Acute viral encephalitis

The result of acute viral encephalitis are neuronal and glia defects occurring with inflammation and edema.

Etiology

 * Mumps, HSV, VZV, EBV.
 * Substantial link to the vector: tick – tick encephalitis, Russian spring encephalitis; mosquito - western equine disease (USA), western Nile encephalitis (Africa).
 * Post-infectious encephalitis – follow childhood infections (measles, chickenpox, rubella), it is not a direct effect of the virus.

Clinical manifestations



 * General manifestations ("influenza"): muscle pain, fever, headache, meningeal reactions, cerebrospinal fluid cell proliferation.
 * Symptoms of brain impairment - focal/diffuse, according to location.
 * With hemisphere involvement → epilepsy, involuntary movements, paresis, confusion, speech disorders.
 * Rhombencephalits = defects in cerebellar and brainstem structures.
 * Mesencephalic defect→ oculomotoric and autonomic disorders.
 * Cerebellar defect→ ataxia, dysarthria.
 * Brainstem defect → nystagmus, quadruparesis, cranial nerve palsy.
 * Spinal cord defect→ mixed motor, sensitive and autonomic dysfunction.

Prognosis

 * Usually lasts for several weeks;
 * the prognosis depends on the type of virus;
 * mortality HSV infection 20-30%, in mumps only 2%;
 * also the neurological consequences vary in severity.

Related articles

 * Encephalitis
 * Viral encephalitis: Rabies, Polio, Herpetic encephalitis, tick-borne encephalitis