Werewolves notwithstanding, the full moon does not influence the frequency of epileptic seizures, reports a University of South Florida study.

"Contrary to the myth, epileptic seizures are not more common during a full moon," said Selim Benbadis, MD, associate professor of neurology and neurosurgery at the USF College of Medicine. "In fact, we found the number of epileptic seizures was lowest during the full moon and highest in the moon's last quarter."

The study was published in the journal Epilepsy & Behavior.

Dr. Benbadis said he decided to investigate the possible relationship between phases of the moon and the frequency of seizures after repeatedly hearing patients claim that their seizures were triggered or worsened by the full moon. "Even some health care professionals believe this, but it's never been scientifically tested," he said.

Dr. Benbadis and his colleagues statistically analyzed 770 seizures recorded over three years in the epilepsy monitoring unit at Tampa General Hospital. Monitoring brain activity in this unit allows physicians to confirm a diagnosis of epilepsy, determine precisely the location and type of seizures a patient experiences and evaluate the best treatment option.

The researchers divided the seizures into epileptic seizures, those caused by electrical disruptions in the brain, and psychogenic nonepileptic seizures, those that are not caused by brain electrical disruptions and tend to be emotional. The most epileptic seizures, 152, were recorded in the moon's last quarter. The researchers found epileptic seizures decreased to their lowest number, 94, during the full moon.

The full moon appeared to slightly, but not significantly, increase psychogenic nonepileptic seizures.

Other studies exploring the potential connection of lunar phases with heart attacks, birth rates, suicides, and psychiatric hospital admissions have found little or no association. Why then, does the belief persist that the moon may have some mystical gravitational power over our health and well being?

In the past, before physicians recognized that epilepsy was caused by processes in a person's own body, the disease's frightening seizures were associated with demonic possession and witchcraft, Dr. Benbadis said. "Some people still seem to like poetic, mysterious and irrational explanations for puzzling diseases like epilepsy."

- University of South Florida Health