By Tara Haelle
Three such devices -- a patch, an arm band system and wrist-worn monitors -- were reviewed in three separate studies and presented this week at an American Epilepsy Society meeting in Philadelphia.
They do not yet have U.S. Food and Drug Administration approval as medical devices for recording seizures. However, their success could be very helpful to neurologists treating patients with epilepsy, said Dr. Clifford Segil, a neurologist at Providence Saint John's Health Center in Santa Monica, Calif. Segil was not involved in the research.
"Wearable technology being used by neurologists is not as up-to-date as technology being used by cardiologists in 2015," Segil said. "Seizures are a very diverse group of disorders, which are not easily managed, and work still needs to be done on how to record brain waves in an abbreviated fashion that will allow neurologists and patients to have an early warning system."
One device, an EEG Patch, is a roughly 1-inch square patch worn on the scalp for seven days. Another is Brain Sentinel, a device worn with a strap on the biceps that measures skeletal muscle electrical activity from the skin (surface EMG) and is under FDA review, according to the researchers. The third method relies on existing wearable technology that records heart rate, blood oxygen in the arteries and electrical conductivity in the skin.
Another epilepsy expert agrees that more detection tools are needed.
"Doctors are often making decisions about medication dose changes, surgical candidacy or decisions about activity restrictions, such as driving, based only on the clinical history provided by the patient," said Dr. Sean Hwang, an attending neurologist at North Shore-LIJ's Epilepsy Care Center in Great Neck, N.Y., who was not involved in the research. "These devices may offer another tool to quantify seizures more reliably, which could have significant impact on treatment decisions."
An estimated 1.2 million U.S. patients with epilepsy have seizures that cannot be managed or controlled, according to background information from Mark Lehmkuhle, chief executive officer and chief technical officer of Epitel Inc., maker of the EEG patch. His research was funded by Epitel, the Epilepsy Foundation and the State of Utah Economic Development Council.
The best way to identify appropriate treatment for seizures requires long-term electroencephalogram (EEG) testing of brain wave patterns in the hospital, an expensive, time-consuming process, said Lehmkuhle. Therefore, most doctors rely on a seizure diary kept by the patient.
"A lot of people with seizures have a hard time reporting the number of seizures they have," Lehmkuhle said. Patients also cannot track seizures that might occur in their sleep.
"Not all seizures involve whole body shaking, tongue biting and loss of consciousness," Segil explained. "Unfortunately, many seizure patients are poor historians as seizures scramble patients' brain electricity and cause amnesia and confusion," he said.
The EEG Patch, a waterproof, self-contained patch with an internal battery, is placed on the scalp in the places where seizures are thought to originate, based on data from an EEG in a clinic. The patch logs and transmits EEG data in the patient over a week, after which the patch is discarded.
The goal of using an EEG Patch is to allow doctors to adjust medication dosage while controlling seizures or to determine how effective a newly added drug or therapy is, Lehmkuhle said.
The Brain Sentinel, a device held by an arm strap, aims specifically to record tonic-clonic seizures, the typical convulsive seizure that lasts one to three minutes.
Dr. Jose Cavazos, co-founder of the San Antonio-based Brain Sentinel company, which funded the research on this product, said, "Generalized tonic-clonic seizures are the most severe seizure type that have the greater probability of accidental problems or injuries."
Researchers compared the Brain Sentinel's ability to detect these seizures to that of video EEG in about 140 patients. The Brain Sentinel sent an alert about 14 seconds after each seizure started and its seizure count matched up 100 percent with the video EEG. False detection of seizures occurred 0.5 times per eight hours, the researchers said.
Two wrist devices that measure heart rate were also presented at the meeting. In a test with 20 patients, 11 patients experienced 24 seizures over a total of 355 hours.
Data from this test found that patients' heart rate increased at least 15 percent during all the seizures. Also, in all but four of the seizures, blood oxygen in the arteries dropped at least 5 percent after the heart rate increase.
The researchers are working to develop a formula that uses the heart rate, blood oxygen and skin electrical conductivity to determine when a seizure has taken place more accurately than using only heart rate. That research was funded partly by the Texas Medical Research Collaborative.
"A device that could be worn between my office visits would be an incredible tool to help me manage my patient's seizure medications," Segil said.
Of the three types of devices, Segil said the patch has the most potential because the Brain Sentinel detects only big seizures, which is already relatively straightforward, and the heart rate devices use the same technology as lie detectors, which could result in "seizure lies."
The EEG Patch would be relatively inexpensive, but the greater cost would be interpreting the data, Lehmkuhle added.
Negative side effects were not reported for these devices in this research.
Data and conclusions presented at meetings are usually considered preliminary until published in a peer-reviewed medical journal.