DEAR DR. DONOHUE: My mother lives with us. She helped raise our children when I was working. I’m afraid she’s coming down with Alzheimer’s disease. How does Alzheimer’s differ from dementia? What medicines are there for it? – A.A.

ANSWER: Dementia is an umbrella word that includes all illnesses where there’s a deterioration of mental capabilities to such a degree that the affected person is unable to cope with run-of-the-mill daily activities. Memory is one of those abilities that is impaired or lost. Language skills, calculation ability, judgment and problem-solving also suffer. Alzheimer’s is the leading cause of dementia, but not the only one. Brain tumors, a disturbance of the circulation of brain fluid (normal pressure hydrocephalus), small strokes and depression are other examples of dementing illnesses. They’re the reasons why doctors order tests for Alzheimer’s patients. Some of these conditions are reversible with treatment; Alzheimer’s isn’t.

However, medicines can perk up mental processes for a time and can possibly slow the progression of the illness. Aricept (donepezil), Razadyne (galantamine) and Exelon (rivastigmine) are three related medicines that raise brain levels of acetylcholine. It’s a brain messenger chemical. Namenda (memantine) is another Alzheimer’s drug that counters the effect of a brain substance that accelerates the progression of Alzheimer’s. It can be combined with one of the drugs from the first mentioned family of drugs. None of these is a cure.

The Alzheimer’s report presents all the aspects of the devastating illness. Readers can obtain a copy by writing: Dr. Donohue – No. 903, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6.75 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

DEAR DR. DONOHUE: Is it possible to have shingles without having the shingles skin rash? My doctor says I have shingles, but there is nothing on my skin. – L.B.

ANSWER: In most cases, shingles causes a skin rash that is on one side of the body. The rash is in a band that sweeps from the back, around the sides and to the front in a slightly downward dip. The band is red, and there are patches of small blisters on it. That’s a rough description.

In rare cases, I am told, no rash appears, only one-sided pain in a similar band distribution. That’s called zoster sine herpete. I must admit I would be hard-pressed to recognize this as shingles.

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