(Hood River, OR)  --  The public's help is being sought in the search for a 15-year-old boy who has a serious brain condition.  Benjamin Nuissl [[ NOOS-ul ]] vanished Monday during a family bike ride in Hood River.  Benjamin's family tells KOIN-TV he has a condition that gives him a tendency to wander and sometimes get himself in trouble.  Benjamin Nuissl has a scar on the right side of his head.  He's about six-foot, with blondish-brown hair.  He has been spotted in downtown Hood River near the Salmo Street Springs and the Gateway Shopping Plaza.