Pinpointing the Source of Migraine Pain
The conventional idea that disabling migraine headaches result from a dilation of blood vessels in the brain is most likely wrong, according to researchers from Johns Hopkins University. Rather, the headaches arise from inflammation of the meninges, the protective tissue layers covering the brain, Dr. Marco Pappagallo told a meeting of the American Academy of Neurology in Toronto on Wednesday.
Pappagallo and his colleagues used a sophisticated form of computed tomography imaging to study the brains of a small number of patients during an active migraine and later, after the headaches had subsided. They injected the patients with a radioactively labeled blood protein called albumin. The imaging showed that the albumin leaked out of blood vessels in the meninges, a sure sign of inflammation.
Pappagallo said he and his colleagues started the study because the symptoms of migraine--including a throbbing headache, nausea, and sensitivity to light or sound--are the same as those associated with meningitis, a viral or bacterial infection of the meninges. The inflammation in migraines, he said, is caused by unusual nerve activity.
In another paper presented the same day, researchers from Thomas Jefferson University in Philadelphia reported that the severity and frequency of migraines could be reduced by injections of botulism toxin, which has previously been found to inhibit overactive muscles. The reductions were observed in the second and third months of treatment.
Migraines afflict as many as 25 million Americans, and are three times as common among women as men.
Treatment Effective With Cerebral Palsy
Botulism toxin can also be useful in treating children with cerebral palsy, according to a report April 19 at the neurology meeting. Dr. Petr Kanovsky and his colleagues at Masaryk University in Brno, Czech Republic, injected botulinum toxin into the calves of 27 children, ages 2 to 7, who were unable to walk or to stand upright because of cerebral palsy. Injections were administered at three- to four-month intervals over the three-year study.
All 27 children showed improved muscle function beginning three to six months after the first injection. Six of them were able to stand upright, without help, for the first time. None of the children experienced side effects.
Vitamin E, Alcohol May Cut Stroke Risk
Daily vitamin E supplements and moderate consumption of alcohol can decrease the risk of stroke, while periodontal disease can increase it, according to three studies presented at the neurology meeting.
Dr. Richard Benson and his colleagues at New York Presbyterian Hospital studied 850 Latino, African American and Caucasian adults who were an average age of 69; 350 of them had had a stroke. They reported Tuesday that those who had not had a stroke were twice as likely to have taken vitamin E supplements.
Dr. Klaus Berger and his colleagues at the University of Munster in Germany studied 22,000 male physicians from the U.S. Physicians’ Health Study, a continuing study of male doctors coordinated at Harvard University. They reported Wednesday that those who consumed between one drink per week and two per day were 20% less likely to have had a stroke.
Dr. Mitchell Elkind and his colleagues at Columbia University studied 52 people who had never had a stroke. They reported Wednesday that the people with the most periodontal disease--gum infections caused by oral bacteria--had the most thickening of their neck arteries. Thickened neck arteries are a strong predictor of stroke risk, Elkind said, so the people with more oral bacteria have a higher risk of eventually suffering a stroke.
2 Studies Focus on Contraceptive Failure
About one in every 10 women using contraceptives experiences an accidental pregnancy associated with contraceptive failure, according to two new studies in the March/April issue of Family Planning Perspectives. But in actual practice, not surprisingly, some methods were found to carry higher risks of failure than others.
Long-term methods requiring no ongoing effort by the user--hormonal implants, injectable contraceptives and the IUD--have a very low failure rate. Methods that require daily actions, such as the pill, the diaphragm and the condom, have slightly higher failure rates. Spermicides, withdrawal and periodic abstinence have considerably higher failure rates.
One study, by researchers from Princeton University, breaks new ground by examining how frequently women discontinue using contraceptives. They found that a typical woman discontinues using a contraceptive nearly 10 times over the course of her reproductive lifetime, and experiences about two contraceptive failures.
Larger Vitamin C Doses Have More Benefits
Daily doses of 200 milligrams of vitamin C are more effective at preventing disease than the currently recommended dose of 60 milligrams per day, according to research by Dr. Mark Levine of the National Institute of Diabetes and Digestive and Kidney Diseases. But Levine and other government scientists said Tuesday that vitamin C taken in the form of supplements is less effective than vitamin C obtained from fruit and vegetables.
The current recommended level of 60 milligrams per day was set in 1980 and reviewed by the National Academy of Sciences in 1989. The recommendation is based on the minimum level necessary to prevent scurvy, a potentially fatal disease marked by fatigue and bleeding.
But the researchers cautioned that levels higher than 200 milligrams are not readily absorbed by the body and may lead to the formation of kidney stones.
Zinc Can Be Life-Saver
for Premature Babies
Giving zinc supplements to small and premature babies can cut infant deaths by one-third, according to studies presented April 18 at a meeting of the Federation of American Societies of Experimental Biology in Washington.
Dr. Robert Black and Dr. Sunil Sazawal of Johns Hopkins University studied 1,250 low-birthweight children at Annamalai University in India. The babies who were given zinc, either alone or with other nutrients, were one-third less likely to die than those not given the trace metal.
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Medical writer Thomas H. Maugh II can be reached at thomas.maugh@latimes.com.
