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Wan N, Weerakkody S. Herpes simplex virus encephalitis: An atypical presentation of delirium. Clin Case Rep 2023; 11:e7123. [PMID: 36992671 PMCID: PMC10040492 DOI: 10.1002/ccr3.7123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/23/2023] [Accepted: 03/09/2023] [Indexed: 03/28/2023] Open
Abstract
Herpes simplex encephalitis (HSE) is the most common cause of infectious encephalitis. Our case is of a 75‐year‐old woman who presented with dysuria and altered mental status. Our case addresses the difficulties in diagnosis and highlights the importance of early recognition of HSE and its associated neurological sequelae.
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Affiliation(s)
- Nicholas Wan
- Department of General Medicine, Flinders Medical CentreBedford ParkSouth AustraliaAustralia
- Adelaide Medical SchoolUniversity of AdelaideAdelaideSouth AustraliaAustralia
| | - Sanath Weerakkody
- Department of General Medicine, Flinders Medical CentreBedford ParkSouth AustraliaAustralia
- College of Medicine and Public Health, Flinders UniversityBedford ParkSouth AustraliaAustralia
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Sehl-Ewert J, Schwaiger T, Schäfer A, Hölper JE, Klupp BG, Teifke JP, Blohm U, Mettenleiter TC. Clinical, neuropathological, and immunological short- and long-term feature of a mouse model mimicking human herpes virus encephalitis. Brain Pathol 2021; 32:e13031. [PMID: 34709694 PMCID: PMC9048517 DOI: 10.1111/bpa.13031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 09/13/2021] [Accepted: 10/04/2021] [Indexed: 12/15/2022] Open
Abstract
Herpes simplex encephalitis (HSE) is one of the most serious diseases of the nervous system in humans. However, its pathogenesis is still only poorly understood. Although several mouse models of predominantly herpes simplex virus 1 (HSV-1) infections mimic different crucial aspects of HSE, central questions remain unanswered. They comprise the specific temporofrontal tropism, viral spread within the central nervous system (CNS), as well as potential molecular and immunological barriers that drive virus into latency while only rarely resulting in severe HSE. We have recently proposed an alternative mouse model by using a pseudorabies virus (PrV) mutant that more faithfully represents the striking features of human HSE: temporofrontal meningoencephalitis with few severely, but generally only moderately to subclinically affected mice as well as characteristic behavioral abnormalities. Here, we characterized this animal model using 6- to 8-week-old female CD-1 mice in more detail. Long-term investigation over 6 months consistently revealed a biphasic course of infection accompanied by recurring clinical signs including behavioral alterations and mainly mild meningoencephalitis restricted to the temporal and frontal lobes. By histopathological and immunological analyses, we followed the kinetics and spatial distribution of inflammatory lesions as well as the underlying cytokine expression in the CNS over 21 days within the acute phase of infection. Affecting the temporal lobes, the inflammatory infiltrate was composed of lymphocytes and macrophages showing a predominantly lymphocytic shift 15 days after infection. A strong increase was observed in cytokines CXCL10, CCL2, CCL5, and CXCL1 recruiting inflammatory cells to the CNS. Unlike the majority of infected mice, strongly affected animals demonstrated extensive temporal lobe edema, which is typically present in severe human HSE cases. In summary, these results support the validity of our animal model for in-depth investigation of HSE pathogenesis.
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Affiliation(s)
- Julia Sehl-Ewert
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Theresa Schwaiger
- Institute of Immunology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.,ViraTherapeutics GmbH, Rum, Austria
| | - Alexander Schäfer
- Institute of Immunology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Julia E Hölper
- Institute of Immunology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.,Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Barbara G Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Jens P Teifke
- Department of Experimental Animal Facilities and Biorisk Management, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Ulrike Blohm
- Institute of Immunology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Thomas C Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
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The GABA A Receptor α2 Subunit Activates a Neuronal TLR4 Signal in the Ventral Tegmental Area that Regulates Alcohol and Nicotine Abuse. Brain Sci 2018; 8:brainsci8040072. [PMID: 29690521 PMCID: PMC5924408 DOI: 10.3390/brainsci8040072] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 04/04/2018] [Accepted: 04/18/2018] [Indexed: 01/06/2023] Open
Abstract
Alcoholism initiates with episodes of excessive alcohol drinking, known as binge drinking, which is one form of excessive drinking (NIAAA Newsletter, 2004) that is related to impulsivity and anxiety (Ducci et al., 2007; Edenberg et al., 2004) and is also predictive of smoking status. The predisposition of non-alcohol exposed subjects to initiate binge drinking is controlled by neuroimmune signaling that includes an innately activated neuronal Toll-like receptor 4 (TLR4) signal. This signal also regulates cognitive impulsivity, a heritable trait that defines drug abuse initiation. However, the mechanism of signal activation, its function in dopaminergic (TH+) neurons within the reward circuitry implicated in drug-seeking behavior [viz. the ventral tegmental area (VTA)], and its contribution to nicotine co-abuse are still poorly understood. We report that the γ-aminobutyric acidA receptor (GABAAR) α2 subunit activates the TLR4 signal in neurons, culminating in the activation (phosphorylation/nuclear translocation) of cyclic AMP response element binding (CREB) but not NF-kB transcription factors and the upregulation of corticotropin-releasing factor (CRF) and tyrosine hydroxylase (TH). The signal is activated through α2/TLR4 interaction, as evidenced by co-immunoprecipitation, and it is present in the VTA from drug-untreated alcohol-preferring P rats. VTA infusion of neurotropic herpes simplex virus (HSV) vectors for α2 (pHSVsiLA2) or TLR4 (pHSVsiTLR4) but not scrambled (pHSVsiNC) siRNA inhibits signal activation and both binge alcohol drinking and nicotine sensitization, suggesting that the α2-activated TLR4 signal contributes to the regulation of both alcohol and nicotine abuse.
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Balan I, Warnock KT, Puche A, Gondre-Lewis MC, Aurelian L. Innately activated TLR4 signal in the nucleus accumbens is sustained by CRF amplification loop and regulates impulsivity. Brain Behav Immun 2018; 69:139-153. [PMID: 29146239 PMCID: PMC5857415 DOI: 10.1016/j.bbi.2017.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 10/31/2017] [Accepted: 11/12/2017] [Indexed: 12/25/2022] Open
Abstract
Cognitive impulsivity is a heritable trait believed to represent the behavior that defines the volition to initiate alcohol drinking. We have previously shown that a neuronal Toll-like receptor 4 (TLR4) signal located in the central amygdala (CeA) and ventral tegmental area (VTA) controls the initiation of binge drinking in alcohol-preferring P rats, and TLR4 expression is upregulated by alcohol-induced corticotropin-releasing factor (CRF) at these sites. However, the function of the TLR4 signal in the nucleus accumbens shell (NAc-shell), a site implicated in the control of reward, drug-seeking behavior and impulsivity and the contribution of other signal-associated genes, are still poorly understood. Here we report that P rats have an innately activated TLR4 signal in NAc-shell neurons that co-express the α2 GABAA receptor subunit and CRF prior to alcohol exposure. This signal is not present in non-alcohol drinking NP rats. The TLR4 signal is sustained by a CRF amplification loop, which includes TLR4-mediated CRF upregulation through PKA/CREB activation and CRF-mediated TLR4 upregulation through the CRF type 1 receptor (CRFR1) and the MAPK/ERK pathway. NAc-shell Infusion of a neurotropic, non-replicating herpes simplex virus vector for TLR4-specific small interfering RNA (pHSVsiTLR4) inhibits TLR4 expression and cognitive impulsivity, implicating the CRF-amplified TLR4 signal in impulsivity regulation.
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Affiliation(s)
- Irina Balan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kaitlin T Warnock
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC, USA
| | - Adam Puche
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Marjorie C Gondre-Lewis
- Department of Anatomy, Laboratory for Neurodevelopment, Howard University College of Medicine, Washington, DC, USA
| | - Laure Aurelian
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA.
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Abstract
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.
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Affiliation(s)
- John W Gnann
- Department of Medicine, Division of Infectious Diseases, Medical University of South Carolina, 135 Rutledge Avenue, MSC 752, Charleston, SC, 29425, USA.
| | - Richard J Whitley
- University of Alabama at Birmingham, 303 CHB, 1600 7th Ave. S, Birmingham, AL, 35233-1711, USA
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June HL, Liu J, Warnock KT, Bell KA, Balan I, Bollino D, Puche A, Aurelian L. CRF-amplified neuronal TLR4/MCP-1 signaling regulates alcohol self-administration. Neuropsychopharmacology 2015; 40:1549-59. [PMID: 25567426 PMCID: PMC4397415 DOI: 10.1038/npp.2015.4] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 12/11/2022]
Abstract
Alcohol dependence is a complex disorder that initiates with episodes of excessive alcohol drinking known as binge drinking. It has a 50-60% risk contribution from inherited susceptibility genes; however, their exact identity and function are still poorly understood. We report that alcohol-preferring P rats have innately elevated levels of Toll-like receptor 4 (TLR4) and monocyte chemotactic protein-1 (MCP-1) that colocalize in neurons from the central nucleus of the amygdala (CeA) and ventral tegmental area (VTA). To examine the potential role of a TLR4/MCP-1 signal, we used Herpes Simplex Virus (HSV) vectors (amplicons) that retain in vivo neurotropism. Infusion of amplicons for TLR4 or MCP-1 siRNA into the CeA or VTA from the P rats inhibited target gene expression and blunted binge drinking. A similarly delivered amplicon for scrambled siRNA did not inhibit TLR4 or MCP-1 expression nor reduce binge drinking, identifying a neuronal TLR4/MCP-1 signal that regulates the initiation of voluntary alcohol self-administration. The signal was sustained during alcohol drinking by increased expression of corticotropin-releasing factor and its feedback regulation of TLR4 expression, likely contributing to the transition to alcohol dependence.
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Affiliation(s)
- Harry L June
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC, USA
| | - Juan Liu
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Kaitlin T Warnock
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC, USA
| | - Kimberly A Bell
- Neuropsychopharmacology Laboratory, Department of Psychiatry and Behavioral Sciences, Howard University College of Medicine, Washington, DC, USA
| | - Irina Balan
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Dominique Bollino
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Adam Puche
- Department of Anatomy and Neurobiology, University of Maryland School of Medicine, Baltimore, MD, USA
| | - Laure Aurelian
- Department of Pharmacology, University of Maryland School of Medicine, Baltimore, MD, USA,Department of Pharmacology and Experimental Therapeutics, University of Maryland, 655 West Baltimore Street, Baltimore, MD 21201, USA, Tel: +1 410 7063895, Fax: +1 410 7062513, E-mail:
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Cohen M, Braun E, Tsalenchuck Y, Panet A, Steiner I. Restrictions that control herpes simplex virus type 1 infection in mouse brain ex vivo. J Gen Virol 2011; 92:2383-2393. [DOI: 10.1099/vir.0.031013-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Elucidating the cellular and molecular factors governing herpes simplex virus type 1 (HSV-1) neurotropism is a prerequisite for understanding HSV-1 encephalitis and for targeting HSV-1-derived vectors for gene transfer to the brain. Earlier we had described an ex vivo system of mouse brain slices and demonstrated a selective and unique infection pattern, mostly around the ventricles. Here, we examined tissue factors controlling HSV-1 infection of brain slices. We demonstrated that heparan sulphate, while an important factor, does not determine the infection pattern. Hyaluronic acid, but not collagen, appears to enhance HSV-1 brain infection. To investigate whether tissue distribution of viral receptors determines the infection pattern, we examined transcription of herpes virus entry mediator and nectin-1 receptor genes in infected and uninfected brain regions. Both the infected and the uninfected regions express the receptors. We also explored the influence of intra-cellular factors. HSV-1 does not preferentially infect proliferating cells in the brain slices, despite its predilection to the ventricular zones. To delineate the step at which the HSV-1 infection cascade is restricted, mRNA was isolated following tissue infection, and transcription of the immediate-early and late viral genes was evaluated. The results indicated that HSV-1 genes are not expressed in regions that do not express a viral reporter gene. Therefore, we conclude that tissue resistance to infection is associated with a block at or prior to the immediate-early mRNA synthesis. Taken together, using the ex vivo system of organotypic culture we describe here extra-cellular and intra-cellular restriction levels of HSV-1 brain infection.
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Affiliation(s)
- Meytal Cohen
- Department of Biochemistry, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- Laboratory of Neurovirology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Efrat Braun
- Department of Biochemistry, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- Laboratory of Neurovirology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Yael Tsalenchuck
- Department of Biochemistry, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
- Laboratory of Neurovirology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Amos Panet
- Department of Biochemistry, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Israel Steiner
- Department of Neurology, Rabin Medical Center, Campus Beilinson, Petach Tikva, Israel
- Laboratory of Neurovirology, IMRIC, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
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Shalchi Z, Bennett A, Hargroves D, Nash J. Diagnostic delay in a case of herpes simplex encephalitis. BMJ Case Rep 2009; 2009:bcr12.2008.1350. [PMID: 21686359 DOI: 10.1136/bcr.12.2008.1350] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
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.
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Affiliation(s)
- Zaid Shalchi
- William Harvey Hospital, Kennington Road, Willesborough, Ashford TN24 0LZ, UK
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Taylor SW, Lee DH, Jackson AC. Herpes simplex encephalitis presenting with exclusively frontal lobe involvement. J Neurovirol 2008; 13:477-81. [PMID: 17994434 DOI: 10.1080/13550280701491131] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The authors report a patient with herpes simplex encephalitis who presented with magnetic resonance imaging (MRI) lesions exclusively in the frontal lobes, including the bilateral anterior cingulate gyri. She is making a good recovery after therapy with intravenous acyclovir. A similar presentation with a fatal outcome was previously reported by Rose et al (Neurology 42: 1809-1812, 1992). MRI shows temporal lesions in most patients with herpes simplex encephalitis, whereas occasional patients have normal imaging. A high index of suspicion for the diagnosis of herpes simplex encephalitis should be maintained when a patient presents with fever and brain lesions involving extratemporal limbic system structures.
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Affiliation(s)
- Sean W Taylor
- Department of Medicine (Neurology), Queen's University, Kingston, Ontario, Canada
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