DEAR DR. DONOHUE: My husband died a year ago from progressive supranuclear palsy. What information can you give me about it? – W.T.

ANSWER: Progressive supranuclear palsy – PSP – is a recently described illness. It strikes people in their 50s and 60s. One of its salient features is the inability to aim the eyes downward. As the illness progresses, upward and sideward eye movement also become impaired. The “supranuclear” part of the name comes from the area of the brain controlling eye motion.

Many of the other symptoms and signs of PSP are similar to those of Parkinson’s disease. In its early stages, the illness is often mistaken for it. PSP patients have stiff muscles, as do Parkinson’s patients. They move slowly, as Parkinson’s patients do. Both PSP patients and Parkinson’s patients are unsteady on their feet, but PSP patients’ unsteadiness is more pronounced, and falling is a hallmark of the illness. They fall suddenly, like a tree that has been axed.

Unlike Parkinson’s patients, PSP patients almost never have a hand tremor. And unlike many Parkinson’s patients, who walk with a forward tilt, PSP patients walk with a backward tilt.

Speech often becomes garbled in PSP, and swallowing can become most difficult.

Parkinson’s medicines are used in PSP, but they are not as successful in controlling PSP symptoms.

The cause of this illness remains unknown.

There is a source of information and help for all PSP patients and their families. It is The Society for Progressive Supranuclear Palsy. The society’s toll-free number is 1-800-457-4777. Canadians, dial 1-866-457-4777. The Web site is www.psp.org. Patients and their relatives will find the society a most supportive friend.

DEAR DR. DONOHUE: I have an awful soreness on the outside of and entrance to my vagina. I have seen lots of doctors and have used lots of prescriptions, ointments and creams with no improvement. Do you have any suggestions? – D.D.

DEAR DR. DONOHUE: Please give me information on vulvodynia. – L.

ANSWER: D.D., I’ve included L.’s letter because you might have what she asks about – vulvodynia (VUL-voh-DEEN-ee-uh). The vulva includes the vaginal opening and nearby structures. Vulvodynia is pain in that area, the cause of which is not definitely known. Although the condition hasn’t attracted a great deal of attention, women who suffer from it number in the millions. They describe the pain as burning or as sharp stabbing like a knife. Pain can be present all the time, or it can arise only when those areas are touched. Often vulvodynia makes sexual relations impossible.

Amitriptyline, a medicine used for depression, has been found useful in suppressing the pain of vulvodynia for some women. Gabapentin, a seizure-control medicine, works for others. Lidocaine ointment can sometimes control this pain. Lidocaine is a numbing agent.

I encourage women with the condition or women who think they might have it to contact the National Vulvodynia Association, founded to spread information on this distressing problem and to support women with it. The association’s Web site is www.nva.org. I know that not everyone has access to a computer. Almost everyone, however, has access to a public library with computers, and the librarians are happy to put the public online.

DEAR DR. DONOHUE: I have arthritis, and I swear I can detect weather changes by how my joints feel. Is this just something in my head? – A.S.

ANSWER: No, it’s in your joints. A number of reports back up your claim. Many studies have shown that arthritis acts up when barometric pressure falls. One study says that arthritis patients’ joint pain increases with each degree drop in temperature.

I can’t give you an explanation why it happens, but it appears to occur in many arthritics.

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.