Diagnosing a movement disorder is complex. In many cases it requires ruling out other possible causes of symptoms. This is especially important since treatment for one disorder may have no effect on another condition. The diagnosis process is likely to take some time and may require appointments with several specialists, including neurologists (physician specializing in the brain and nerves), rheumatologists (physician specializing in muscles) or ophthalmologists (physician specializing in the eyes).

A physical examination and neurological examination are often vital to the diagnosis of movement disorders. During these examinations, a physician will test balance, reflexes and eye movement. The examinations will also check for other signs and symptoms that may be indicative of certain movement disorders or other diseases.

The physician will also likely review the patient’s medical history. This will include a description of the patient’s symptoms, including details on when symptoms began and how long they typically last. Many of the movement disorders are inherited, so the patient may also be asked about the occurrence of similar symptoms or movement disorders in family members.

In addition to these basic examinations, other tests are likely to be required to diagnose a movement disorder. These may include:

• Blood test, urine test and spinal tap. Fluid samples may be tested for enzymes and other indicators of movement disorders. In rare cases, blood may also be tested for antibodies that may indicate Sydenham’s chorea. DNA tests may also be performed on fluid samples to identify or eliminate disorders resulting from genetic mutations.
  
  
• Imaging tests. Several non-invasive or minimally invasive techniques allow physicians to view a patient’s brain, nerves and muscles. In some case, these tissues may show damage that is characteristic of certain diseases. Types of imaging tests include MRI (magnetic resonance imaging), CAT scan (computed axial tomography), PET scan (positron emission tomography) and SPECT scan (single photon emission computed tomography).

• Electromyogram (EMG) and nerve conduction velocity (NCV) tests. Measures electrical activity of muscles and nerves. Results may indicate portions of the body with reduced or blocked signal activity. Certain movement disorders may be recognized by characteristic results of these tests.
  
  
• Electroencephalogram (EEG). Measurement of the electrical activity of the brain using electrodes placed on the scalp. Brain damage may be suspected when the electrical activity occurs in atypical patterns or is greater or less than expected.
  
  
• Muscle or nerve biopsy. Removing a sample of muscle or nerve for microscopic examination. Many of the movement disorders result from damage to muscles or nerves that may become apparent when viewed through a microscope.