Ten healthy female students at a rural, co-ed North Carolina high school had repeated bouts of seizures, swooning and hyperventilation over a four-month period in 2002 - an outbreak that experts are calling an example of mass hysteria.

The first girl began experiencing seizures in August. Over the next few weeks, more girls began to show the same symptoms. The attacks escalated throughout the fall months, then appeared to taper off by the winter holiday break.

One student experienced at least 30 attacks. All but one of the girls had no history of seizures.

Most of the attacks occurred while students were at school but not in class, such as during breaks or in hallways between classes.

Five of the students were current or former cheerleaders, but only two shared a classroom. None appeared to be experiencing more than their normal share of life’s stressors, such as family problems or history of depression.

To investigate why these girls were experiencing seizures, Dr. E. Steve Roach of Wake Forest University in North Carolina and Dr. Ricky L. Langley of the North Carolina Department of Health and Human Services interviewed the students and their parents, and spoke with teachers and the school nurse. They also reviewed the students’ class schedules and medical records, and tested the high school’s buildings for environmental contaminants.

Writing in the Archives of Neurology, the authors conclude that the evidence “strongly suggested” that the girls were experiencing an episode of mass hysteria, defined as “the simultaneous occurrence of related signs or symptoms with a psychogenic basis in multiple individuals in a group.”

The authors explain that they suspect mass hysteria because the episodes largely occurred at the same place, there was no other obvious explanation for them, and all of the girls’ symptoms appeared and disappeared at around the same time.

Moreover, previous research has shown that mass hysteria typically strikes women more often than men, and may also occur more frequently in children and adolescents, they write.

Many episodes of mass hysteria are triggered by harmless odors or when a “prominent” person begins showing symptoms, they add. No environmental trigger was found, and since the first girl to experience seizures was a cheerleader and four others were as well, Roach and Langley suggest that seeing the symptoms in these girls “could have encouraged additional students to develop similar episodes.”

Unfortunately, mass hysteria was not seriously considered as a possibility until after some time had passed, the authors note. By then, some girls said they had been teased, were unable to drive, and their mysterious conditions had placed a strain on family and personal life.

Moreover, “had the similarities between these individuals been noted earlier,” some of the girls could have avoided some unnecessary diagnostic procedures and treatment, the investigators add.

“Although the underlying dynamics that initiate and perpetuate mass hysteria are poorly understood, its prompt recognition allows physicians to avoid unnecessary tests and treatments and to reassure both the affected individuals and the public,” they write.

SOURCE: Archives of Neurology, August 2004.