Late Onset Multiple Sclerosis (MS)

Helpful Highlights

• MS can appear at any age but most commonly manifests between the ages of 20 and 40, and it affects women two to three times as often as men.

• The average age of people with MS is increasing, but knowledge of the disease in people over age 55 remains sparse.

• Almost one million people in the United States have MS, making it one of the most common causes of neurological disability among young adults in North America.

• Late-onset MS (LOMS) makes up about 5% of MS cases.

What it is

Multiple sclerosis (MS) is an autoimmune disease wherein the body destroys the protective fatty covering (myelin sheath) of nerve fibers in the brain and spinal cord and leaves scarring (sclerosis, also called lesions or plaques). This causes communication problems between the brain and the rest of the body. The disease can also cause permanent damage or deterioration of the underlying nerve fibers.

MS is an unpredictable disease that affects people differently. Some people with MS may have only mild symptoms while others may lose their ability to see clearly, write, speak, or walk.

Compared to classic MS, late-onset MS (LOMS) is characterized by a more progressive course and greater delay in diagnosis, and unlike adult-onset MS, the first presentation of LOMS is usually motor dysfunction and disability.

Causes and risk factors

The cause(s) of MS is not fully understood but various factors are believed to trigger the immune system to attack the myelin sheath. According to the National Institute of Neurological Disorders and Stroke, possible causes include:

• Genetics - an inherited susceptibility to development)

• Environmental factors - specifically smoking or vitamin D deficiency

• Infections - specifically the Epstein-Barr virus (EBV), which causes infectious mononucleosis

• Immunosenescence - age-related changes in the immune system

Symptoms and diagnosis

The symptoms of LOMS are similar to those of early-onset MS, though may present slightly differently. For instance, some symptoms may occur more frequently in LOMS, there may be fewer relapses, and as mentioned earlier progression is generally faster.

Symptoms may include fatigue, difficulty walking, numbness or tingling, muscle weakness, and problems with coordination and balance. Research suggests that the key symptoms of LOMS are motor dysfunctions, sensory disturbances, and visual impairments.

It can be difficult to diagnose MS at any age, but it is typically harder with LOMS, as doctors must consider other age-related causes when making a diagnosis. There is a significant overlap of these symptoms with other age-related conditions.

Medical professionals typically rely on a combination of clinical history, neurological examinations, and advanced imaging techniques such as magnetic resonance imaging (MRI) to assess the presence of demyelinating lesions in the central nervous system. Additionally, cerebrospinal fluid analysis and evoked potential tests may be employed to support the diagnosis.

Tips for those caring for a loved one with MS

If you are caring for someone with MS, the National Multiple Sclerosis Society suggests that you:

• Seek support. Be careful not to neglect your own emotional and physical health.

• Plan for unpredictability. You should not avoid making plans with your loved one but allow for flexibility in any arrangements and keep things simple to avoid distress. It is also a good idea to have contacts who can help at short notice.

• Get help. Sometimes, there are too many tasks to take on all alone. Consider involving family or friends, or if feasible, hiring help with household chores or caregiving tasks.

• Look into available financial resources. Depending on where you live, you may have access to assistance programs to help with caregiving.