. >> this is the magic ivig. this is what we've been waiting for. they finally flew it in last night. >> reporter: for 26-year-old tessa gallo waiting four months for a shipment of medication is just part of the medical ordeal. there's painful iv hookup. >> i took close to three hours to find her vein. >> reporter: and the 12 hours it takes to get the medication infused and on this day it all became too much. >> this is the worst disease i've ever been through. it's not easy for me. >> reporter: tessa suffers from an autoimmune disorder called pans or pediatric acute onset neuropsychiatric syndrome that struck her one day when she was a happy, healthy 13-year-old. >> overnight on july 8th, 2011, tessa a drugically changed. >> reporter: the dramatically changed. >> reporter: a patient's antibodies attack the part of their brain that regulate behavior causing ocd, tics and other syndromes. >> became psychotic, developmentally delayed and i knew something was wrong. unfortunately, it took about ten months to figure out her diagnose, that it was actuall