Late-Onset MS: Discover What's Different

Late-Onset MS (After Age 50) Differs in Important Ways

Pensive senior woman
Juanmonino/Getty Images

Do you or someone you care about have multiple sclerosis (MS)? If so, at what age was it diagnosed? Late-onset MS is commonly defined as the occurrence of the first symptoms after age 50. (Adult-onset MS is most often diagnosed in people who are in their mid-20s to 30s.)

MS “Basics”

MS is a chronic disease of the central nervous system (CNS), which includes your brain, spinal cord, and optic (eye) nerves.

In MS, your immune system attacks nerve cells and the fatty myelin sheath surrounding them, causing scarring.

The myelin scar tissue “jams” communication between your brain and your body. The resulting distortion and blocking of messages between the brain and spinal cord leads to the symptoms and disability that occur in MS.

According to the National Multiple Sclerosis Society, MS is two to three times more common in women than in men.

It’s not yet known what “turns on” the immune system response in a person who gets MS. However, this appears to occur in people with an inherited (genetic) susceptibility to the disease who are exposed to one or more environmental “triggers.”

Late-Onset MS: The Differences and the Diagnosis

Elderly people are diagnosed with MS in an estimated 4% to 9.6% of cases. Unfortunately, the disease is harder to diagnose in people over 50, for a variety of reasons.

MS has not been studied in the elderly as much as in younger adult patients.

This is important because the disease may vary in a number of ways between younger and older people, including different symptoms. So symptoms of late-onset MS may not suggest the diagnosis to doctors who are more familiar with MS symptoms in younger adults.

In late-onset MS, the person’s symptoms can easily mimic those of other disorders. Conditions with MS-like symptoms that can make it harder to diagnose MS include:

Symptoms of late-onset MS can be mistaken for signs of normal aging. For example, on a magnetic resonance imaging (MRI) scan of the brain (an important diagnostic test for MS), a doctor may mistake the white-matter brain damage caused by MS for brain changes due to blood vessel (vascular) disease.

Some symptoms of late-onset MS that can overlap with conditions of normal aging include:

You may be interested to learn that a person’s age, when diagnosed with MS, also affects the course of the disease.

Although CNS damage in late-onset MS is similar to that seen in young adults, older people usually start showing signs of disability sooner. They are also more likely to be diagnosed with progressive MS, in which the symptoms are ongoing (as compared to the relapsing-remitting form of the disease) and get worse as time passes.

A prompt and accurate diagnosis is as critically important in late-onset MS as it is at any age. Why? Because promptly starting treatment with disease-modifying medications (DMDs) can reduce MS attacks and new lesions as well as slow the progress of the disease.


"Study Explains Why MS Is More Common in Women Than in Men." Healthline News (2014).  

"Definition of MS." National Multiple Sclerosis Society (2016).

"When MS strikes later in life."

"How is a multiple sclerosis diagnosis made?"

Continue Reading