Over the past century, many medical problems have been solved or tamed: polio and influenza, for example. But many more such mysteries continue to vex researchers, as well as those who suffer from them. 48 Hours takes an inside look at a few of these enigmas. Melissa's Story: After an auto accident, a young Colorado woman named Melissa Holley is paralyzed. She travels to Israel to undergo an experimental procedure that may allow her to walk again. She is the first human subject for the treatment, which tries uses hormones to encourage the spinal nerves to regrow. Will it work? Threatening to kill the pilot and take the airplane down, a responsible family man goes berserk on an Alaska Airlines flight. Did an encephalitis virus in his brain cause him to lose control? A dedicated father finds that his son is afflicted with a rare genetic disease. He begins a long, exhausting quest for a cure, raising money and encouraging research. Can he help save his son? Hope Young, music therapist and founder of the Center for Music Therapy in Austin, Texas, uses music to help treat brain injuries. She and her staff treat patients suffering from Parkinson’s, Alzheimers, traumatic brain injury, Tourette’s syndrome, autism, depression and several other diseases. They usrhythm and melody to relieve symptoms and, in some cases, offer hope for a cure.