Recurrent Herpes Simplex Virus Encephalitis After Neurologic Surgery

Surgical Management in Herpes Simplex Encephalitis: Illustrative Case Report and Systematic Review of the Literature

BACKGROUND

Herpes simplex virus (HSV) is a common cause of viral encephalitis and can result in refractory seizures. Although HSV encephalitis (HSVE) is treated primarily with acyclovir, surgery can play a role in medically intractable cases.

OBJECTIVE

To systematically review cases describing surgery for the treatment of severe HSVE. We also present an illustrative case of anterior temporal lobectomy (ATL) for refractory status epilepticus in a patient with unilateral HSVE. This case demonstrates one clinical context in which surgery can be a useful adjunct.

METHODS

We performed a systematic review using PubMed and Google Scholar, including case reports and series describing surgical interventions for HSVE. Clinical data were extracted from 54 publications that incorporated 67 patient cases.

RESULTS

Surgical decompression occurred at a wide range of times after the onset of illness, although most patients were operated on 4 or more days after HSVE symptoms began. Numerous reports indicated that decompressive craniectomy, temporal lobectomy, and hematoma removal could treat intractably elevated intracranial pressure because of HSVE with favorable long-term outcomes. We describe an additional case in which a 52-year-old woman with HSVE developed refractory right temporal lobe seizures. After ATL, the seizures resolved with significant clinical improvement.

CONCLUSION

Surgical treatment can be a useful adjunct for treatment of HSVE. There is substantial variability in the timing of surgical decompression in patients with HSVE, which can be necessary up to approximately 3 weeks after illness onset. ATL should be considered for refractory status epilepticus in HSVE with a unilateral seizure focus.

[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.

Relapse of Herpes Simplex Encephalitis by Epilepsy Surgery 35 Years after the First Infection: A Case Report and Literature Review

Late relapse of herpes simplex encephalitis (HSE) is defined as the recurrence of HSE more than 3 months after the initial exposure. The postoperative diagnosis of HSE following neurosurgery is complicated because the clinical presentation can mimic other common complications of neurosurgery. Cerebrospinal fluid polymerase chain reactions (CSF-PCR) is the gold standard for the diagnosis of HSE. We describe a case of late HSE relapse after epilepsy surgery in a patient who required a brain biopsy due to repeated negative CSF-PCR results. A 38-year-old woman had a history of HSE from the age of 3 years. She had intractable epilepsy from the age of 20 years and underwent right posterior quadrant disconnection (PQD) at the age of 38 years. Postoperatively, she had a right hemispheric intracerebral hemorrhage (ICH) and her consciousness was gradually worsening. Her consciousness improved after removal of the ICH. However, her consciousness gradually deteriorated again. Fluid-attenuated inversion recovery (FLAIR) revealed bilateral hyperintensity in the frontal lobes, including the white matter. CSF-PCR for herpes simplex virus (HSV) was performed twice, but yielded negative results. We performed a brain biopsy to target FLAIR hyperintensity in the right frontal lobe. PCR of the brain specimen was positive for HSV. Her consciousness improved with acyclovir, methylprednisolone, and cyclophosphamide. To our knowledge, this is a case of HSE induced by epilepsy surgery which had the longest duration until relapse after the initial HSE episode. A brain biopsy can be used to confirm the diagnosis of suspected HSE when CSF-PCR results are negative.

Herpes simplex meningitis after vestibular schwannoma surgery: illustrative case

BACKGROUND

Herpes is the most common cause of viral encephalitis in the young population. Herpes meningitis following brain surgery is very rare, however. Only a few cases are reported in the literature, and only one concerned an infection after vestibular schwannoma surgery.

OBSERVATIONS

The authors report a case of a 44-year-old patient who developed severe herpes meningitis a few days after removal of a large cystic vestibular schwannoma.

LESSONS

Herpes simplex virus meningitis following a posterior fossa surgery must be considered when patients develop atypical symptoms a few days after surgery.

Management and results of epilepsy surgery associated with acyclovir prophylaxis in four pediatric patients with drug-resistant epilepsy due to herpetic encephalitis and review of the literature

PURPOSE

Herpes simplex virus encephalitis (HSE) is the most common cause of sporadic viral encephalitis in children and is responsible for epilepsy in approximately half of patients. In addition to medical treatment, epilepsy surgery may be offered to drug-resistant patients but carries a high risk of relapse of herpetic encephalitis. We are reporting our series of patients operated on between 2000 and 2019 with the systematic administration of acyclovir (ACV).

RESULTS

Four pediatric patients aged 4.5-12.8 years with drug-resistant epilepsy post-HSE underwent a tailored focal resection following invasive recordings (three patients) and a complete callosotomy (one patient). The total number of the surgical procedures for the four patients was eight, and a systematic administration of ACV as a prophylactic treatment of herpetic encephalitis relapse was done at each step. No patients had a relapse and the ACV was well-tolerated in all the cases. Following surgery two patients are seizure free, the patient who underwent callosotomy is Engel 3 and the fourth patient, in whom a large epileptic zone has contraindicated a second surgery, is Engel 4.

CONCLUSIONS

Our series demonstrated the dramatic efficacy of systematic ACV prophylaxis during all cranial surgeries. Moreover, our results on epilepsy, together with those of the literature, encourage more consideration regarding epilepsy surgery in this specific etiology. All types of surgical procedures (curative or palliative) can be offered to the patients, but in the case of focal surgery, due to the poor anatomical limits, invasive recordings are highly recommended.

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.

Meningoencefalitis por herpes simple: una visión de la infección viral que causa el mayor compromiso cerebral

La inflamación del sistema nervioso central secundaria a la infección por la familia herpesviridae puede generar un compromiso difuso del parénquima encefálico, la cual puede ser fatal en ausencia de un rápido diagnóstico y tratamiento. Objetivo: revisar las diferentes características biológicas, fisiopatológicas, clínicas, terapéuticas y pronóstico de la meningoencefalitis causada por VHS-1 y 2. Materiales y métodos: revisión de la literatura científica (revisión crítica), llevada a cabo mediante las bases de datos Medline y buscadores específicos IMBIOMED, PUBMEDE, SCIENCEDIRECT, SCIELO, con un total de 150 artículos, se priorizaron 67 los cuales fueron leídos a profundidad. Resultados y discusión: debido el neurotropismo del herpes virus simple puede causar neuroinvasividad, neurotoxicidad y latencia en el SNC. Por sus características semiológicas inespecíficas se requiere un estudio exhaustivo para lograr el diagnóstico acertado. Los métodos actuales tales como neuroimágenes y PCR han aportado al esclarecimiento del diagnóstico etiológico de esta patología. La detección temprana de la entidad y la instauración precoz del tratamiento, se asocian con un aumento en la tasa de supervivencia y a una disminución de las secuelas neurológicas. Conclusión: conocer la biología del virus, su comportamiento, las características clínicas y el tratamiento de la entidad es una estrategia eficaz para disminuir secuelas y desenlaces fatales.

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.

HSV-Encephalitis Reactivation after Cervical Spine Surgery

Background

Herpes simplex virus encephalitis (HSVE) is a viral neurological disorder that occurs when the herpes simplex virus (HSV) enters the brain. The disorder is characterized by the inflammation of the brain and a significant decline in mental status. HSVE reactivation after neurosurgery, although rare, can cause severe neurological deterioration. The high morbidity rate among untreated patients necessitates prompt diagnosis and management.

Case Description

We report a case of a 78-year-old woman with no known prior history of HSVE and declining mental status eleven days after a posterior C3-T1 decompression and instrumented fusion following resection of an intradural extramedullary tumor, confirmed to be meningioma on final pathology. Reactivation of HSV-1 encephalitis was suspected to be the underlying cause of her symptoms, though MRI scans of the brain for HSVE were negative. The patient reacted positively to a 21-day treatment of acyclovir and was discharged with a neurological status comparable to her preoperative baseline. This case contributes to the literature in that it is the first reported instance of HSVE reactivation after intradural cervical spinal surgery with negative MRI findings.

Conclusion

We recommend utilizing multiple tests, including PCR, EEG, and MRI, for postoperative neurosurgery patients that have decreased mental status in order to quickly and correctly diagnose/treat patients who are HSVE positive. Clinicians should consider the possibility of receiving false-negative results from PCR, CSF, EEG, or MRI tests before terminating treatment for HSVE reactivation.

Corroboration of a Major Role for Herpes Simplex Virus Type 1 in Alzheimer's Disease

Strong evidence has emerged recently for the concept that herpes simplex virus type 1 (HSV1) is a major risk for Alzheimer’s disease (AD). This concept proposes that latent HSV1 in brain of carriers of the type 4 allele of the apolipoprotein E gene (APOE-ε4) is reactivated intermittently by events such as immunosuppression, peripheral infection, and inflammation, the consequent damage accumulating, and culminating eventually in the development of AD. Population data to investigate this epidemiologically, e.g., to find if subjects treated with antivirals might be protected from developing dementia—are available in Taiwan, from the National Health Insurance Research Database, in which 99.9% of the population has been enrolled. This is being extensively mined for information on microbial infections and disease. Three publications have now appeared describing data on the development of senile dementia (SD), and the treatment of those with marked overt signs of disease caused by varicella zoster virus (VZV), or by HSV. The striking results show that the risk of SD is much greater in those who are HSV-seropositive than in seronegative subjects, and that antiviral treatment causes a dramatic decrease in number of subjects who later develop SD. It should be stressed that these results apply only to those with severe cases of HSV1 or VZV infection, but when considered with the over 150 publications that strongly support an HSV1 role in AD, they greatly justify usage of antiherpes antivirals to treat AD. Three other studies are described which directly relate to HSV1 and AD: they deal respectively with lysosomal changes in HSV1-infected cell cultures, with evidence for a role of human herpes virus type 6 and 7 (HHV6 and HHV7) in AD, and viral effects on host gene expression, and with the antiviral characteristics of beta amyloid (Aβ). Three indirectly relevant studies deal respectively with schizophrenia, relating to antiviral treatment to target HSV1, with the likelihood that HSV1 is a cause of fibromyalgia (FM), and with FM being associated with later development of SD. Studies on the link between epilepsy, AD and herpes simplex encephalitis (HSE) are described also, as are the possible roles of APOE-ε4, HHV6 and HSV1 in epilepsy.

Approach to recurrent Herpes Simplex Encephalitis in children

Herpes Simplex Encephalitis (HSE) is one of the commonest viral encephalitis and its recurrence is being increasingly reported were HSE relapse rate came up to 5%. Both herpes simplex virus (HSV) types can lead to encephalitis and it was established that HSV-1 is capable of nervous system invasion, latency, and recurrence. The recurrence of HSE used to be attributed to immunological compromise, but reports show many cases have no obvious immune system impairment. Further investigations revealed genetic predispositions to HSV infection that would explain the host vulnerability to its recurrence. In this review, we discuss the gene mutations that may predispose to recurrent HSE and the importance of early diagnosis and treatment.

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.