Diagnosis of Movement Disorders
Diagnosis of movement disorders involves taking a family history and a history of symptoms, and performing a physical examination (including neurological examination) and various diagnostic tests (e.g., blood tests, imaging tests).
Blood tests may include a complete blood count (CBC), a creatine kinase test, and a DNA analysis. In some cases, a cerebrospinal fluid (CSF) analysis also is performed.
Cerebrospinal fluid analysis involves performing a spinal tap, or lumbar puncture. In this procedure, about 2 tablespoons of cerebrospinal fluid is drawn into a needle inserted between two lumbar vertebrae and then examined under a microscope.
Imaging tests, including computed tomography (CT scan), magnetic resonance imaging (MRI scan), and positron emission tomography (PET scan), may be used to detect damage (e.g., shrinkage) in the basal ganglia, structural abnormalities, and stroke.
An electromyogram (EMG) and an electroencephalogram (EEG) also may be performed. These tests are used to monitor electrical activity within the body and can help detect nerve and muscle disorders. EMG involves placing electrodes on the skin (surface EMG) or into the muscle (intramuscular EMG) to record electrical activity of the muscle. In an EEG, electrodes are attached to the scalp and connected to a machine that records electrical impulses in the brain.
A muscle biopsy may also be performed to distinguish between nerve and muscle disorders. This procedure, which is performed under local anesthesia, involves making a small incision and removing a sample of muscle for microscopic evaluation. Following the procedure, patients may experience minor pain and bruising at the biopsy site for about 1 week.