Neurologic complications of infectious mononucleosis

Solid organ transplant-related central nervous system infections

PURPOSE OF REVIEW

Central nervous system (CNS) infections in solid organ transplant (SOT) recipients may present atypical or nonspecific symptoms. Due to a wider range of infectious agents compared with immunocompetent hosts, diagnosis is challenging. This review categorizes CNS infections in SOT recipients by cause.

RECENT FINDINGS

New studies have reported new data on the epidemiology and the risk factors associated with each specific pathogen described in this review. Additionally, we included the treatment recommendations.

SUMMARY

The latest findings give us an insight into the different pathogens causing infectious neurologic complications in SOT recipients.

Adult-Onset Acute Disseminated Encephalomyelitis with Epstein-Barr Virus Infection

We present the case of a 22-year-old man who was diagnosed with tonsillitis and treated with antibiotics. Although the symptoms subsided, 1 week later, he presented with weakness in the lower limbs and was hospitalized. The weakness in the lower limbs worsened; he developed difficulty speaking and was transferred to our hospital. Laboratory tests showed a white blood cell count of 10,600/μL (24% atypical lymphocytes). Positive results were obtained for immunoglobulin M (IgM) antibody against Epstein-Barr virus (EBV) viral capsid antigen. EBV-deoxyribonucleic acid quantification in blood yielded positive results. Magnetic resonance imaging (MRI) revealed a hyperintensity in the spinal cord at the Th11 level of the lower spine on T2-weighted imaging (T2WI). In addition, T2WI and fluid-attenuated inversion recovery imaging showed hyperintense lesions on the right cerebral peduncle, bilateral thalami, posterior leg of the left internal capsule, and right corona radiata. We diagnosed acute disseminated encephalomyelitis (ADEM) with EBV and initiated steroid pulse therapy. Symptoms, along with the lesions seen on MRI, subsequently ameliorated. This case suggests that ADEM can be difficult to diagnose, but careful diagnosis is crucial since appropriate treatment is necessary to improve the symptoms.

Acute Horner syndrome secondary to glandular fever due to Epstein Barr virus infection

We present a clinical situation where a 47-year old female patient consulted with left partial ptosis and miosis that started, two weeks before, with an episode of glandular fever secondary to Epstein-Barr infection. Apraclonidine 0.5% and Phenylephrine 1% drop testing was performed with results consistent with suspected left Horner Syndrome (HS), with a probable postganglionic location. Magnetic Resonance Angiography (MRA) at the moment of the acute presentation did not show any image suggesting carotid arterial dissection but showed irregular narrowing of the left internal carotid artery on its paravertebral extracranial way, consistent to enlarged intra-carotid sheath lymphoid tissue. A week later, a Doppler ultrasound was performed, showing bilateral images compatible with internal carotid arterial dissection. When Postganglionar HS is suspected, the first aetiology to rule out is a carotid arterial dissection because of its potentially fatal outcome and for being a more described entity as postganglionic HS aetiology. However, it is also evidenced that a certain diagnose is not always possible. Furthermore, we describe the enlarged internal carotid artery sheath lymphoid tissue as a possible cause of sympathetic nerve disruption causing a Postganglionar HS, although not common.

Epstein-Barr virus infection presenting as encephalitis in HIV—Phenomenon not seen frequently

Epstein-Barr virus (EBV) infection can rarely present as encephalitis in HIV patients. We report a case of a 22-year-old female patient, diagnosed to have HIV infection 8 years back. She presented with headache and altered behavior for a week and focal fits for 2 days. Neurological examination was unremarkable. Cerebrospinal fluid (CSF) examination revealed lymphocytic pleocytosis with raised protein. EBV was detected in CSF using polymerase chain reaction test. Magnetic resonance imaging of the brain revealed T2/fluid-attenuated inversion recovery hyperintensities involving the left frontal cortex, left thalamus, and right medial temporal cortex. The patient was started on antiviral therapy considering the diagnosis of EBV encephalitis. The patient completely recovered over the next few weeks.

Clinical significance of Epstein-Barr virus polymerase chain reaction in cerebrospinal fluid

Purpose

Epstein-Barr virus (EBV) is implicated in various neurological conditions. However, the relationship between EBV DNA in cerebrospinal fluid (CSF) and central nervous system (CNS) infection is unclear. We evaluated the clinical manifestation of patients with EBV DNA detected in CSF.

Methods

We reviewed the medical records of patients admitted to Seoul National University Hospital from January 2000 to March 2021 who underwent EBV polymerase chain reaction (PCR) tests in CSF. The subjects were divided into positive and negative groups depending on the presence of EBV DNA, and further clinical information was obtained from positive patients.

Results

CSF EBV PCR tests were performed in 807 patients, and 57 (7.1%) tested positive. Pleocytosis was common (81.1%) in CSF samples with EBV DNA detected, and the proportion was significantly higher than that in samples that were EBV PCR negative (44.5%, p < 0.0001). Among 57 patients with EBV DNA detected in CSF, 51 (89.5%) were diagnosed with CNS infection or inflammatory disorders. Of the 51 patients, 31 (60.8%) had possible etiologies other than EBV. Follow-up evaluation was conducted in 19 of 20 patients, and 63.2% showed a favorable outcome.

Conclusion

Positive EBV PCR in CSF is mostly nonspecific and should be interpreted with caution. A comprehensive workup is needed to identify other etiologies before considering EBV as the sole culprit.

Downbeat Nystagmus in a 7-Year-Old Girl With Epstein-Barr Virus-Associated Meningitis and Cerebellitis

Downbeat nystagmus is a type of jerk nystagmus that may be seen in patients with lesions affecting the vestibulocerebellum. This is a case of a 7-year-old girl presenting with a history of fever, headache, and episodic vertigo with downbeat nystagmus. The diagnosis of Epstein-Barr virus meningitis with acute cerebellitis was made by contrast magnetic resonance imaging, cerebrospinal fluid analysis, and serum Epstein-Barr virus titers. Contrast magnetic resonance imaging demonstrated enhancement of the meninges and inferior cerebellar folia, correlating with the neuroophthalmological symptom of downbeat nystagmus.

Fatal Epstein-Barr virus infection in an immunocompetent host: a postmortem diagnosis

Meningoencephalitis is the most common neurological complication related to Epstein-Barr virus (EBV), and in immunocompetent adults, it is most commonly self-limited. We describe a case of fatal EBV infection characterized by meningoencephalitis, foci of myocarditis and interstitial nephritis in an immunocompetent 74-year-old man. The postmortem diagnosis was made based on the presence of EBV DNA in the cerebrospinal fluid and by immunohistochemical assay that showed spots of intracellular positivity to anti-EBV antibody in brain tissue.

Neuroimmunology - the past, present and future

Neuroimmunology as a separate discipline has its roots in the fields of neurology, neuroscience and immunology. Early studies of the brain by Golgi and Cajal, the detailed clinical and neuropathology studies of Charcot and Thompson's seminal paper on graft acceptance in the central nervous system, kindled a now rapidly expanding research area, with the aim of understanding pathological mechanisms of inflammatory components of neurological disorders. While neuroimmunologists originally focused on classical neuroinflammatory disorders, such as multiple sclerosis and infections, there is strong evidence to suggest that the immune response contributes to genetic white matter disorders, epilepsy, neurodegenerative diseases, neuropsychiatric disorders, peripheral nervous system and neuro-oncological conditions, as well as ageing. Technological advances have greatly aided our knowledge of how the immune system influences the nervous system during development and ageing, and how such responses contribute to disease as well as regeneration and repair. Here, we highlight historical aspects and milestones in the field of neuroimmunology and discuss the paradigm shifts that have helped provide novel insights into disease mechanisms. We propose future perspectives including molecular biological studies and experimental models that may have the potential to push many areas of neuroimmunology. Such an understanding of neuroimmunology will open up new avenues for therapeutic approaches to manipulate neuroinflammation.

Primary Epstein-Barr virus infection in immunocompetent patients with acute transverse myelitis and a combination of polyradiculitis and anterior horn syndrome as neurological manifestations

Neurological manifestations of a primary Epstein-Barr virus (EBV) infection are rare. We describe a case with acute transverse myelitis and another case with a combination of polyradiculitis and anterior horn syndrome as manifestations of a primary EBV infection.The first case is a 50-year-old immunocompetent male diagnosed with acute transverse myelitis, 2 weeks after he was clinically diagnosed with infectious mononucleosis. The second case is an 18-year-old immunocompetent male diagnosed with a combination of polyradiculitis and anterior horn syndrome while he had infectious mononucleosis. The first patient was treated with methylprednisolone. After 1 year, he was able to stop performing clean intermittent self-catheterisation. The second patient completely recovered within 6 weeks without treatment.Primary EBV infection should be considered in immunocompetent patients presenting with acute transverse myelitis and a combination of polyradiculitis and anterior horn syndrome. Antiviral treatment and steroids are controversial, and the prognosis of neurological sequelae is largely unknown.

Primary Epstein-Barr virus infection

Epstein-Barr virus (EBV) infects about 90% of adults worldwide. It is the main cause of infectious mononucleosis, which is observed most frequently in adolescents. The disease can last several weeks and is characterized by lymphocytosis, sore throat, lymphadenopathy, and fatigue. Exposure to oral secretions during deep kissing has been identified as the major source for primary EBV infection in adolescents. Oral secretions are also thought to be the source for younger children through intimate intact or sharing food and eating utensils, although this has not been confirmed. Unlike most acute viral illnesses such as influenza, the incubation period of symptomatic primary EBV infection is unusually long, lasting about six weeks. Diagnosis is typically made by heterophile antibody tests and/or EBV-specific antibody tests. Long-term consequences may result from acquisition of the virus, including nasopharyngeal carcinoma and lymphomas. Nevertheless, there remains a surprising dearth of knowledge regarding the establishment of an immune response to persistent EBV infection, especially during the incubation period. This lack of knowledge has impaired our ability to develop an effective prophylactic EBV vaccine, despite various attempts. Our greatest challenges in EBV research are to develop a prophylactic vaccine and devise treatment strategies for persons already infected with EBV.

Imaging spectrum of central nervous system complications of hematopoietic stem cell and solid organ transplantation

Neurologic complications are common after hematopoietic stem cell transplantation (HSCT) and solid organ transplantation (SOT) and affect 30-60% of transplant recipients. The aim of this article is to provide a practical imaging approach based on the timeline and etiology of CNS abnormalities, and neurologic complications related to transplantation of specific organs. The lesions will be classified based upon the interval from HSCT procedure: pre-engraftment period <30 days, early post-engraftment period 30-100 days, late post-engraftment period >100 days, and the interval from SOT procedure: postoperative phase 1-4 weeks, early posttransplant syndromes 1-6 months, late posttransplant syndromes >6 months. Further differentiation will be based on etiology: infections, drug toxicity, metabolic derangements, cerebrovascular complications, and posttransplantation malignancies. In addition, differentiation will be based on complications specific to the type of transplantation: allogeneic and autologous hematopoietic stem cells (HSC), heart, lung, kidney, pancreas, and liver. Thus, in this article we emphasize the strategic role of neuroradiology in the diagnosis and response to treatment by utilizing a methodical approach in the work up of patients with neurologic complications after transplantation.

Vaccinations for Neuroinfectious Disease: A Global Health Priority

Vaccines for neuroinfectious diseases are becoming an ever-increasing global health priority, as neurologic manifestations and sequelae from existing and emerging central nervous system infections account for significant worldwide morbidity and mortality. The prevention of neurotropic infections can be achieved through globally coordinated vaccination campaigns, which have successfully eradicated nonzoonotic agents such as the variola viruses and, hopefully soon, poliovirus. This review discusses vaccines that are currently available or under development for zoonotic flaviviruses and alphaviruses, including Japanese and tick-borne encephalitis, yellow fever, West Nile, dengue, Zika, encephalitic equine viruses, and chikungunya. Also discussed are nonzoonotic agents, including measles and human herpesviruses, as well as select bacterial, fungal, and protozoal pathogens. While therapeutic vaccines will be required to treat a multitude of ongoing infections of the nervous system, the ideal vaccination strategy is pre-exposure vaccination, with the ultimate goals of minimizing disease associated with zoonotic viruses and the total eradication of nonzoonotic agents.

Herpes Simplex Virus Type 1 and Other Pathogens are Key Causative Factors in Sporadic Alzheimer's Disease

This review focuses on research in epidemiology, neuropathology, molecular biology, and genetics regarding the hypothesis that pathogens interact with susceptibility genes and are causative in sporadic Alzheimer's disease (AD). Sporadic AD is a complex multifactorial neurodegenerative disease with evidence indicating coexisting multi-pathogen and inflammatory etiologies. There are significant associations between AD and various pathogens, including Herpes simplex virus type 1 (HSV-1), Cytomegalovirus, and other Herpesviridae, Chlamydophila pneumoniae, spirochetes, Helicobacter pylori, and various periodontal pathogens. These pathogens are able to evade destruction by the host immune system, leading to persistent infection. Bacterial and viral DNA and RNA and bacterial ligands increase the expression of pro-inflammatory molecules and activate the innate and adaptive immune systems. Evidence demonstrates that pathogens directly and indirectly induce AD pathology, including amyloid-β (Aβ) accumulation, phosphorylation of tau protein, neuronal injury, and apoptosis. Chronic brain infection with HSV-1, Chlamydophila pneumoniae, and spirochetes results in complex processes that interact to cause a vicious cycle of uncontrolled neuroinflammation and neurodegeneration. Infections such as Cytomegalovirus, Helicobacter pylori, and periodontal pathogens induce production of systemic pro-inflammatory cytokines that may cross the blood-brain barrier to promote neurodegeneration. Pathogen-induced inflammation and central nervous system accumulation of Aβ damages the blood-brain barrier, which contributes to the pathophysiology of AD. Apolipoprotein E4 (ApoE4) enhances brain infiltration by pathogens including HSV-1 and Chlamydophila pneumoniae. ApoE4 is also associated with an increased pro-inflammatory response by the immune system. Potential antimicrobial treatments for AD are discussed, including the rationale for antiviral and antibiotic clinical trials.

Transient seizure-related MRI abnormalities in a child with primary Epstein-Barr virus infection

We describe the case of a 6-year-old girl with typical infectious mononucleosis syndrome complicated by clustered right hemiconvulsions and disturbed consciousness. Diffusion-weighted magnetic resonance imaging on admission demonstrated reduced diffusion in the left temporo-posterior cortex and pulvinar of the ipsilateral thalamus. Her neurological symptoms resolved completely by the next day, with complete disappearance of abnormal signal intensities on magnetic resonance imaging (MRI). Elevated cerebrospinal fluid interleukin (IL)-6 with normal IL-10 might indicate a neuroprotective role of IL-6 rather than injury. We concluded that the MRI abnormalities could have been due to the seizure activity itself rather than Epstein-Barr virus-associated encephalitis. The recognition of transient seizure-related MRI abnormalities may help in the diagnostic approach to MRI changes in suspected encephalopathy.

Imaging of Herpesvirus Infections of the CNS

OBJECTIVE

Herpesviridae are a family of DNA viruses remarkable for their ability to both promote acute infection and enter a latent phase with potential of reactivation. Herpes infections are ubiquitous throughout the human life span, regardless of the degree of immunocompetence.

CONCLUSION

We review the virology and clinical manifestations of each herpesvirus, with emphasis on recent advances in knowledge and characteristic neuroimaging findings important for diagnosis and appropriate clinical management.

Horner syndrome in glandular fever: a case report

OBJECTIVE

This study aimed to present and discuss the case of a patient with known glandular fever who presented with Horner syndrome.

CASE REPORT

A 35-year-old patient with known glandular fever developed acute unilateral Horner syndrome, a previously undescribed complication of this common illness. Magnetic resonance imaging and magnetic resonance angiography showed that enlarged intra-carotid sheath lymphoid tissue was likely to be the underlying cause of sympathetic nerve disruption. The case is described, the anatomy of the sympathetic chain is discussed and possible alternative pathophysiological mechanisms are reviewed.

CONCLUSION

This is the first report in the worldwide literature of Horner syndrome arising as a result of compression from enlarged lymph nodes in glandular fever.

Epstein-Barr virus encephalitis in a renal transplant recipient manifesting as hemorrhagic, ring-enhancing mass lesions

Epstein-Barr virus (EBV) encephalitis has been infrequently described in immunocompromised patients. Here, we report a unique case of biopsy-proven EBV encephalitis in a renal transplant recipient presenting with altered mental status, prominent visual disturbances, and hemorrhagic, ring-enhancing mass lesions on magnetic resonance imaging. The patient was successfully treated with a prolonged course of antivirals. This case illustrates the difficulty in interpretation of cerebrospinal fluid EBV polymerase chain reaction assay, given the lack of specificity in immunocompromised patients.

Infectious mononucleosis

Infectious mononucleosis is a clinical entity characterized by pharyngitis, cervical lymph node enlargement, fatigue and fever, which results most often from a primary Epstein-Barr virus (EBV) infection. EBV, a lymphocrytovirus and a member of the γ-herpesvirus family, infects at least 90% of the population worldwide, the majority of whom have no recognizable illness. The virus is spread by intimate oral contact among adolescents, but how preadolescents acquire the virus is not known. During the incubation period of approximately 6 weeks, viral replication first occurs in the oropharynx followed by viremia as early as 2 weeks before onset of illness. The acute illness is marked by high viral loads in both the oral cavity and blood accompanied by the production of immunoglobulin M antibodies against EBV viral capsid antigen and an extraordinary expansion of CD8(+) T lymphocytes directed against EBV-infected B cells. During convalescence, CD8(+) T cells return to normal levels and antibodies develop against EBV nuclear antigen-1. A typical clinical picture in an adolescent or young adult with a positive heterophile test is usually sufficient to make the diagnosis of infectious mononucleosis, but heterophile antibodies are not specific and do not develop in some patients especially young children. EBV-specific antibody profiles are the best choice for staging EBV infection. In addition to causing acute illness, long-term consequences are linked to infectious mononucleosis, especially Hodgkin lymphoma and multiple sclerosis. There is no licensed vaccine for prevention and no specific approved treatment. Future research goals are development of an EBV vaccine, understanding the risk factors for severity of the acute illness and likelihood of developing cancer or autoimmune diseases, and discovering anti-EBV drugs to treat infectious mononucleosis and other EBV-spurred diseases.

Infectious Mononucleosis

Infectious mononucleosis is a clinical entity characterized by sore throat, cervical lymph node enlargement, fatigue, and fever most often seen in adolescents and young adults and lasting several weeks. It can be caused by a number of pathogens, but this chapter only discusses infectious mononucleosis due to primary Epstein-Barr virus (EBV) infection. EBV is a γ-herpesvirus that infects at least 90% of the population worldwide. The virus is spread by intimate oral contact among teenagers and young adults. How preadolescents acquire the virus is not known. A typical clinical picture with a positive heterophile test is usually sufficient to make the diagnosis, but heterophile antibodies are not specific and do not develop in some patients. EBV-specific antibody profiles are the best choice for staging EBV infection. In addition to causing acute illness, there can also be long-term consequences as the result of acquisition of the virus. Several EBV-related illnesses occur including certain cancers and autoimmune diseases, as well as complications of primary immunodeficiency in persons with the certain genetic mutations. A major obstacle to understanding these sequelae has been the lack of an efficient animal model for EBV infection, although progress in primate and mouse models has recently been made. Key future challenges are to develop protective vaccines and effective treatment regimens.

Central nervous system syndromes in solid organ transplant recipients

Solid organ transplant recipients have a high incidence of central nervous system (CNS) complications, including both focal and diffuse neurologic deficits. In the immunocompromised host, the initial clinical evaluation must focus on both life-threatening CNS infections and vascular or anatomic lesions. The clinical signs and symptoms of CNS processes are modified by the immunosuppression required to prevent graft rejection. In this population, these etiologies often coexist with drug toxicities and metabolic abnormalities that complicate the development of a specific approach to clinical management. This review assesses the multiple risk factors for CNS processes in solid organ transplant recipients and establishes a timeline to assist in the evaluation and management of these complex patients.

Cerebral vasculitis and encephalitis due to Epstein-Barr virus in a patient with newly diagnosed HIV infection

Epstein-Barr virus (EBV) is a common infection which usually produces mild or no symptoms in immunocompetent individuals. In human immunodeficiency virus (HIV) associated immunosuppression it is most commonly associated with malignancy which usually occurs at very low CD4+ cell counts. We describe a newly diagnosed HIV-positive patient who presented with headaches and cerebellar signs. She was incorrectly diagnosed with cerebral tuberculosis (TB) infection based on the histology report from a cerebellar biopsy specimen. After extensive investigation including cerebrospinal fluid sampling and reanalysis of the brain biopsy specimens she was found to have EBV-associated cerebral vasculitis and encephalitis and was successfully treated with valganciclovir and steroids. Whilst there are a few reports of EBV-associated encephalitis, cerebral vasculitis secondary to EBV in the context of HIV infection has not previously been described in the literature.

Recent advances in the understanding of infectious mononucleosis: are prospects improved for treatment or control?

Symptomatic primary Epstein-Barr virus infection is known more commonly as infectious mononucleosis, an illness known for afflicting adolescents and younger adults as a febrile illness accompanied by pharyngitis and lymphadenopathy. Historically believed to be generally benign, infectious mononucleosis has been linked more recently to increased risks of developing Hodgkin's lymphoma and multiple sclerosis. Advances in the understanding of host immune responses to Epstein-Barr virus have begun to elucidate the reasons why younger children typically experience subclinical infection whereas older individuals develop infectious mononucleosis. This review will highlight recent advances in the understanding of primary Epstein-Barr virus infection, and whether prospective treatments or vaccine strategies may affect native infection and its sequelae.

[Peripheral nervous system involvement in the course of herpes virus infections]

The herpes viruses are associated with both central and pe-ripheral nervous system complications. Patients with symptoms suggestive of herpes viruses infections coexisting with peri-phe-ral nervous system manifestations, especially Guillain-Barré syndrome, mononeuropathy, plexopathy and radiculopathy, should be screened for the herpes viruses infections in the differential diagnosis. The purpose of this review is to discuss the etiology, pathogenesis and treatment of the neuropathies in the course of herpes viruses infections.

Clinical characteristics of patients with Epstein Barr virus in cerebrospinal fluid

Background

The role of Epstein-Barr (EBV) virus in central nervous system (CNS) infections is not fully resolved. It is clearly associated with lymphoproliferative disease of immunosuppressed persons, and may cause encephalitis.

Methods

We reviewed the medical records, imaging and laboratory findings of all patients EBV DNA PCR positive in cerebrospinal fluid (CSF) during 2000 to 2009 in the Helsinki University Central Hospital.

Results

We identified 32 patients with EBV DNA in CSF. 11 had history of allogeneic hematopoietic stem cell transplantation, 7 solid organ transplantation and 5 HIV/AIDS. 5 patients had no preceding immunodeficiency.

In 8 of the cases, another pathogen was identified in CSF. These were M. tuberculosis (2), T. gondii (2), Aspergillus (1), Herpes simplex virus 1 (1), C. neoformans (1) and Human herpesvirus 6 (1). Altogether in 15/32 (47%) of the cases the clinician had a strong suspicion of cause other than EBV for the patients' CNS symptoms/findings.

Of note, 7 of 11 (64%) patients with stem cell transplantation had encephalitis (univariate odds ratio 5.6; confidence Interval 1.1-27.4). Of these 6 had no other pathogen identified.

Conclusions

EBV DNA was often found together with other microbial findings in CSF of immunocompromised patients. EBV seems to be associated with encephalitis in stem cell transplant recipients.

Epstein-Barr virus infection and central nervous system involvement after orthoptic liver transplant

Epstein-Barr virus (EBV) infection presenting as encephalitis in seronegative adults in the context of solid organ transplantation is rarely reported. EBV seroconversion illnesses in the adult population after organ transplantation are quite uncommon. This report describes a case of encephalitis due to EBV infection after liver transplantation in an adult patient. The patient was seronegative for EBV pretransplant. She showed persistent viral replication indicated by high levels of EBV DNA in the serum, which raised concerns for future development of post-transplant lymphoproliferative disorder. The report discusses the management of such patients, awareness of EBV infection and earlier diagnosis by use of EBV PCR in adult immunocompromised individuals where infection may cause particular problems.

Progress and problems in understanding and managing primary Epstein-Barr virus infections

Epstein-Barr virus (EBV) is a gammaherpesvirus that infects a large fraction of the human population. Primary infection is often asymptomatic but results in lifelong infection, which is kept in check by the host immune system. In some cases, primary infection can result in infectious mononucleosis. Furthermore, when host-virus balance is not achieved, the virus can drive potentially lethal lymphoproliferation and lymphomagenesis. In this review, we describe the biology of EBV and the host immune response. We review the diagnosis of EBV infection and discuss the characteristics and pathogenesis of infectious mononucleosis. These topics are approached in the context of developing therapeutic and preventative strategies.

Unusual MRI findings in an immunocompetent patient with EBV encephalitis: a case report

Blackground

It is well-known that Epstein-Barr virus (EBV) can affect the central nervous system (CNS).

Case presentation

Herein the authors report unusual timely Magnetic Resonance Imaging (MRI) brain scan findings in an immunocompetent patient with EBV encephalitis.

Diffusion weighted MRI sequence performed during the acute phase of the disease was normal, whereas the Fast Relaxation Fast Spin Echo T2 image showed diffuse signal intensity changes in white matter. The enhancement pattern suggested an inflammatory response restricted to the brain microcirculation. Acyclovir and corticosteroid therapy was administered. After three weeks, all signal intensities returned to normal and the patient showed clinical recovery.

Conclusion

This report demonstrates that EBV in an immunocompetent adult can present with diffuse, reversible brain white matter involvement in the acute phase of mononucleosis. Moreover, our case suggests that a negative DWI sequence is associated with a favorable improvement in severe EBV CNS infection. More extensive studies are needed to assess what other instrumental data can help to distinguish viral lesions from other causes in the acute phase of disease.

Epstein-Barr Virus Infection associated with Acute Recurrent Laryngeal Nerve Palsy

Introduction

Epstein-Barr virus (EBV) belongs to the group of human herpes viruses and can cause the clinical syndrome of infectious mononucleosis. EBV infection has been reported to cause several neurological complications. However, cranial nerve deficits are rare and have been infrequently reported. To our knowledge, recurrent laryngeal nerve palsy in EBV acutely infected patients has been reported only once with a case of bilateral laryngeal nerve palsy.

Case presentation

A case of a 41-year-old female Caucasian patient with a positive serology of active EBV infection developing acute recurrent laryngeal nerve palsy is presented. Fiberoptic rhinolaryngoscopy with stroboscopy showed complete paralysis of the left vocal cord in abduction with abundant secretions, consistent with unilateral recurrent laryngeal nerve paralysis. Full recovery over a 6-month follow-up period has been achieved by starting immediate speech therapy.

Conclusion

Our case report confirms the possible involvement of EBV infection in recurrent laryngeal nerve palsy. This rarely described association should be taken into account as an extremely rare differential diagnosis in patients suffering from recurrent laryngeal nerve paralysis and fatigue symptoms with muscle pain. To minimize the risk of permanent palsy, immediate speech therapy is recommended.

Detection of DNA of six human herpesviruses in the cerebrospinal fluid of immunocompetent non-herpetic acute limbic encephalitis patients

In order to determine whether six other human herpesviruses, aside from herpes simplex virus, are associated with non-herpetic acute limbic encephalitis in immunocompetent individuals, real-time PCR was used to detect the DNA of herpesviruses in CSF collected from 61 patients with this form of encephalitis. Five of the human herpesviruses tested were not detected in any of the 61 CSF samples. EBV DNA was detected in one CSF sample. The EBV DNA-positive patient was a 36-year-old woman who presented with fever, headache, mild somnolence, and the typical neuroimaging findings.

Acute Appendicitis, Peritonitis, Shock and Encephalitis; A rare combination caused by Epstein-Barr virus

A nine-year old girl presented in shock preceded by fever vomiting, lower abdominal pain and rebound tenderness with signs of peritonitis. Ultrasonography supported a diagnosis of acute appendicitis confirmed later by the presence of peritoneal fluid and by histopathology. She had also the clinical picture of meningo-encephalitis with positive meningeal signs and an abnormal electroencephalogram (EEG). Cerebrospinal fluid (CSF) showed high protein, normal cell count and normal pressure. Brain CT scan and MRI were normal. The polymerase chain reaction (PCR) in the blood was highly positive for Epstein Barr virus (EBV). She improved dramatically after urgent appendectomy with supportive management. This case is unusual in presenting with a combination of acute appendicitis, peritonitis and shock associated with acute encephalitis.

Fatal Epstein-Barr virus encephalitis in a 12-year-old child: an underappreciated neurological complication?

BACKGROUND

A 12-year-old boy presented to a community hospital with fever, malaise and fatigue. A polymerase chain reaction test of the cerebrospinal fluid was positive for Epstein-Barr virus. Despite intensive care treatment and antiviral drugs, the patient died 1 month after his initial presentation.

INVESTIGATIONS

Physical examination, polymerase chain reaction analysis of the cerebrospinal fluid, brain MRI, immunohistochemistry and molecular biological investigations of postmortem brain samples.

DIAGNOSIS

Epstein-Barr Virus encephalitis.

MANAGEMENT

Aciclovir, intensive care treatment with intubation, sedation, antiepileptic drugs.

Epstein-Barr virus acute encephalomyelitis in a 13-year-old boy

The association of acute myelopathy and encephalopathy is reported in a 13-year-old boy. Signs and symptoms of infectious mononucleosis, presence of heterophile antibodies, anticapsid antibodies and Epstein-Barr virus DNA detected in cerebrospinal fluid, disclosed a primary or reactivated infection by Epstein-Barr virus. Outcome was rapid and benign with complete clinical recovery in 1 month, after pulse therapy with methylprednisolone. Epstein-Barr virus is a known agent related to acute disseminated encephalomyelitis, by immune mediated mechanisms. However, in this case, cortical involvement in magnetic resonance imaging, short time between infectious mononucleosis and central nervous system manifestations, and the presence of viral DNA in cerebrospinal fluid, raised the possibility of a direct action of the virus in central nervous system. Acute myelopathy associated to Epstein-Barr virus encephalitis has been rarely reported in children.

Mononucleosis and athletic participation: an evidence-based subject review

Infectious mononucleosis (IM) is a common medical condition that afflicts thousands of young athletes each year. Despite the self-limited nature of this disorder, the variability of the clinical presentation and the rare risk of splenic rupture routinely present sports medicine clinicians with difficult return-to-play decisions. Currently there are no evidence-based guidelines regarding the management of the athlete with IM. This review discusses the available research data pertaining to the management of IM in young athletes and develops questions for future clinical research.

Guillain-Barré syndrome with optic neuritis and a focal lesion in the central white matter following Epstein-Barr virus infection

We report a case of Guillain-Barré syndrome (GBS) accompanied by optic neuritis and a central white matter lesion subsequent to Epstein-Barr virus (EBV) infection. A 49-year-old man presented with visual disturbance and hemiparesis one week after developing cold-like symptoms. T2- and diffusion-weighted brain MRI showed a high-signal intensity lesion in the left internal capsule. The patient's visual acuity improved during steroid pulse therapy, but his hemiparesis progressed to quadriparesis. Nerve conduction studies showed demyelination predominant in the distal nerve terminals, consistent with GBS. Serological testing suggested EBV reinfection. Our findings indicate that EBV-related central and peripheral demyelination can occur simultaneously and can be successfully treated with a combination of corticosteroids and immunoglobulin.

[Isolated neuritis of the oculomotor nerve in infectious mononucleosis]

A 19-year-old immune-competent patient developed right-sided headache and, subsequently, subacute diplopia. On clinical examination he had incomplete right oculomotor palsy. Cranial MRI showed pathologic contrast enhancement of the right oculomotor nerve at its exit point from the mesencephalon, and the CSF displayed slight pleocytosis. The following relevant differential diagnoses were not supported by additional examinations: neurosarcoidosis, Lyme neuroborreliosis, neurosyphilis, tuberculous meningitis, viral meningitis (HIV, VZV, CMV), CNS lymphoma, vasculitis associated with rheumatic disease, Tolosa-Hunt syndrome, and diabetic neuropathy. However, on the basis of blood lymphocytosis, positive heterophile antibody test (Paul-Bunnell test), the presence of IgM antibodies against Epstein-Barr virus capsid antigen, and elevated transaminases, infectious mononucleosis was diagnosed. Isolated neuritis of the oculomotor nerve is a rare parainfectious manifestation of infectious mononucleosis.

Neuroimaging of herpesvirus infections in children

Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics.

Acute disseminated encephalomyelitis following infectious mononucleosis

Two months following an Epstein-Barr virus infection, a 17-year-old white female presented with seizures, intermittent visual changes, and altered mental status. Magnetic resonance imaging showed white matter changes of acute disseminated encephalomyelitis with a predilection for posterior cerebral artery distributions but without radiological evidence of arteritis. Epstein-Barr virus titers and polymerase chain reaction analysis results for the virus were consistent with postinfectious acute disseminated encephalomyelitis. The symptoms and signs improved following treatment with high-dose corticosteroids and intravenous immunoglobulin. Although Epstein-Barr virus can cause acute viral encephalomyelitis, the authors report a case of acute disseminated encephalomyelitis months after acute Epstein-Barr virus infection.

Pediatric Epstein-Barr virus-associated encephalitis: 10-year review

Many neurologic manifestations of Epstein-Barr virus (EBV) infection have been documented, including encephalitis, aseptic meningitis, transverse myelitis, and Guillain-Barré syndrome. These manifestations can occur alone or coincidentally with the clinical picture of infectious mononucleosis. Since 1994, The Hospital for Sick Children has maintained a prospective registry of all children admitted with acute encephalitis. This report summarizes all cases of Epstein-Barr virus-associated encephalitis compiled from 1994 to 2003. Twenty-one (6%) of 216 children, median age 13 years (range 3-17 years), in the Encephalitis Registry were identified as having evidence of Epstein-Barr virus infection. This evidence consisted of convincing Epstein-Barr virus serology and/or positive cerebrospinal fluid polymerase chain reaction (PCR). One patient had symptoms of classic infectious mononucleosis; all others had a nonspecific prodrome, including fever (n = 17; 81%) and headache (n = 14; 66%). Slightly less than half (n = 10; 48%) had seizures and often had electroencephalograms showing a slow background (n = 12; 57%). Many demonstrated cerebrospinal fluid pleocytosis (n = 17; 81%), and 71% (n = 15) had abnormal magnetic resonance imaging findings. Two patients died, 2 suffered mild deficits, and 16 were neurologically normal at follow-up. Most patients with Epstein-Barr virus encephalitis do not show typical symptoms of infectious mononucleosis. Establishing a diagnosis of Epstein-Barr virus encephalitis can be difficult, and, consequently, a combination of serologic and molecular techniques should be used when investigating a child with acute encephalitis. Most children make full recoveries, but residual neurologic sequelae and even death can and do occur.

Infectious mononucleosis: return to play

Infectious mononucleosis most commonly affects adolescents and young adults with a febrile illness accompanied by pharyngitis,lymph node enlargement, and transient fatigue. The diagnosis is usually confirmed with demonstration of heterophile antibodies. Typical signs and symptoms are reviewed, along with pitfalls in diagnosis and management. The rare complication of splenic rupture serves to focus recommendations for returning athletes to strenuous physical activities. Because careful prospective studies of infectious mononucleosis in athletes are lacking, review of available literature suggests that clinicians may recommend a return to all sports in those without spleen enlargement 4 weeks after the onset of illness.

Optic neuropathy: puls/minus

A 26-year-old Asian woman presented with bilateral disk swelling, retinal exudates and infarcts. Evaluation found the underlying cause of the hypertensive optic neuropathy to be renal artery stenosis due to Takayasu's arteritis.