Encephalitis means inflammation of the brain tissue (unlike meningitis which
is inflammation of the membranes that cover the brain). Although it may be caused by a bacterial infection, it's usually due to a virus. Most cases are unrelated or sporadic. Although the underlying infection may be contagious, encephalitis itself cannot be passed from person to person. Outbreaks or epidemics of encephalitis are often spread via insect bites. Only certain
viruses are able to get through into the central nervous system, and fortunately even in these cases, encephalitis is rare.
Causes include herpes simplex (the virus that causes cold sores) which usually lies dormant in the nerves until something triggers it to travel along the nerve to the skin and cause a cold sore. However, very occasionally it will travel in the opposite direction up to the brain, resulting in encephalitis. It usually affects the temporal lobes (affecting memory or speech) or the frontal lobes (affecting emotions and behaviour) and can cause severe damage. Common childhood viruses (Measles, Chickenpox, Rubella) can also cause the condition;less common causes can be mumps, Epstein-Barr (the glandular fever virus), HIV, cytomegalovirus (CMV)and various other viral infections.
The symptoms of encephalitis range from minimal to very severe. Initial symptoms may seem like flu, such as fever, headaches, neck stiffness, lethargy and a general sense of being unwell. The headache may grow more severe and vomiting may then develop. In severe cases the fever becomes very high and there may be increasing confusion, drowsiness, and seizures.The elderly and the very young are most at risk. In mild cases symptoms may settle in a matter of days but in severe cases it can take weeks or months to recover and the affected person may need long term help for complications such as epilepsy, or problems with memory, speech, balance or behaviour.
When fever comes on, with restlessness, anxiety, fearfulness, dry skin,thirst.
Distracted and incapable of mental exertion from much mental work of different kinds in rapid succession.
Loss of memory "funk" before an examination.
Shrill cries in sleep, nervous fidgetiness.
When caused by a blow, at the beginning. Cicuta and Hypericum may have to be considered, if convulsions follow.
When there is delirium, patient tries to escape, flushed face, dilated pupils. Congestion of face, bright eyes,
dilated pupils, active delirium.
Cerebral stasis. In over-worked subjects.
Exceedingly irritable; everything makes him angry. Headache as if it would split open; greatly aggravated by
motion, opening the eyes, or stopping; relieved by pressure and closing the eyes. Congestive headache as if the
forehead would burst open, sometimes with epistaxis. Confusion of the head, a distracted state of the sensorium.If
there is little delirium, but much pain, white tongue, nausea; when effusion appears to have taken place,
depression and stupor coming on. Non-inflammatory congestion of brain, arising from exposure to intense cold, from
sea-sickness,or suppressed menses.
Pale subjects with tendency to large tonsils; brain weakness after much worry, or after illness.
Tight sensation from sunstroke.
Retrocession of eruptions; difficult dentition.
Determination of blood to the head; congestion after great losses of blood.
Vertigo, sensation of band round temples, inability to concentrate thought.
Violent throbbing, congestion from exposure to sun or heat from suppression of menses, or in pregnancy.
Great depression, much pain in the back of the head and neck. With typhoid conditions, loaded tongue.
Mental states consequent upon head injury.
Brain affections of infants with great drowsiness.
Oppression, drowsiness, constipation.
Brain-fag Nervous prostration.
After Apis and other medicines, hot head, cold feet in those subject to eruptions. Chronic cases heat at vertex,
faint feeling, feet cold or else burning.
Great indifference; lack of will-power to undertake anything.
Chronic headache, nervousness, and loss of memory from overwork;sufferings < by cold and > by warmth.
Weak memory, dull intellect.
From loss of sleep.