How Is MS Diagnosed?

Understanding How Doctors Test for MS and Make a Diagnosis

Currently, no individual symptoms or single laboratory test can be used to diagnose a person with MS. Physicians must instead rely on several strategies to determine if enough criteria are met to confidently make a diagnosis and rule out other possible causes of symptoms the patient is experiencing. Some of these strategies for diagnosing MS include:

  • Thorough examination of a patient’s medical history
  • Magnetic resonance imaging (MRI)
  • Evoked potential (EP) testing
  • Spinal fluid analysis

Criteria for Diagnosing Multiple Sclerosis

To make a proper MS diagnosis, physicians must:

  • Find evidence of damage in at least two separate areas of the central nervous system (CNS) – including the brain, spinal cord and optic nerves
  • Find evidence of damage occurring at least one month apart
  • Rule out all other possible diagnoses

The Revised McDonald Criteria makes the process easier and more efficient in diagnosing MS in new patients, even if they have only experienced one MS attack. The updated criteria include specific guidelines for MRI (magnetic resonance imaging), VEP (visual evoked potentials) and cerebrospinal fluid analysis to speed up MS diagnosis.

Tools Doctors Use to Test for MS

While there is no one definitive MS test, physicians use the following tools to help in diagnosing MS in patients:

MRI: MRI is the best imaging technology to detect scarring or MS plaques in different parts of the central nervous system (CNS). This test can also distinguish old MS plaques from those that are currently active or new.

Visual Evoked Potential (VEP): Evoked potential (EP) tests record the nervous system’s electrical response to stimulation to isolated sensory pathways – such as visual, auditory or general sensory. Because slowed response time is a result of damage to myelin, EPs can often find the existence of scarring along nerve pathways, something neurological exams may miss. Visual evoked potentials are found to be most useful in confirming MS diagnosis.

Blood Tests: Currently, there are no definitive blood tests for diagnosing MS, but they can be used to rule out other conditions that may mimic MS symptoms, including Lyme disease, collagen-vascular diseases, rare hereditary disorders and acquired immune deficiency syndrome (AIDS).

Learn More from Shepherd Center

Looking for more information about MS? Explore our other multiple sclerosis educational resources:

Please contact us at 404-352-2020 if you have additional questions about multiple sclerosis.