Infection
---Infecting and inflammation can attack the brain of the central nervous system, sometimes with serious results. Luckily, the body’s defences make such events fairly uncommon.
---Infective agents include bacteria, fungi and viruses. Sometimes one involved the whole nervous system, but certain germs specialise in attacking special regions. Infections involving a particular part of the nervous system are named accordingly. Of the two major types found in the head, encephalitis ("brain inflammation") affects the brain, meningitis afflicts the meninges - the brain’s protective outer coverings.
---Organisms sometimes invade the brain directly through a wound penetrating the skull, or from an infected ear of nasal sinus. Some organisms reach the brain from other parts of the body via the bloodstream or by tracking through nerves. The nature of any disease in the nervous system depends on the organism involved, how fast the infection develops, where it is located. Infections inside the head tend to produce inflammation with nausea, vomiting and fever. Light may hurt the eyes, and the patient may feel drowsy, fall unconscious or suffer confusion, convulsions and partial paralysis. Meningitis may produce a stiff neck. Fear of water (hydrophobia) and maniacal behaviour be features of rabies (its Latin name for "madness")
---Brain infections may visibly affect the brain. In meningitis pus and inflamed blood vessels may block the flow of cerebrospinal fluid between the brain’s innermost meningeal covering, fluid presses on the brain. Encephalitis inflames cells in the cerebral cortex, white matter, basal ganglia and brainstem, actually killing off numbers of neurons. Rabies - a viral disease spread by saliva from the bite of an infected creature of person - leaves traces called inclusion bodies in the brain’s cerebellum, hippocampus and medulla. Poliomyelitis - caught by breathing in a virus - attacks motor neurons in the spinal cord and sometimes the brainstem, to cause paralysis and muscle wasting. Treatment depends on the cause of the disease.
---Antibiotics help to cure meningitis due to bacteria. Unfortunately, nothing kills the encephalitis virus and doctors can only give drugs to lower the patient’s temperature, control convulsions, and if needs be, draw off spinal fluid to reduce fluid pressure on the brain. However, encephalitis-like symptoms sometimes spring from an abscess due to local brain infection that can be treated by antibiotics and drawing pus from the abscess through a hypodermic needle.
---These infections vary in their outcome. Rabies is almost always fatal once symptoms appear. Meningitis can often be completely cured, encephalitis may lead to total recovery or death. Either infection can cause lasting damage to brain or nearby structures. Poliomyelitis may leave total paralysis or no more than a slight disability. Luckily, poliomyelitis and rabies can both be prevented by immunisation.
Sources of Infection
Bacteria, viruses and fungi can enter the brain via several routes:
Direct penetration through a wound in the skull
Spread of bacteria from an abscess in an infected ear.
Spread of infection from the nasal sinuses after a cold influenza, etc.
Infection may be carries by the blood stream from a distant part of the body.
Viruses such as that causing rabies travel through peripheral nerve toward the brain. The time the virus take to reach the brain depends on the distance of an infected bite from the head - rabies may take many months to develop after a bite in the leg.
Brain Infections
Encephalitis. The encephalitis virus infects and inflames large areas of the cerebral cortex, basal ganglia and brainstem. Many neurons throughout the stem may be killed.
Rabies. The rabies virus invades the cerebellum, hippocampus and medulla. The resulting hydrophobia (fear of water) may be so intense that the sufferer is unable to swallow his or her own saliva, and if this stage is reached, the disease in invariably fatal.
Meningitis. Inflammation of the pathways of the cerebrospinal fluid is usually caused by a virus or a bacterium, although occasionally, a fungus or amoeba is to blame. The inflammation of the pia mater, which is the most likely of the meninges to be affected and is the one closest to the brain.
Polioencephalitis. The polioencephalitis virus grows in and ultimately kills motor neurons in the spinal cord and brainstem, resulting in often severe paralysis.
Disease Symtoms Cures Infection
1) Nausea, vomiting and fever.
2) Light may hurt the eyes.
3) Drowsiness.
4) Unconsciousness, confusion, convulsions and partial paralysis.
5) Fear of water (hydrophobia).
6) Maniacal behaviour be features of rabies.Antibiotics used
in some cases