Tim Tritch, age 11, of Casper, Wyo., for his question:

WHAT CAUSES NEURITIS?

Neuritis is the injury of a nerve. Often the injury is an inflammation although it can be caused by the breakdown of a nerve with little inflammation involved.

It is unusual for germs to cause neuritis, although the germs of some diseases may do so. Certain poisonous substances are known to attack the nerves. Among these are lead, arsenic and methyl alcohol.

When such poisons circulate through the body, it is usual for many nerves, both sensory and motor, to be affected.

Also, lack of proper vitamins is sometimes the cause of severe neuritis.

When a sensory nerve is affected, the area from which the nerve comes may be painful. There may be a "track of pain" along the path of the nerve. These pains are called neuralgias.

With neuritis there may be a sensation of being pricked with pins and needles; the part may feel numb or "asleep"; it may tingle or burn; or it may feel as if ants were crawling on it. When a motor nerve is inflamed, there may be a weakness and even paralysis of the muscles which are stimulated by the nerve.