Tests for MS

There is no simple test for MS. To make a diagnosis, neurologists typically use a combination of tests to rule out other conditions and look for signs of MS.

To diagnose MS, a neurologist will follow a set of guidelines called the McDonald Criteria. This involves several tests to see if the criteria are met. Watch the ‘Testing for MS’ animation series below to learn more about these different tests.

Neurological Exam

Neurological exams play a key role in diagnosing Multiple Sclerosis (MS). These exams help neurologists evaluate how well your central nervous system is working. MS can damage the protective coating around nerves called myelin, slowing down signals and causing symptoms like muscle weakness or numbness.
During the exam, a neurologist will check your reflexes, balance, coordination, and other functions to pinpoint where your symptoms might be coming from. While this test alone can’t confirm MS, it’s an important first step in the diagnostic process.

Magnetic resonance imaging (MRI)

Magnetic Resonance Imaging, or MRI is currently the most accurate, non-invasive imaging method to detect demyelination and diagnose MS. An MRI scan uses powerful magnets to create detailed pictures of the brain and spinal cord. This helps doctors spot areas of damage which could be signs of MS. MRI scans can help doctors see how much damage has occurred and where it has taken place.

Lumbar puncture or spinal tap

A Lumbar Puncture (spinal tap) is a useful tool that can help doctors diagnose Multiple Sclerosis (MS). During this test, a doctor takes a small sample of the fluid around your brain and spinal cord, called cerebrospinal fluid, or CSF. The sample is sent to a lab for signs of MS, such as antibodies in the fluid. These antibodies indicate that your immune system is active in your brain and spinal cord.

Evoked potentials tests

An Evoked Potentials Test help doctors understand how quickly messages travel along your nerves. These tests can be a useful tool for diagnosing multiple sclerosis particularly at the earlier stages of MS before symptoms appear. Your brain generates electrical currents when processing information from your senses. Evoked potential tests measure the time it takes for your brain to receive signals from the eyes, ears and skin. If MS has damaged myelin, the protective coating around your nerves, messages from your nerves may travel more slowly.

Blood tests

There is no definitive blood test to diagnose MS but certain blood tests can help rule out or confirm other conditions with similar symptoms.