DEAR DR. DONOHUE: My wife, 78, has had headaches, some memory problems and confusion. A brain scan showed hydrocephalus. We were referred to a neurosurgeon, and he ordered an infusion study. We have waited six weeks for that appointment. At an earlier appointment, we met someone who had had the infusion study and then had a shunt placed. He said he got his life back. Someone else told us that 10 percent of people diagnosed with Alzheimer’s disease really have normal pressure hydrocephalus, which is fixable. What is your reaction to this? – J.R.

ANSWER: Dementia is a fog that descends on the brain, erasing memory and impairing many other mental functions. Alzheimer’s disease is the major cause of dementia. However, there are other causes, and one of them is normal pressure hydrocephalus. I can’t vouch for the statement that 10 percent of Alzheimer’s patients have NPH, but I am sure there are a few who do. I don’t want to raise false hopes for Alzheimer’s patients.

In NPH, the balance between the production and absorption of cerebrospinal fluid is lost. The volume of fluid within the brain increases and compresses it. That leads to the signs and symptoms of NPH.

The three major indicators of NPH are an abnormal walk, a diminution of memory and other mental functions (dementia) and an urgency to empty the bladder with frequent loss of bladder control. The NPH gait is one where steps are taken slowly, in short strides and with the legs wide apart. People look as though their feet are glued to the ground and they have difficulty turning themselves. A person doesn’t need all three criteria to merit the diagnosis.

If signs, symptoms and tests, including a brain scan and the infusion test your wife is going to have, point to normal pressure hydrocephalus, then drainage of the excess brain fluid often can restore a person’s life, as the man you met in the doctor’s office said. A thin, plastic tube (a shunt) drains the fluid to other body sites where it is absorbed.

Alzheimer’s disease is far and away the leading cause of dementia. The booklet on Alzheimer’s disease describes it and its treatments in detail. To order a copy, write to: Dr. Donohue – No. 903, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Will you repeat the article on a runny nose when eating? My husband has it, and it’s embarrassing to him. – J.W.

ANSWERS: Some explain why noses run upon eating by invoking sensitivity to temperature changes, i.e., hot or cold food. Or it could be that spices start the nose dripping. Chewing might trigger a reflex that makes the nose run. And, in all truth, the reason could be something that remains a mystery.

Atrovent nasal spray, a prescription item, can sometimes stanch the drip. A drying antihistamine taken an hour before meals is another way to keep the nose dry. People shouldn’t resort to medicine before every meal. They should save it for occasions when a drippy nose is a source of embarrassment.

This curiosity has a name, gustatory rhinorrhea.

DEAR DR. DONOHUE: My neighbor has been told he has high blood pressure, but he continues to drink every Friday, Saturday and Sunday. Is alcohol dangerous for someone with high blood pressure? – J.R.

ANSWER: People with high blood pressure should limit their alcohol intake — one drink a day for women, two for men. More than those amounts can raise blood pressure, and three or more drinks a day almost certainly raise it. Some people with high blood pressure are quite sensitive to alcohol and have to stay away from alcoholic beverages completely.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com.