 | What Your Doctor Is Reading | | |
Update From the Medical Journals: May 2008
May 30, 2008  By Mary Pickett, M.D.
Harvard Medical School What's the latest news in the medical journals this month? Find out what your doctor is reading. Experts Say "Repositioning" is Best Treatment for Vertigo The May 27 issue of Neurology contains an updated guideline for the treatment of vertigo. Vertigo is the sensation that either your body or surroundings are spinning or falling, even when you are not truly moving. The most common cause of vertigo is benign paroxysmal positional vertigo (BPPV), which results in vertigo symptoms when you turn your head. Although it may sound unlikely, the guideline emphasizes that a specialized head-turning maneuver is the best first-line treatment for BPPV based on evidence for its effectiveness. Your balance center is located in each inner ear in what is called the "labyrinth," or the "semi-circular canals." They keep you balanced because fluid and nerve endings shift their position inside the curved bony tunnels whenever you rotate your head or accelerate your speed. Nerve signals are triggered by the shifting fluid, and send the message that you are in motion. Sometimes mineral deposits (mostly calcium deposits) float in the fluid, interrupting the smooth flow of the fluid during your movements. This causes your balance-center nerves to send out signals in the wrong pattern. This is what causes the symptoms in BPPV. By following a carefully planned pattern of head motions, the calcium deposits can be stirred and "steered" through the curved bony tunnels. This allows the deposits to be moved to a place where they can settle without triggering a nerve signal. The mildly acrobatic pattern of head movements is called canalith repositioning, "particle repositioning," or the "Epley maneuver." For the maneuver to be effective, a trained physical therapist needs to guide you through the movements. Some primary care or ENT doctors do the maneuver as well. Professionals have been skeptical about the value of particle repositioning. Small studies (36 to 66 patients) have shown good results, however. Between 50% and 90% of people with BPPV who were randomly assigned to receive the repositioning maneuver reported improvements compared with 10% to 27% of people who received a random series of head turns. The relief from symptoms is usually immediate, and in most cases long-lasting. Back to top Temporary Use of Beta Blockers Has More Risks than Benefits for Most Surgical Patients "Beta blockers" help lower blood pressure and prevent the heart from racing. By easing the stress on the heart, they can reduce the risk of having a heart attack — a known complication of surgery. As a result, these drugs are often given to a person before surgery and during the recovery period. On May 12 the Lancet released a study online that raises concerns about this short-term use of beta-blocker drugs. Although non-fatal heart attacks are less frequent with beta blockers, this study suggests that the risk for stroke and death is higher when these medicines are used in the weeks following surgery. More than 8,000 patients from 190 hospitals in 23 different countries participated. All of these patients were having fairly significant non-cardiac surgeries. Half of the patients were randomly assigned to start on a beta blocker (extended-release metoprolol) several hours prior to surgery and for 30 days afterwards. The other half of the patients were treated with a placebo pill for the same period of time. In the 30 days following surgery, there was a 27% reduced risk for heart attack in the metoprolol group, and a lower rate of the irregular heart rhythm, known as atrial fibrillation. However, the risk of death was increased by 33% and the risk of stroke was doubled for people on metoprolol. Treated patients were more likely to have dangerously low blood pressure and dangerously slow heart rates for parts of their recovery. This study did not look at cardiac surgeries. Beta blockers play an important role in cardiac surgery, such as coronary artery bypass, by preventing heart rhythm changes after the operation. People who take a beta blocker to treat high blood pressure, heart failure or other heart disease should definitely not stop their beta blocker before an operation, whether it is a cardiac or non-cardiac surgery. If you are planning non-cardiac surgery and you are not taking a beta blocker now, this study might convince you and your doctors that temporary use of a beta blocker would pose more of a risk than a benefit for you. Taking a beta blocker during and after surgery still could be worthwhile for some people who are at high risk for heart attack, particularly if there is ample time to adjust to the dosage before surgery. This study will significantly change the thinking and practice of doctors with surgical patients. Back to top More News in Brief - Fall Prevention Training Is Essential After Stroke. A study in the May 16 issue of Stroke: Journal of the American Heart Association showed a startling figure: In the first six months after a stroke, 37% of people will have at least one significant fall; 77% of the falls occur in the home. To prevent falls, it is helpful to strengthen the lower legs with exercises and participate in a balance-training program. Good lighting in the home is essential along with appropriate rails or grab-bars, non-skid rugs and removal of any obstacles that pose a falling threat.
- Benefits Come Quickly After You Quit Smoking. In an article from the May 7 issue of the Journal of the American Medical Association (JAMA), researchers analyzed how quickly heart and cancer risks improve when people quit smoking. The researchers used data collected from the Nurses' Health Study, a large observational study of more than 100,000 women's health and lifestyle habits funded by the National Institutes for Health. Women who quit smoking were followed over time and compared with women who did not quit. Within five years of quitting, the women who stopped smoking had a 13% lower risk of premature death. Much of this improvement was explained by lower rates of heart attack and stroke. The women who quit smoking also had a 21% lower risk of dying from lung cancer within 5 years, compared with women who did not quit.
- Major Groups Recommend Home Blood Pressure Monitors. The American Heart Association, American Society of Hypertension and the Preventive Cardiovascular Nurse's Association recommended in a joint statement that everyone with high blood pressure should regularly measure their blood pressure using a home monitor. The statement was published May 22 in Hypertension: Journal of the American Heart Association. Home monitors can help determine whether the blood pressure reading in the doctor's office is accurate, or whether it is artificially high due to anxiety ("white coat hypertension"). Home monitoring can help people stick with their medication regimen and lead to quicker action when blood pressure is not well-controlled.
Back to top Mary Pickett, M.D. is a lecturer for Harvard Medical School and an assistant professor of medicine at Oregon Health & Science University. At OHSU, she is a director of student programs and she oversees teaching of students and medical residents. She practices general internal medicine in Portland, Ore.
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