CHECKUP : WOMAN'S STROKE LINKED TO BACKWARD EXTENSION OF NECK.

A routine trip to the beauty parlor may have caused a healthy 42-year-old woman to suffer a stroke, British doctors report.

While her hair was being washed, the woman's neck was extended backward into a sink, which apparently caused the stroke by damaging an artery in her neck, the doctors wrote in a recent letter to the international medical journal the Lancet.

Upon leaving the salon, the woman felt uneasy walking and noticed a numbness in her left hand. Over the next two days, the numbness on the left side of her body increased until she could no longer use her left leg. Tests taken after she was admitted to the hospital showed that damage to a neck artery was preventing the proper flow of oxygen-rich blood to the brain.

After treatment with drugs to break up blood clots at the site of the injury, the woman made a good recovery, according to the report.

Cardiac headaches?: Headaches that begin during exercise and go away with rest may be a sign of heart disease, according to New York researchers. They reported on seven patients who suffered so-called cardiac headaches. In each case, headache during exercise disappeared after the patient had been treated for heart disease with drugs, surgery or both.

Vertigo reality: British researchers may have found a nondrug treatment for the dizziness of vertigo: having a person rotate inside a 3-D flight simulator.

In a study of 15 people with benign positional vertigo, a common condition characterized by spinning sensation, nausea and dizziness, 70 percent of the patients had no symptoms after being rotated backward in the device, which was originally designed as an arcade game.

By comparison, 15 additional patients with the disorder were rotated forward in the flight simulator, but none of their symptoms abated.

According to the researchers, the nauseating spinning sensation of vertigo is caused by free-floating particles in the inner ear that move within the ear's semicircular canals when a person moves his head.

Simply getting in and out of or rolling over in bed triggers brief dizziness in people with the condition, according to the American Academy of Neurology in Minneapolis.

By rotating the head and body backward in a full circle, the researchers, led by Dr. Thomas Lempert of the National Hospital for Neurology in London, speculated that these particles would move out of the semicircular canal, thereby curing vertigo.

Chemo by the clock: Timing may be of the essence when it comes to giving chemotherapy to cancer patients, French researchers report.

Administering chemotherapy in accordance with the body's internal ``clock,'' or circadian rhythms, is less toxic and more effective than the standard method, the researchers said in the international medical journal the Lancet.

Chronotherapy is the relatively new practice of timed treatment. This approach to drug delivery currently is being applied to several diseases including high blood pressure and asthma.

Researchers, led by Dr. Francis Levi of the Hopital Paul Brousse in Villejuif, suspected that giving the anti-cancer drug therapy at times when cancer cells are most active would result in the best outcomes, with more cancer cells and fewer healthy cells destroyed. They determined these times to be 4 a.m. and 4 p.m.

In the study of 186 patients with advanced colorectal cancer, half of the patients received the same amount of the anti-cancer drugs around the clock for five-day courses at 16-day intervals. Others received fluctuating doses of chemotherapy, with peak doses at 4 a.m. and 4 p.m., over each five-day course.

The researchers concluded that 51 percent of the chronotherapy group responded well to their treatment, compared with 29 percent of the standard treatment group.

And the chronotherapy group continued to respond to treatment for a little over six months, compared with under five months for those in the standard chemotherapy group.

In addition, the rate of severe gastrointestinal side effects was reduced five-fold in the chronotherapy group, compared with the standard treatment group. And the chronotherapy method halved the rate of other side effects such as loss of sensitivity in the hands, the researchers reported.

Three years after treatment, however, similar numbers of patients in both groups were still alive - just over 20 percent, the study showed.