Disorders of the nervous system
The nervous system can be damaged by injury and disease. Axons in the central nervous system cannot regrow after being damaged, but nerves in the peripheral nervous system may recover. Severely damaged nerve cells that die cannot be replaced. Most neurons that perform a specific job are grouped together in the brain. Because of this grouping arrangement, called localization of function, damage to one area of the brain may affect only certain abilities and leave others intact. In some cases, undamaged areas of the brain gradually assume control of functions lost when another area of the brain was damaged. This action is called recovery of function.
Encephalitis & Meningitis