Statins can increase the risk of developing peripheral neuropathy, according to a study in the May 14 Neurology. Across all cases, people taking statins were four times more likely to develop peripheral neuropathy than those who were not taking statins. Researchers identified 166 cases of known first-time neuropathy with no known cause. Of those, 35 had a definite diagnosis, 54 were probable cases, and 77 were possible cases. Nine of the people with neuropathy had taken statins for an average of 2.8 years. For the definite neuropathy group, the statin users’ risk of developing neuropathy was 16 times higher than that of the control group. Taking statins for longer periods of time and taking higher doses of them also increased the risk. However, “the positive benefits of statins … far outweigh the potential risk of developing neuropathy,” said study author David Gaist, MD, PhD. “These findings shouldn’t affect doctor or patient decisions to start using statins.”

A group of Northwestern University researchers has reported the first evidence showing that tau must be present to enable beta-amyloid to induce the degeneration of brain cells that occurs in Alzheimer’s disease. The findings were published in the April 30 Proceedings of the National Academy of Sciences. Results of the group’s experiments showed that neurons with normal amounts of tau degenerated in the presence of beta-amyloid, while neurons specially treated to be devoid of tau did not degenerate. “Our results underscore the importance of tau in the pathogenesis of this devastating disease and open a new chapter in deciphering the toxic pathways activated by beta-amyloid,” said Adriana Ferreira, MD.

Researchers have concluded that there is no evidence of an increased chance of major birth defects occurring in the offspring of women with epilepsy who do not take antiepileptic medications during pregnancy. According to their meta-analysis, the risk for congenital malformations in offspring of untreated women was not found to be significantly higher than that in healthy controls. In contrast, the offspring of women who were treated with antiepileptic medications had higher incidence of major malformations than did healthy controls. “This information is reassuring for women with epilepsy who do not need to take antiepileptic drugs. It is also important for … physicians, who may choose to discontinue antiepileptic drugs during the first trimester in order to reduce the risk of major malformations,” said Dr. Gideon Koren, the study’s principal investigator, in his presentation to the Pediatric Academic Societies Annual Meeting in Baltimore, Maryland.

Women whose routine mammograms reveal calcification in the blood vessels of the breasts are at increased risk for stroke, according to a study presented at the American Heart Association’s Asia Pacific Scientific Forum. The study reported on 16,305 women who underwent routine mammography between 1964 and 1973 at Kaiser Permanente Hospitals. Their health history was tracked for 20 years. Women with breast blood vessel calcification had a 54% increased risk of ischemic stroke, compared to women without calcification. Additionally, the study found that calcification of blood vessels inside the breast was more common among older women, those who had a low educational background, those with diabetes, and those who had three or more children.

A new study shows that Parkinson’s disease causes widespread damage to the sympathetic nervous system, affecting sympathetic nerve endings in the heart, thyroid, and kidney. Published in the April 23 Neurology, the study examined 18 patients with Parkinson’s disease and orthostatic hypotension, 23 patients with Parkinson’s disease only, and 16 healthy controls. All patients with Parkinson’s disease and orthostatic hypotension had abnormal blood pressure responses to the Valsalva maneuver and significant loss of sympathetic nerve endings in the left side of the heart, while 75% of patients with only Parkinson’s disease had lost sympathetic nerve endings in one or more areas of the heart, and six of the patients had abnormal Valsalva responses. Patients with Parkinson’s disease also had fewer sympathetic nerve endings in the thyroid and kidneys, compared to controls. Researchers suggest the findings may help explain the blood pressure problems commonly found in Parkinson’s disease and may lead to new treatments for the disease.

A heart attack or stroke in a close family member should send a signal that one is at higher risk of suffering the same, yet this potentially lifesaving message may be lost on young adults. Researchers followed almost 4,000 young adults in a large-scale study of cardiovascular disease development. Their findings, published in the May American Journal of Preventive Medicine, contradicted the expectation that healthy behaviors and improvements in indicators of risk would be greater among those young adults whose family history of cardiovascular disease had taken a turn for the worse than in those whose family members were in good cardiovascular health. Rates of smoking and smoking cessation were no different between the two groups, nor were there significant changes in physical activity level, weight, blood pressure, or blood chemistry that would indicate reduced cardiovascular risk in those with dangerous family histories. Because the study did not address the “issue of perceived risk of disease following a change in family history,” the researchers postulated that their results might be explained by the fact that young adults simply “don’t realize that a heart attack or stroke in a close family member signals increased personal risk.”

older men with higher testosterone levels performed better on tests of cognition, according to a new study by University of California, San Francisco, researchers. The study, published in the April Journal of the American Geriatrics Society, examined 300 older men, testing them for concentration, memory, attention, language, and other cognitive skills. “The men in the study with higher levels of bioavailable testosterone … did significantly better on these cognitive tests than men with lower levels,” said lead author Kristine Yaffe, MD. However, Dr. Yaffe did not recommend that men begin taking testosterone to improve cognition. “Our study … doesn’t prove that testosterone supplements can prevent cognitive decline. We will need the results of large randomized clinical trials in older men before we can confidently say that testosterone supplements are beneficial and safe,” she said.

According to research presented at the Experimental Biology 2002 meeting in New Orleans, atorvastatin has proven effective in reversing paralysis in a mouse model of multiple sclerosis. Stanford University researchers found that oral treatment with atorvastatin could prevent both the acute and relapsing forms of experimental autoimmune encephalomyelitis in mice, and could also reverse symptoms in mice with the chronic relapsing form of the disease. Compared with control mice, the mice treated with atorvastatin had much less central nervous system inflammation. A close comparison of the lymphocytes of atorvastatin-treated and control mice showed that atorvastatin prevented the induction of pro-inflammatory cytokines and induced secretion of anti-inflammatory cytokines. The results suggest that atorvastatin and other statins may have implications for the treatment of multiple sclerosis and other autoimmune inflammatory diseases.

According to a study published in the May Nature Medicine, researchers at Stanford University Medical Center have uncovered thousands of genes that may be involved in multiple sclerosis. Genes that were over- or under-expressed in multiple sclerosis as compared to normal brain samples were isolated using microarray technology. Among the genes expressed at high levels were those for cytokines, a histamine receptor, and proteins associated with pregnancy. According to Lawrence Steinman, MD, the results could lead to the regular use of antihistamines to treat multiple sclerosis. “It sure is easier to start with a drug that’s approved for over-the-counter use,” he said.

Neurons thought to play a key role in sudden infant death syndrome are located near some of the largest arteries in the brain, according to a study in the May Nature Neuroscience. Using imaging and electron microscopy, researchers at Yale School of Medicine showed that serotonergic neurons in laboratory rats are located right next to large arteries in the brain, where they are ideally situated for sensing carbon dioxide in arterial blood. The findings support a new theory that infants who succumb to sudden infant death syndrome have developmental abnormalities in these neurons, which may regulate a response to high carbon dioxide levels during sleep. “The normal response is to wake up slightly, turn the head, and breathe harder,” said senior investigator George Richerson, MD. “There is evidence that some infants that die of sudden infant death syndrome lack this normal protective response.”

NR

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