A case of clinically mild encephalitis with a reversible splenial lesion (MERS) after mumps vaccination

Reversible splenial lesion syndrome type II in youth mimicking acute ischemic stroke like onset: A case report

BACKGROUND

Reversible splenial lesion syndrome (RESLES) is a newly recognized syndrome. Its typical pathologic findings is a reversible progress correlated with transiently reduced diffusion lesion in the splenium of the corpus callosum. The common clinical symptoms include mildly altered states consciousness, delirium, and seizure.

METHODS

We presented a 21-year-old patient with signs of acute ischemic stroke (AIS), including symptoms of weakness on the right upper limb and aphasia, lasting 50 minutes until he was taken to the emergency. He just had a cough 20 days ago.

RESULTS

An elevated level of white blood cell count, neutrophil count, monocyte count, protein of cerebrospinal fluid was found in laboratory examinations. Magnetic resonance imaging revealed distinct lesions involving white matter in the splenium of the corpus callosum and frontal-parietal cortex on both cerebral hemispheres. Digital subtraction angiography examination was also unremarkable. The patient recovered to baseline within 4 days. We treated the patient with glucocorticoid, antiviral drugs, butylphthalide, and dehydrating drugs. In addition, the follow-up brain magnetic resonance imaging scan showed reduced lesions. AIS-like symptoms did not occur during a 30-day follow-up period.

CONCLUSION

This patient with reversible splenial lesion syndrome type II exhibited AIS-like symptoms, which was uncommon on clinical. This case extends the recognized clinical phenotypes for this disorder.

Cytotoxic lesion of the corpus callosum in pediatrics: A case report

Cytotoxic lesions of the corpus callosum are considered a clinical-radiological syndrome that generates transitory damage to the corpus callosum; especially in the splenium, with a multicausal origin such as drugs, malignant neoplasms, infections, subarachnoid hemorrhage, metabolic disorders, and traumas. The clinical presentation varies in severity. Some patients have complete recovery in a few days, while others present a more serious clinical, requiring admission to pediatric intensive care. We present a case of a pediatric patient with cytotoxic lesions of the corpus callosum (CLOCCs) confirmed by brain magnetic resonance imaging (MRI). The patient was admitted due to gastrointestinal symptoms, progressing to altered consciousness, postural instability, dysarthria, and paroxysmal events. A literature search of all reported cases of compromises of CLOCCs was carried out to identify the different terms used to describe this syndrome and consolidated a report of utility in the clinic of this pathology.

"Reversible cytotoxic lesion of the corpus callosum following SARS-CoV-2 mRNA vaccine administration: a finding to be aware of"

Cytotoxic lesions of the corpus callosum (CLOCCs) are a clinical-radiological spectrum of disorders secondary to several etiopathogeneses. Cytotoxic lesions of the corpus callosum are typically associated with mild clinical symptoms including fever, headache, confusion, and altered mental status. We present a case of a 51-year-old Caucasian woman who developed a reversible lesion of the splenium of the corpus callosum associated with small round-shaped white matter hyperintensities after the first dose of SARS-CoV-2 mRNA vaccine. Magnetic resonance imaging is fundamental for diagnosis and no treatment is generally required.

Multisystem Inflammatory-like Syndrome in a Child Following COVID-19 mRNA Vaccination

A 12-year-old male was presented to the hospital with acute encephalopathy, headache, vomiting, diarrhea, and elevated troponin after recent COVID-19 vaccination. Two days prior to admission and before symptom onset, he received the second dose of the Pfizer-BioNTech COVID-19 vaccine. Symptoms developed within 24 h with worsening neurologic symptoms, necessitating admission to the pediatric intensive care unit. Brain magnetic resonance imaging within 16 h of admission revealed a cytotoxic splenial lesion of the corpus callosum (CLOCC). Nineteen days prior to admission, he developed erythema migrans, and completed an amoxicillin treatment course for clinical Lyme disease. However, Lyme antibody titers were negative on admission and nine days later, making active Lyme disease an unlikely explanation for his presentation to hospital. An extensive workup for other etiologies on cerebrospinal fluid and blood samples was negative, including infectious and autoimmune causes and known immune deficiencies. Three weeks after hospital discharge, all of his symptoms had dissipated, and he had a normal neurologic exam. Our report highlights a potential role of mRNA vaccine-induced immunity leading to MIS-C-like symptoms with cardiac involvement and a CLOCC in a recently vaccinated child and the complexity of establishing a causal association with vaccination. The child recovered without receipt of immune modulatory treatment.

Reversible Splenial Lesion Syndrome with Some Novel Causes and Clinical Manifestations

Objective Reversible splenial lesion syndrome (RESLES) is a clinical radiological syndrome characterized by a reversible lesion of the splenium of the corpus callosum with a decreased apparent diffusion coefficient (ADC) value. The clinical manifestations of RESLES are diverse. Methods Fifteen cases of adult RESLES patients (10 males and 5 females) were retrospectively selected from the radiology system using the key word "corpus callosum" at a university-affiliated tertiary care hospital between May 1, 2015 and December 31, 2019. The possible precipitating factors, clinicoradiological findings and modified Rankin Scale (mRS) on follow-up were then analyzed. Results The patient ages ranged from 22 to 53 years old. The mean age was 34 years old. The most common neurological symptoms included headache (3/15), dizziness (3/15), first onset of seizure (3/15), paroxysmal blurred vision (2/15), vertigo (2/15), amnesia (2/15), and confused consciousness without seizure (2/15), followed by drowsiness (1/15), paresthesia (1/15), dysmetria (1/15) and dysarthria (1/15). The precipitating factors included infection, seizure, anti-epileptic treatment with levetiracetam, carbamazepine, valproate, hyperglycemia, hypoglycemia, cerebral venous sinus thrombosis, and rabies vaccine injection prior to the onset of RESLES. All cases were carefully followed up and had excellent prognoses. Conclusion RESLES manifests as variety of symptoms with less specificity and precipitating factors. Paroxysmal blurred vision may be a relatively specific symptom of RESLES. Levetiracetam, carbamazepine or valproate could be the cause of RESLES, exposure to the rabies vaccine could be another predisposing factors for RESLES as well. RESLES type 1 was therefore found to be highly "reversible" with an excellent prognosis.

Rotavirus-associated seizures and reversible corpus callosum lesion

Rotavirus is a non-enveloped double-stranded RNA virus that causes severe gastroenteritis in children, but complications are rarely reported. Some reports have shown that rotavirus can induce diverse complications of the central nervous system, such as seizures, encephalopathy with a reversible splenial lesion, encephalitis, cerebral white matter abnormalities, and cerebellitis. Here, we present a 2-year-old patient with seizures, who had an isolated splenial lesion in the corpus callosum on neuroimaging, and the rotavirus antigen detected in faeces.

[Syndrome of mild encephalopathy with a reversible splenial corpus callosum lesion]

Mild encephalopathy with a reversible splenial lesion (MERS) is a clinico-radiological syndrome that has been associated with a variety of underlying etiologies including viral and bacterial infections, epilepsy and antiepileptic drug cessation, hypoglycemia and electrolyte imbalance. We report a case of a 24-year-old woman who had an isolated splenial lesion in the corpus callosum on neuroimaging associated with MERS.

Mild encephalopathy with a reversible splenial lesion mimicking transient ischemic attack: A case report

BACKGROUND

Reversible splenial lesion syndrome (RESLES) is a newly recognized syndrome, and a reversible progress associated with transiently reduced diffusion lesion in the splenium of the corpus callosum (SCC) is the typical pathological finding. The routine clinical symptoms include mildly altered states of consciousness, delirium, and seizures.

METHODS

We presented a 14-year-old patient with signs suggestive of transient ischemic attack (TIA), including triple episodic weakness on the right upper limb, slurred speech, and bucking, lasting several hours in each time 2 days ago. She just had a slight cold 2 weeks ago.

RESULTS

No evidence of abnormality was found in laboratory examinations except an elevated percentage of lymphocyte. Magnetic resonance imaging revealed lesions in splenium of the corpus callosum and frontal-parietal subcortex on both cerebral hemispheres. Cerebrovascular examination was also unremarkable. The patient recovered to baseline within 25 hours. No treatment was given to her in hospital. In addition, the follow-up brain magnetic resonance imaging scan showed reduced lesions. TIA-like symptoms did not occur during a 30-day follow-up period.

CONCLUSION

This young patient with RESLES type II exhibited TIA-like symptoms, which was not previously reported in literature. This case extends the recognized clinical phenotypes for this disorder.

Reversible splenial lesion syndrome associated with lobar pneumonia: Case report and review of literature

BACKGROUND

Reversible splenial lesion syndrome (RESLES) is a rare clinico-radiological disorder with unclear pathophysiology. Clinically, RESLES is defined as reversible isolated splenial lesions in the corpus callosum, which can be readily identified by magnetic resonance imaging (MRI) and usually resolve completely over a period of time. RESLES could be typically triggered by infection, antiepileptic drugs (AEDs), poisoning, etc. More factors are increasingly recognized.

METHODS AND RESULTS

We reported herein an 18-year-old female patient with lobar pneumonia who developed mental abnormalities during hospitalization. An isolated splenial lesion in the corpus callosum was found by head MRI and the lesion disappeared 15 days later. Based on her clinical manifestations and radiological findings, she was diagnosed with lobar pneumonia associated RESLES. We further summarize the up-to-date knowledge about the etiology, possible pathogenesis, clinical manifestations, radiological features, treatment, and prognosis of RESLES.

CONCLUSION

This report contributes to the clinical understanding of RESLES which may present with mental abnormalities after infection. The characteristic imaging of reversible isolated splenial lesions in the corpus callosum was confirmed in this report. The clinical manifestations and lesions on MRI could disappear naturally after 1 month without special treatment.

Reversible splenial lesion syndrome associated with encephalitis/encephalopathy presenting with great clinical heterogeneity

BACKGROUND

Reversible splenial lesion syndrome (RESLES) is a disorder radiologically characterized by reversible lesion in the splenium of the corpus callosum (SCC). Most of patients with RESLES associated with encephalitis/encephalopathy were identified in Japanese population, but almost no Chinese patients were diagnosed as RESLES associated with encephalitis/encephalopathy.

METHODS

Possible patients with reversible isolated SCC lesions were retrieved from January 2012 to July 2015 using keyword "restricted diffusion and isolated SCC lesion" in MRI report system from a large academic center. The clinical, laboratory and radiological data were summarized.

RESULTS

A total of 15 encephalitis/encephalopathy patients (9 males and 6 females) were identified with a reversible isolated SCC lesion. Except for 13 patients with fever symptom, 8 patients also had cold symptoms before the onset of neurological symptoms. The neurological symptoms included headache, vertigo, seizure, disturbance of consciousness, and delirious behavior. Thirteen patients completely recovered within 1 month, but 2 patients who were subjected to mechanical ventilation had persistent neurological deficits. The initial MRI features showed isolated ovoid or extending SCC lesions with homogeneous hyperintense on diffusion weighted imaging (DWI) and decreased apparent diffusion coefficient (ADC) values. The follow-up MRI revealed that isolated SCC lesions with diffuse restriction disappeared at 10 to 32 days after the initial MRI study. Fractional anisotropy map revealed the decreased value of SCC lesion in a severe case with poor prognosis.

CONCLUSIONS

RESLES associated with encephalitis/encephalopathy is a reversible syndrome with an excellent prognosis in most patients, while a few patients required ventilator supporting at the early stage might have severe neurological sequelae. Reversible signal changes on DWI and ADC are identified in all patients, but fractional anisotropy values can be decreased in severe patient with neurological sequelae.

Expanding the spectrum of MERS type 2 lesions, a particular form of encephalitis

We report on a 13-year-old boy who presented with signs suggestive of encephalitis and in whom magnetic resonance imaging revealed lesions in the genu and splenium of the corpus callosum and symmetrical lesions bilaterally in the center semiovale. This clinical-radiologic entity was previously reported in the literature and was given the acronym MERS type 2 (mild encephalitis with reversible splenial) lesion. The clinical, radiologic, and biochemical characteristics of the patient with MERS type 2 lesions presented in this article show some differences with those in previously reported patients. His clinical recovery was particularly slow, cerebrospinal fluid was abnormal, and on magnetic resonance imaging the typical time course of MERS type 2 lesions resolving through a phase of solitary lesions in the splenium of the corpus callosum, the so-called type 1 lesions, was not seen. He is also the first patient in whom mycoplasma pneumoniae was found to be associated with MERS type 2 lesions. These findings further expand the spectrum of MERS type 2 lesions. The question raises whether the MERS type 2 lesion represents a new type of encephalitis or a particular radiologically recognizable subtype of postinfectious encephalitis. In the article, previously reported patients with MERS type 2 lesions are reviewed.

Mild Encephalopathy with Reversible Splenial Lesion in Children

Mild encephalopathy with reversible splenial lesion (MERS) is a recently described clinico-radiological syndrome. It is characterised by acute mild encephalopathy and changes in the splenium of the corpus callosum on brain magnetic resonance imaging (MRI). MERS has been described mainly in East Asian populations. Infection, particularly influenza, is the most common association. The prognosis is generally favourable with spontaneous resolution of clinical and radiological abnormalities. We report two cases of non-influenza MERS in children, one associated with varicella, and discuss their differing clinical presentations.

[A case of clinically mild encephalitis/encephalopathy with a reversible splenial lesion associated with anti-glutamate receptor antibody]

We report the case of an 18-year-old boy who presented with disturbance of consciousness and generalized seizures following flu-like symptoms such as high fever and arthralgia. T2 and diffusion weighted brain magnetic resonance images showed a hyperintense ovoid lesion in the splenium of the corpus callosum and T, weighted images showed a hypointense lesion; the lesion completely disappeared on repeat imaging after 3 days. Antiglutamate epsilon2 receptor antibodies were detected in his cerebrospinal fluid. Although the patient had several episodes of generalized seizures, he completely recovered within 3 months. Our patient had a clinically mild encephalitis/encephalopathy with a reversible splenial lesion following flu-like symptoms, which indicated viral infection. As compared to previously reported cases, our case was characteristic because of the protracted recovery shown by the patient. Anti-glutamate epsilon2 receptor antibodies may be associated with prolonged generalized seizures in the case of our patient. Our results also suggest that anti-glutamate epsilon2 receptor antibodies may play a role in the pathogenesis of this condition.