Posts Tagged seizure activity
PHILADELPHIA — Costly in-hospital video electroencephalography (EEG) monitoring for epilepsy may soon be replaced by wearable seizure detection devices — at least that seems to be where the technology is headed.
Some of the new devices, all relatively small and discreet and variously worn on the arm, scalp, and wrist, were highlighted here at the American Epilepsy Society (AES) 69th Annual Meeting.
One of these monitoring units detects generalized tonic-clonic (GTC) seizure activity. The Brain Sentinel GTC Seizure Detection and Warning System appears to have a very low false-positive rate, José Cavazos, MD, PhD, a board-certified epileptologist and cofounder of Brain Sentinel, the company behind the new device, reported.
The portable device, currently under US Food and Drug Administration regulatory review, provides real-time analysis of surface electromyography (sEMG) data to detect GTC seizures. It also has an alarm that alerts caregivers in the event of such a seizure.
The longitudinal clinical data that it captures should help guide treatment, Dr Cavazos said.
The system includes a discreet detection device, base station (laptop), and cellular wireless router. The detection device is attached to the biceps with an adhesive patch that has three pre-gelled sEMG electrodes.
“We have fine-tuned the algorithm to understand the recruiting properties of muscle cells in the biceps muscle,” Dr Cavazos told a press briefing. “This is a direct reflection of brain activity; meaning that if you stimulate the brain, muscles are going to contract.”
He added that collecting information from muscles, which are connected directed via neurons to the brain, may be less susceptible to artefacts than devices that collect biometric signals through other means.
A new study, funded by the company and presented here, compared the device to “gold standard” video EEG (vEEG) in patients at 11 epilepsy monitoring units across the United States. All parties were blinded to the seizure alert status of the device.
The analysis included 7326 hours of sEMG and vEEG data collected in 142 participants wearing the device. When the device was properly used, its sensitivity to identify GTC seizures was 100% compared with vEEG review. The false-negative rate was 0.48 per 8 hours.
“This device certainly can provide some peace of mind to some patients,” said Dr Cavazos.
Asked to comment on Dr Cavazos’s device, R. Edward Hogan, MD, professor and director, Adult Epilepsy Center, Washington University, St Louis, Missouri, thought it was promising in helping to track seizures, which can be useful in determining whether treatments are working.
Tracking seizures has traditionally been difficult, said Dr Hogan. “Overall, people remember only about half of their seizures,” he said. “So right off the bat, there’s a problem with people not remembering just by the nature of what happens to the brain during seizures.”
An effective seizure tracker can also improve safety. Because seizures can cause injuries — patients often fall and hurt themselves — a convenient device that alerts caregivers and others of a seizure “would be great,” said Dr Hogan.
He was encouraged by the low false-positive rate of this new device. “You don’t want a system that goes off all the time.”
The study authors, he said, “have looked at the pattern of how the muscle contraction changes,” and the false-positive rate they picked up with the device was “pretty good.”