Herpes simplex encephalitis and subsequent cytomegalovirus encephalitis after chemoradiotherapy for central nervous system lymphoma: a case report and literature review

Metagenomic search of viral coinfections in herpes simplex encephalitis patients

Little is known about concomitant central nervous system (CNS) infections by more than one virus. Current diagnostics are based on molecular tests for particular pathogens making it difficult to identify multi-viral infections. In the present study, we applied DNA- and RNA-based next-generation sequencing metagenomics (mNGS) to detect viruses in cerebrospinal fluids from 20 patients with herpes simplex encephalitis. Coinfection was detected in one patient: sequences in cerebrospinal fluids matched enterovirus A (2.660 reads; 4% of recovered genome) and enterovirus B (1.571 reads; 13% of recovered genome). Subsequent PCR combined with serotyping allowed to identify human echovirus 6, a representative of enterovirus B. Several other mNGS hits (human pegivirus, Merkel cell polyomavirus, human papillomavirus type 5) were not considered to represent a genuine signal as they could not be confirmed by specific RT-PCR/PCR. HSV DNA, while being detectable by PCR in every patient, was detected by mNGS in only one. In conclusion, contaminations and false signals may complicate mNGS interpretation; however, the method can be useful in diagnostics of viral coinfections in CNS, particularly in the case of rare pathogens.

Herpes simplex encephalitis in patients receiving chemotherapy and whole-brain radiation therapy

Herpes simplex encephalitis (HSE) is a very severe infection of the central nervous system (CNS) caused mainly by herpes simplex virus type 1 (HSV-1) and occasionally by herpes simplex virus type 2 (HSV-2). After relapse or drug-resistant to chemotherapy, whole-brain radiation therapy (WBRT) is a mainstay of treatment in patients with both identifiable brain metastases and CNS lymphoma. Although HSV-1 encephalitis predominantly affects immunocompetent host, HSV encephalitis may be more common in immune-suppressed patients than is currently recognized. Disease presentation may be atypical including lack of pleocytosis in cerebrospinal fluid (CSF). We report four patients diagnosed with HSE following chemotherapy and WBRT. The occurrence of HSE in patients with cancer seems not to be increased compared to the general population, but as our case series shows, a high level of suspicion is needed by the treating physician to diagnose HSE early in patients presenting with new neurological symptoms following WBRT.

Central Nervous System Infections Complicating Immunosuppression and Transplantation

PURPOSE OF REVIEW

This article reviews infections associated with cancer treatments and immunosuppressive/immunomodulatory therapies used in both neoplastic and non-neoplastic conditions, including hematopoietic cell transplantation and solid organ transplantation. It provides a clinical approach to the most commonly affected patient groups based on clinicoanatomic presentation and disease-specific risks resulting from immune deficits and drugs received.

RECENT FINDINGS

The clinical presentations, associated neuroimaging findings, and CSF abnormalities of patients with central nervous system infections who are immunocompromised may differ from those of patients with central nervous system infections who are immunocompetent and may be confused with noninfectious processes. Triggering of brain autoimmunity with emergence of neurotropic antibodies has emerged as a recognized parainfectious complication. New unbiased metagenomic assays to identify obscure pathogens help clinicians navigate the increasing range of conditions affecting the growing population of patients with altered immunity.

SUMMARY

Despite evidence-based prophylactic regimens and organism-specific antimicrobials, central nervous system infections continue to cause significant morbidity and mortality in an increasing range of patients who are immunocompromised by their conditions and therapies. Multiple new drugs put patients at risk for progressive multifocal leukoencephalopathy, which has numerous imaging and clinical manifestations; patients at risk include those with multiple sclerosis, for whom infection risk is becoming one of the most important factors in therapeutic decision making. Efficient, early diagnosis is essential to improve outcomes in these often-devastating diseases.

Cytomegalovirus meningitis in a patient with relapsed acute myeloid leukemia

Cytomegalovirus meningitis/meningoencephalitis is a potentially fatal complication following hematopoietic stem cell transplantation that causes significant morbidity and mortality. In the pre-transplant setting, a few cases involving lymphoid malignancies have been reported. However, there have been no reports of patients with myeloid malignancies. A 36-year-old man with relapsed acute myeloid leukemia received high-dose cytarabine-containing salvage chemotherapies and then developed grade 4 lymphopenia for more than one month. Subsequently, the patient developed pyrexia, accompanying headache, nausea, and vomiting with no abnormal brain imaging. Despite receiving antimicrobial treatment, his febrile status and headache persisted. Given that the patient had symptoms consistent with viral meningitis with no evidence of etiology other than positive cytomegalovirus-DNA in his cerebrospinal fluid and cytomegalovirus pp65 antigenemia, cytomegalovirus meningitis was diagnosed. After commencing ganciclovir treatment, the patient's headache and febrile status rapidly improved. Cytomegalovirus meningitis/meningoencephalitis is rare before hematopoietic stem cell transplantation, but may be useful in differential diagnoses in heavily treated acute myeloid leukemia patients with central nervous system symptoms.

Case of Primary Central Nervous System Lymphoma Arising at Site of Remote Herpes Encephalitis

BACKGROUND

Primary central nervous system lymphoma (PCNSL) is a rare malignancy that usually arises in the context of severe immunosuppression but has incompletely understood etiology, limiting effective treatments.

CASE DESCRIPTION

We present the case of an 81-year-old immunocompetent man who developed a PCNSL in the right temporal lobe, at the site of a remote episode of herpes simplex virus (HSV) encephalitis 8 years prior. There are numerous viruses with known oncogenic associations; however, to our knowledge, this is the first reported case of PCNSL with an antecedent HSV infection.

CONCLUSIONS

We discuss this case in the context of our current understandings of the pathogenesis of HSV encephalitis and PCNSL and postulate mechanisms through which the 2 could be associated.

Neurologic emergencies in HIV-negative immunosuppressed patients

HIV-negative immunosuppressed patients comprise a heterogeneous group including transplant patients, patients undergoing treatment with immunosuppressors, uremic patients, alcoholics, undernourished patients, diabetics, patients on dialysis, elderly patients, and those diagnosed with severe or neoplastic processes. Epileptic seizures, focal neurologic signs, and meningoencephalitis are neurologic syndromes that require urgent action. In most of these situations, neuroimaging tests are necessary, but the findings can be different from those observed in immunocompetent patients in function of the inflammatory response. Infectious disease is the first diagnostic suspicion, and the identification of an opportunistic pathogen should be oriented in function of the type and degree of immunosuppression. Other neurologic emergencies include ischemic stroke, cerebral hemorrhage, neoplastic processes, and pharmacological neurotoxicity. This article reviews the role of neuroimaging in HIV-negative immunodepressed patients with a neurologic complication that requires urgent management.

Double encephalitis with herpes simplex virus type II and cytomegalovirus in an elder Chinese: a case report

Herpes simplex encephalitis is a rare disease. In adults, most of the reported cytomegalovirus (CMV) infections are seen in immunocompromised patients. We present a case of 67-year-old Chinese male with the coinfection of CMV and herpes simplex virus type II (HSV-II). He had no history of being treated with immunosuppressants, showed symptoms of psychosis and was scored 109 on the Positive and Negative Syndrome Scale. This patient presented with a rare case of coinfection of CMV and herpes simplex virus type II with psychotic symptoms.

Neurological complication of non Hodgkin lymphoma in childhood: experience from a single center in Turkey

PURPOSE

Lymphomas are the third most common childhood malignant disease after leukemia and central nervous system (CNS) tumors. Early diagnosis of these complications will reduce mortality and morbidity. In this study we aimed to review the neurological complications of childhood non Hodgkin Lymphoma (NHL).

PATIENTS AND METHODS

Forty four children with NHL between 2006 and 2012 were investigated retrospectively and 14 cases with neurological complications were identified.

RESULTS

The most common symptom was alteration of the consciousness (10 patients, 71.4 %) followed by convulsion (5 patients, 35.7 %), and hallucination (4 patients, 28.5 %); headache, eye pain, neurogenic bladder, speech disability and facial paralysis, and hemiplegia, were less common and each of them was seen in 1 (7.1 %) of the patients. The neurological complications were mostly seen in children with precursor T lymphoblastic lymphoma followed by anaplastic large cell lymphoma. The complications were secondary to medications (Eight patients) infection (two patients); CNS relapse (two patients); or CNS involvement of the primary disease (two patients). Chemotherapy-related neurologic complications were secondary to intrathecal methotrexate, L-asparaginase, vincristine, and ifosfamide

CONCLUSION

Advanced disease and PTLL subtype can be suggested as predictors of neurological complication. The survival rates of neurological complications are fairly good unless it is secondary to involvement of the primary disease. In patients with drug-induced neurological complications, the treatment can be safely re-administered after controlling the neurological complications. Therefore, clinicians managing children with NHL must be informative about neurological complications.

CNS infections in patients with cancer

PURPOSE OF REVIEW

This article provides a practical clinical approach to potential CNS infections in patients with cancer, discusses problematic presentations of posterior reversible encephalopathy syndrome and immune reconstitution inflammatory syndrome, and includes specific testing and treatment recommendations for bacterial meningitis, invasive fungal infections, and opportunistic viral infections.

RECENT FINDINGS

The major deficits predisposing patients with cancer to CNS infection are neutropenia, barrier disruption, B-lymphocyte or immunoglobulin deficiency, and impaired T lymphocyte-mediated immunity. Evolving patterns of drug resistance and prophylactic antimicrobial regimens have altered the timing and range of organisms causing infections. Increasingly intensive immunosuppression has made new groups of patients vulnerable to infections such as progressive multifocal leukoencephalopathy. New MRI sequences offer the potential to diagnose such infections earlier, at a stage when they are more treatable.

SUMMARY

Despite improved prophylactic and therapeutic antibiotic regimens, CNS infections remain an important source of morbidity and mortality among several cancer patient groups, particularly those patients undergoing craniotomy and those with hematologic malignancies receiving either hematopoietic cell transplantation or other intensive chemotherapy regimens.

Herpes simplex virus encephalitis despite normal cell count in the cerebrospinal fluid

OBJECTIVES

To describe herpes simplex virus encephalitis despite normal cell count in the cerebrospinal fluid in patients with malignoma after whole brain irradiation.

INTERVENTIONS

Blood and cerebrospinal fluid analysis and magnetic resonance imaging.

MEASUREMENTS AND MAIN RESULTS

Three male and two female patients with malignoma and a recent history of whole-brain irradiation presented with impaired consciousness with or without epileptic seizure. Although cerebrospinal fluid analysis revealed a normal cell count, herpes simplex virus DNA was detected in all samples by polymerase chain reaction.

CONCLUSIONS

In patients with impaired consciousness, epileptic seizure, or temporal lobe symptoms of new onset and a recent history of brain irradiation with normal cerebrospinal fluid, an atypical anergic course of herpes simplex virus encephalitis should be considered. Herpes simplex virus polymerase chain reaction should be used as method of choice to detect herpes simplex virus genomes as early as possible rather than relying on routine cerebrospinal fluid parameters. Importantly, antiviral therapy should be started without delay in any case of faint suspicion and should be continued until herpes simplex virus encephalitis is clearly ruled out.

Central nervous system infections in immunocompromised patients: update on diagnostics and therapy

Infections of the central nervous system (CNS) are increasingly reported in patients with malignancies. Heavily immunocompromised patients like those after allogeneic stem cell transplantation (SCT) or previous T cell depleting treatment regimens (e.g. with fludarabine or alemtuzumab) are at highest risk for cerebral infections. The spectrum of causative organisms may vary greatly, depending on the underlying malignancy, its treatment and various other factors. Toxoplasma gondii and fungi are the leading causative organisms in patients after allogeneic SCT, but also viruses such as herpes simplex virus or JC virus may be detected in these patients. Definitive diagnosis of cerebral infection still remains a high challenge, although diagnostics have improved by the wide availability of imaging techniques and polymerase chain reaction in recent years. Novel therapeutic options are arising, particularly for fungal CNS infections. Here, we summarise aspects on epidemiology, clinical symptoms and prognosis of CNS infections in patients with malignancies. Additionally, we give an overview on the diagnostics and management of cerebral infections in these patients including evidence evaluation of efficacy of treatment.