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.

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.

Decompressive craniectomy for herpes simplex encephalitis complicated by frank intracerebral hemorrhage: a case report and review of the literature.

BACKGROUND: Herpes simplex encephalitis is the most common type of sporadic encephalitis worldwide. Frank intracerebral hemorrhage complicating the disease course in herpes simplex encephalitis patients is rare, especially cases where surgical decompression is necessary. Here, we report a previously healthy female with herpes simplex encephalitis who underwent surgical decompression due to temporal lobe hemorrhage. CASE PRESENTATION: A previously healthy 34-year-old Korean female presented with fever, myalgia and severe headache. Brain MRI showed a high T2 signal intensity change and diffuse swelling of the right temporal lobe. Polymerase chain reaction testing of the cerebrospinal fluid confirmed the presence of herpes simplex virus 1. The patient was admitted for close observation and intravenous acyclovir. On hospital day 3, she had a sudden onset of vomiting and severe headache. Brain CT showed frank temporal lobe hemorrhage. Despite aggressive medical treatment, she became increasingly drowsy. Ultimately, she underwent emergency right decompressive craniectomy, expansile duraplasty and intracranial pressure monitor insertion. The patient recovered fully without any neurological deficits or neuropsychological problems. She was discharged after completion of 2 weeks of acyclovir and returned 2 months later for cranioplasty. CONCLUSIONS: Patients with severe herpes simplex encephalitis complicated by intracerebral hemorrhage or malignant cerebral edema should undergo aggressive medical treatment. Surgical decompression should also be actively considered in these severe cases to prevent further neurological deterioration.

Decompressive craniectomy as salvage treatment in herpes simplex encephalitis: Two case reports.

Herpes simplex encephalitis is a rare disease with significant morbidity and mortality, although targeted therapy is widely available. This report presents two cases of herpes simplex encephalitis in previously healthy, young adults treated with acyclovir, who developed severe brain edema. Decompressive craniectomy prevented imminent brain herniation and a fatal outcome in both of these patients.

Multimodal management of severe herpes simplex virus encephalitis: A case report and literature review.

BACKGROUND: Herpes simplex encephalitis (HSE) is the most frequent sporadic encephalitis in the world. In severe cases of HSE, the pathology usually progresses with an increase in intracranial pressure secondary to cerebral edema and/or hemorrhagic necrosis. Currently no high-power studies exist regarding the management of severe HSE and most of the papers reported in the literature are case reports. Decompressive craniectomy, effective in some cases of pharmaco-resistant intracranial hypertension (ICH) resulting from other causes, may be suggested in severe HSE, with several good results reported in the literature. CASE DESCRIPTION: The case of a 26-year-old man with severe HSE and a subsequent ICH is reported. In dealing with an ICH rebellious to conservative treatment, it was decided to perform a right decompressive hemicraniectomy, associated with a right temporal polectomy. The postoperative evolution was satisfactory, with normal neuropsychological tests and a Glasgow Outcome Scale of 1. CONCLUSION: Although herpes simplex encephalitis is sometimes devastatingly complicated by intracranial hypertension, its management lacks consensus and reliable data in the literature remains scarce. Surgical as well as conservative treatment, used together in a multimodal approach, may hold the key to a greater control of intracranial pressure, thus resulting in a better outcome. In this multimodal management, the window of opportunity where surgery may be considered is small, and must be discussed further and more precisely in future articles.

Case of Primary Central Nervous System Lymphoma Arising at Site of Remote Herpes Encephalitis.

BACKGROUND: Primary central nervous system lymphoma (PCNSL) is a rare malignancy that usually arises in the context of severe immunosuppression but has incompletely understood etiology, limiting effective treatments. CASE DESCRIPTION: We present the case of an 81-year-old immunocompetent man who developed a PCNSL in the right temporal lobe, at the site of a remote episode of herpes simplex virus (HSV) encephalitis 8 years prior. There are numerous viruses with known oncogenic associations; however, to our knowledge, this is the first reported case of PCNSL with an antecedent HSV infection. CONCLUSIONS: We discuss this case in the context of our current understandings of the pathogenesis of HSV encephalitis and PCNSL and postulate mechanisms through which the 2 could be associated.

Epilepsy surgery for epileptic encephalopathy as a sequela of herpes simplex encephalitis: case report.

Herpes simplex virus (HSV) encephalitis can manifest with different clinical presentations, including acute monophasic illness and biphasic chronic granulomatous HSV encephalitis. Chronic encephalitis is much less common, and very rare late relapses are associated with intractable epilepsy and progressive neurological deficits with or without evidence of HSV in the cerebrospinal fluid. The authors report on an 8-year-old girl with a history of treated HSV-1 encephalitis when she was 13 months of age and focal epilepsy when she was 2 years old. Although free of clinical seizures, when she was 5, she experienced behavioral and academic dysfunction, which was later attributed to electrographic focal seizures and worsening electroencephalography (EEG) findings with electrical status epilepticus during slow-wave sleep (ESES). Following a right temporal lobectomy, chronic granulomatous encephalitis was diagnosed. The patient's clinical course improved with the resolution of seizures and EEG abnormalities.

Unusual Clinical Presentation and Role of Decompressive Craniectomy in Herpes Simplex Encephalitis.

Decompressive craniectomy in pediatric central nervous infections with refractory intracranial hypertension is less commonly practiced. We describe improved outcome of decompressive craniectomy in a 7-year-old boy with severe herpes simplex encephalitis and medically refractory intracranial hypertension, along with a brief review of the literature. Timely recognition of refractory intracranial hypertension and surgical decompression in children with herpes simplex encephalitis can be life-saving. Additionally, strokelike atypical presentations are being increasingly recognized in children with herpes simplex encephalitis and should not take one away from the underlying herpes simplex encephalitis.

A review of the combined medical and surgical management in patients with herpes simplex encephalitis.

BACKGROUND: Herpes simplex encephalitis (HSE) is a devastating and severe viral infection of the human central nervous system. This viral encephalitis is well known to cause severe cerebral edema and hemorrhagic necrosis with resultant increases in intracranial pressure (ICP). While medical management has been standardized in the treatment of this disease, the role of aggressive combined medical and surgical management including decompressive craniectomy and/or temporal lobectomy has not been fully evaluated. In addition, while barbiturate coma has been studied for treatment of status epilepticus associated with infectious encephalitis, its use for treatment of encephalitis associated intractable intracranial hypertension has not been fully reported. CASE DESCRIPTION: We report the case of a 22 year old female with severe herpetic encephalitis requiring aggressive ICP management utilizing all modalities (both medical and surgical) known to control ICP. She continues to have memory deficits but has made a good recovery with a Glasgow Outcome Scale score of 5. CONCLUSION: We provide evidence that aggressive combined medical and surgical therapy is warranted even in cases of severe HSE with transtentorial herniation, as there is evidence for the potential of good recovery. A detailed literature review of the medical and surgical management strategies in this disease is presented.

Modulation of neural stem/progenitor cell proliferation during experimental Herpes Simplex encephalitis is mediated by differential FGF-2 expression in the adult brain.

Neural stem cells (NSCs) respond to inflammatory cues induced during brain injury and are thought to be involved in recovery from brain damage. Little is known about NSC response during brain infections. The present study evaluated NSC proliferation during Herpes Simplex Virus-1 brain infection. Total numbers of nestin(+) NSCs increased significantly in infected brains at 6 days post infection (p.i.). However, by 15 days p.i. the nestin(+) population decreased significantly below levels observed in uninfected brains and remained depressed through 30 days p.i. This initial increase in NSC population occurred concurrently with increased brain cell proliferation, which peaked at 3 days p.i. On closer examination, we found that while actively proliferating Sox2(+) NSCs increased in number at 6 days p.i., proliferating DCX(+) neuroblasts contributed to the increased response at 3 days p.i. However, overall proliferation decreased steadily from 15 days p.i. to below control levels. To determine the mechanisms involved in altering NSC proliferation, neurotrophin and growth factor expression profiles were assessed. FGF-2 gene expression increased at 5 days p.i. and was robustly down-regulated at 15 days p.i. (>1000-fold), which was further confirmed by increased FGF-2 immunostaining around the lateral ventricles. Furthermore, supplementing infected animals with recombinant FGF-2, at 15 days p.i., significantly increased the number of proliferating brain cells. These findings demonstrate that the temporal changes in NSC proliferation are mediated through the regulation of FGF-2 and that the NSC niche may benefit from supplementation with FGF-2 during HSV-1 brain infection.

Craniectomía descompresiva en encefalitis herpética: caso clínico / Decompressive craniectomy in herpes simplex encephalitis. Clinical case

Introduction: The morbidity and mortality of herpes simplex encephalitis (HSE) have decreased with the use of acyclovir. However, some patients develop focal hemorrhagic necrosis and edema in the temporal lobe, with a subsequent elevation of intracranial pressure. Clinical cases: We report the clinical outcomes of two children with HSE who developed severe intracranial hypertension and impending uncal herniation refractory to profound sedation, osmotic agents and moderate hyperventilation. Decompressive craniectomy allowed an effective control of intracranial pressure and a favorable neurological outcome at discharge in both patients. Conclusions: Decompressive craniectomy could be considered as a rescue treatment strategy in patients with life-threatening intracranial hypertension due to severe herpetic encephalitis.

Introducción: La morbimortalidad de la encefalitis herpética ha disminuido con el uso de aciclovir. Sin embargo, algunos pacientes pueden evolucionar con necrosis focal hemorrágica y edema cerebral con posterior elevación de la presión intracraneal. Casos clínicos: Reportamos el curso clínico de dos niños con encefalitis herpética complicada con hipertensión intracraneal refractaria al tratamiento con sedación profunda, agentes osmóticos e hiperventilación. Ambos pacientes desarrollaron signos de enclavamiento uncal por lo que se realizó una craniectomía descompresiva precoz, que permitió un control de la presión intracraneal y una evolución neurológica favorable al alta. Conclusiones: La craniectomía descompresiva podría ser considerada como una alternativa terapéutica de rescate en pacientes con encefalitis herpética e hipertensión endocraneana refractaria a la terapia medica.

Decompressive craniectomy for encephalitis with brain herniation: case report and review of the literature.

BACKGROUND: Decompressive craniectomy (DC) has been sporadically used in cases of infectious encephalitis with brain herniation. Like for other indications of DC, evidence is lacking regarding the beneficial or detrimental effects for this pathology. METHODS: We reviewed all the cases of viral and bacterial encephalitis treated with decompressive craniectomy reported in the literature. We also present one case from our institution. These data were analyzed to determine the relation between clinical and epidemiological variables and outcome in surgically treated patients. RESULTS: Of 48 patients, 39 (81.25 %) had a favorable functional recovery and 9 (18.75 %) had a negative course. Only two patients (4 %) died after surgical treatment. A statistically significant association was found between diagnosis (viral and bacterial encephalitis) and outcome (GOS) in surgically treated patients. Viral encephalitis, usually caused by herpes simplex virus (HSV), has a more favorable outcome (92.3 % with GOS 4 or 5) than bacterial encephalitis (56.2 % with GOS 4 or 5). CONCLUSIONS: Based on this literature review, we consider that, due to the specific characteristics of infectious encephalitis, especially in case of viral infection, decompressive craniectomy is probably an effective treatment when brain stem compression threatens the course of the disease. In patients with viral encephalitis, better prognosis can be expected when surgical decompression is used than when only medical treatment is provided.

Early decompressive hemicraniectomy in fulminant herpes simplex encephalitis.

Herpes encephalitis can be a life-threatening condition, despite early instauration of acyclovir treatment. In particular patients may succumb to rapidly progressive cerebral oedema. We report a 66-year patient with a Glasgow Coma Score (GCS) of 6 and incipient uncus herniation of the right temporal lobe on the third day. Decompressive hemicraniectomy was immediately performed. The long-term outcome was satisfactory with unassisted gait and a Barthel Index score of 70 after 9 months.

Early decompressive hemicraniectomy in fulminant herpes simplex encephalitis.

Herpes encephalitis can be a life-threatening condition, despite early instauration of acyclovir treatment. In particular patients may succumb to rapidly progressive cerebral oedema. We report a 66-year patient with a Glasgow Coma Score (GCS) of 6 and incipient uncus herniation of the right temporal lobe on the third day. Decompressive hemicraniectomy was immediately performed. The long-term outcome was satisfactory with unassisted gait and a Barthel Index score of 70 after 9 months.

The surgical management of infections involving the cerebrum.

OBJECTIVE: Infection involving the cerebrum is a true neurosurgical emergency that requires rapid diagnosis and appropriate surgical and medical intervention to achieve good clinical outcome. METHODS: Because of the potential for devastating neurological sequelae, it is imperative that neurosurgeons be involved in the diagnosis and management of these serious conditions once an infection is suspected. With the advent of computed tomography and magnetic resonance imaging, it is now possible to detect an infectious process early in its course and follow the response to therapy. Although significantly more effective than in the past, antimicrobial therapy alone is insufficient to eradicate most intracranial infections, especially in the presence of compression or displacement of the cerebrum. Surgery remains an essential part of the management of intracranial infection because of its ability to provide immediate relief from pressure on neural structures and thereby result in clinical improvement. RESULTS: The most common infections affecting the brain, namely, cranial epidural abscess, subdural empyema, brain abscess, viral infection, tuberculosis, and neurocysticercosis, can each be associated with significant mass effect on the cerebrum that is greatly reduced through surgery. This relief, in combination with newer antimicrobial agents that have an improved ability to cross the blood brain barrier, has led to a reduction in the infection-related morbidity and mortality rates associated with intracranial infections. CONCLUSION: Combining advanced imaging and surgical techniques in the form of intraoperative magnetic resonance image-guided neurosurgery may further enhance clinical outcomes in these once uniformly fatal diseases.