A new test is giving doctors and patients a clearer picture of Parkinson’s disease, and Parkinson’s syndrome. Nuclear medicine specialists at Orlando Regional Medical Center (ORMC) are now using DaTscan – the first Food and Drug Administration-approved imaging agent to help diagnose patients with suspected Parkinsonian syndromes, such as Parkinson’s disease — a neurodegenerative disorder that afflicts nearly 1.5 million Americans, with an additional 50,000 to 60,000 new cases identified each year. ORMC is the first hospital in Central Florida certified to perform the test.
“With a more timely diagnosis we can manage the disease earlier, which leads to better outcomes for patients,” said Mary Hart MD, nuclear medicine chair, ORMC.
DaTscan, by GE Healthcare, is performed by injecting a tiny dose of a radioactive tracer, followed by a painless imaging procedure called SPECT (single photon emission computed tomography), to search for dopamine transporters (DaT). Dopamine, a brain chemical responsible for movement control diminishes in patients with Parkinson’s disease causing tremor, slowness of movement, muscle stiffness and balance problems. The tracer binds to the dopamine transporters and the scan produces images that provide visual evidence of the presence of dopamine transporters. The entire procedure requires three to four hours.
“A normal image resembles two large commas or crescents in the brain,” said Dr. Hart. “Because dopamine levels drop in patients with Parkinson’s disease and other Parkinsonian syndromes, one or both of the normal crescents is not visible or may appear more like a period or oval.”
While a diagnosis of Parkinson’s syndromes presents a challenge, the confirmation of the correct diagnosis can make a difference in treatment and progression of the disease.
“DaTscan studies show upwards of 90 percent accuracy in diagnosing early, mid and late stages of Parkinson’s disease,” said Dr. Hart. “When presented with more reliable diagnostic data from the DaTscan, studies show that the treating physician alters his choice of treatment more than 40 percent of the time. This evidence based affect on clinical management is important because it shows that the procedure leads to more appropriate treatment for improved outcomes.”
More definitive testing may avoid or end years of expensive testing for a conclusive diagnosis, which can be delayed for as many as six years. Clinical examinations, particularly early in the disease when symptoms are slight, can be inconclusive or misleading. Incorrectly labeling Parkinson’s syndromes as an unrelated movement disorder, such as essential tremor, can delay effective treatment.
“‘Knowledge is power,’ especially in the case of medical conditions,” said Dr. Hart. “This test helps patients and their families face, and overcome the fears and frustrations inherent with uncertain diagnoses. If we can confirm that a patient does not have Parkinson’s disease, or Parkinson’s syndromes, it is a big relief. Confirmation of Parkinson’s disease is just as critical to know because it helps the patient and family members plan for the future.”
by Sabrina Childress
