Empiric Acyclovir Is Infrequently Initiated in the Emergency Department to Patients Ultimately Diagnosed With Encephalitis

Clinical characteristics and outcomes of patients with Herpes Simplex Encephalitis in Vietnam: a retrospective study

BACKGROUND

Herpes simplex encephalitis (HSE) is an important central nervous infection with severe neurological sequelae. The aim of this study was to describe clinical characteristic and outcomes of patients with HSE in Vietnam.

METHODS

This was a retrospective study of 66 patients with herpes simplex encephalitis who admitted to the National Hospital for Tropical Diseases, Hanoi, Vietnam from 2018 to 2021. The detection of herpes simplex virus (HSV) in cerebrospinal fluid was made by the real-time PCR assay. We reported the clinical manifestation on admission and evaluated clinical outcomes at the hospital discharge by modified Rankin Scale (mRS). Multivariate logistic regression analysis was used to analyze the independent risk factors of severe outcomes.

RESULTS

Of the 66 patients with laboratory confirmed HSE, the median age was 53 years (IQR 38-60) and 44 patients (69.7%) were male. The most common manifestations included fever (100%), followed by the consciousness disorder (95.5%). Other neurological manifestation were seizures (36.4%), memory disorders (31.8%), language disorders (19.7%) and behavioral disorders (13.6%). Conventional magnetic resonance imaging (MRI) showed 93.8% patients with temporal lobe lesions, followed by abnormalities in insula (50%), frontal lobe (34.4%) and 48.4% of patients had bilateral lesions. At discharge, 19 patients (28.8%) completely recovered, 15 patients (22.7%) had mild sequelae, 28 patients (42.4%) had moderate to severe sequelae. Severe neurological sequelae were memory disorders (55.8%), movement disorders (53.5%), language disorders (30.2%). Multivariate logistic regression analysis showed that Glasgow score decrement at admission, seizures, and time duration from onset of symptoms to the start of Acyclovir treatment > 4 days were independent factors associated with severe outcomes in HSE patients.

CONCLUSION

Glasgow score decrement, seizures and delay treatment with Acyclovir were associated with the poor outcome of patients with HSE.

Austrian syndrome: Report of one case and a systematic review of case reports - new insights

OBJECTIVE

The objective of this review was to gain new insight into the rare condition, Austrian syndrome: the triad of endocarditis, meningitis and pneumonia caused by Streptococcus pneumoniae.

METHODS

A systematic review of case reports was conducted using the PRISMA guideline. Cases were rigorously screened to meet a set of well-defined inclusion criteria. Relevant data was aggregated and reported using descriptive statistics.

RESULTS

Seventy-one cases from 69 case reports were included in the final review. The mean age was 56.5 years with a male-to-female ratio of 2.4:1. Alcoholism was reported in 41% of patients. Altered mental state (69%) and fever (65%) (mean temperature on admission = 38.9°C) were the commonest presenting symptoms. The mean duration of symptoms before presentation to the hospital was 8 days. The aortic valve was most commonly affected (56%). The mean duration of antibiotic therapy was 5.6 weeks. Seventy percent of patients were admitted to the intensive care unit (ICU). Fifty-six percent of patients had valvular surgery. The average length of stay in the hospital was 36.9 days. Mortality was recorded in 28% of patients.

CONCLUSION

Austrian syndrome is rare but deadly. The true incidence is unknown but is commoner in middle-aged men and in alcoholics. Affected patients are usually critically unwell, often requiring ICU admission and prolonged hospital stays. Treatment is aggressive including prolonged courses of antibiotics and often, surgery. Despite these, the case fatality rate is high, with death occurring in over a quarter of patients. Surgery appears to be associated with better prognosis.

Clinical and Health System Impact of Biofire Filmarray Meningitis/Encephalitis Routine Testing of CSF in a Pediatric Hospital: An Observational Study

BACKGROUND

Rapid cartridge-based molecular test panels targeting multiple pathogens are increasingly available, improve pathogen detection and reduce turn-around-time but are more expensive than standard testing. Confirmation that these test panels contribute to improved patient or health service outcomes is required.

METHODS

In March 2021, our pediatric hospital laboratory implemented the BioFire Filmarray™ meningitis/encephalitis (M/E) panel as an additional routine test for all cerebrospinal fluid (CSF) samples collected from infants <90 days or from any patient in the emergency department. A retrospective chart review was done to ascertain changes in clinical outcomes, antimicrobial prescribing practices, and hospital length of stay, comparing two discrete 6-month periods: preimplementation (March-August 2019) and postimplementation (March-August 2021).

RESULTS

Both pre- and postimplementation groups were similar at baseline, except the preimplementation group had a higher proportion of infants with enterovirus and parechovirus meningitis. There was no significant difference between the groups in terms of median length of stay (2.94 vs 3.47 days, p = 0.41), duration of antibiotic treatment (2.0 vs 2.3 days, p = 0.25), need for central venous access (12.9% vs 17%, p = 0.38) or hospital-in-the-home admission (9.4% vs 9%, p = 0.92). A similar proportion of infants received aciclovir (33% vs 31%), however, a reduction in duration was observed (1.36 vs 0.90 days, p = 0.03) in the postimplementation period.

CONCLUSIONS

Introduction of the Biofire Filmarray™ M/E panel for routine testing of CSF samples reduced the duration of antiviral prescribing but had only a minor impact on antibiotic prescribing practices or health service outcomes in our pediatric hospital. The introduction of new laboratory testing needs to be supported by a comprehensive stewardship program to see optimal outcomes from new testing platforms.

Atypical presentation of West Nile encephalitis

West Nile virus (WNV) causes both sporadic infection and outbreaks that may be associated with severe neurologic involvement. The infection is transmitted to humans mainly by mosquito bites, and the virus is preserved in a cycle in which birds are the main host. The typical involvement of the central nervous system is completely indistinguishable from meningitis and encephalitis related to other pathogens.  In this report we described the atypical presentation of a WNV meningoencephalitis in a 81-y.o. female patient, showing psychiatric manifestations at the onset. Anamnestic information was essential to progress to the correct diagnosis. Targeted search for the causative agent of meningoencephalitis was perfected after learning that the patient lived in an area adjacent to a nature reserve.

Herpes simplex virus encephalitis mimicking acute ischemic stroke

Background

Infections of the central nervous system might present in an acute form such as to be similar with the clinical characteristics of a stroke. This situation will hamper a correct diagnosis and a prompt treatment that can otherwise be successful.

Case Description

We present the case of a herpes virus encephalitis that came up in the emergency department with an admission diagnosis of ischemic cerebral accident. Being the symptomatology unclear, the findings of magnetic resonance of the brain oriented versus an infectious disorder. The lumbar tap confirmed the presence of herpes simplex virus (HSV) 1 virus and an antiviral therapy was administered, leading to resolution of the condition within the 3 weeks of hospitalization.

Conclusion

HSV infections may mimic stroke and therefore should be included in the differential diagnosis of atypical acute nervous conditions. In neurological events of acute nature, especially in febrile patients whose brain imaging is suspicious or inconclusive, the eventuality of a herpetic encephalitis should be kept in mind. This will lead to a prompt antiviral therapy and to a favorable outcome.

An Autopsy Case of Varicella Zoster Virus Encephalitis with Multiple Brain Lesions

Varicella-zoster virus (VZV) encephalitis in the absence of vasculopathy may rarely occur in association with herpes zoster. We herein report the case of a 67-year-old woman with non-Hodgkin's lymphoma undergoing chemotherapy who presented with an acute alteration in consciousness. Magnetic resonance imaging of the brain revealed multiple and nonspecific lesions of hyperintensity with mild edema in the cortex and subcortex. She was treated with intravenous acyclovir. However, two days after admission, the patient died and was diagnosed with VZV encephalitis. This case highlights the risk of VZV reactivation with severe neurological complications in patients undergoing immunosuppressive therapy.

Management of adult infectious encephalitis in metropolitan France

Infectious encephalitis is a severe disease leading to a high mortality and morbidity. The most frequent causes include Herpes simplex virus, Varicella Zoster virus, Listeria monocytogenes, and Mycobacterium tuberculosis. Urgent treatment is required (anti-infective therapy and nonspecific supportive care). The aim of this study was to define treatment strategy, empirical and after microbiological documentation at 48hours, through a systematic literature review.

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.

Epstein-Barr virus encephalitis presenting as cerebellar hemorrhage

Epstein-Barr virus (EBV) belongs to the human herpesvirus family and is ubiquitously found in the adult human population. The most common clinical manifestation of EBV is the syndrome of infectious mononucleosis. Central nervous system involvement by EBV is rare, with very few cases of EBV encephalitis reported in the literature. The majority of these cases report cerebral cortical changes on magnetic resonance imaging. We present a rare case of EBV encephalitis in a young patient with meningitis-like symptoms and cerebellar hemorrhage on magnetic resonance imaging.

Herpes Simplex Encephalitis: Lack of Clinical Benefit of Long-term Valacyclovir Therapy

BACKGROUND

Despite the proven efficacy of acyclovir (ACV) therapy, herpes simplex encephalitis (HSE) continues to cause substantial morbidity and mortality. Among patients with HSE treated with ACV, the mortality rate is approximately 14%-19%. Among survivors, 45%-60% have neuropsychological sequelae at 1 year. Thus, improving therapeutic approaches to HSE remains a high priority.

METHODS

Following completion of a standard course of intravenous ACV, 87 adult patients with HSE (confirmed by positive polymerase chain reaction [PCR] for herpes simplex virus DNA in cerebrospinal fluid) were randomized to receive either valacyclovir (VACV) 2 g thrice daily (n = 40) or placebo tablets (n = 47) for 90 days (12 tablets of study medication daily). The primary endpoint was survival with no or mild neuropsychological impairment at 12 months, as measured by the Mattis Dementia Rating Scale (MDRS). Logistic regression was utilized to assess factors related to the primary endpoint.

RESULTS

The demographic characteristics of the 2 randomization groups were statistically similar with no significant differences in age, sex, or race. At 12 months, there was no significant difference in the MDRS scoring for VACV-treated vs placebo recipients, with 85.7% and 90.2%, respectively, of patients demonstrating no or mild neuropsychological impairment (P = .72). No significant study-related adverse events were encountered in either treatment group.

CONCLUSIONS

Following standard treatment with intravenous ACV for PCR-confirmed HSE, an additional 3-month course of oral VACV therapy did not provide added benefit as measured by neuropsychological testing 12 months later in a population of relatively high-functioning survivors.

CLINICAL TRIALS REGISTRATION

NCT00031486.

Results of a multinational study suggest the need for rapid diagnosis and early antiviral treatment at the onset of herpetic meningoencephalitis

Data in the literature regarding the factors that predict unfavorable outcomes in adult herpetic meningoencephalitis (HME) cases are scarce. We conducted a multicenter study in order to provide insights into the predictors of HME outcomes, with special emphasis on the use and timing of antiviral treatment. Samples from 501 patients with molecular confirmation from cerebrospinal fluid were included from 35 referral centers in 10 countries. Four hundred thirty-eight patients were found to be eligible for the analysis. Overall, 232 (52.9%) patients experienced unfavorable outcomes, 44 died, and 188 survived, with sequelae. Age (odds ratio [OR], 1.04; 95% confidence interval [CI], 1.02 to 1.05), Glasgow Coma Scale score (OR, 0.84; 95% CI, 0.77 to 0.93), and symptomatic periods of 2 to 7 days (OR, 1.80; 95% CI, 1.16 to 2.79) and >7 days (OR, 3.75; 95% CI, 1.72 to 8.15) until the commencement of treatment predicted unfavorable outcomes. The outcome in HME patients is related to a combination of therapeutic and host factors. This study suggests that rapid diagnosis and early administration of antiviral treatment in HME patients are keys to a favorable outcome.

Delays in Initiation of Acyclovir Therapy in Herpes Simplex Encephalitis

Background:

Diagnosis of herpes simplex encephalitis (HSE) is based on clinical findings, MRI, and detection of herpes simplex virus (HSV) DNA in cerebrospinal fluid (CSF) using polymerase chain reaction amplification. Delays in starting treatment are associated with poorer clinical outcomes. We assessed the timing of initiation of acyclovir therapy in HSE.

Methods:

Inpatient databases from seven hospitals in Winnipeg, Manitoba were used to identify individuals diagnosed with encephalitis and HSE from 2004 to 2009. The time taken to initiate therapy with acyclovir and the reasons for delays were determined.

Results:

Seventy-seven patients were identified; 69 (90%) received acyclovir; in the others a non-HSV infection was strongly suspected. Thirteen patients were subsequently confirmed to have HSE. Acyclovir was initiated a median of 21 hours (3-407) after presentation in encephalitis cases, and a median of 11 hours (3-118) in HSE. The most common reason for delay was a failure to consider HSE in the differential diagnosis, despite suggestive clinical features. Where therapy was delayed in HSE patients, the decision to begin acyclovir was prompted by transfer of the patient to a different service (55%), recommendations by consultants (18%), imaging results (18%), and CSF pleocytosis (9%).

Conclusions:

Delays in initiating acyclovir for HSE are common, and are most often due to a failure to consider HSE in a timely fashion on presentation. In order to improve patient outcomes, physicians should be more vigilant for HSE, and begin acyclovir therapy expeditiously on the basis of clinical suspicion rather than waiting for confirmatory tests.

Current practice patterns regarding diagnostic investigations and empiric use of acyclovir by Canadian pediatric emergency physicians in febrile neonates

OBJECTIVE

The aim of this study was to assess current attitudes and approaches to the febrile neonate in terms of diagnostic investigations and empiric treatment of suspected herpes simplex virus (HSV) infection.

METHODS

Between March 2010 and November 2010, a survey describing a hypothetical case of a febrile neonate presenting to the ED without clear signs of an HSV infection was sent to tertiary care pediatric emergency physicians across Canada. Participants were asked multiple choice and open-ended questions to obtain information about their choice of investigations, empiric treatment, and impression of the likelihood of HSV in the case. Survey data were analyzed using univariate statistics.

RESULTS

Blood culture (98.6%), complete blood count (99.3%), lumbar puncture (81.2%), and nasopharyngeal swabs for respiratory viruses (61.6%) were most commonly performed by the 139 respondents, whereas 33% reported they would send cerebrospinal fluid for HSV polymerase chain reaction. Most (76%) would administer empiric antibiotics, whereas 5.8% included acyclovir to their treatment regimen. Greater than 50% included positive maternal history as an important factor in determining a febrile neonate's risk of HSV infection. Thirty-four percent reported that the wellness of the child, the presence of skin changes (37%), and the presence of any worrisome neurologic sign or symptom (37%) would influence their decision for investigations and empiric administration of acyclovir.

CONCLUSIONS

Canadian pediatric emergency physicians are aware of risk factors for neonatal HSV infection and tailor their history and diagnostic investigations toward the diagnosis of HSV infection, but very few empirically administer acyclovir. Examination of future Canadian HSV guidelines for this patient population is warranted.

Pitfalls in the management of headache in the emergency department

Headache is the fifth most common primary complaint of patients presenting to an emergency department (ED) in the United States. The emergency physician (EP) plays a unique role in the management of these patients, one that differs from that of the primary care physician, the neurologist, and other specialists. Diagnostic nomenclature used in the ED is necessarily less specific, as care is more appropriately focused on the relief of symptoms and the identification of life-threatening causes. By seeking a limited number of specific critical features on history and physical examination, the EP can minimize the risk of overlooking one of these dangerous causes of headache. When certain features are present, empirical therapies and diagnostic testing should be initiated in the ED. The most frequently encountered pitfalls in the management of patients with headache in emergency medicine practice, and those with the greatest likelihood to adversely affect patient outcomes, are discussed.

Diagnostic delay in a case of herpes simplex encephalitis

Herpes simplex encephalitis (HSE) is the most frequent cause of sporadic fatal encephalitis in the Western world. Definitive diagnosis by viral PCR of cerebrospinal fluid (CSF) and treatment with aciclovir have improved the prognosis significantly. Nevertheless, the condition is rare and presents with non-specific symptoms that can easily be mistaken for systemic infection or non-infective encephalopathy. We report a case of HSE which was not recognised by four separate doctors, leading to substantial delay in diagnosis and treatment. Our patient presented with fever, headaches, altered behaviour and generalised bradykinesia. This was initially diagnosed as otitis interna (labyrinthitis) and, subsequently, an ischaemic stroke. There was a delay of 10 days in the initiation of aciclovir from symptom onset. MRI and CSF PCR confirmed herpes simplex virus type-1 (HSV-1) infection. The patient improved on aciclovir, but is disabled with word-finding difficulties and cognitive slowing.

Management of suspected herpes simplex virus encephalitis in adults in a U.K. teaching hospital

The outcome of herpes simplex virus (HSV) encephalitis is improved with prompt initiation of aciclovir treatment. Delays are common, but there is little understanding of why they occur. The case notes of 21 adults admitted with suspected HSV encephalitis over one year were reviewed. The median (range) duration of illness was 2.5 (1-99) days. Seventeen (81%) patients had a lumbar puncture (LP) performed, at a median (range) time of 24 (2-114) hours after encephalitis was suspected. Lumbar puncture was delayed for a computed tomography (CT) scan in 15 patients, but only one of these had contraindications to an immediate LP. The median (range) time from presentation to starting aciclovir was 48 (2-432) hours. HSV-PCR (polymerase chain reaction) was requested on cerebrospinal fluid from 12 patients, one of whom was positive. Five (24%) patients were given the wrong dose of aciclovir. Overall the management of suspected HSV encephalitis was often sub-optimal, with delays in LP occurring due to unnecessary CT scans, and the wrong aciclovir dose administered. Guidelines for the management of suspected encephalitis are needed.

Central nervous system infections in the systemic vasculitides

PURPOSE OF REVIEW

Central nervous system infections are not uncommon in systemic vasculitides. Being vigilant of central nervous system infections as an alternative consideration, instead of systemic vasculitides per se, could prove to be lifesaving in certain circumstances.

RECENT FINDINGS

Common pathogens, such as tuberculosis, Cryptococcus, and Listeria, still occur commonly as the major causes of central nervous system infection in systemic vasculitides. However, rare pathogens could be responsible among those immunocompromised hosts, and they should not be overlooked. The manifestation of central nervous system infection tends to be atypical among systemic vasculitides patients. History, physical, and cerebrospinal fluid analyses are still time-honored approaches to establishing the correct diagnosis. Newer techniques such as interferon-gamma release assay for tuberculosis, cerebrospinal fluid cytokine, or chemokine profiling need further validation and careful interpretation among such a special patient population. Immune disturbance, mainly due to immunosuppressive therapy, and polymorphism of the innate immune pathway (for example, Toll-like receptor) could be susceptibility factors for certain central nervous system infections. The biologic agents (for example, anti-tumor necrosis factor alpha, and B-cell depletion therapy) represent novel methods for treating systemic vasculitides, but they raise a critical issue owing to their increased likelihood for being associated with opportunistic infections.

SUMMARY

Despite the recent progress in this special field, the mortality of central nervous system infection in systemic vasculitides is still high, and the prognostic factors are still largely undetermined.

Emergency department management of meningitis and encephalitis

Bacterial meningitis and viral encephalitis are infectious disease emergencies that can cause significant patient morbidity and mortality. Clinicians use epidemiologic, historical, and physical examination findings to identify patients at risk for these infections, and central nervous system (CNS) imaging and lumbar puncture (LP) may be needed to further evaluate for these diagnoses. The diagnosis of bacterial meningitis can be challenging, as patients often lack some of the characteristic findings of this disease with presentations that overlap with more common disorders seen in the emergency department. This article addresses considerations in clinical evaluation, need for CNS imaging before LP, interpretation of cerebrospinal fluid results, standards for and effects of timely antibiotic administration, and recommendations for specific antimicrobial therapy and corticosteroids.