenium of corpus callosum with no contrast enhancement. With empirical and support treatment, her neurological examination was completely normal by the 18th hour. The nasopharyngeal respiratory adenoviral PCR resulted positive. She was discharged with total clinical and radiological resolution on the 10th day of admission. The case was diagnosed with MERS type-2 which is rarely associated with adenoviral infection. This report is the first case of adenovirus related MERS type-2 in a Turkish child. Pediatricians, child neurologists, child infection specialists and radiologists should recognize this condition to ensure appropriate diagnosis.

Clinically Mild Encephalopathy With a Reversible Splenial Lesion Type 2 Caused by Human Herpesvirus 6 Infection

BackgroundClinically mild encephalopathy with a reversible splenial lesion (MERS) is the second commonest cause of encephalopathy. Several pathogens have been detected in patients with MERS type 2, such as influenza A and B, but little is known about the proportion of cases of MERS type 2 with this pathogenesis. Human herpesvirus 6 (HHV6) is the second commonest pathogen causing acute encephalopathy. However, HHV6 has not been previously reported in patients with MERS type 2. Patient DescriptionIn this report, we describe a five-year-old boy with MERS type 2 caused by HHV6 infection. The present case was diagnosed with MERS type 2 caused by HHV6 infection based on the characteristic clinical course, the results of the virus testing, and imaging findings. DiscussionThis is the first description of MERS type 2 caused by HHV6 infection. Although there is a report of MERS type 1 caused by HHV6 infection, there are no detailed reports in the literature about MERS type 2 associated with HHV6 infection. Thus the clinical findings associated with MERS type 2 caused by HHV6 infection are poorly understood. This report indicates that HHV6 can cause MERS type 2.

The assessment of mild encephalopathy with a reversible splenial lesion (MERS) using high b-value DWI

Introduction:Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) was shown to have a transient reduction in diffusion. Such changes would be used as an early detection to reduce excessive treatments and promote recovery without sequelae. The current research evaluated the high b-value (b = 3000 s/mm2) diffusion-weighted imaging (DWI) assessment in MERS.Methods:Sixteen pediatric patients showed MERS used DWI (b = 1000 and 3000 s/mm2). To record number of lesions, the signal intensities, signal-to-noise ratios (SNRs), contrast-to-noise ratios (CNRs), contrast ratios (CRs), the apparent diffusion coefficients (ADCs) were measured in the normal parenchyma and lesions.Results:Lesions were more apparent with high b-value. The ADC values and CNR in the lesions and surrounding normal brain parenchyma were relatively low at a high compared to standard b-value DWI (SNR: 144.67 ± 33.03, 85.72 ± 31.50; CNR: 20.82 ± 17.64, 49.62 ± 33.06; for b = 1000 and 3000 s/mm2). The CR was significantly higher at a high compared to low b-value DWI (CR: 0.06 ± 0.07 versus 0.40 ± 0.14).Conclusion:High b-value DWI could detect more lesions and could obviously improve the detection of lesions in pediatric patients with MERS.

Varying Patterns of CNS Imaging in InfluenzaA Encephalopathy in Childhood.

The brain imaging findings in children with neurological complications associated with influenza Ainfections are presented and analyzed and pathological imaging changes including atypical intracerebral hemorrhages in these patients are discussed. Neuroimaging findings in six children with influenza encephalopathy following influenza Ainfection between 2012-2017 were retrospectively investigated. Of these five underwent magnetic resonance imaging (MRI) and one computed tomography (CT). Gene analysis was performed in two cases with acute necrotizing encephalitis of childhood (ANEC). The MRI findings of one child were concordant with mild encephalopathy with areversible splenial lesion (MERS); this patient recovered but remained aphasic. In two cases MRI showed typical bilateral thalamic lesions as afeature of ANEC; genetic testing facilitated the diagnosis in one case. One of the patients died, the other showed little improvement. The remaining three patients had multiple diffuse cerebral hemorrhages predominantly affecting the supratentorial white matter after influenza Ainfection complicated by pneumonia, rhabdomyolysis and sepsis requiring extracorporeal membrane oxygenation (ECMO). Neurological complications in children associated with influenza Ainfection may include MERS and ANEC. Additionally, atypical disseminated intracerebral hemorrhages as a complication of influenza Ainfection is reported.

Mild encephalopathy with a reversible splenial lesion in a girl with acute pyelonephritis.

We report the case of a 12-year-old girl who had mild encephalopathy with a reversible splenial lesion (MERS) associated with acutepyelonephritis caused by Escherichia coli. The patient was admitted with a high fever, and she was diagnosed with acute pyelonephritis based on pyuria and the results of urine culture, which detected cefotaxime-sensitive E. coli. Although intravenous cefotaxime and tobramycin were administered, her fever persisted and her C-reactive protein level increased to 307 mg/L. On day 3 of admission, she demonstrated abnormal neuropsychiatric symptoms, such as delirium, ataxia, and word salad. Magnetic resonance imaging (MRI) of the brain performed on day 4 showed marked hyperintensities in the bilateral corpus callosum and deep white matter on diffusion-weighted images, with corresponding diffusion restriction on apparent diffusion coefficient mapping. No abnormalities or pathogens were detected in the cerebrospinal fluid; however, lipopolysaccharides (LPS, endotoxin) were detected in plasma (41.6 pg/mL), associated with acute neurological deterioration. Her clinical condition gradually improved, and no neurological abnormalities were observed on day 6. Follow-up brain MRI performed 2 weeks later showed near-disappearance of the previously noted hyperintense lesions. In this patient, we first proved endotoxemia in a setting of MERS. The release of LPS following antibiotic administration might be related to the development of MERS in this patient. The possibility of MERS should be considered in patients who present with acute pyelonephritis and demonstrate delirious behavior.

Mild Encephalitis/Encephalopathy with a Reversible Splenial Lesion Associated with Rhinovirus Infection

We report a 7-year-old patient with mild encephalopathy with a reversible splenial lesion (MERS) presenting with recurrent delirious behavior, hallucinations and seizures following common cold.

Mild encephalopathy with reversible splenial lesion: An important differential of encephalitis

Mild encephalopathy with a reversible splenial lesion (MERS) is a clinico-radiological syndrome characterized by a transient mild encephalopathy and a reversible lesion in the splenium of the corpus callosum on MRI. This syndrome has almost universally been described in children from Japan and East Asia. Here we describe seven cases of MERS occurring in Caucasian Australian children from one centre seen over a 3 year period. All patients had a fever-associated encephalopathy (n = 7), which presented with confusion (n = 4), irritability (n = 3), lethargy (n = 3), slurred speech (n = 3), drowsiness (n = 2) and hallucinations (n = 2). Other neurological symptoms included ataxia (n = 5) and seizures (n = 1). These symptoms resolved rapidly over 4–6 days followed by complete neurological recovery. In all patients, MRI performed within 1–3 days of onset of encephalopathy demonstrated a symmetrical diffusion-restricted lesion in the splenium of the corpus callosum. Three patients had additional lesions involving other parts of the corpus callosum and adjacent periventricular white matter. These same three patients had mild persisting white matter changes evident at followup MRI, while the other patients had complete resolution of radiological changes. A potential trigger was present in five of the seven cases: Kawasaki disease, Salmonella, cytomegalovirus, influenza B and adenovirus (all n = 1). Elevated white cell count (n = 4), elevated C reactive protein (n = 5) and hyponatremia (n = 6) were commonly observed. CSF was performed in four patients, which showed no pleocytosis. This case series of MERS demonstrates this condition occurs outside of East Asia and is an important differential to consider in children presenting with acute encephalopathy.

Marked elevation of interleukin-6 in mild encephalopathy with a reversible splenial lesion (MERS) associated with acute focal bacterial nephritis caused by Enterococcus faecalis

This report describes two cases of mild encephalitis/encephalopathy with reversible splenial lesion (MERS) associated with acute focal bacterial nephritis (AFBN). The patients, who presented with fever and delirious behavior, exhibited hyponatremia and markedly elevated interleukin (IL)-6 in cerebrospinal fluid (CSF) and serum. Enterococcus faecalis was detected in the urine culture. After ampicillin treatment, their consciousness improved without neurological sequelae. Moreover, a diffusion-weighted MRI abnormality, i.e., intensified signals in splenium of the corpus callosum, disappeared. MERS is a possible complication of AFBN. Elevated CSF IL-6 levels suggest that remote activation of intracerebral immune response through the immune–neuroendocrine pathway might play an important role in the pathophysiology of MERS.

A Case of Mild Encephalopathy with a Reversible Splenial Lesion Associated with G5P[6]Rotavirus Infection

We report a case of mild encephalopathy with a reversible splenial lesion (MERS) associated with acute gastroenteritis caused by rotavirus (RV) infection. The patient (male, 4 years and 3 months old) was admitted to our hospital for diarrhea and afebrile seizures. Head MRI revealed a hyperintense signal in the splenium of the corpus callosum on DWI and a hypointense signal on the ADC-map. After awakening from sedation, the patient's disturbance of consciousness improved. On day 5 after admission of the illness, the patient was discharged from the hospital in a good condition. Electroencephalography on day 2 after admission was normal. On day 8 of admission, head MRI revealed that the splenial lesion had disappeared. RV antigen-positive stools suggested that RV had caused MERS. This RV genotype was considered to be G5P[6]; it may have spread to humans as a strain reassortment through substitution of porcine RV into human RV gene segments. This extremely rare genotype was detected first in Japan and is not covered by existing vaccines; this is the first sample isolated from encephalopathy patients. Few reports have investigated RV genotypes in encephalopathy; we believe that this case is valuable for studying the relationship between genotypes and clinical symptoms.

Kawasaki disease complicated by mild encephalopathy with a reversible splenial lesion (MERS)

We reported four patients (2 to 10years) with Kawasaki disease complicated by clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS). All were treated with γ-globulin (2 to 6g/kg) after the diagnosis of Kawasaki disease, the fever being alleviated between day 6 and 25. One of two patients exhibiting a poor response to γ-globulin had a cardiac aneurysm as a sequela. Their neurological manifestations (delirious behavior and drowsiness), laboratorial hyponatremia, and radiological abnormalities completely disappeared. It is important for pediatricians to acknowledge that MERS can be observed in patients with Kawasaki disease, especially in older children, and that they might be at high risk for cardiac abnormalities.

Sisters with clinically mild encephalopathy with a reversible splenial lesion (MERS)-like features; Familial MERS?

We first report sisters presenting with clinically mild encephalitis/encephalopathy with a reversible splenial lesion (MERS)-like features, i.e., mild and reversible neurological manifestations, and MRI finding of a reversible lesion with transiently reduced diffusion in the corpus callosum associated with symmetrical white matter. The distributions of the white matter lesions (more extensive) and Na levels (normal) were different from those reported for sporadic MERS patients (subcortical white matter close to the central sulci, and hyponatremia), which suggested that the pathophysiology of the sisters with MERS-like features might be different from that of sporadic MERS. Some genetic factors might be involved in MERS, especially in some patients with extensive white matter lesions.