Seizures most common during full moon

By Charnicia E. Huggins

NEW YORK (Reuters Health) - The idea that the full moon can influence mental or physical behavior may be more than mere superstition. New study findings suggest that people with epilepsy experience more seizures during a full moon.

"Our results supported the ancient belief of periodic increased seizure frequency during full-moon days," study author Dr. Panagiotis Polychronopoulos, of the University of Patras Medical School in Greece, told Reuters Health.

"However, this could not be generalized in the general population, since we studied a sample of patients with epilepsy," he cautioned.

The different phases of the moon have long been associated with changes in human behavior, according to folklore, with some believing that the lunar phases can trigger epilepsy or psychiatric disturbances. Studies investigating the potential association have yielded conflicting results.

Seizures in epileptics may be triggered by various environment-related phenomena, the researchers add. Epileptics and many emergency room physicians and nurses believe that moon can influence a patient's mental health status.

Polychronopoulos and his colleagues investigated this relationship in a study of 859 epileptic patients - mostly women -- who visited an emergency department from 1999 to 2003. The researchers reviewed all neurology-related records of those admitted for epileptic seizures, and correlated their visits with the various the phases of the moon during the same period.

Overall, there was a "striking increase" in the number of seizures that occurred among men and women on days in which there was a full moon, the investigators report in the journal Neurology.

Slightly more than one third (34.2 percent) of seizures occurred on full-moon days versus 21.4 percent of seizures that occurred on days in which there was a new moon. Also, 21.9 percent of seizures occurred during last quarter lunar days and 22.5 percent of seizures occurred during first quarter lunar days.

"According to our results, we might assume that the full moon could be considered as a triggering factor of seizures," Polychronopoulos told Reuters Health.

The reason for the association between full moons and more frequent seizures is unknown. Other researchers have suggested it may be due to some interaction between the patients and the environment, while others have proposed that the vulnerable to seizures may be due to certain environmental or inherent factors specific to each individual.

Polychronopoulos and his co-authors suggest that "lunar phases and especially the full moon are included in the large variety of seizure-inducing factors such as stress, insomnia, and weather changes." Still, the exact mechanism by which various phases of the moon trigger seizures is unclear, they add.

According to Polychronopoulos, "whether a direct effect of the moon or an indirect effect via the influence of patients' behavior -- change of activities, particularly at night -- should be linked to increased seizure frequency remains unclear."

"In our opinion, the latter is more likely," he added.

SOURCE: Neurology, May 9, 2006.]