Transient widespread cortical and splenial lesions in acute encephalitis/encephalopathy associated with primary Epstein–Barr virus infection

EBV-associated CNS infection in an immunocompetent adult: A case report and literature review

EBV infections rarely cause CNS involvement. For young adult patients with suspected CNS infection, bacterial and other common viral infections should be excluded first and treated empirically until proven otherwise. Challenges in diagnosing EBV-associated CNS infection, emphasizing the role of CSF PCR in confirming the diagnosis.

Epstein-Barr Virus Encephalitis: A Review of Case Reports from the Last 25 Years

Although uncommon, Epstein-Barr virus-related neurological disorders represent the seventh most frequent cause of infectious encephalitis in adults. The limited number of publications on EBV encephalitis mainly document isolated clinical cases. This study aimed to summarize published data on EBV encephalitis. A systematic literature search identified 97 EBV encephalitis cases. In the selected cases, EBV-related neurological disorders manifested as lymphocytic pleocytosis in the cerebrospinal fluid (CSF) with moderate hyperproteinorachia. The EBV PCR test was positive in 87% of the CSF samples, with wide-ranging viral loads. When encephalitis occurred in the context of past EBV infections, all of the EBV PCR tests on CSF samples were positive. On the contrary, negative EBV PCR tests on CSF samples occurred only in the context of primary infections. EBV PCR was rarely carried out on blood samples, contributing minimally to the diagnosis. For the treatment of EBV encephalitis, Aciclovir was used alone in 29% of cases, and in association with other drugs in 40% of cases. Ganciclovir (30%), corticoids (52%), and immunoglobulins (15%) were mainly used in association with other drugs. Cerebral imaging was abnormal in 69% of cases, mostly in the cerebellum and basal ganglia. This work highlights that the EBV PCR test on CSF samples is currently the main laboratory diagnostic test to diagnose EBV encephalitis. This diagnostic test is useful; however, it is imperfect. New complementary diagnostic tools, approved treatments, and standardized practices could improve patient management.

Treatment Options for Epstein-Barr Virus-Related Disorders of the Central Nervous System

Epstein-Barr virus (EBV), a causative agent for several types of lymphomas and mucosal cancers, is a human lymphotropic herpesvirus with the capacity to establish lifelong latent infection. More than 90% of the human population worldwide is infected. The primary infection is usually asymptomatic in childhood, whereas infectious mononucleosis (IM) is common when the infection occurs in adolescence. Primary EBV infection, with or without IM, or reactivation of latent infection in immunocompromised individuals have been associated with a wide range of neurologic conditions, such as encephalitis, meningitis, acute disseminated encephalomyelitis, and cerebellitis. EBV is also involved in malignant lymphomas in the brain. An increasing number of reports on EBV-related disorders of the central nervous system (CNS) including the convincing association with multiple sclerosis (MS) have put in focus EBV-related conditions beyond its established link to malignancies. In this review, we present the clinical manifestations of EBV-related CNS-disorders, put them in the context of known EBV biology and focus on available treatment options and future therapeutic approaches.

THE NEUROLOGICAL MANIFESTATIONS AND FUNCTIONAL INDEPENDENCE IN PATIENTS WITH ENCEPHALOPATHIES OF DIFFERENT TYPES

OBJECTIVE

Aim: To access the neurological manifestations and activities of daily living in patients with encephalopathy of one of the following types: post-infectious, chronic traumatic encephalopathy, alcohol-induced, and microvascular ischemic disease of the brain.

PATIENTS AND METHODS

Materials and Methods: In the period of 2021-2022 we examined 520 patients, who signed the informed consent, taking into account their age, sex, occupation, the cause, and the disease duration. Such parameters were evaluated, as the data of neurological manifestations, the activities of daily living (Barthel index), cognitive functioning (MoCA-test), and statistical methods (Statistica 13.0).

RESULTS

Results: A probable influence of the age factor on the frequency of occurrence of different types of encephalopathies was established (χ2=235.05; p<0.001). The cognitive impairment was diagnosed in 53.79 % of patients with CTE, 66.21% with SVD, and 58.82% with AE. 40% of patients with CTE are dependent on their activities of daily living, among patients with SVD - 31,72 %, among patients with AE - 44.12%, among patients with PIE - 53.91%. 17.97% of patients with PIE had moderate dependence by the Barthel index. Thus, the severity of disability doesn't depend on the age or sex of patients but is correlating with the duration of the disease.

CONCLUSION

Conclusions: The neurological manifestations in patients with encephalopathies and their activities of daily living were studied profoundly and the data obtained opened new directions in the following research.

HaNDL syndrome: a reversible cerebral vasoconstriction triggered by an infection? A case report and a case-based review

Background

The syndrome of transient Headache and Neurological Deficits with cerebrospinal fluid (CSF) Lymphocytosis (HaNDL) is classified among secondary headaches attributed to “non-infectious, inflammatory intracranial disease”. Despite its classification among secondary headaches, the current definition of HaNDL does not contemplate a causal agent. Thus, the aetiology, as well as the pathogenesis of both the headache and the transient focal deficits, remains unknown.

Case presentation

We describe a 29-year-old healthy male developing episodes of thunderclap headaches associated with recurrence of hemiparesis/hemi-paraesthesia; CSF showed lymphocytosis 200/mm³ and increased albumin; brain MRI revealed widespread leptomeningeal enhancement and a non-enhancing, circular diffusion restriction in the splenium of corpus callosum. Screening for neurotropic pathogens detected Epstein-Barr (EBV) DNA in serum and CSF, interpreted as a primary EBV infection once the seroconversion of EBV nuclear antigen (EBNA) IgM to IgG was proven on follow-up. Transcranial Doppler detected, during headache, increased flow velocity in middle cerebral arteries, possibly indicating vasospasm. Oral nimodipine was administered, with prompt clinical recovery, resolution of CSF/MRI abnormalities, and normalization of flow velocities in middle cerebral arteries.

Case-based review

Although the definition of HaNDL does not contemplate a viral trigger or abnormal brain imaging, we found other literature cases of HaNDL associated with direct or indirect signs of CNS infection.

Conclusions

At least in a proportion of patients, a viral aetiology may have a role in HaNDL. Whatever the aetiology, we suggest that the pathogenic mechanism may rely on the (viral or other) agent ultimately triggering cerebral vasoconstriction, which would explain both focal symptoms and headache. Calcium channel blockers might be a therapeutic option.

Case Report: Epstein-Barr Virus Encephalitis Complicated With Brain Stem Hemorrhage in an Immune-Competent Adult

Encephalitis caused by Epstein-Barr virus infection is uncommon, but most patients have a good outcome after symptomatic treatment. The infiltration of mononuclear cells in blood vessels and necrosis resulting from the immune response to Epstein-Barr virus infection in a very small number of patients seem to be the main cause of death. We describe a fatal case of Epstein-Barr virus encephalitis diagnosed by next-generation sequencing in an immune-competent adult but progressed to brainstem hemorrhage.

Epstein-Barr Virus Infection in the Development of Neurological Disorders

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B-cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.

Mild encephalitis/encephalopathy with a reversible splenial lesion secondary to encephalitis complicated by hyponatremia: A case report and literature review

RATIONALE

Mild encephalitis/encephalopathy with a reversible splenial lesion (MERS) is an infection-associated encephalitis/encephalopathy syndrome that is predominately caused by a virus. MERS has no direct association with central nervous system (CNS) infections or inflammation. Non-CNS infections may cause reversible lesion in the splenium of corpus callosum. Recently, there have been reports of many patients with hyponatremia related MERS. Interleukin-6 (IL-6) was also found elevated in serum and in cerebrospinal fluid (CSF) in patients with MERS. The role of IL-6 in the non-osmotic release of vasopressin is crucial. Persistent hyponatremia may be linked to this effect. The following is a case report of MERS secondary to encephalitis, complicated by hyponatremia. We will summarize the latest research and progress regarding MERS.

PATIENT CONCERNS

A 31-year-old man was admitted to our department with a 5-day history of fever and headache. His initial diagnosis was encephalitis and hyponatremia; during this period the patient also developed MERS secondary to the encephalitis.

DIAGNOSES

Encephalitis was diagnosed by reviewing the history of fever, headache, neck rigidity and Kerning sign (+) on clinical examination. Lab tests revealed: serum VCA IgG (+), EBNA-1 IgG (-), EBV IgM (-), and inflammation in the analysis of CSF. Cranial MRI+C showed that the blood vessels on the surface of the brain were obviously increasing and thickening and diffuse slow waves were detected on the electroencephalogram (EEG). The patient's hyponatremia aggravated on the third day of hospitalization. On the fourth day of hospitalization, the patient was somnolent, apathetic, and slow. Magnetic resonance imaging (MRI) of the brain, with a T2-weighted fluid attenuated inversion recovery image, showed high-signal intensity in the splenium of the corpus callosum (SCC) on the fifth day of hospitalization. Diffusion-weighted imaging (DWI) showed splenial hyperintensity as a "boomerang sign" and reduced diffusion on apparent diffusion coefficient (ADC) maps. Cranial MRI findings returned to normal after 1 month. The diagnosis of MERS was confirmed.

INTERVENTIONS

We administered an intravenous drip infusion of acyclovir and prescribed oral sodium supplementation.

OUTCOMES

The patient's neurological symptoms gradually improved. The MRI lesion in the SCC disappeared on the 30th day.

LESSONS

In patients with encephalitis accompanied by hyponatremia, elevated IL-6 or urinary β2-microglobulin (β2MG), and exacerbations such as sudden somnolence, delirium, confusion, and seizures, the possibility of secondary MERS should be investigated, in addition to the progression of encephalitis.

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.

Cytotoxic Lesions of the Corpus Callosum That Show Restricted Diffusion: Mechanisms, Causes, and Manifestations

Cytotoxic lesions of the corpus callosum (CLOCCs) are secondary lesions associated with various entities. CLOCCs have been found in association with drug therapy, malignancy, infection, subarachnoid hemorrhage, metabolic disorders, trauma, and other entities. In all of these conditions, cell-cytokine interactions lead to markedly increased levels of cytokines and extracellular glutamate. Ultimately, this cascade can lead to dysfunction of the callosal neurons and microglia. Cytotoxic edema develops as water becomes trapped in these cells. On diffusion-weighted magnetic resonance (MR) images, CLOCCs manifest as areas of low diffusion. CLOCCs lack enhancement on contrast material-enhanced images, tend to be midline, and are relatively symmetric. The involvement of the corpus callosum typically shows one of three patterns: (a) a small round or oval lesion located in the center of the splenium, (b) a lesion centered in the splenium but extending through the callosal fibers laterally into the adjacent white matter, or (c) a lesion centered posteriorly but extending into the anterior corpus callosum. CLOCCs are frequently but not invariably reversible. Their pathologic mechanisms are discussed, the typical MR imaging findings are described, and typical cases of CLOCCs are presented. Although CLOCCs are nonspecific with regard to the underlying cause, additional imaging findings and the clinical findings can aid in making a specific diagnosis. Radiologists should be familiar with the imaging appearance of CLOCCs to avoid a misdiagnosis of ischemia. When CLOCCs are found, the underlying cause of the lesion should be sought and addressed. ^©RSNA, 2017 An earlier incorrect version of this article appeared online. This article was corrected on February 13, 2017.

Encephalitis with reversible splenial and deep cerebral white matter lesions associated with Epstein-Barr virus infection in adults

BACKGROUND

Approximately 200 cases of mild encephalitis with reversible splenial (MERS) and deep cerebral white matter lesions have been reported since MERS was first defined in 2004. MERS occurs more frequently in children; in adults, only ~60 cases have been reported. Until now, only four cases of MERS in adults have been associated with Epstein-Barr virus (EBV).

CASE PRESENTATION

We report three adult cases of MERS associated with EBV infection in China. For all three patients, cranial magnetic resonance imaging (MRI) indicated solitary reversible splenial and/or perilateral ventricle white matter lesions with reduced diffusion. In the present report, all patients were adults presenting with high fever, headache, apathy, and confusion, as well as significant signs of meningeal inflammation. These symptoms peaked 10-14 days after disease onset, with serious hyponatremia (112-129 mmol/L), an elevated cerebrospinal fluid white blood cell count (80-380/mm³), and significantly increased protein levels (1,010-1,650 mg/dL). Cranial MRI indicated abnormal signal intensity in the splenium of corpus callosum and symmetrically reversible lesions scattered in the thalamus and deep cerebral white matter. The clinical symptoms tended to improve after ~10-14 days of antiviral treatment. However, these patients recovered more slowly than patients with viral meningitis.

CONCLUSION

MERS associated with EBV infection in adults occurs less frequently but with more severe symptoms than in children. EBV infection should be considered for patients with MERS symptoms. MERS has a good prognosis.