Herpes simplex encephalitis and bilateral acute retinal necrosis syndrome after craniotomy

[Viral retinitis]

Viruses belonging to the herpes family group, including HSV (herpes simplex virus) 1 and 2, VZV (varicella zoster virus) and CMV (cytomegalovirus) are the leading causes of necrotizing retinitis. These viral retinal necroses generally manifest in three forms, depending on the patient's immune status: acute retinal necrosis (ARN), progressive outer retinal necrosis (PORN) and CMV retinitis. Although specific, effective drug treatments are available today, early treatment initiation is essential to avoid sight-threatening complications.

Understanding Herpes Simplex Virus Type 1 Versus Herpes Simplex Virus Type 2 Encephalitis After Neurosurgery: A Case Series and Literature Review

Abstract Background: Herpes simplex virus encephalitis (HSVE) is a rare post-operative infection that can be fatal if treatment is delayed. Herpes simplex virus type 1 (HSV-1) is a more common cause of encephalitis than herpes simplex virus type 2 (HSV-2), however, a significant overlap exists. The goal of this project was to understand the frequency and trend of HSVE after neurosurgery through a case series at our institution and in the literature with a focus on comparing HSV-1 versus HSV-2. Patients and Methods: A literature review of all published cases and case series of HSVE after neurosurgery was performed. Descriptive statistics comparing HSV-1 and HSV-2 encephalitis were computed. Data on demographics, symptoms, surgery, treatment, immunosuppression, imaging findings, steroids, and mortality were collected. Results: We identified 55 total cases of HSVE post-neurosurgery. These included 28 cases of HSV-1, 10 cases of HSV-2, and 17 cases of HSV-unspecified encephalitis. There were no differences in age, gender, symptoms, surgery, or latency between surgery and symptom onset between HSV-1 and HSV-2. Mortality was higher with HSV-1 versus HSV-2 although not statistically significant. The primary surgical indication varied substantially between HSV-1 and HSV-2. Conclusions: Herpes simplex virus encephalitis is often overlooked in the setting of encephalitis after surgery. A high index of suspicion is needed to prevent a delay in treatment.

[Reactivation of latent viruses in Neurology]

After establishing latent infection, some viruses can be reactivated by the alteration of host immunological conditions. First, we reviewed viruses that can cause neuronal damage by reactivation. Then we focused on the herpes simplex virus (HSV). The reactivation leads to neuronal damages through two possible mechanisms; "reactivation of a latent herpes virus" by which viruses can cause direct virus neurotoxicity, and "post-infectious immune inflammatory response" by which a focal reactivation of HSV leads to an inflammatory reaction. The former is radiologically characterized by cortical lesions, the latter is characterized by subcortical white matter lesions. We experienced a female, who underwent the right posterior quadrantectomy and then developed recurrent herpes encephalitis caused by herpes simplex reactivation, which pathologically demonstrated inflammation in the white matter, suggesting a post-infectious immune inflammatory response. The patient was successfully treated with immunosuppressants. The reactivation of the HSV is extremely rare in Japan. Neurologists should recognize this condition because this disorder will increase as epilepsy surgery gains more popularity.

Herpes simplex reactivation following neurosurgery: case report and review of the literature

Herpes simplex encephalitis is a common viral encephalitis associated with significant morbidity and mortality if not diagnosed and treated early. Neurosurgery may be an impetus for viral reactivation, either from direct nerve manipulation or high-dose steroids often administered during cases. The authors present the 40th known case of herpes simplex virus (HSV) encephalitis following neurosurgical intervention and review the previously reported cases. In their review, the authors observed positive HSV polymerase chain reaction (PCR), which had initially been negative in several cases. In cases in which there is high suspicion of HSV, it may be prudent to continue antiviral therapy and retest CSF for HSV PCR. Antiviral therapy significantly reduces mortality associated with HSV encephalitis.

HSV-1 encephalitis relapse after epilepsy surgery: a case report and review of the literature

Herpes simplex encephalitis relapses have been rarely reported, with only few cases occurring after neurosurgical interventions. A young man presented a late herpes simplex encephalitis relapse after left antero-mesial temporal resection for his refractory temporal lobe epilepsy. Eight days after surgery, he developed fever and aphasia. CSF PCR revealed more than 12,000 copies/ml of HSV-1 DNA. Intravenous acyclovir was immediately started with a complete recovery. Postoperative herpes simplex encephalitis can occur as primary infection or as relapse of previous infection. Surgical manipulation of brain parenchyma in the site of a previous infection can act as a trigger for viral reactivation. Early onset of antiviral therapy is fundamental and it is a strong predictor of clinical outcome. Despite no studies on prophylactic treatment with acyclovir in patients with previous herpes simplex encephalitis candidate to neurosurgery are available, we suggest that prophylactic treatment should be recommended.

Acute retinal necrosis in a patient with remote severe herpes simplex encephalitis

A 60-year-old man with a history of severe herpes simplex virus type 1 (HSV-1) encephalitis 2 years prior presented with acute onset of visual loss in the left eye. Dilated funduscopic examination showed retinitis and occlusive vasculitis with retinal necrosis. PCR of the vitreous fluid was positive for HSV-1, and he was diagnosed with acute retinal necrosis (ARN) due to HSV-1. The patient was treated with intravenous acyclovir and intravitreous foscarnet for 2 weeks, followed by high dose oral valacyclovir for 2 weeks. He was subsequently placed on planned life-long suppressive valacyclovir. His case demonstrates that acute visual loss concomitant with or subsequent to HSV-1 encephalitis warrants suspicion of ARN. Prompt therapy with effective antiviral medication is necessary to reduce the risk of sight-threatening complications. Chronic suppression with oral antiviral therapy after ARN is recommended to prevent involvement of the contralateral eye, though there is no consensus on the duration and dosage of antivirals.

Bilateral Acute Retinal Necrosis: Clinical Features and Outcomes in a Multicenter Study

Purpose: To describe clinical features and outcome in bilateral acute retinal necrosis (BARN). Methods: Observational retrospective longitudinal review of ocular findings. Results: Thirty eyes of 15 patients (age 44.1 ± 15.8). Delay of involvement between eyes was 57.2 ± 105.2 months (median 3, range 0.5-360). Herpes simplex virus (HSV)-1 was the most frequent (20 eyes, 66.6%), followed by HSV-2 (five eyes, 16.7%) and varicella zoster virus (VZV, four eyes, 13.3%). Visual acuity worsened in 7 (23%) eyes, improved in 4 (13%), and remained stable in 19 (63%). Major complications included retinal detachment (11 eyes, 36%), optic atrophy (11 eyes, 33%), proliferative vitreoretinopathy (four eyes, 13.3%), neovascular glaucoma (four eyes, 13.3%), phthisis bulbi (three eyes, 10%). Symptoms-to-referral average time was 2.7 ± 1.0 weeks (range 1-4). Conclusions: In our study BARN was associated with severe visual outcome and high rate of ocular complications. Although BARN is a rare disease, the course is aggressive, regardless prompt referral in tertiary-care uveitis centers.

Sequential retinal necrosis secondary to varicella zoster in unrecognised long-standing HIV infection: patient safety report

A retired woman with left ophthalmic shingles of over 2 years’ duration attended with bilateral vision loss and systemic upset. Acute retinal necrosis with detachment was detected on right fundus examination. Cataract in left eye precluded funduscopy. Ocular ultrasonography revealed fibrotic retinal detachment in the left eye. MRI brain and orbits also showed signals of retinal detachment. No abnormal MRI signal within the optic nerve or brain was found. Varicella zoster virus was detected in ocular aqueous and blood samples. High-dose intravenous acyclovir was administered. HIV test was positive with a very low CD4 count. Antiretroviral medications were prescribed. There was no recovery of vision. She was certified as blind, and social services were involved in seeking to provide alterations to her home in view of her severe disability. This case highlights the importance of suspecting HIV in patients with severe or chronic ophthalmic shingles. Images and implications for clinical practice are presented.

A Rare Case of Concurrent Herpes Simplex Encephalitis and Glioblastoma Multiforme

Herpes encephalitis superimposed on an intracranial malignancy has previously been described mainly in the context of malignancy imitating infection or in the postoperative setting after neurosurgical intervention. We report a rare case of de novo presentation of concurrent herpes encephalitis and glioblastoma. A 63-year-old man presented with status epilepticus and subsequent magnetic resonance imaging (MRI) brain showed a right temporal enhancing lesion with mass effect. He underwent a craniotomy and debulking of this lesion, which on subsequent histology was positive for herpes simplex virus (HSV) antigens and HSV DNA was confirmed by polymerase chain reaction analysis. The sample however also had some hypercellular areas with atypical astrocytes. Our patient recovered well from surgery and was eventually commenced on acyclovir albeit with a delay of 3 weeks due to the initial diagnostic dilemma. However, he re-presented with lethargy and confusion a further 3 weeks later and an MRI scan showed recurrence of the temporal lesion with MR spectroscopy more suggestive of high-grade glioma. He, therefore, underwent a further debulking surgery and the histology revealed a WHO Grade 4 glioblastoma with some residual areas of inflammation. A diagnosis of 2 co-existing pathologies namely HSV encephalitis and glioblastoma was thus reached. Unfortunately, due to poor performance status, he could not undergo chemo-radiotherapy and died 8 months after presentation. Immuno-modulators, expressed locally and globally in glioma patients, are likely to render them susceptible to infections. There are an increasing number of reports of HSV encephalitis in the glioma setting postoperatively. However, we report a de novo presentation which has only been recognized once before in the 1970s. Recognition of HSV encephalitis in glioma patients in the de novo and also the postoperative context is important for commencing early treatment and preventing poor outcomes.

Defining nervous system susceptibility during acute and latent herpes simplex virus-1 infection

Herpes simplex viruses are neurotropic human pathogens that infect and establish latency in peripheral sensory neurons of the host. Herpes Simplex Virus-1 (HSV-1) readily infects the facial mucosa that can result in the establishment of a latent infection in the sensory neurons of the trigeminal ganglia (TG). From latency, HSV-1 can reactivate and cause peripheral pathology following anterograde trafficking from sensory neurons. Under rare circumstances, HSV-1 can migrate into the central nervous system (CNS) and cause Herpes Simplex Encephalitis (HSE), a devastating disease of the CNS. It is unclear whether HSE is the result of viral reactivation within the TG, from direct primary infection of the olfactory mucosa, or from other infected CNS neurons. Areas of the brain that are susceptible to HSV-1 during acute infection are ill-defined. Furthermore, whether the CNS is a true reservoir of viral latency following clearance of virus during acute infection is unknown. In this context, this review will identify sites within the brain that are susceptible to acute infection and harbor latent virus. In addition, we will also address findings of HSV-1 lytic gene expression during latency and comment on the pathophysiological consequences HSV-1 infection may have on long-term neurologic performance in animal models and humans.

Herpes simplex encephalitis as a complication of neurosurgical procedures: report of 3 cases and review of the literature

BACKGROUND

Herpes simplex virus (HSV) is the most common identified cause of focal encephalitis worldwide. However, postoperative HSV encephalitis (HSVE) is a rare complication of neurosurgical procedures and a significant clinical challenge

METHOD

We describe 3 cases of postoperative HSVE and review all published reports. A total of 23 cases were identified.

DISCUSSION

Clinical heterogeneity represents a diagnostic challenge in the postoperative setting. Cerebral magnetic resonance imaging showed typical findings in a minority of patients only, whereas HSV-specific polymerase chain reaction on the cerebrospinal fluid proved to be a valuable test. The postoperative viral pathophysiology remains a subject of debate. The rate of adverse outcome is high and early antiviral treatment seems to be a strong predictor of clinical outcome.

CONCLUSION

We recommend early empirical treatment for any patient presenting with post-neurosurgical lymphocytic meningo-encephalitis, and prophylactic antiviral treatment for patients with a history of previous HSVE who will undergo a neurosurgical procedure.

Recurrent Herpes Simplex Virus Encephalitis After Neurologic Surgery

BACKGROUND

The herpes simplex virus (HSV) is the most common cause of sporadic encephalitis worldwide. Even with proper treatment, this infection is associated with a mortality rate of 19%-30% and with potential neurologic sequelae. Recurrences of encephalitis are rare and limited to a few cases in the literature. Although the mechanism of reactivation has not yet been clarified, in our patient, the surgery might have acted as a precipitating factor.

CASE DESCRIPTION

The case involved a female 10-year-old patient with a history of type 1 HSV encephalitis since 24 months of age. Secondarily, the patient developed postherpetic epilepsy in the following years. At 10 years old, she was referred to the epilepsy surgery service, and an elective right temporal lobectomy was performed. After surgery, the patient experienced severe clinical deterioration characterized by fever, severe headache, and altered state of consciousness. Encephalitis was diagnosed based on a positive polymerase chain reaction for HSV in the cerebrospinal fluid. The symptoms remitted after 8 weeks of treatment with acyclovir. The histopathologic diagnosis was a chronic encephalitic process with late secondary parenchymal changes without specific viral cytopathic findings. The only limitation that persisted was related to fine movements of the left hand. One year after surgery, the patient rejoined her school activities and is currently free of seizures.

CONCLUSIONS

HSV encephalitis is a rare but serious complication that should be suspected in cases of unexplained postoperative fever with altered consciousness, especially in patients with histories of encephalitic states.

Herpes Simplex Type 2 Encephalitis After Craniotomy: Case Report and Literature Review

BACKGROUND

Herpes simplex encephalitis (HSE) after neurosurgical procedures is extremely uncommon, and the few published case reports mainly described herpes simplex virus type 1 (HSV-1) as being culpable. We present a rare case of HSV-2 encephalitis after craniotomy and describe its pathophysiology and optimal management.

CASE DESCRIPTION

A 70-year-old woman underwent an elective resection of a recurrent left sphenoid wing meningioma and clipping of a left middle cerebral artery aneurysm, the latter having been found incidentally. She returned to our department with clinical findings suggestive of meningitis 12 days after the operation. Her lack of response to empiric antibiotic treatment, taken together with the lymphocyte-predominant initial cerebrospinal fluid obtained by lumbar puncture and the electroencephalographic indications of encephalopathy, led to the suspicion of a diagnosis of HSE, which was later confirmed by a polymerase chain reaction test positive for HSV-2. The patient was then successfully treated with intravenous acyclovir for 2 weeks followed by another week of oral acyclovir treatment before being discharged.

CONCLUSIONS

The present case stresses the importance of recognizing the relatively rare entity of HSE after craniotomy. Timely correct diagnosis will expedite the initiation of appropriate treatment.

Reactivation of herpes simplex virus-1 following epilepsy surgery

Purpose

The present study reports a case of encephalitis due to herpes simplex virus-1 (HSV-1), following surgical manipulation of the site of a primary infection.

Methods

Herpes simplex virus-1 infection was confirmed by CSF PCR and DNA sequencing.

Results

The patient was an 11-year-old girl who required temporal lobe surgery for epilepsy. She had meningoencephalitis due to HSV at the age of 20 months, and she was treated with acyclovir. Three years later, the patient developed uncontrolled seizures that became more frequent and changed in character at 11 years of age. On the 12th postoperative day, she developed fever and seizures, and she was diagnosed with HSV-1 by positive CSF PCR. She was treated with acyclovir (30 mg/kg/day for 21 days). In this report, we describe the patient and review the relevant literature.

Conclusion

The authors stress the potential risk of reactivation of HSV encephalitis after intracranial surgery. Herpes simplex virus encephalitis must be considered in neurosurgical patients who develop postoperative seizures and fever.

Herpes simplex reactivation or postinfectious inflammatory response after epilepsy surgery: Case report and review of the literature

Background:

Herpes simplex virus encephalitis (HSVE) is the most morbid clinical syndrome associated with the human herpes virus. Despite treatment with appropriate dosages of acyclovir, neurologic relapse of HSV infection have been reported after cranial surgery. Rarely, neurological deterioration due to postinfectious inflammatory response without demonstrable HSV reactivation may recur following cranial surgery.

Case Description:

We report a case of a 17-year-old girl who presented with a HSVE relapse on the 6^th postoperative day following resective surgery for medically refractory epilepsy and review the literature. Postinfectious inflammatory reaction may be the underlying mechanism in cases with no HSV identified on cerebrospinal fluid (CSF) or brain polymerase chain reaction (PCR), such as in the current case.

Conclusion:

HSVE must be suspected in patients with previous history of HSVE and postoperative fever associated with an altered state of consciousness and/or seizures. Considering the high mortality and morbidity rates associated with HSVE, an adequate prophylactic administration of acyclovir should be considered for patients with previous history of HSVE undergoing neurosurgical procedures, especially when surgery involves the site of a previous herpetic lesion.

Neonatal herpes simplex virus type-1 central nervous system disease with acute retinal necrosis

We report a case of neonatal herpes simplex virus (HSV)-1 central nervous system disease with bilateral acute retinal necrosis (ARN). An infant was presented at 17 days of age with focal seizures. Cerebrospinal fluid polymerase chain reaction was positive for HSV-1 and brain magnetic resonance imaging showed cerebritis. While receiving intravenous acyclovir therapy, the infant developed ARN with vitreous fluid polymerase chain reaction positive for HSV-1 necessitating intravitreal foscarnet therapy. This is the first reported neonatal ARN secondary to HSV-1 and the first ARN case presenting without external ocular or cutaneous signs. Our report highlights that infants with neonatal HSV central nervous system disease should undergo a thorough ophthalmological evaluation to facilitate prompt diagnosis and immediate treatment of this rapidly progressive sight-threatening disease.

Nosocomial Herpes Encephalitis: rare but treatable with early MR diagnosis

Nosocomial/hospital acquired herpes encephalitis is rare and is usually undiagnosed in its early phase because of the non-specific clinical picture and low level of clinical and neuroimaging suspicion. There is a paucity of data in radiology literature for this entity, specifically in the settings of surgery and trauma. We describe two cases of nosocomial herpes simplex encephalitis to demonstrate the imaging clues that might lead to an early diagnosis of this disease.

An unusual case of herpes simplex viral encephalitis following acute retinal necrosis after administration of a systemic steroid

Acute retinal necrosis (ARN), a viral retinal disease with poor visual prognosis, following herpes simplex encephalitis (HSE) are uncommonly seen, and there has been no case yet reported of the reverse situation. We herein present the reverse situation, an immune-competent patient with HSE following ARN. A 57-year-old man who had been under steroid therapy for retinal vasculitis the prior two weeks, presented with abrupt confusion and high fever. His cerebrospinal fluid study and brain magnetic resonance imaging revealed typical HSE. Ophthalmic examination and polymerase chain reaction of the vitreous specimen revealed ARN by herpes simplex virus type 2. Intravenous acyclovir treatment improved his encephalitis symptoms and retinal necrosis. This case implies that ARN may be a risk factor for HSE and the virus may reach the brain from the eye. Inappropriate administration of a systemic steroid may exacerbate herpes viral infection in the retina, with subsequent spread to the brain.

Acute Retinal Necrosis after Herpetic Encephalitis

PURPOSE: To report a case of unilateral acute retinal necrosis after herpetic encephalitis CASE REPORT: A young man was referred with a chief complaint of blurred vision and pain of the left eye 1 month after herpetic encephalitis in the left frontotemporal lobe. The patient had multiple foci of retinitis in the retinal periphery associated with vitritis, blot retinal hemorrhage and retinal arteriolitis. The impression of acute retinal necrosis was confirmed by polymerase chain reaction of aqueous humor by detecting herpes simplex virus type 2; therefore, the patient received intravenous acyclovir. CONCLUSION: Herpetic encephalitis may be a risk factor for acute retinal necrosis. The virus may reach the eye by the trans-axonal route. Prophylaxis with acyclovir may be necessary after herpetic encephalitis to prevent acute retinal necrosis.

Unilateral Acute Retinal Necrosis 2 Months After Herpes Simplex Encephalitis

A case with unilateral acute retinal necrosis (ARN) following herpes simplex virus (HSV) encephalitis was reported. A 40-year-old man presented with unilateral visual loss. He had a history of HSV encephalitis 2 months previously, and had been successfully treated with intravenously acyclovir. The ophthalmologic examination in his left eye suggested ARN syndrome. The best-corrected visual acuity was 20/222. Magnetic resonance imaging (MRI) showed high density signals from the optic chiasm to optic disc. The patient underwent encircling scleral buckling, lensectomy, and vitrectomy with endolaser photocoagulation and silicone oil tamponade. Postoperatively, the high density signals on MRI decreased, the retina maintained attached, and the visual acuity at the final visit improved to 20/20. Unilateral ARN can develop after HSV encephalitis. Acyclovir should be administered over the long term to control the virus.

Herpes simplex encephalitis after craniopharyngioma surgery

A 13-year-old girl exhibited rapid deterioration in mental status 15 days after surgery for craniopharyngioma. Serial CT scanning detected progression of a low-density lesion on the left frontotemporal lobe. The serum level of C-reactive protein was elevated and polymerase chain reaction identified herpes simplex virus DNA in the cerebrospinal fluid. Antiviral therapy with high-dose acyclovir (10 mg/kg 3 times daily) was begun. She recovered and could speak short sentences, but dysphasia and right hemiparesis remained. Early diagnosis and active treatment of herpes simplex encephalitis is essential for improving prognosis and saving lives.

Optic chiasm involvement secondary to herpetic encephalitis. A case report

Herpes simplex (HSV) encephalitis is one of the most common central nervous system (CNS) viral infections in adults. Early diagnosis is essential for treatment. We describe the case of a 70-year-old man who reported sudden bilateral reduction of visus. Four days after admission the patient showed high fever, followed the next day by a generalised convulsive crisis and coma. A first magnetic resonance imaging (MRI) showed no alterations, whereas the second showed the usual patterns of HSV encephalitis. With a clinical suspicion of herpetic encephalitis an intravenous therapy with acyclovir was established. The diagnosis of herpetic encephalitis was confirmed by cerebrospinal fluid (CSF) detection of herpes simplex DNA sequences. A further ten days later we performed a third MRI, demonstrating the typical pattern of HSV encephalitis and an increase in size and signal of the optic chiasm.

A mutant deleted for most of the herpes simplex virus type 1 (HSV-1) UOL gene does not affect the spontaneous reactivation phenotype in rabbits

The mechanisms involved in the herpes simplex virus type 1 (HSV-1) latency-reactivation cycle are not fully understood. The latency-associated transcript (LAT) is the only HSV-1 RNA abundantly detected during neuronal latency. LAT plays a significant role in latency because LAT(-) mutants have a reduced reactivation phenotype. Several novel viral transcripts have been identified within the LAT locus, including UOL, which is located just upstream of LAT. The authors report here on a mutant, DeltaUOL, which has a 437-nucleotide deletion that deletes most of UOL. DeltaUOL replicated similarly to its wild-type parental McKrae HSV-1 strain in infected cells, the eyes, trigeminal ganglia, and brains of mice and rabbits. It was indistinguishable from wild-type virus as regards explant-induced reactivation in mice, and spontaneous reactivation in rabbits. In contrast, DeltaUOL was significantly less virulent in mice. Thus, UOL appears to be dispensable for the wild-type reactivation phenotype while appearing to play a role in neurovirulence in ocularly infected animals.

Varicella zoster virus acute retinal necrosis following eye contusion: case report

BACKGROUND

Acute retinal necrosis is a sight-threatening disease caused by the group of herpesviruses. The aim of this paper is to report a case of acute retinal necrosis following ocular trauma in a patient initially treated with vaso-active drugs and corticosteroids for presumed ocular ischemic syndrome.

CASE PRESENTATION

A 51-years-old otherwise healthy man, who suffered from sudden visual loss in the left eye following contusion, was commenced on vaso-active drugs and systemic corticosteroids for suspected ocular ischemic syndrome with extensive swelling of the optic disc and macular edema. Subsequently, vision in the initially uninvolved right eye decreased. Polymerase chain reaction of vitreous samples and retinal biopsy confirmed varicella zoster virus. Despite intensive treatment with intravenous antiviral medication, the patient became completely blind in both eyes.

CONCLUSION

Initial treatment of acute, unexplained visual decrease with systemic corticosteroids may lead to visual loss in patients with developing acute retinal necrosis. Ocular trauma could have induced and corticosteroid treatment promoted reactivation of a latent viral infection in our patient.

Identification of a protein encoded in the herpes simplex virus type 1 latency associated transcript promoter region

Herpes simplex virus type 1 (HSV-1) establishes a lifelong latency in the neurons of its host. Sporadically, the latent virus reactivates and spreads back to the original site of infection and causes recrudescent diseases. The only gene actively transcribed during neuronal latency is the latency associated transcript (LAT) gene. Several transcripts have been detected in the important LAT promoter region. However, no polypeptides coded by these transcripts are known. In this communication, we reported the cloning, sequencing, and characterization of a transcript immediately upstream of LAT. We designated this gene UOL (Upstream of LAT). The UOL RNA is polyadenylated, expressed as a late gene in infected cells, transcribed in the same direction as LAT, and contains an open reading frame (ORF) capable of encoding a protein of 96 amino acids with a predicted molecular mass of 11 kDa. The UOL transcript contains 466 nucleotides in length. The 5' end of the UOL transcript starts at nucleotide 118,266 and the 3' end of the UOL transcript ends at nucleotide 118,731 based on the published 17syn+ genomic sequence. The UOL protein was detected in infected cell lysates by immunoprecipitation using an antibody raised against UOL ORF synthetic peptide. More importantly, sera from mice infected with wild-type HSV-1 but not sera from mice infected with a mutant with the UOL region deleted recognized the UOL ORF, expressed in Escherichia coli, on Western blots. These results suggest that a UOL protein is in HSV-1 infected tissue culture cells and in mice infected with HSV-1.

Nécrose rétinienne aiguë bilatérale associée à une méningo-encéphalite à Herpes simplex virus 2

INTRODUCTION

Acute retinal necrosis syndrome (ARN syndrome) is a rare viral disease with a poor prognosis in most cases. It is characterized by substantial ocular inflammation with progressive retinal necrosis, occlusive vasculitis and sometimes extraocular features.

CASE REPORT

We report the case of a 62-year-old woman who was referred for a suspicion of a stroke. Ophthalmological examination revealed a profound bilateral visual loss due to extensive retinal necrosis. The patient was immediately treated with antiherpetic drugs. ARN syndrome with meningoencephalitis caused by herpes simplex virus type 2 was confirmed by PCR studies performed on aqueous humor and cerebrospinal fluid. Herpes simplex virus 2 (IgG+ , IgM-) was probably reactivated after intrathecal injection of steroids because of pain associated with narrowing of the lumbar vertebral canal. The patient was treated with intravenous Acyclovir for 3 weeks. After 4 months, both retinas were detached.

DISCUSSION AND CONCLUSION

ARN syndrome caused by herpes simplex virus 2 most often occurs after reactivation of the latent virus in patients with a neurological medical history or congenital infection. Antiviral treatment must begin early to decrease risks of bilateralization and complications.

Postoperative herpes simplex virus encephalitis after neurosurgery: case report and review of the literature

Herpes simplex virus encephalitis is an unusual diagnosis for postoperative sepsis that occurs after a neurosurgical procedure. We describe a patient for whom early diagnosis and aggressive medical and surgical treatment resulted in a good outcome.

Polymerase chain reaction as a rapid diagnostic tool for therapy of acute retinal necrosis syndrome

Herpesviruses are involved in the pathogenesis of acute retinal necrosis syndrome (ARN). A rapid and accurate diagnosis of herpetic infections is crucial for prompt administration of a specific antiviral therapy. The purpose of this study was to evaluate a polymerase chain reaction (PCR)-based assay to detect herpesvirus DNA in the aqueous humor of clinical samples from ten patients with uveitis and clinical suspicion of ARN. Samples were assayed for herpes simplex virus type 1-2 (HSV 1-2), varicella zoster virus (VZV) and cytomegalovirus (CMV). Clinical suspicion of ARN was confirmed for four patients. Two patients (one with bilateral ARN) tested PCR-positive for VZV DNA and the other two were positive for HSV 1-2 DNA. CMV DNA was not detected in any of the samples, and no sample was positive for DNA from more than one virus. The remaining patients did not show any evidence of herpesvirus DNA in their aqueous samples. Our findings demonstrate that the use of PCR for detecting herpesvirus DNA in aqueous humor of uveitic subjects may be a valuable tool for early diagnosis of acute retinal necrosis syndrome and for timely administration of a suitable therapy.

Herpes simplex virus type 1 encephalitis associated with acute retinal necrosis syndrome in an immunocompetent patient

PURPOSE

The onset of acute retinal necrosis secondary to herpes simplex encephalitis is exceptional. We report such an association in an immunocompetent patient, in whom the genome of herpes simplex virus type 1 (HSV-1) was identified successively at both sites of infection.

METHODS

Polymerase chain reaction (PCR) assay of HSV-1 in cerebrospinal fluid (CSF) and aqueous humour.

RESULTS

An immunocompetent patient aged 40 years presented with HSV-1 encephalitis, which was confirmed by imaging, viral serology and identification of the HSV-1 genome in the CSF. The subject's immunological profile was normal. The patient was treated with foscavir. Six weeks after clinical recovery and negative PCR, the patient presented with a unilateral acute retinal necrosis syndrome. Polymerase chain reaction of the aqueous humour was positive, while serology and PCR of the CSF remained negative.

CONCLUSION

Identification of the HSV-1 genome at the two successive sites of infection stresses the possibility of brain-to-eye transmission of HSV-1.

Infectious morbidity in critically ill patients with cancer

Infection frequently complicates the course of cancer treatment and often adversely affects the outcome. Patients have a greater tendency for acquiring infections caused by opportunistic microorganisms. Agents with low virulence potential may lead to invasive and often life-threatening infections because of altered host immune function. The immune dysfunction may be caused by the underlying malignancy, by antineoplastic chemotherapy, or by invasive procedures during supportive care.

Herpes simplex virus type 2 as a cause of acute retinal necrosis syndrome in young patients

PURPOSE

To determine the causative virus in acute retinal necrosis (ARN) syndrome in a series of patients by calculation of modified Witmer coefficients.

DESIGN

Noncomparative case series.

PARTICIPANTS

Ten patients with ARN syndrome from four medical centers.

METHODS

Aqueous samples, vitreous samples, or both were collected prospectively during surgery from patients with a clinical diagnosis of ARN syndrome. Serologic measures of intraocular and serum antibodies to potentially causative viruses were measured by enzyme-linked immunosorbent assay.

MAIN OUTCOME MEASURES

Modified Witmer coefficients (immunoglobulin G and immunoglobulin A) for herpes simplex virus types 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV), and cytomegalovirus (CMV), as well as adenovirus type 2, were calculated from aqueous or vitreous samples, or both.

RESULTS

Intraocular antibody measurements were strongly suggestive of a single diagnosis in 9 of 10 patients tested. Modified Witmer coefficients demonstrated intraocular antibody production to HSV in five patients and antibodies to VZV in four patients, and the measurement was inconclusive in one patient. No patients were positive for adenovirus or CMV. Strain-specific antibody titers demonstrated that all HSV-positive patients were reactive only to HSV-2. Herpes simplex virus type 2 was found predominantly in younger patients with ARN syndrome (mean age, 21.2 +/- 10 years; range, 17-39 years), whereas VZV was more commonly seen in older patients (mean age, 40.8 +/- 12.2 years; range, 29-58 years; P = 0.033). Immunoglobulin A testing confirmed immunoglobulin G testing in all patients examined.

CONCLUSIONS

Although VZV is thought to be the most common cause of ARN syndrome, HSV-2 is an important cause of ARN syndrome, particularly in younger patients. Because infection with HSV-2 has important medical ramifications, these results suggest that determination of a causal agent should be considered in some cases of ARN syndrome.

Viral causes of the acute retinal necrosis syndrome

PURPOSE

The primary goal of this study was to determine the viral cause of the acute retinal necrosis syndrome in 28 patients (30 eyes). A secondary goal was to investigate possible associations between viral cause and patient age, and viral cause and central nervous system disease.

METHODS

A retrospective case series in which we reviewed the laboratory results and clinical histories of 28 patients (30 eyes) diagnosed with acute retinal necrosis syndrome, from whom vitreous or aqueous specimens were received, for diagnostic evaluation using previously described polymerase chain reaction-based assays.

RESULTS

Varicella-zoster virus, herpes simplex virus, and cytomegalovirus (CMV) DNA were detected in aqueous and/or vitreous specimens from 27 of 28 patients (29 of 30 eyes with a clinical history of acute retinal necrosis syndrome). No sample was positive for DNA from more than one virus. Varicella-zoster virus DNA was detected in 13 patients (15 eyes). Median age was 57 years. Herpes simplex virus type 1 DNA was detected in seven patients (seven eyes). Median age was 47 years. Six of these patients had a history of herpes simplex virus encephalitis. Herpes simplex virus type 2 DNA was detected in six patients (six eyes). Median age was 20 years. Three of these patients had a likely history of meningitis. Cytomegalovirus DNA was detected in one patient who was immunosuppressed iatrogenically. No viral DNA was detected in one patient from whom a sample was taken after 6 weeks of acyclovir therapy.

CONCLUSIONS

The data suggest that varicella-zoster virus or herpes simplex virus type 1 cause acute retinal necrosis syndrome in patients older than 25 years, whereas herpes simplex virus type 2 causes acute retinal necrosis in patients younger than 25 years. A history of central nervous system infection in a patient with acute retinal necrosis syndrome suggests that herpes simplex virus is likely to be the viral cause.