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

Diagnostic clues in herpes encephalitis following radiation therapy

INTRODUCTION

Herpes encephalitis is known to affect patients undergoing brain radiotherapy, but early diagnosis and treatment, the foremost determinants of disease outcome, remain challenging in this patient population. This can be due to attribution of symptoms to the brain tumor and radiation side effects, as well as patients' atypical clinical presentation. Here we sought to highlight pearls and pitfalls in the clinical course and diagnostic workup which may facilitate timely diagnosis and improve disease outcome.

METHODS

Six patients with post radiation herpes encephalitis were identified in a retrospective review of Hadassah Medical Center medical records of between 2007 and 2022. Their clinical course, brain imaging, labs and EEG findings were included in the study.

RESULTS

All six patients presented with fever and a confusional state and four had seizures. Lumbar puncture showed mild CSF pleocytosis in two of five patients, and PCR was positive for HSV1 in four out of five. MRI showed typical findings in all patients, though they were misinterpreted in two of six as disease exacerbation. EEG showed non convulsive status epilepticus in three patients. Outcome was favorable in half of patients.

DISCUSSION

In patients undergoing radiotherapy to the brain and neck, fever and confusional state accompanied by new onset seizures, seizure exacerbation, changes in seizure lateralization and status epilepticus should lead one to consider a diagnosis of herpes encephalitis. A high index of suspicion, a timely workup and empiric treatment in this patient population can alter disease outcome.

Herpes simplex encephalitis with normal brain magnetic resonance imaging and normocellular initial cerebrospinal fluid

Case presentation: However, after four days, the patient's HSE diagnosis was confirmed by the detection of herpes simplex virus type 1 (HSV1) via polymerase chain reaction (PCR) testing. This case highlights the importance of utilizing multiple diagnostic aids and not solely relying on initial test results, as infections may not appear in CSF analysis or MRI scans initially. Furthermore, this case also emphasizes the necessity of initiating empirical treatment based on clinical signs and symptoms, even in cases where diagnostic tests initially appear negative. Prompt and efficient diagnosis and treatment are crucial in managing HSE and preventing long-term neurological damage.

Conclusion: This case of HSE underscores the significance of a multifaceted diagnostic approach and timely intervention in managing this potentially severe and life-threatening condition. As mentioned, sometimes the infection does not appear in CSF analysis initially, nor does its effects appear in MRI. HSV PCR remains the golden test to confirm the diagnosis of HSE.

Clinical features, etiologies, and outcomes of central nervous system infections in intensive care: A multicentric retrospective study in a large Brazilian metropolitan area

PURPOSE

The goal of this study was to investigate severe central nervous system infections (CNSI) in adults admitted to the intensive care unit (ICU). We analyzed the clinical presentation, causes, and outcomes of these infections, while also identifying factors linked to higher in-hospital mortality rates.

MATERIALS AND METHODS

We conducted a retrospective multicenter study in Rio de Janeiro, Brazil, from 2012 to 2019. Using a prediction tool, we selected ICU patients suspected of having CNSI and reviewed their medical records. Multivariate analyses identified variables associated with in-hospital mortality.

RESULTS

In a cohort of 451 CNSI patients, 69 (15.3%) died after a median 11-day hospitalization (5-25 IQR). The distribution of cases was as follows: 29 (6.4%) had brain abscess, 161 (35.7%) had encephalitis, and 261 (57.8%) had meningitis. Characteristics: median age 41 years (27-53 IQR), 260 (58%) male, and 77 (17%) HIV positive. The independent mortality predictors for encephalitis were AIDS (OR = 4.3, p = 0.01), ECOG functional capacity limitation (OR = 4.0, p < 0.01), ICU admission from ward (OR = 4.0, p < 0.01), mechanical ventilation ≥10 days (OR = 6.1, p = 0.04), SAPS 3 ≥ 55 points (OR = 3.2, p = 0.02). Meningitis: Age > 60 years (OR = 234.2, p = 0.04), delay >3 days for treatment (OR = 2.9, p = 0.04), mechanical ventilation ≥10 days (OR = 254.3, p = 0.04), SOFA >3 points (OR = 2.7, p = 0.03). Brain abscess: No associated factors found in multivariate regression.

CONCLUSIONS

Patients' overall health, prompt treatment, infection severity, and prolonged respiratory support in the ICU all significantly affect in-hospital mortality rates. Additionally, the implementation of CNSI surveillance with the used prediction tool could enhance public health policies.

Chronic liver disease and hepatic encephalopathy patients with new-onset focal motor status epilepticus: Indicates herpetic encephalitis

Seizures are not common in cases with chronic liver disease. Overall seizures have been reported in 20-30% of cases in chronic liver disease associated with hepatic encephalopathy. We report two cases of chronic liver disease patients who presented with new-onset refractory focal status epilepticus (SE). Both patients had encephalitis and seizures which responded only when acyclovir was added to the treatment with antiepileptic medication. Herpes encephalitis should be considered as a possible diagnosis in new-onset focal seizures or focal SE in patients with chronic liver disease with or without hepatic encephalopathy, pending further investigations.

Varicella-Zoster meningitis with normal CSF cellularity: a rare case report

Varicella-zoster virus (VZV) meningitis is a one of the manifestations of VZV reactivation which usually presents with fever, headache, and is sometimes preceded by a dermatomal vesicular rash. CSF analysis is the cornerstone investigation in helping to identify the causative organism or in orienting the physician toward a possible agent. CSF analysis in Viral meningitis usually reveals lymphocytic pleocytosis. However, normal CSF analysis with viral meningitis -despite being rare- has been reported especially with bacterial causes. Therefore, a first CSF puncture cannot rule out infection and a second one might be warranted if there is still high suspicion of viral meningitis with no diagnosis made by PCR. Here we present a case of an 89-year-old female who had signs and symptoms of meningitis with normal CSF analysis. However, polymerase chain reaction (PCR) was positive for VZV. The patient was treated accordingly, and she recovered fully.

Diagnostic approach and treatment regimens in adult patients suffering from antibody-mediated or paraneoplastic encephalitis

Identification of patients with antibody-mediated encephalitis poses a diagnostic challenge and any delay in that respect will increase the interval until initiation of immunotherapy and may negatively affect the patient´s clinical outcome. Within this review we focus on therapeutic strategies in antibody-mediated encephalitis and propose how to proceed with patients, who are suspected to have encephalitis of unknown origin. We further briefly outline differences in treatment of paraneoplastic and antibody-mediated encephalitis according to its pathomechanisms.

Central nervous system infection in the intensive care unit: Development and validation of a multi-parameter diagnostic prediction tool to identify suspected patients

Background

Central nervous system infections (CNSI) are diseases with high morbidity and mortality, and their diagnosis in the intensive care environment can be challenging. Objective: To develop and validate a diagnostic model to quickly screen intensive care patients with suspected CNSI using readily available clinical data.

Methods

Derivation cohort: 783 patients admitted to an infectious diseases intensive care unit (ICU) in Oswaldo Cruz Foundation, Rio de Janeiro RJ, Brazil, for any reason, between 01/01/2012 and 06/30/2019, with a prevalence of 97 (12.4%) CNSI cases. Validation cohort 1: 163 patients prospectively collected, between 07/01/2019 and 07/01/2020, from the same ICU, with 15 (9.2%) CNSI cases. Validation cohort 2: 7,270 patients with 88 CNSI (1.21%) admitted to a neuro ICU in Chicago, IL, USA between 01/01/2014 and 06/30/2019. Prediction model: Multivariate logistic regression analysis was performed to construct the model, and Receiver Operating Characteristic (ROC) curve analysis was used for model validation. Eight predictors—age <56 years old, cerebrospinal fluid white blood cell count >2 cells/mm³, fever (≥38°C/100.4°F), focal neurologic deficit, Glasgow Coma Scale <14 points, AIDS/HIV, and seizure—were included in the development diagnostic model (P<0.05).

Results

The pool data’s model had an Area Under the Receiver Operating Characteristics (AUC) curve of 0.892 (95% confidence interval 0.864–0.921, P<0.0001).

Conclusions

A promising and straightforward screening tool for central nervous system infections, with few and readily available clinical variables, was developed and had good accuracy, with internal and external validity.

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.

Continuous video electroencephalogram for herpes simplex encephalitis: a case report and literature review

Background

Electroencephalogram (EEG) is an important tool for the diagnosis of herpes simplex virus encephalitis (HSE). However, the diagnosis of non-convulsive status epilepticus (NCSE) in HSE is challenging without the help of continuous video EEG (CVEEG), and whether EEG is a predictor of outcome remains controversial.

Case presentation

A 63-year-old woman presented with a 5 day history of fever, coma and seizures. Results of EEG, magnetic resonance imaging and polymerase chain reaction (PCR) in cerebrospinal fluid (CSF) were suggestive of herpes simplex encephalitis-1 (HSE-1). Preliminary EEG showed periodic discharges at the prefrontal and temporal lobes, which were particularly synchronized with intermittent lip smacking movements, and the discharges were terminated by diazepam. After 2-week treatment with acyclovir, high-dose hormone pulse therapy and high-dose immunoglobulin therapy, the CSF was improved, but the patient’s consciousness became worsen, consistent with the diffuse slow waves in the delta range and low voltage of EEG activity. In the following 1 month, the patient had non-responsiveness to pain and sound as shown by CVEEG with diffuse slow waves. Sometimes paroxysmal very slow waves (0.5–1 Hz) were synchronized with intermittent paroxysmal eye movements, pupil abnormality, and sweating in the frontal area. After 2 months of treatment, the EEG abnormalities improved to have alpha rhythm.

Conclusion

The CVEEG not only helps identify NCSE but can also be used to monitor HSE progression.

Cerebral HSV-1 Vasculitis as a Fatal Complication of Immunosuppression in Non-Hodgkin´s Lymphoma: A Case Report and Review of the Literature

Patients with lymphoma are predisposed to infection because of the immunocompromised state related to the disease itself and as a consequence of chemo-/radiotherapy. Here, we report a case of Herpes-simplex virus encephalitis (HSE) in an immunosuppressed patient with splenic marginal zone lymphoma (SMZL), a rare indolent variant of non-Hodgkin´s lymphoma (NHL). The course was complicated febrile neutropenia and HSV-1-related cerebral vasculitis causing progressive ischemic stroke. This case illustrates the expanding spectrum of atypical clinical and radiological manifestations of HSE in patients treated with myelotoxic drugs. Moreover, we summarize the few central nervous system manifestations of SMZL reported in the literature and discuss distinct causes of neurological deterioration in patients with NHL.

Immunomodulatory Strategies in Herpes Simplex Virus Encephalitis

Herpes simplex virus 1 (HSV-1) can be responsible for life-threatening HSV encephalitis (HSE). The mortality rate of patients with HSE who do not receive antiviral treatment is 70%, with most survivors suffering from permanent neurological sequelae. The use of intravenous acyclovir together with improved diagnostic technologies such as PCR and magnetic resonance imaging has resulted in a reduction in the mortality rate to close to 20%. However, 70% of surviving patients still do not recover complete neurological functions. Thus, there is an urgent need to develop more effective treatments for a better clinical outcome. It is well recognized that cerebral damage resulting from HSE is caused by viral replication together with an overzealous inflammatory response. Both of these processes constitute potential targets for the development of innovative therapies against HSE. In this review, we discuss recent progress in therapy that may be used to ameliorate the outcome of patients with HSE, with a particular emphasis on immunomodulatory agents. Ideally, the administration of adjunctive immunomodulatory drugs should be initiated during the rise of the inflammatory response, and its duration should be limited in time to reduce undesired effects. This critical time frame should be optimized by the identification of reliable biomarkers of inflammation.

Relapse of herpes simplex encephalitis in a patient with metastatic small cell lung cancer following scalp sparing whole brain radiotherapy

Herpes simplex virus is the most common cause of severe and potentially fatal sporadic encephalitis worldwide. Recurrence of neurologic symptoms after resolution of the initial episode of HSV encephalitis and despite adequate treatment with intravenous acyclovir is well recognized albeit rare. Most of these recurrences had no evidence of replicating virus and are immune in nature with only a minority of these recurrences representing true virologic relapses. Immunocompromised patients are predominantly at greater risk for virologic relapse of HSV encephalitis with potentially severe and at times fatal consequences. We describe a patient with small cell lung cancer and brain metastasis who underwent chemotherapy, treatment with dexamethasone and whole brain radiotherapy who subsequently suffered two episodes of HSV encephalitis three months and seven months after completion of radiotherapy and while on dexamethasone treatment.

Herpes simplex virus encephalitis in a patient receiving ustekinumab associated with extensive cerebral oedema and brainshift successfully treated by immunosuppression with dexamethasone

Herpes simplex virus (HSV) encephalitis affects 2-4 people per million/year. Immunocompomised patients can have atypical presentations of HSV encephalitis, including a lack of cerebrospinal fluid (CSF) pleocytosis. We present the case of a patient who was receiving ustekinumab therapy for psoriasis which inhibits interleukin (IL)-12 and IL-23 signalling pathways. The initial presentation was suggestive of encephalitis, but he was discharged prior to the reporting of HSV positivity due to the lack of CSF pleocytosis. On representation, he had worsening symptoms and imaging showed midline shift, indicating cerebral oedema despite the immunosupressant effects of ustekinumab. He required intensive care unit support and treatment with high dose aciclovir and dexamethasone; after a month of treatment he made a good recovery. This case is the first to report a link between ustekinumab and HSV encephalitis, and also emphasises that imunocompromised patients can lack CSF pleocytosis and develop significant cerebral oedema which responds to immune suppression.

To what extent can clinical characteristics be used to distinguish encephalitis from encephalopathy of other causes? Results from a prospective observational study

Background

Recognizing patients with encephalitis may be challenging. The cardinal symptom, encephalopathy, has a wide array of differential diagnoses. In this prospective study we aimed to explore the etiology of encephalitis and to assess the diagnostic accuracy of symptoms and clinical findings in patients with encephalitis in an encephalopathic population.

Methods

Patients with acute onset of encephalopathy (n = 136) were prospectively enrolled from January 2014–December 2015 at Oslo University Hospital, Ullevaal. Clinical and biochemical characteristics of patients who met the case definition of encephalitis were compared to patients with encephalopathy of other causes.

Results

Among 136 patients with encephalopathy, 19 (14%) met the case-definition of encephalitis. For 117 patients other causes of encephalopathy were found, infection outside the CNS was the most common differential diagnosis. Etiology of encephalitis was confirmed in 53% (4 bacterial, 4 viral, 1 parasitic, and 1 autoimmune). Personality change, nausea, fever, focal neurology, recent travel history, and low inflammation markers were significantly more abundant in patients with encephalitis, but the diagnostic accuracy for individual parameters were low (area under the curve (AUC) < 0.7). The combination of fever (OR = 6.6, 95% CI, 1.6–28), nausea (OR = 8.9, 95% CI, 1.7–46) and a normal level of ESR (erythrocyte sedimentation rate < 17 mm/hr, OR = 6.9, 95% CI, 1.5–33) was significant in multivariate analysis with an AUC (area under the curve) of 0.85 (95% CI, 0.76–0.94). Moderately increased pleocytosis in CSF (5-100 × 10⁶/L) further increased the diagnostic accuracy of this combination, AUC 0.90 (95% CI, 0.81–0.98).

Conclusions

There is a wide diversity in differential diagnoses in patients with encephalopathy, and no single symptom or finding can be used to predict encephalitis with high accuracy in this group. The combination of fever, nausea and a low ESR in an encephalopathic population, increased the diagnostic accuracy of encephalitis compared to solitary parameters. The triad could be a useful clinical tool for early diagnosis of encephalitis, and these patients should be considered for further diagnostics such as lumbar puncture (LP).

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3570-2) contains supplementary material, which is available to authorized users.

Herpes simplex virus encephalitis temporally associated with dimethyl fumarate-induced lymphopenia in a multiple sclerosis patient

BACKGROUND

Dimethyl fumarate (DMF) is approved as first line therapy for relapsing-remitting multiple sclerosis (RRMS). In some (3%) patients, DMF induces a marked lymphopenia. Herpes simplex encephalitis (HSE) may occur in lymphopenic subjects under treatment with immune-suppressive drugs.

CASE PRESENTATION

We report a case of a 39-year-old female patient with RRMS that developed HSE temporally associated with a marked and sudden drop in lymphocyte count, from 1200/µl to 600/µl, in the peripheral blood. HSE DNA was demonstrated in the cerebrospinal fluid. HSE had the features that characterize HSE occurring in immunosuppressed subjects, i.e. less prominent CSF pleocytosis, bilateral and mainly cortical involvement and less extensive tissue necrosis. Antiviral therapy determined a progressive, although incomplete, improvement. Three months later the patient presented only a mild short-term memory deficit and sporadic episodes of inappropriate emotionality. Lymphocyte count returned to normal values (1120/µl) after DMF discontinuation.

CONCLUSION

Our case of HSE in a lymphopenic DMF-treated RRMS patient, points out the necessity of further studies on DMF-related lymphopenia, especially whether it implies an impaired immunity against viruses.

A Fatal Case of Herpes Simplex Encephalitis with Two False-Negative Polymerase Chain Reactions

An 88-year-old man presented with a 1-month history of altered mental status and seizures. His electrographic and imaging findings were suggestive of herpes simplex encephalitis (HSE), for which he was empirically treated with acyclovir. He underwent two lumbar punctures 3 days apart; both cerebrospinal fluid analyses tested negative for herpes simplex virus (HSV) by polymerase chain reaction (PCR). These negative results and his continued deterioration after 9 days of acyclovir therapy prompted treatment with steroids for possible autoimmune encephalitis. Shortly after the change in management, the patient died from cardiac arrest. At autopsy, his brain showed both gross and microscopic evidence of encephalitis and was positive for HSV by immunohistochemistry. This fatal case of HSE emphasizes the limitations of HSV PCR and the importance of clinical suspicion in the diagnosis and management of this disease.

Herpes Simplex Encephalitis: an Update

PURPOSE OF REVIEW

The goal of this review is to provide an update on current thinking regarding herpes simplex encephalitis (HSE), emphasizing new information about pathogenesis, diagnosis, and immune responses. Specific questions to be addressed are the following: (1) Is there a genetic predisposition to HSE? (2) What clinical approaches have the greatest impact on improving the long-term outcomes in patients with HSE? And (3) are there immune-mediated mechanisms that may account for relapsing HSE?

RECENT FINDINGS

Toll-like receptor 3 (TLR 3) plays an important role in innate immune responses, including generation of interferons. Multiple single-gene errors in TLR 3 interferon pathways have recently been described in children that result in increased susceptibility to HSE. Conversely, studies in both animal models and humans indicate that both cytolytic viral replication and immune-mediated responses (including cytotoxic T lymphocytes and immune mechanisms mediated by TLR 2) contribute to the pathology of HSV, suggesting possible new therapeutic approaches. In terms of treatment, data clearly indicate that a longer duration between onset of symptoms and initiation of effective antiviral therapy correlates directly with less favorable clinical outcome. Recurrent or relapsing HSE may occasionally occur, but recent observations indicate that many instances of "relapsing HSE", especially in children, are more often anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis triggered by the antecedent HSV infection. Innate immune responses are critical for defense against HSV; genetic defects in this system may predispose patients to HSE. During acute HSE, exuberant immune responses may contribute to the CNS pathology, suggesting that selective immunosuppressive therapy, coupled with potent antiviral drugs, may eventually play a role in the therapeutic management of HSV. While overall clinical outcomes of HSE remain suboptimal, the initiation of high-dose acyclovir therapy as early as possible in the course of the illness provides the best chance for a patient to survive with minimal neurologic damage. Distinguishing relapsing HSE from autoimmune anti-NMDAR antibody encephalitis is critically important because therapeutic approaches will be very different.

Herpes simplex encephalitis without cerebrospinal fluid pleocytosis in a patient with bullous pemphigoid: a case report

A 78-year-old woman was diagnosed with bullous pemphigoid 2 months ago, and she had been treated with steroid and plasmapheresis. She developed sudden fever, vomiting, disorientation, and abnormal behavior. Diffusion weighted images and fluid-attenuated inversion recovery (FLAIR) magnetic resonance (MR) images showed high-intensity signals in the right temporal lobe hippocampus and right insular cortex. Cerebrospinal fluid (CSF) examination showed normal cell count (4/mm(3)), but was positive for HSV1-DNA by PCR. She was diagnosed with herpes simplex encephalitis (HSE), and acyclovir was started on the first day of admission. She had complete recovery, and was discharged. She didn't show CSF pleocytosis throughout her course of HSE. No CSF pleocytosis could be due probably to her immunosuppressed state under the steroid therapy for bullous pemphigoid. Because the morbidity and mortality of HSE is drastically reduced by early antiviral treatment, it is important to accelerate the diagnosis and treatment of HSE, especially in immunosuppressed or immunocompromised hosts.

A study on viral CNS inflammation beyond herpes encephalitis

The early diagnosis of herpes simplex virus encephalitis (HSVE) enables induction of antiviral therapy in this potentially life-threatening disease. The study aimed to determine clinical findings including cerebrospinal fluid (CSF) data and MRI imaging in HSVE patients and to identify features distinguishing HSVE from encephalitis of other viral etiologies. We retrospectively reviewed consecutive patients who were diagnosed with viral encephalitis between 2000 and 2014 at the University Hospital Halle. Forty-nine patients with viral encephalitis were identified. A viral etiology could be confirmed by PCR or antibody testing in 22/49 (44.9 %) of patients (15 (30.6 %) HSV, 5 (10.2 %) VZV, 2 (4.1 %) EBV). In HSVE, typical findings were focal slowing in electroencephalophy (EEG) (80 %, p = 0.021) and presence of cortical (86.7 %, p = 0.030) lesions in MRI. Restricted diffusion was particularly helpful in detection of early signal abnormalities in HSVE (p = 0.014). In 27/49 (55.1 %) of patients, no causative agent could be elucidated. In these patients, 15/27 (55.6 %) experienced a rather "benign" disease course with no MRI pathology despite initially HSVE mimicking clinical picture. However, CSF was significantly different showing a higher amount of granulocytes and activated lymphocytes. The remaining 12/27 (44.4 %) patients developed MRI changes consistent with encephalitis, in 4 of these patients, disease course was fatal. Beside PCR-based serology as standard procedure, MRI including diffusion-weighted images and EEG represent additional tools in early HSVE diagnosis. CSF cytology might be particularly supportive in differentiating likely benign forms of encephalitis.

Acute encephalitis in the immunocompromised individual

PURPOSE OF REVIEW

This article describes recent advances in the diagnosis and management of encephalitis in immunocompromised individuals.

RECENT FINDINGS

Herpes simplex virus (HSV) and varicella zoster virus (VZV) are common causes of encephalitis in immunocompromised individuals, although clinical manifestations may be atypical, and thus challenging to recognize. Recently, an increased incidence of HSV and VZV central nervous system infections has been reported in association with novel immunosuppressive and immunomodulatory treatments. The free-living ameba Balamuthia mandrillaris causes granulomatous encephalitis predominantly in immunocompromised individuals and is associated with nearly uniform fatality. In the setting of organ transplantation, the recipient's immunocompromised state along with the potential for donor-transmitted infections can result in a unique epidemiology of encephalitis, including infection by human herpes virus-6 and BK virus. Recent studies utilizing next-generation sequencing techniques have identified several pathogens, including Leptospira santarosai and a neurotropic astrovirus, as causes of encephalitis in immunocompromised individuals.

SUMMARY

Diagnosis and management of encephalitis is challenging in immunocompromised individuals, in part because of atypical clinical presentations and the presence of uncommon or novel infectious agents. Unbiased techniques for pathogen discovery are likely to play an increasing role in the diagnosis of central nervous system infections in immunocompromised individuals.

HSV Encephalitis with Normal CSF - A Case Report with Review of Literature

Herpes simplex virus encephalitis (HSVE) is one of the most potentially fatal infectious disease that should be detected as early as possible. The combination of clinical history and examination, brain computed tomography or magnetic resonance imaging (MRI) and lumbar puncture have been used to establish a diagnosis. The authors present a case of HSVE with normal CSF analysis, but typical MRI findings consistent with HSE and CSF PCR positive for Herpes simplex virus1 DNA, who responded to Acyclovir therapy with complete recovery.

Herpes simplex encephalitis in glioma patients: a challenging diagnosis

OBJECTIVES

In recent years, herpes simplex encephalitis (HSE) has been reported with increasing frequency in settings of immunosuppression, such as acquired immunodeficiency, transplantation and cancer. As observed, in immunocompromised individuals HSE presents peculiar clinical and paraclinical features, and poorer prognosis.

METHODS

Here we describe a retrospective series of seven cases of HSE in patients with high-grade glioma (HGG), collected among three institutions in a 5-year period (during this time, a total of 1750 patients with HGG were treated).

RESULTS

Diagnosis of the condition was particularly challenging due to the confounding clinical presentation and the atypical biological findings. As a result, antiviral treatment was started with a sharp delay compared with immunocompetent hosts. Prognosis was poor, with high short-term mortality and severe residual disability in survivors.

CONCLUSIONS

The substantial incidence of HSE observed in our centres together with the difficulty in diagnosing the condition suggest that the incidence of this complication may be highly underestimated. The aim of our report is to strengthen the observation of HSE in patients with HGG and outline the key elements that may allow its diagnosis.

Relationship of herpes simplex encephalitis and transcranial direct current stimulation--a case report

We report a rare case of relapsing herpes simplex encephalitis in a-37-year-old patient which was previously confirmed by positive polymerase chain reaction, herpes simplex virus (HSV) type1 IgG antibodies in cerebrospinal fluid and characterized on MRI. During the first admission, he was treated with continuous acyclovir treatment for one month with clinical improvement except for residual aphasia, for which he received a course of outpatient transcranial direct current stimulation (tDCS). A constant current of 1.2 mA was applied for 20 min twice daily. After the 4th day the patient was found to be irritable and uncooperative by staff and family members. A subsequent MRI showed significant deterioration of the lesion on comparison to the first MRI which led to discontinuation of tDCS.The relatively rapid exacerbation of HSV in only a few days is unusual. Our aim is to discuss if tDCS is related to HSV relapse and in doing so highlight possible mechanisms.

Herpes simplex encephalitis as a complication of whole-brain radiotherapy: a case report and review of the literature

A 55-year-old male recently diagnosed with stage IV lung adenocarcinoma presented with altered mental status approximately 1 week after the completion of 14 fractions of whole-brain radiotherapy (WBRT) for brain metastases. On admission, he was somnolent but oriented and without focal neurological deficits. Brain imaging revealed marked regression of his brain metastases. Laboratory values were only significant for hyponatremia with urine hyperosmolality consistent with syndrome of inappropriate antidiuretic hormone secretion. The patient developed seizures 3 days after admission, at which time cerebrospinal fluid was significant for positive herpes simplex virus (HSV)-1 PCR but with a negative cell count, and acyclovir was started for HSV encephalitis (HSE). After 3 weeks of acyclovir 10 mg/dl i.v. 3 times per day, he had significant neurological recovery and was discharged. Although HSE is a relatively rare condition, it is the most common cause of sporadic encephalitis in Western countries. Since the pathogenesis is believed to be due to the reactivation of latent HSV, it is possible that patients who are immunosuppressed are at higher risk for HSE. In addition, patients who are immunosuppressed or immunocompromised often present atypically, which may delay time to diagnosis and treatment, thus significantly worsening prognosis. This case report intends to raise awareness of this severe condition in the context of patients who have received WBRT and immunosuppressive therapy. In addition, important considerations of diagnosis and treatment of HSE in this patient population are discussed.

Case definitions, diagnostic algorithms, and priorities in encephalitis: consensus statement of the international encephalitis consortium

BACKGROUND

Encephalitis continues to result in substantial morbidity and mortality worldwide. Advances in diagnosis and management have been limited, in part, by a lack of consensus on case definitions, standardized diagnostic approaches, and priorities for research.

METHODS

In March 2012, the International Encephalitis Consortium, a committee begun in 2010 with members worldwide, held a meeting in Atlanta to discuss recent advances in encephalitis and to set priorities for future study.

RESULTS

We present a consensus document that proposes a standardized case definition and diagnostic guidelines for evaluation of adults and children with suspected encephalitis. In addition, areas of research priority, including host genetics and selected emerging infections, are discussed.

CONCLUSIONS

We anticipate that this document, representing a synthesis of our discussions and supported by literature, will serve as a practical aid to clinicians evaluating patients with suspected encephalitis and will identify key areas and approaches to advance our knowledge of encephalitis.

Herpes simplex virus type 1 encephalitis and unusual retinitis in a patient with systemic lupus erythematosus

In this report we discuss a case of a patient with systemic lupus erythematosus who developed herpes simplex virus type 1(HSV-1) infection presenting with encephalitis as well as necrotic and non-necrotic retinitis. The patient presented with typical clinical symptoms and radiologic abnormalities consistent with HSV-1 encephalitis and HSV-1 retinitis in patients with HIV infection, but lacked cerebrospinal fluid pleocytosis and had bilateral retinitis with poor visual acuity. To the best of our knowledge, this is the first such case reported in the literature.

Pitfalls associated with the diagnosis of herpes simplex encephalitis

Herpes simplex encephalitis (HSE) still remains a serious illness with high morbidity and mortality. The characteristic presentation of HSE usually consists of fever, headache, and altered mental function. We present three patients with atypical features of HSE. First, a 48-year-old man with symptomatic posttraumatic epilepsy, who developed a gastrointestinal infection, seizures, and fever. After significant clinical improvement, the patient had fever again and developed a status epilepticus, which led to the diagnosis of HSE. Second, an 84-year-old woman with hyperactive delirium after levofloxacin intake. Cranial computed tomography (CCT) revealed hypodense temporal changes, prompting lumbar puncture and diagnosis of HSE. Third, a 51-year-old diabetic woman presented with fever and acute confusion. As CCT and cell count of cerebrospinal fluid (CSF) were normal, infection and hyperglycemia as initial diagnoses were postulated. Due to aphasic symptoms, the differential diagnosis of a stroke was taken into account. Thus a second lumbar puncture led to the correct diagnosis of HSE. These atypical presentations need a high grade of suspicion and a high willingness to reconsider the initial working diagnosis, in order to prevent a diagnostic delay.

Can infections cause Alzheimer's disease?

Late-onset Alzheimer's disease (AD) is the most prevalent cause of dementia among older adults, yet more than a century of research has not determined why this disease develops. One prevailing hypothesis is that late-onset AD is caused by infectious pathogens, an idea widely studied in both humans and experimental animal models. This review examines the infectious AD etiology hypothesis and summarizes existing evidence associating infectious agents with AD in humans. The various mechanisms through which different clinical and subclinical infections could cause or promote the progression of AD are considered, as is the concordance between putative infectious agents and the epidemiology of AD. We searched the PubMed, Web of Science, and EBSCO databases for research articles pertaining to infections and AD and systematically reviewed the evidence linking specific infectious pathogens to AD. The evidence compiled from the literature linking AD to an infectious cause is inconclusive, but the amount of evidence suggestive of an association is too substantial to ignore. Epidemiologic, clinical, and basic science studies that could improve on current understanding of the associations between AD and infections and possibly uncover ways to control this highly prevalent and debilitating disease are suggested.