Diagnosis

Evoked Potential (EP) Test. This is a simple and painless electrical test of nerve function that assesses how long it takes nerve impulses from the eye, ear, or skin to reach the brain.

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) scans are important diagnostic tools in MS and are used for diagnosing multiple sclerosis, tracking changes over time, and helping to determine treatment effectiveness.

Click the icon to see an image of a brain MRI.

Making a Diagnosis and Tracking the Disease. Magnetic resonance imaging (MRI) scans can detect bright patches that indicate injured tissue (lesions) caused by MS. Such lesions may also indicate other conditions such as infections, migraines, or clots. Importantly, a very sensitive MRI technique using enhancement by an contrast material called gadolinium can indicate recent activity by showing if the blood-brain barrier has been broken down (the first step in the development of MS lesions). Detecting lesions and treating MS early in the disease process may help reduce progression. Many experts therefore now advocate performing a brain MRI as soon as symptoms appear.

Once diagnosed, periodic follow-up MRIs can be used to track the disease and effectiveness of treatments in two ways:

• By distinguishing new lesions from old ones
• Revealing increasing or decreasing numbers of lesions within the central nervous system over time

Unfortunately, neither the rate nor the number of new or growing lesions necessarily predicts whether symptoms will worsen or if the patient will develop secondary progressive MS.

Measuring Atrophy in Brain and Spinal Cord. As myelin, axons, oligodendrocytes, and neurons are destroyed, the brain begins to shrink. Processing MRI images to determine brain volume may be a useful way to monitor progression and treatment effects. MRI can also detect shrinkage in the spinal cord, which is proving to be a very strong marker of disease progression. A variation of MRI, magnetic resonance spectroscopy (MRS), provides information on the biochemistry of the brain, and may be particularly helpful in detecting this destructive aspect of MS.