Parkinson's Disease Diagnosis

Parkinson's Disease diagnosis can be tricky. Without looking at the cells of the brain itself, there are no definitive tests, exams or studies which can be performed that make the diagnosis. Because there are other diseases which can share some of the common symptoms of Parkinson's disease, it can be difficult to distinguish this disease from others and make a confident diagnosis.

However, an accurate diagnosis is required to initiate the most appropriate management and treatment plan for Parkinson's disease. The treatment and prognosis of other similar diseases may be quite different.

Therefore, patients with symptoms suggestive of Parkinsons disease generally undergo a thorough work-up by a competent neurologist with experience in diagnosing Parkinsons. This generally consists of a thorough history and physical examination, focusing on the patient's symptoms, their personal and family history and an examination of the nervous system, focusing on motor function which is most affected by Parkinson's.

A Parkinson's disease diagnosis is considered a "diagnosis of exclusion". Because there is no gold-standard test that can be performed to confirm the diagnosis, all other similar or related diseases must be ruled out before the confident diagnosis of Parkinsons Disease can be made. This may include tests and imaging studies (such as brain MRI or CT scan) to help rule out other potential causes of the patient's symptoms.

Even though there are other diseases which can present with similar symptoms, most do not overlap 100% in the details of their presentation. Therefore, careful care is taken to document all the signs and symptoms in each patient to make sure Parkinsons Disease is the best fit diagnosis, rather than some other diagnosis.

Other movement disorders which may have some similar symptoms include Huntington's Disease, multisystem atrophy, Lewy body dementia, progressive supranuclear palsy, corticobasal degeneration and others. Likewise, Alzheimer's disease, the most common cause of dementia, should be distinguished from Parkinsons, in which dementia can occur but is generally a later finding in more advanced disease. Other causes of tremor (such as essential tremor or "limb-shaking TIAs) and abnormal gait (normal pressure hydrocephalus, etc.) should be ruled out as well. As you can see, because the differential diagnosis is quite large, an experience physician is needed to help make a Parkinson's disease diagnosis.

Once the diagnosis is confident, then management options can be discussed.