Encephalitis history and symptoms


 * Associate Editors-In-Chief: Priyamvada Singh, MBBS [mailto:psingh@perfuse.org]

Overview
Adult patients with encephalitis may present with acute onset of fever, headache, confusion, weakness and sometimes seizures. Younger children or infants may present with irritability, anorexia and fever. Less commonly, photophobia, stiffness of the neck can occur if meningeal involvement occurs simultaneously with brain involvement. Rarely, patients may present with stiffness of the limbs, slowness in movement and clumsiness, and hallucination depending on which specific part of the brain is involved. The symptoms of encephalitis are caused by the brain's defense mechanisms activating to get rid of the infection.

History

 * History of mosquito or tick bites or exposure to mouse/rat droppings. Additionally, history of animal bite and exposure to a bat to rule out rabies should be done.
 * Patients may have symptoms of a cold or stomach infection prior to symptoms onset.

Common symptoms

 * Acute confusion or decreased levels of consciousness.
 * Amnesia (short or long term)
 * Behavioral or personality change
 * Light sensitivity (Photophobia), neck stiffness, neck pain (suggesting meningeal irritation)
 * Seizure (Generalized or focal)
 * Headache
 * Lethargy
 * Vomiting
 * Decreased appetite
 * Clumsiness, unsteady gait

Less common symptoms

 * Flaccid paralysis
 * Backache

Varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, measles virus, or mumps virus

 * Rash, swelling of neck glands can be seen

Herpes simplex virus

 * can be seen in neonates
 * Herpes specific lesion in skin, eye and mouth ulcers
 * Poor feeding
 * Decreased alertness
 * Seizures, Body stiffness
 * Irritability and crying more often (these symptoms may get worse when the baby is picked up)
 * Soft spot on the top of the head may bulge out more
 * Vomiting

Toxoplasma virus

 * Common in immuno-compromised patients (common in HIV patients presenting with neurological manifestations)

St Louis encephalitis

 * Painful urination
 * Pus in urine

West Nile fever

 * Extreme lethargy