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    Diagnosing Parkinson’s Disease

    By Frederic H. Fahey, DSc


    Frederic H. Fahey, DSc, serves as of Nuclear Medicine Physics and PET at Children’s Hospital Boston and is an associate professor of Radiology at Harvard Medical School. He is currently president of the Society of Nuclear Medicine and Molecular Imaging. Fahey has written 54 journal articles and published 15 book chapters and serves as an expert consultant for the International Atomic Energy Agency.

    Parkinson’s disease affects as many as one million people in the United States, yet thousands may not even know they have it. While the most obvious symptoms of the disease are movement-related, including shaking, rigidity, slowness of movement, and difficulty with walking; sometimes Parkinson’s can be very mild or mimic other neurodegenerative disorders, making it hard to diagnose. For those living with these symptoms, it can often be frustrating.

    A diagnosis of Parkinson’s disease is usually made based on the patient’s medical history and a neurological examination. The physician conducts an interview specifically looking for principal motor symptoms (movement problems) that would exclude a diagnosis of Parkinson’s disease. Common presentations of the disease are usually easily diagnosed. Diagnosis can be difficult, however, when the symptoms are not fully typical of Parkinson’s disease.

    It’s important for those living with neurodegenerative disorders to know with what disease they are dealing so they can proceed with the appropriate treatment. With an accurate diagnosis of Parkinson’s disease, physicians can predict the course of the disease and personalize treatment for each individual patient. Without the correct diagnosis, patients can suffer needlessly or experience harmful side effects of inappropriate therapies.

    A new test for Parkinson’s disease now is available that may help these individuals who are in limbo, without a definitive diagnosis. A new diagnostic tool was approved last year by the U.S. Food and Drug Administration that, when used as an adjunct to clinical evaluation, can greatly enhance the diagnostic accuracy for patients with suspected Parkinson’s disease. The agent—iodine-123 Ioflupane—is used with single photon emission computed tomography (SPECT) to image the function of the dopamine transporter in the brain. Loss of function in the dopamine transporter can be indicative of the early stages of Parkinson’s disease. Results from the scan can help physicians differentiate Parkinson’s disease from essential tremor, neuroleptic (psychiatric medication for psychosis)-induced parkinsonism, and psychogenic parkinsonism.

    For those living with neurodegenerative disorders, this new non-invasive and painless imaging test is a welcome advance in helping to better determine the cause of the many frustrating symptoms of neurological disorders. Knowing the root of the problem, as well as the severity and progression of the disease, is essential to getting a treatment plan that can make a difference.


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