“Is my MS slowly worsening, or am I just getting older?" 

Many of my patients, especially those over 40, ask this question.  Although it seems like a fairly basic question, it may actually be difficult to answer.  The answer has important implications for optimizing one’s treatment regimen.

MS, aging, and deconditioning
There are symptoms of MS, especially those associated with progressive, or slowly worsening, MS, which may mimic aging.  These symptoms include fatigue or heaviness of the legs, reduced walking endurance, decreased walking stability, slow decrease in vision, or simply an overall decrease in endurance.  These symptoms may be mild and may very slowly worsen over time.

To add to the potential confusion, decreased exercise, which may occur along with aging, may also cause symptoms that are similar to those of MS, such as leg heaviness, decreased endurance, and decreased walking stability.  This is known as physical deconditioning, or, more simply, being out of shape.  Deconditioning may not have a large impact on day-to-day function in those with no neurological problems.  However, in those with MS (and other neurological conditions), a relatively small decline in the amount of exercise may cause a significant reduction in function. 

Distinguishing between MS and aging
How can one tell the difference between aging and worsening MS?  This is a complex question.  As a result, it should definitely be discussed with your physician.  Areas that should be considered include:

Symptoms
It is important to note the specific symptoms that you have and how these symptoms develop over time.  These features of your symptoms may be very helpful in differentiating between aging and MS.  For example, symptoms that develop slowly over months, especially decreased endurance and visual difficulties, may be aging-related.  Slowly developing physical symptoms that develop in the setting of decreased exercise may be due to aging as well as physical deconditioning.  Symptoms that are more likely to be MS-related include those that develop over the course of days, involve impaired sensation or coordination, or affect a specific portion of the body, such as one side of the body or one leg or one arm.

Neurological exam
As part of an evaluation, a neurologist does a neurological exam.  This exam, which provides valuable information about the functioning of the nervous system, may help to distinguish between aging and worsening MS.  If the exam has changed in a way that a very specific part of the nervous system is involved, such as a particular region of the spinal cord, then this is more likely to be MS-related.  In contrast, aging is more likely when a person has complaints of decreased endurance or decreased walking stability but the neurological exam has not changed. 

MRI
Like the neurological exam, MRI provides specific information about the nervous system.  While the neurological exam shows the function of the nervous system, MRI shows the structure of the nervous system.  Since aging does not show any readily apparent changes on MRI and MS may cause white spots known as lesions, MRI may help determine whether one’s symptoms are due to aging or MS.

Conclusion
Distinguishing between aging and worsening MS is extremely important.  If MS is worsening, then it is important to change one’s MS treatment regimen.  Likewise, if one is experiencing aging-related changes, then modifying the MS treatment will not be helpful and, if it causes side effects, could actually be harmful.  For situations in which it is thought that physical deconditioning may play a role, a trial of increased exercise may help clarify the situation.

Due to the complexity and importance of these issues, it is very important to discuss your particular situation with your physician.