Epilepsy or Psychological Seizures?

June 12, 2006 -- A surprisingly large percentage of epilepsy patients who do not respond to drug treatment don't really have epilepsy at all. It often takes a decade or longer for these patients to get a correct diagnosis -- but new research finds there are simple clues that can make a correct diagnosis easier.

A patient's eye movements during a seizure can help distinguish seizurescaused by epilepsy from those psychological in nature.

That is the finding from one of three new studies examining the diagnosis of non-epileptic seizures published in the June issue of the journal Neurology.

Videos of Seizures

Researchers from the Barrow Neurological Institute in Phoenix, Ariz. reviewed videos of 221 people having seizures. They found that 50 of the 52 people having non-epileptic seizures closed their eyes during the event, while 152 of 156 having epileptic seizures kept their eyes open or blinked until the seizure was over.

Researcher and neurologist Steve S. Chung, MD, says that observation could potentially shorten the time to an accurate diagnosis for many patients.

"We need to confirm these results, but these findings could help guide us toward the appropriate diagnosis early on," he says. "In our experience, family members can accurately describe whether a patient's eyes were open or closed during a seizure."

Getting a Correct Diagnosis

Roughly one in three patients with a diagnosis of epilepsy is not helped by anti-seizure drugs. It is believed that as many as a third of these patients don't have epilepsy at all.

Instead of being caused by abnormal electrical activity in the brain, as is the case with epilepsy, the non-epileptic seizures are psychological in origin.

University of South Florida neurologist Selim R. Benbadis, MD, tells WebMD that it takes an average of seven to nine years for patients with psychological non-epileptic seizures to get a correct diagnosis.

Recording Electrical Signals

This can usually be done with a video-electroencephalogram (EEG), but that test is not performed as often as it should be, Benbadis says. An EEG records electrical signals in the brain through sensors placed on the scalp. In the video-electroencephalogram, patients are videotaped while their EEG is recorded, usually over the course of several days.

"Neurologists don't tend to suspect non-epileptic seizures early on, even when the patient is not responding to drugs," Benbadis says. "They often try different drugs for years without success."

Understanding the difference between epileptic and non-epileptic seizures could help raise suspicion earlier and help a large number of patients avoid years of unnecessary drug treatment, Benbadis says.

Health Trauma May Trigger Seizures

In a second study, researchers compared 26 people whose non-epileptic seizures began when they were aged 55 or older with 241 people whose non-epileptic seizures started at a younger age.