Trained Dogs Not Always Detecting Epileptic Seizures
Sometimes they're picking up on psychological seizures, study claims
TUESDAY, Jan. 23, 2007 (HealthDay News) -- Many dogs that are trained to detect epileptic seizures are actually predicting psychological seizures rather than "true" epileptic attacks, new research suggests.
"It's important to define what kind of seizures these patients have because we use anti-convulsant drugs to treat epilepsy, and we use other therapies for the nonepileptic seizures," explained Dr. Gregory L. Krauss, an associate professor of neurology at Johns Hopkins University School of Medicine in Baltimore.
Krauss was lead author of one of two papers documenting the phenomenon in the Jan. 23 issue of Neurology.
"These papers by no means indicate that seizure dogs aren't doing something, but that many of the patients who request seizure dogs represent a small population of patients with seizures that are psychologically based," said Dr. Orrin Devinsky, director of the Comprehensive Epilepsy Center at New York University. "That specific group, who often have co-morbid psychiatric illness, are the ones that are most actively seeking out seizure dogs."
Specially trained "seizure dogs" allegedly can pick up on extremely subtle physiological changes in their human companion that may begin 45 to five or 10 minutes before an actual attack. The dogs then warn the humans so they can find a safe environment or take precautionary measures.
The two studies looked at a total of seven people who had seizure-response dogs. Most were monitored with video electroencephalogram (EEG) tests to detect abnormal electrical activity in the brain, such as that which causes epileptic seizures.
Four of the participants had no abnormal electrical activity during their seizures and were diagnosed instead with psychogenic nonepileptic seizures (PNES). Another person did not have an EEG test but was still diagnosed with psychological seizures. Two of the individuals did have epilepsy.
"We found that six of the eight patients who obtained dogs didn't have epilepsy," Krauss said. Since the report was submitted for publication, the researchers saw three more patients with seizure-response dogs. Two had PNES and one had epilepsy (her dog paced before seizures). Those with PNES were referred for psychological or psychiatric treatment.
"Nonepileptic seizures are probably much more common than people recognize," Devinsky said.
"About 10 percent of the patients we see at epilepsy centers don't have epilepsy but have psychogenic seizures," Krauss added. "It's a physical manifestation of an emotional problem, a form of abnormal coping. A lot of them are stress reactions."
"We're just cautioning people who provide these dogs and the public seeking out these dogs to make sure they have a firm diagnosis of epilepsy before matching them with this specially trained dog," he continued.
A second study in the same issue of the journal found that some patients with epilepsy can predict, on their own, when they are about to have an attack.
The finding could one day impact treatment: Individuals who can accurately predict an attack may be able to take preventive medication. It might also lead to an enhanced quality of life for patients.
Learn more about seizure dogs at the Epilepsy Foundation.