QUESTION: I live in a high Lyme-disease area and suspect I had it about a year ago. Now I am having some leg burning. Incidentally, I also have episodes of forgetfulness. I was really shocked when my doctor told me these symptoms can be associated with Lyme disease. Can this be so with so much time passed? - C.H.

ANSWER: Yep. Long after coming down with the illness, a very few patients do develop memory loss, mood changes, even sleeping disturbances. Some also develop the late leg-burning sensation you report. Antibiotics improve things, as in the initial Lyme infection.Warning: Because such symptoms are quite common and Lyme disease relatively rare, one must accept this new information with caution. You need unequivocal evidence of prior Lyme tic infection before you can begin to draw links between it and such latter-day symptoms.

QUESTION: I am 35 and recently had my second child five weeks premature. He was delivered C-section because of placenta previa. We moved two weeks before this. Can placenta previa be linked to lifting heavy objects? Or is it because of the age of the mother? What are the chances of it happening again? - A.R.

ANSWER: Placenta previa is partial or complete detachment of the placenta from the uterine lining, to which it closely adheres. It is usually a problem of later pregnancy (the last three months).

Placenta previa is always serious, depending on the degree of separation. The common signs of it are abdominal pain and bleeding, sometimes premature labor.

Women over 35 are more likely to have this problem than are younger females, so age does seem to play a role. And it is more common among women who have high blood pressure. However, most of the time, no specific cause can be found.

As to the role of trauma, the evidence isn't clear. Certainly, a direct trauma as from a car accident can do it. The idea of stress of lifting is an iffy matter. Were the lifting to elevate blood pressure sufficiently, then the placenta problem might ensue.

QUESTION: My brother tested positive for AIDS. That was two years ago, and he looks and feels fine. Yet, his doctor has him on AZT medicine. What can this accomplish, since he does feel so good? - B.F.

ANSWER: AZT (zidovudine) helps salvage your brother's T-4 cells, and that statement may require some explanation.

As you know, the AIDS virus destroys the immune system. It goes after certain cells, more specifically the T-4 lymphocytes, blood cells that constitute our strongest bulwark against infections. Without such cells, germs we are normally able to live with suddenly become life-threatening organisms of serious infection.

These days, people who test positive for AIDS are checked for their T-4 cell counts. If the number begins to fall, then zidovudine is administered to salvage those that remain. This is why your brother is on the medicine. By preserving these T-4 cells, he will be less apt to contract infections from opportunistic germs eager to break through his weakened immune system.

QUESTION: I have a sister who was diagnosed as having had cytomegalovirus (CMV) at some time in her life. She is always tired and could sleep at any time. Her doctor seems to think the virus has something to do with it. He could find nothing wrong with her and did extensive blood work. Could you tell me about this particular virus? - C.C.

ANSWER: So common is CMV infection that in parts of the world nearly 100 percent of inhabitants have had it. Most never realize that fact, so mild are its symptoms. There are exceptions, though.

If a fetus is infected with the virus, it might get pneumonia, and an infection can cause trouble for those with a transplanted organ. It also is troublesome for those whose immune system is not up to snuff.

A few individuals may develop a situation similar to that of mononucleosis, in which fatigue occurs. Now CMV is one of those viruses that live on and on in the body, like mono, but whether it causes recurring illness or latter-day symptoms is unknown.

1991 North America Syndicate Inc.