George Hendrickson gives his son Eliyah, 3, a drink after giving him medication while picking him up from school Wednesday, Feb. 24, 2016, in the parking lot of Hawthorne Elementary School in Sioux Falls. Eliyah suffers from Dravet Syndrome, also known as severe myoclonic epilepsy of infancy (SMEI), which is a type of epilepsy. South Dakota Senators voted 20-15 to advance a measure that would legalize the use of cannabidiol (CBD), a derivative of marijuana, for severe seizure disorders. Hendrickson said they've basically seen a complete neurological regression in Eliyah since mid-January when his seizures increased. "His ability to walk, stand against objects, walk with assistance, feed himself, chew food, make eye contact and interact physically and play, we've lost all of that," Hendrickson said, "he's basically gone back to being six-months old again." Hendrickson explained that for Eliyah CBD would be used as seizure control. "If it can become our main seizure control, it's better to be on it than it is the pharmaceuticals--in our view--because you look at all the known side effects of the pharmaceuticals and they're horrendous," Hendrickson explained.