Friday, June 23, 2006

Seizures are not a synonym for Epilepsy

Not all seizures are caused by epilepsy, but psychological seizures can be hard for even trained medical professionals to distinguish from epileptic seizures, new research has found.

Psychological - or psychogenic - non-epileptic seizures are triggered by psychological conditions such as emotional trauma, not by the abnormal electrical activity in the brain that causes epileptic seizures. However, treating people who have psychological seizures with epilepsy drugs or other epilepsy therapies can produce unwanted, potentially fatal, consequences, the researchers warned.

A trio of new studies, in the June issue of Neurology, explore the issue of psychogenic non-epileptic seizures (PNES), which affect between 5 percent and 20 percent of people thought to have epilepsy.

"(PNES) are a neurological manifestation of an underlying psychological conflict. These are seizures, but they're not epileptic seizures," explained Dr. W. Curt LaFrance Jr., an assistant professor of psychiatry and neurology at Brown Medical School, and director of neuropsychiatry at Rhode Island Hospital in Providence.

"Any way that an epileptic seizure can present, a non-epileptic seizure can present," he added. That's why it can be so hard to tell the difference between these seizures until a video electroencephalogram (vEEG) to measure electrical activity in the brain is conducted.

LaFrance co-authored an editorial in the journal focused on psychogenic non-epileptic seizures. He noted that it takes an average of seven years before someone who experiences PNES receives a correct diagnosis. During that time, they are often treated with increasing doses of anti-epileptic medications, paralytic drugs and sometimes mechanical ventilation.

Side effects from these medications and treatments can be significant and the costs extremely high. In his editorial, LaFrance estimated that the expense of repeated medical tests and treatments for PNES may run as high as $900 million annually in the United States.

Diagnosing PNES in the emergency room can be especially challenging, according to one of the studies in Neurology. That's because the patients are in the middle of a seizure and don't respond to anti-epileptic medication. That could mean one of two things - the patient has what's known as "refractory" epilepsy, which doesn't respond to drugs, or he or she could be having a non-epileptic seizure.

Refractory epilepsy "is a neurological emergency that requires rapid treatment escalation, including the administration of intravenous anticonvulsant anesthetics," said the study's lead author, Dr. Martin Holtkamp, from Charite Universitatsmedizin in Berlin, Germany. "These drugs have a lot of side effects, such as respiratory depression and patients are ventilated mechanically. The decision to administer anesthetics has to be made immediately. The majority of patients with PNES are misdiagnosed and consequently treated for true refractory epilepsy, and severe and fatal side effects have been reported."

In Holtkamp's study, the researchers found that people with PNES were often younger, often already had port systems for intravenous access implanted, needed higher levels of medications and had lower blood levels of creatine kinase.

Another study, this one from St. Joseph's Hospital and Medical Center in Phoenix, found that one possible way to spot PNES is to note whether or not the patient's eyes remain open during a seizure. This study looked at more than 200 people who had seizures, 52 of whom were eventually diagnosed with PNES. Of those 52, 50 had closed eyes during their seizures. Of the 156 with epilepsy, 152 had open eyes during their seizures.

"These findings suggest that ictal (seizure) eye closure is a highly reliable indicator for PNES," the authors wrote.

The third study included 267 people with PNES. Twenty-six were over the age of 55. Because PNES is generally considered a disorder of younger people - those under 50 - the Scottish researchers wanted to see if there were any significant differences in older people with PNES. And, in fact, the researchers did find differences. The older group was more likely to be male and not have suffered sexual abuse. They were also more likely to have other serious physical health problems than younger people with PNES.

In many cases, LaFrance explained, people with PNES have a history of trauma or abuse. Sometimes a bad accident or even brain surgery can trigger these types of seizures. And, he added, the seizures sometimes don't start until years after the triggering event.

What's most important, he said, is to get an accurate diagnosis.

"Video EEG is the gold standard. People can be fooled by just using history alone," LaFrance said.

Once PNES has been diagnosed - and it's possible to have both PNES and epilepsy - then the patient should be weaned off anti-epileptic medications, or at least have the dose lowered in the case of mixed PNES and epilepsy. Generally, people with PNES are treated with psychotherapy or medications other than anti-epileptics to treat their seizures, he said.

Additionally, LaFrance said, "We still need good, controlled treatment trials for patients with non-epileptic seizures to advance from the limited treatment research that presently exists in the literature. He and his colleagues are currently conducting three different research trials for the treatment of PNES, including medication to treat co-existing anxiety and depression, cognitive behavioral therapy and family therapy.

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