Doctors diagnose it by conducting a physical exam that's often unreliable, but that's about to change.
William used to be a professional welterweight fighter. Today, he's fighting a different yet powerful opponent--Parkinson's Disease.
"I got Parkinson's," said William, "Parkinson's ain't got me."
Debora Bergstrom is also battling the condition. Parkinson's causes tremors, balance problems and speech issues. The mom of three was diagnosed 4 years ago by a neurologist.
"She told me to stand up, walk; she rotated my arms and hands and said yes, you have Parkinson's," said Bergstrom.
Many people wait years before getting that diagnosis. Doctors physically examine patients for the telltale symptoms to formulate their conclusion. But their observations aren't always accurate. 40 percent of Parkinson's patients are undiagnosed and at least 10 percent who are diagnosed don't really have it.
Doctor Louise Thomson says a new imaging test called DaTscan, is giving doctors a glimpse inside the Parkinson's brain. DaTscan is the first FDA approved diagnostic imaging test for the assessment of movement disorders such as Parkinson's. First, doctors inject patients with a tracer. Then they scan the brain for dopamine, a chemical that Parkinson's patients lack. Thomson says the test can tell doctors if the patient has Parkinson's or just a tremor disorder, which is treated differently.
"This is a game changer," said Thomson, "It's going to lead to earlier diagnosis and clearer diagnosis for patients with tremor."
An earlier diagnosis means patients can start treatments sooner, potentially slowing symptom development of this devastating disease. For William and Debora, every symptom-free day matters. Now, doctors are one step closer to figuring that out.