Encephalitis is an inflammation of the brain caused by a viral infection. Sometimes the immune system may mistakenly attack its own tissues that result in encephalitis. This pathology is an acute inflammation that comes suddenly, develops rapidly and needs urgent medical help. Encephalitis may emerge as a consequence of some other diseases, for instance, measles, chickenpox or herpes.
There are no universal signs of encephalitis because the symptoms depend on the type of pathogen as well as the place of where it penetrated the brain.
General cerebral symptoms include the following:
a headache that is commonly felt in all parts of the head
nausea and vomiting that brings no relief
weakness and loss of ability to work
impairment of consciousness that varies from a slight drowsiness to the deep depression of consciousness accompanied by the loss of response to external stimuli
fever that is accompanied by the rise of body temperature over 38 °C.
Specific symptoms that are associated with the damage to a particular brain area include the following manifestations.
Frontal lobe. If a frontal lobe is damaged, the symptoms are as follows:
reduction in intelligence;
silly behavior characterized by stupid jokes and excessive desire to talk
speech disorder called motor aphasia, i.e. very unclear speech
stretching lips like sucking that may emerge spontaneously or touch any object with lips
unsteadiness while walking.
Temporal lobe. The damage of the temporal lobe may be manifested by the following symptoms:
speech disorders, namely sensory aphasia, i.e. the patient does not understand the speech addressed to him, though hears it well. His native tongue sounds to him as a foreign language.
loss of visual fields, that means the absence of any part of the visual field
seizures that occur in the limbs or in the entire body.
Parietal lobe. Parietal lobe damage reveals itself with such symptoms as:
lack of sensitivity in a certain part of the body. The patient does not feel touches, temperature, and pain
impaired ability to count
wrong perception of the body proportions. The patient may be sure that his limbs become longer or even some additional limbs appeared
denial of the disease.
Cerebellum. The defeat of the cerebellum may be manifested by the following symptoms:
poor coordination of movements
unsteadiness while walking. The patient walking deflected to the side and may even fall
movements of eyes resemble those of pendulum, i.e. they move horizontally from side to side
decreased muscle tone (muscle hypotonia).
Most often, inflammation of the brain does not develop separately from the meningeal membranes, so the following symptoms of meningitis (i.e. inflammation of meningeal membranes) may appear:
the tension in suboccipital muscles that makes the patient hold his head thrown back constantly;
a severe headache;
photophobia that is manifested by a pain in the eyes when the patient looks at any source of light or when the room lamps are lit.
Additional symptoms are also possible in case of encephalitis including the following ones:
increased muscle tone
involuntary body movements
violation of the eyeball movements
drooping of the upper eyelid
sleep disturbance that is manifested as drowsiness and may last from a week to several months
fever and high body temperature are possible in case of severe intoxication.