QUESTION: Recently, my mother had a brain hemorrhage from a ruptured aneurysm. She had surgery and the aneurysm was clamped. She is now recovering. I have now learned for the first time that my maternal grandmother died from the same condition. I am concerned about the hereditary factor. I've questioned my physician and have tried to research the matter at the library but have been unable to get answers. Is the condition inherited? Should I have some diagnostic investigation? Are there precautions to take? - Mrs. G.L.

ANSWER: Once medical schools taught that aneurysms (bulges) in brain arteries were genetic. Now, we are not so sure.Perhaps there is a tendency to form such aneurysms, which is a semantic way of saying that certain family backgrounds may be involved. We just aren't sure. Perhaps an inherent weakness in the blood vessel wall favors this bulging.

So where do you stand? Recommendations are fuzzy in cases like yours. Frankly, most authorities do not see the need for investigation, since the likelihood of finding an aneurysm is quite remote anyway.

I can't add more than this. If you are uneasy, you have a right to ask for a CAT scan or an MRI scan of the brain, even though the experts recommend against that in such cases. I don't know what else to say.

QUESTION: I am told there is scarcely anything that can be done for fungus under the nails (finger and toe). Is that true or false? - R.W.D.

ANSWER: Fungus under the nails isn't impossible to treat, but there is no quick or sure remedy. Cure is so difficult because the medicine has to penetrate to the part of the nail where growth begins. The antifungal medicine is incorporated into the nail substance as it continues its outward growth to full length. That can take four to six months for a fingernail, up to a year for a toenail.

Toenails pose a special problem, for in addition to its slow growth, its environment works against fungus cure. We keep our feet warmer and moister than our hands. Socks and shoes enclose the nails in this fungus-favoring climate.

If you are willing to put up with long treatment, up to a year, you have a chance of getting rid of the fungus. Griseofulvin is one of the medicines used, orally, for people with nail fungus problems. Some cannot tolerate the oral medicine for such lengths of treatment. I'm sending you the nail problems report. Other readers may order by writing Dr. Donohue/No.22, Box 830, Gibbstown, NJ 08027-9909, enclosing a long, stamped, self-addressed envelope and $2.

QUESTION: When my son was 6 he had rheumatic fever from a strep infection. He developed diabetes when he was in his 20s. He's now 40 and has been on insulin for years. I always felt there was some connection between his strep throat, the rheumatic fever and his diabetes. What do you think? - G.F.

ANSWER: I know of no connection between strep infection and diabetes. I can't find any expert confirmation of such a connection. For the time being, you have to say the two illnesses were not linked. There is a more definite link between an earlier pancreas viral infection and subsequent development of diabetes.

Dr. Donohue welcomes reader mail but regrets that, due to the tremendous volume received daily, he is unable to answer individual letters. Readers' questions are incorporated in his column whenever possible.