What Is It?
Herpes encephalitis is a form of viral encephalitis
caused specifically by a herpes virus. The herpes virus directly infects brain tissue causing inflammation and injury. This cause of encephalitis is generally one of the more severe, and can lead to significant nervous system injury and even coma and death.
There are several types of herpes viruses in the herpes family of viruses. This family of viruses includes the herpes simplex viruses, varicella-zoster (which causes chicken pox and shingles), cytomegalovirus and Epstein-Barr virus (the most common cause of mononucleosis).
Herpes encephalitis is generally caused by the herpes simplex I virus. The herpes simplex viruses are generally separated into type I and II. Type I is very common and generally presents with oral blisters and cold sores. Type II most commonly causes genital sores and ulcers. Although rare, herpes simplex type 1 can occasionally move to the brain and cause encephalitis.
What Types of Symptoms Are Typical?
While the symptoms can vary from patient to patient, herpes encephalitis can cause sore throat, fever, headache, stiff neck, vomiting, drowsiness, hyperactivity and general weakness. As it progresses, more severe injury to the nervous system can occur and lead to personality changes, paralysis, hallucinations, seizures and even coma. In its more severe forms, it can lead to death if not treated or if resistant to treatment.
The herpes virus tends to localize to the temporal lobes of the brain and can cause hemorrhage there and very frequently results in seizures.
How Is The Diagnosis Typically Made?
As with other forms of viral encephalitis, neurological examination and many tests and studies may be required to diagnosis encephalitis caused by herpes simplex. While the disease can sometimes be diagnosed based solely on the symptoms and the radiological appearance of the brain inflammation, some patients will require special testing of the cerebrospinal fluid (through a lumbar puncture) or brain tissue (obtained by biopsy) to make the final diagnosis.
What Are Some Common Treatments?
Because this form of encephalitis can be quite severe and cause profound nervous system injury, most patients with suspected or diagnosed herpes encephalitis are hospitalized. However, it is one of the few forms of viral encephalitis for which there are medications which can be prescribed. Acyclovir and other drugs in its class (such as gancyclovir) are usually prescribed to attempt to limit the severity of the disease. Treatment with these drugs may decrease the symptoms somewhat and reduce the death rate. However, these drugs are not a cure-all and some patients may not respond well to the drugs or may suffer permanent neurological injury regardless.
Each patient should consult their own treating physicians about the most appropriate treatment options in their specific case.
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This site is not intended to offer medical advice. Every patient is different, and only your personal physician can help to counsel you about what is best for your situation. What we offer is general reference information about various disorders and treatments for your education.