Dexamethasone in Herpes Simplex Virus Encephalitis

Dexamethasone in Herpes Simplex Virus Encephalitis Open Label Randomized Controlled Trial With an Observer-blinded Evaluation at 6 Months

Encephalitics is a serious condition in which the brain becomes inflamed (swollen). It usually happens as a direct result of virus, such as herpes simplex virus (HSV).

HSV encephalitis is often treated with the drug acyclovir (an antiviral drug which slows the growth and spread of HSV in the body). Despite this however, around 2 out of every 3 people will have memory difficulties long term. Dexamethasone is a corticosteroid medication, which works by preventing the release of natural chemicals in the body which cause inflammation. It is possible that dexamethasone could help to reduce in swelling of the brain may improve the recovery of patients with HSV encephalitis. The aim of this study is to find out whether treatment with dexamethasone can improve long-term health outcomes in adults with HSV Encephalitis.

Inclusion Criteria:

- Suspected encephalitis criteria: Acute or subacute (up to 4 weeks) alteration in consciousness, cognition, personality or behaviour* persisting for > 24 hours Laboratory confirmed HSV by positive PCR on CSF sample.

• Receiving intravenous aciclovir dosed at 10mg/kg TDS or at a reduced dose in renal impairment
• Age ≥ 18 years
• Person affiliated to social security
• Written informed consent has been given by the patient or their legal representative

Exclusion Criteria:

• Currently receiving oral or injectable corticosteroid therapy; including treatment with oral or injectable corticosteroids in the last 30 days.

• History of hypersensitivity to corticosteroids

• Immunosuppression secondary to:

  • Known HIV infection & CD4 count under 200cell/mm3
  • Biologic therapy or other immunosuppressive agents [azathioprine, methotrexate, ciclosporin]
  • Solid organ transplant on immunosuppression
  • Bone marrow transplant
  • Currently undergoing a course of chemotherapy or radiotherapy
  • Known immunodeficiency syndrome [other than HIV]
  • Known haematological malignancy

• Pre-existing indwelling ventricular devices

• Peptic ulcer disease in the last 6 months: defined as a peptic ulcer seen at previous endoscopy or an upper gastrointestinal bleed causing ≥ 2 unit haemoglobin drop

• Currently on an antiretroviral regime containing rilpivirine

• Patients under legal protection, administrative or judicial control

• Pregnancy / Breast feeding and parturient

• Subject in exclusion period of another study