Herpetic encephalitis is caused by the same Herpes simplex virus that causes cold on the lips and genitals. Herpetic encephalitis has a high mortality and persistent neurological sequelae are observed in survivors. Find out what the symptoms of herpetic encephalitis are and how they are treated. When can cold sores end in encephalitis?
Herpetic encephalitis(HSE) is caused by the herpes simplex virus - HSV (herpes simlex virus or HHV - human herpes virus). The most common fault is HSV-1, the virus that causes cold sores. The virus responsible for genital herpes, HSV-2, is responsible for only 10 percent of cases.
It should also be emphasized that HSV-2 usually causes mild viral infections of the CNS - lymphocytic meningitis, inflammation of the spinal cord or inflammation of the nerve roots.
HSV-1 and HSV-2 are members of theHerpetiviridaefamily, which also includes:
- cytomegalovirus (CMV, cytomegalovirus)
- herpes zoster (VZV, Varicella-zoster virus)
- mononucleoses (EBV, Epstein-Barr virus)
- human herpes virus type 6 and type 7 (HHV-6, HHV-7, human herpes virus)
- simian herpesvirus type B (HBLV, human B-lymphotropic herpesvirus)
Herpetic encephalitisis relatively rare , butis associated with high mortality(with proper treatment, it reaches 30 percent, while in the case of untreated patients as much as 70 percent) and with numerous complications. The highest incidence of herpetic encephalitis among adults is between the ages of 60 and 64.
Prognosis depends on early diagnosis, initiation of antiviral therapy, and proper medical care. It is estimated that in Poland 150-200 people suffer from herpetic encephalitis every year, half of them die because of late diagnosis of the disease.
Herpetic encephalitis is most often caused byreactivation of the virusalready present in the body (this is called secondary infection) in a situation of a significant decrease in immunity. Immunocompromised people (e.g. transplant patients, AIDS patients, undernourished people,with cancer), but also people exposed to high stress, overloaded with work and pregnant women are more exposed to HSE, especially those with severe course.
Primary infectioncauses approximately 30 percent of herpetic encephalitis - it is seen primarily in patients under 18 years of age, as well as in newborns who become infected at birth. Primary encephalitis is usually caused by HSV-2 and is most often asymptomatic.
Herpetic encephalitis - symptoms
The first symptoms of herpetic encephalitis may resemble the beginning of the flu. They are:
- feeling unwell
- feeling broken
- weakness
- lack of appetite
- fever
- chills
- nausea
- vomiting
- muscle aches and joint pain
After 2-5 days,symptoms typical of encephalitis start to appear :
- fever - occurs in 90% of cases, and its absence should raise doubts as to the correct diagnosis
- headache
- neck stiffness and other meningeal symptoms (shoulder and pubic symptom)
- personality changes (97 percent of patients)
- speech disorders (76 percent of patients)
- incoherence (40 percent of the sick)
- hemiparesis (38 percent of patients)
- impairment of cranial nerves (32%)
- visual field reduction (14 percent of patients)
- optic disc edema (14 percent of patients)
- epileptic seizures - focal and generalized attacks occur in 70 percent of patients with confirmed disease
- herpetic skin lesions occur in 25 percent of patients
It is estimated that about20 percent of casesherpetic encephalitisare mild- symptoms are limited to fever only, so it's important is to perform a lumbar puncture to confirm the presence of the virus in the cerebrospinal fluid.
Herpetic encephalitis - diagnosis and treatment
The primary diagnostic method for herpetic encephalitis is the polymerase chain reaction (PCR) test - the sensitivity of this test is approximately 94-98 percent and specificity is 98-100 percent.
In addition, changes in the brain can be confirmed by magnetic resonance imaging (it shows them in 90 percent of patients), computed tomography, which confirms the disease in about 2/3 of patients. The least specific and sensitive test is electroencephalography.
Untreated herpetic encephalitis leads to death in as many as 70 percent of patients , therefore treatment should be initiated as soon as possible.
Antiviral treatment includes antiviral drugs - vidarbine and acyclovir. An antibiotic with good penetration through the blood-brain barrier is also often administered. In addition, anticonvulsants are used and efforts are made to reduce intracranial hypertension.
Herpetic encephalitis - complications
Herpetic encephalitis, even early diagnosed and properly treated, often leads to irreversible damage to the nervous system, with consequences such as:
- epilepsy
- visual impairment
- hearing impairment
- mental retardation
- paresis
