Diagnostic Tests for Neurological Disorders - Crozer-Keystone Health System - PA

Diagnostic Tests for Neurological Disorders

Evaluating and diagnosing damage to the nervous system is complicated and complex. Many of the same symptoms occur in different combinations among the different disorders. To further complicate the diagnostic process, many disorders do not have definitive causes, markers, or tests.

In addition to a complete medical history and physical examination, diagnostic procedures for nervous system disorders may include the following:

Electroencephalogram (EEG)

An electroencephalogram detects abnormalities in the brain waves or electrical activity of the brain. During the procedure, electrodes consisting of small metal discs with thin wires are pasted on the scalp. The electrodes detect tiny electrical charges that result from the activity of the brain cells. The charges are amplified and appear as a graph on a computer screen or as a recording that may be printed out on paper. Your doctor then interprets the reading.

Electromyography (EMG)

Electromyography (EMG) measures muscle response or electrical activity in response to a nerve’s stimulation of the muscle. The test is used to help detect neuromuscular abnormalities.

During the test, one or more small needles (also called electrodes) are inserted through the skin into the muscle. The electrical activity picked up by the electrodes is then displayed on an oscilloscope (a monitor that displays electrical activity in the form of waves). An audio-amplifier is used so the activity can be heard.

EMG measures the electrical activity of muscle during rest, slight contraction, and forceful contraction. Muscle tissue does not normally produce electrical signals during rest. When an electrode is inserted, a brief period of activity can be seen on the oscilloscope, but after that, no signal should be present.

After all of the electrodes have been inserted, you may be asked to contract the muscle, for example, by lifting or bending your leg. The action potential (size and shape of the wave) that this creates on the oscilloscope provides information about the ability of the muscle to respond when the nerves are stimulated. As the muscle is contracted more forcefully, more and more muscle fibers are activated, producing action potentials.

Medical Imaging

Computed tomography (CT) Scan

Computed Tomography (CT or CAT scan) is a noninvasive diagnostic imaging procedure that uses a combination of X-rays and computer technology to produce horizontal, or axial, images (often called slices) of the body. A CT scan directs multiple narrow beams of X-rays (radiation) around a specific body site that create a multi-dimensional view of a patient’s body.

Magnetic resonance imaging (MRI)

Magnetic Resonance Imaging (MRI) is a radiation-free, usually non-invasive way to produce high-quality pictures inside the body from multiple planes. MRI picks up the body’s radiofrequency signals and converts them into three-dimensional images.

PET/CT

A PET/CT scan allows physicians to measure the body's abnormal molecular cell activity to detect cancer, brain disorders and heart disease. PET scans are simple, painless, and fast, providing real life answers to better diagnose illness, guide treatment options, and give patients ultimate control over their critical and vital healthcare decisions.

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