Tests and diagnosis

By Mayo Clinic Staff

To diagnose multiple sclerosis, doctors will evaluate you, review your medical history and review your symptoms. Doctors will also conduct a physical examination. Doctors may order several tests to diagnose multiple sclerosis and rule out other conditions that may have similar signs and symptoms.

Blood tests

Analysis of your blood can help rule out some infectious or inflammatory diseases that have symptoms similar to multiple sclerosis.

Spinal tap (lumbar puncture)

In this procedure, a doctor or nurse inserts a needle into your lower back to remove a small amount of spinal fluid for laboratory analysis. Doctors test the fluid for abnormalities associated with multiple sclerosis, such as abnormal levels of white blood cells or proteins.

This procedure also can help rule out viral infections and other conditions that can cause neurological symptoms similar to those of multiple sclerosis.

Magnetic resonance imaging (MRI)

An MRI uses powerful magnets and radio waves to produce detailed images of your brain, spinal cord and other areas of your body. An MRI can reveal lesions, which may appear due to myelin loss in your brain and spinal cord. However, these types of lesions also can be caused by rare conditions, such as lupus, or even common conditions such as migraine and diabetes. The presence of these lesions isn't definitive proof that you have multiple sclerosis.

Doctors may inject a dye into a blood vessel that may help highlight "active" lesions. This helps doctors know whether your disease is in an active phase, even if no symptoms are present.

Evoked potential test

This test measures electrical signals sent by your brain in response to stimuli. An evoked potential test may use visual stimuli or electrical stimuli in which short electrical impulses are applied to your legs or arms. This test can help detect lesions or nerve damage in your optic nerves, brainstem or spinal cord even when you don't have any symptoms of nerve damage.

Dec. 15, 2012