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Stopping a Seizure in a Flash... of Light

"If I ever have a seizure, just step back and watch the show. Or, if you feel up to it, you can move away any dangerous objects from where I'm shaking and maybe throw me a pillow, but don't get too close because apparently I kick and bite. I might yell and scream, too, so feel free to tell me to shut up. Just know that I probably won't be listening."

Those simple, frank instructions on how to deal with an epileptic seizure came from the mouth of my college roommate, Sam. A modest genius, an epileptic, and now a medical student at Northwestern University, Sam knew what he was talking about. In the event of an epileptic seizure, there's really little that a bystander can do besides spectate. Just let the violent shakes, convulsions, and cries run their course. (Though a 911 call is definitely in order if the seizure lasts longer than five minutes.)


a condition that affects approximately 2 million Americans, occurs when

permanent changes in brain tissues cause the brain to be too excitable

or jumpy, resulting in repeated, unpredictable seizures. Unfortunately, there's currently no safe and effective method for

stopping a seizure, so as Sam suggested, watching and waiting truly is the best option.

But that could one day change.

shutterstock_117246937.jpgIn a study just published in Nature Neuroscience, scientists at Stanford University illuminate a technique effective at halting epileptic seizures in lab rats by using targeted flashes of light to stop specific neurons from firing in the thalamus, a brain region that relays sensory and motor information to the cerebral cortex.

The researchers accomplished the feat in two parts. First off, by examining rats suffering epileptic seizures as a result of stroke, they gleaned that thalamus activity was clearly involved with causing or maintaining seizures.

Second, the researchers sought to ascertain whether or not mitigating this activity would alleviate or even stop a seizure altogether. To do this, they expressed a light-activated ion channel within the affected neurons of the thalamus. The channel was designed to reduce neuronal firing when flashed with yellow light. A device containing multiple electrodes was implanted in the thalamus to emit the light. At seizure onset, the implant was activated, which promptly halted excited neuronal activity as well as the seizure. The rats immediately resumed normal behavior.

Going further, the scientists designed an implantable system capable of detecting and silencing seizures within one second of initiation. The method proved reliable for nearly a year after being implanted in two rats with stroke-induced chronic epilepsy.

"Disruption of seizures at their onset with closed-loop control, via a brief targeted inhibition of thalamocortical cells... is a promising potential therapeutic approach for otherwise untreatable epilepsies," the researchers say, "as it would not affect normal brain activity between seizures, as might other therapeutic approaches, such as surgical lesions or chronic treatment with pharmacological agents."

Using flashes of light to halt seizures is not remotely close to being ready for use in humans, but the research suggests that targeting and silencing neurons within the thalamus can provide relief from seizures caused by a stroke or brain injury. Perhaps, one day, epileptics might not have to fret about seizing at inconvenient times, and their friends won't have to stand idly by and watch.

(Image: Epilepsy Road Sign via Shutterstock)