Diagnosing Parkinson’s Disease

NYU Langone doctors diagnose Parkinson’s disease, which is a brain disorder that progressively affects coordination, speech, and fine motor tasks, such as writing.

The condition is caused by a loss of function of nerve cells—called neurons—in the brain, including those that release a chemical called dopamine. When levels of dopamine and other brain chemicals are too low, a person can develop a variety of symptoms, including difficulty with movement, speech, mood, and thinking.

Symptoms and Risk Factors

Motor, or movement-related, symptoms of Parkinson’s disease may include shaking in the arms, legs, hands, and face. Stiffness, slow movements, and trouble with coordination and balance are also associated with this condition.

People with Parkinson’s disease may also have difficulty with speech. For example, a person with Parkinson’s disease may speak in a monotone or quiet voice.

Other symptoms can include fewer facial expressions, also known as “facial masking,” and difficulty with writing, buttoning, or other fine motor tasks. Later in the course of this condition, a person may have trouble swallowing and experience worsening balance and frequent falls.

Even early on, Parkinson’s disease can cause nonmotor symptoms, including anxiety, depression, constipation, a reduced sense of smell, urinary incontinence, dizziness when standing, fatigue, and sleep disorders. As the disease progresses, a person may experience hallucinations or cognitive impairment.

Parkinson’s disease can occur at any age, but it most commonly affects people older than age 50. The condition is likely caused by a combination of genetic and environmental factors. Pesticide exposure and drinking well water, for example, have been associated with an increased risk of Parkinson’s disease.

Diagnostic Exam

Often, a diagnosis of Parkinson’s disease can be made during an appointment with a movement disorders specialist and is based on symptoms alone. Further testing is typically not necessary. However, doctors sometimes order imaging studies, such as an MRI scan, to help confirm a diagnosis.

NYU Langone specialists in movement disorders are trained to recognize and diagnose Parkinson’s disease and other movement disorders, including unusual and rare disorders, or unusual presentations of the condition. Our specialists usually diagnose Parkinson’s disease during a clinical examination.

To make or confirm a diagnosis, physicians at NYU Langone’s Fresco Institute for Parkinson’s and Movement Disorders start by taking a thorough medical history in which they review your symptoms and ask about any medications you are taking. They then perform a detailed neurological examination, in which they look for signs of Parkinson’s disease or related disorders.

Your doctor rules out other possible causes of your symptoms, such as the side effects of medications, rare disorders similar to Parkinson’s disease, stroke, or normal pressure hydrocephalus.

MRI Scans

Your doctor may order an MRI scan to look for evidence of disorders other than Parkinson’s disease, such as a prior stroke or normal pressure hydrocephalus. In this imaging test, a magnetic field and radio waves create computerized, three-dimensional images of the brain.

DaTscan™

A DaTscan™ uses a small amount of a radioactive tracer, which is injected into a vein. It then travels to the brain and binds to a protein that is present in neurons that release dopamine. This protein is known as the dopamine transporter.

A machine similar to but smaller than an MRI machine, called a single photon emission computed tomography, or SPECT, scanner, is used to measure the levels of dopamine transporter binding to the tracer in the brain.

People with Parkinson’s disease and related disorders have reduced levels of binding compared with people who have other movement disorders, such as those who have essential tremor, in which dopamine transporter binding is normal. This test can help your doctor confirm or rule out a diagnosis of Parkinson’s disease.