Human herpesvirus 1 meningoencephalitis after trigeminal neuralgia surgery

[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.

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.

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.

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.