What is Multiple Sclerosis? Understanding the Basics of MS

Multiple sclerosis (MS) is a potentially disabling disease of the brain and spinal cord (central nervous system). In MS, the immune system attacks the protective sheath (myelin) that covers nerve fibers and causes communication problems between your brain and the rest of your body. Ultimately, the disease can cause the nerves themselves to deteriorate or become permanently damaged.

I’m Dr. Oliver Tobin, a neurologist from Mayo Clinic, and this guide will walk you through the essentials of multiple sclerosis: its nature, who it affects, symptoms, diagnosis, and available treatments. Whether you’re seeking information for yourself or a loved one, we aim to provide you with a comprehensive understanding of MS.

Understanding Multiple Sclerosis: An Attack on Myelin

Multiple sclerosis is an autoimmune disease where the body’s immune system mistakenly attacks myelin, the protective covering of nerve fibers in the brain, spinal cord, and optic nerves. Think of myelin as the insulation surrounding an electrical wire. This insulation is crucial for the efficient transmission of nerve signals. When myelin is damaged in MS, it exposes the nerve fibers, disrupting and slowing down, or even blocking, nerve signal transmission. Damage to the nerve fibers themselves can also occur.

While the body has some capacity to repair myelin damage, this repair is often imperfect, leading to the formation of lesions or scars. This scarring is the hallmark of the disease, hence the name “multiple sclerosis,” meaning “multiple scars.”

It’s important to understand that while everyone experiences a natural loss of brain and spinal cord cells with age, MS accelerates this process in affected areas. When MS damages a region of the brain or spinal cord, nerve cells in that area die off at a faster rate compared to healthy regions. This nerve cell loss is typically a slow process, unfolding over decades, and often manifests as a gradual onset of walking difficulties over several years.

Multiple sclerosis is categorized into different types, with relapsing-remitting multiple sclerosis (RRMS) being the most prevalent. RRMS is characterized by periods of new or worsening symptoms (relapses) followed by periods of remission.

Who is at Risk for Multiple Sclerosis? Exploring Risk Factors

The exact cause of MS remains unknown, but research has identified several factors that can increase the risk of developing the condition or trigger its onset.

Age: While MS can manifest at any age, it most commonly begins between 20 and 40 years old.
Vitamin D and Sunlight Exposure: Low vitamin D levels and limited exposure to sunlight, which is essential for the body’s vitamin D production, are linked to a higher risk of MS. Individuals with MS and low vitamin D levels often experience more severe disease progression.
Weight: Being overweight increases the likelihood of developing MS, and for those with MS, it can contribute to more severe disease and faster progression.
Smoking: Smoking in individuals with MS is associated with more frequent relapses, worsened progressive disease, and more pronounced cognitive symptoms.
Sex: Women are significantly more susceptible to relapsing-remitting MS, being two to three times more likely to develop it than men.
Genetics: The general population has a relatively low risk of MS (around 0.5%). However, this risk doubles to approximately 1% if a parent or sibling has MS, indicating a genetic component.
Infections: Certain viral infections have been implicated in MS, notably the Epstein-Barr virus (EBV), the cause of mononucleosis.
Latitude: Higher prevalence rates of MS are observed in regions further from the equator, including Canada, the northern United States, New Zealand, southeastern Australia, and Europe. This geographical pattern may be related to sunlight exposure and vitamin D levels.
Ethnicity: White individuals, particularly those of Northern European descent, have the highest risk of MS. People of Asian, African, and Native American descent have a lower risk.
Autoimmune Diseases: Having pre-existing autoimmune conditions such as autoimmune thyroid disease, pernicious anemia, psoriasis, type 1 diabetes, or inflammatory bowel disease slightly elevates the risk of MS.

Recognizing the Symptoms of Multiple Sclerosis

MS symptoms can vary widely from person to person and can depend on the location of affected nerve fibers. Symptoms can also fluctuate in severity and may come and go (relapses and remissions).

Relapse symptoms typically develop over 24 to 48 hours, last for several days to weeks, and then gradually improve, often with near-complete recovery (80 to 100 percent).

Common symptoms of MS include:

Vision Problems: Optic neuritis, or inflammation of the optic nerve, can lead to vision loss in one eye.
Muscle Weakness: Loss of strength or power in an arm or leg.
Sensory Disturbances: Numbness, tingling, or a “pins and needles” sensation, often starting in the legs and ascending.
Spasms: Muscle stiffness and involuntary muscle spasms.
Fatigue: Persistent and overwhelming tiredness, one of the most common and debilitating symptoms.
Depression: Mood changes and feelings of sadness or hopelessness.
Incontinence: Bladder and bowel control problems.
Sexual Dysfunction: Difficulties with sexual function.
Walking Difficulties: Problems with balance, coordination, and gait, often developing gradually over time.

It’s crucial to note that these symptoms can also be associated with other medical conditions. Therefore, experiencing these symptoms does not necessarily mean you have MS, but it warrants medical evaluation.

Diagnosing Multiple Sclerosis: A Multifaceted Approach

Currently, there is no single definitive test to diagnose MS. Diagnosis relies on a combination of factors and the process involves ruling out other conditions that can mimic MS. Doctors use a set of criteria and assessments to establish a diagnosis.

Four key features are crucial for diagnosing MS:

Typical MS Symptoms: Presence of characteristic symptoms such as vision loss in one eye, limb weakness, or sensory disturbances lasting more than 24 hours.
Physical Examination Findings: Neurological examination to identify physical signs consistent with MS, such as abnormal reflexes, muscle weakness, or sensory deficits.
MRI (Magnetic Resonance Imaging): MRI scans of the brain and spinal cord are essential to visualize lesions or plaques characteristic of MS. It’s important to note that brain MRIs can show abnormalities in a significant percentage of people over 40 due to age-related changes, so the specific pattern and characteristics of lesions are crucial for MS diagnosis.
Spinal Fluid Analysis (Lumbar Puncture): Analysis of cerebrospinal fluid obtained through a spinal tap can reveal specific markers indicative of MS, such as oligoclonal bands.
Blood Tests: Blood tests are performed to exclude other diseases that may present with similar symptoms to MS.
OCT (Optical Coherence Tomography) Test: An OCT scan, a non-invasive imaging technique, may be recommended to measure the thickness of nerve layers at the back of the eye, which can be affected in MS.

Treatment and Management of Multiple Sclerosis

While there is currently no cure for MS, significant advancements have been made in treatments to manage the disease, reduce relapses, slow progression, and alleviate symptoms.

The cornerstone of MS management is a multidisciplinary medical team. Working with a team of specialists is essential to address the diverse symptoms and challenges associated with MS.

For managing MS relapses, doctors may prescribe corticosteroids to reduce inflammation and shorten the duration of attacks. In cases where relapse symptoms are unresponsive to steroids, plasmapheresis (plasma exchange), a procedure similar to dialysis, may be considered. Plasma exchange has shown to be effective in improving symptoms for approximately 50% of individuals who do not respond to steroids.

Disease-modifying therapies (DMTs) are a crucial aspect of long-term MS management. There are over 20 FDA-approved DMT medications available, designed to prevent MS attacks, reduce the formation of new MRI lesions, and slow disease progression. The choice of DMT is individualized based on factors such as disease activity, subtype of MS, and patient preferences.

Living Well with Multiple Sclerosis: A Holistic Approach

Living with MS can present challenges, but with appropriate medical care, support, and lifestyle adjustments, individuals with MS can lead fulfilling lives.

Rehabilitation: Consulting with physiatrists, physical therapists, and occupational therapists is vital to address physical limitations and improve function. Physical therapy helps maintain mobility, strength, and balance. Occupational therapy focuses on adapting daily tasks and environments to enhance independence.
Physical Activity: Regular physical activity is strongly encouraged for people with MS. Exercise can help manage fatigue, improve muscle strength, balance, and overall well-being.
Mental Health Support: Addressing mental health is crucial. Maintaining social connections with friends and family, engaging in hobbies, and seeking support groups can combat isolation and depression. It’s important to be kind to yourself, acknowledge limitations, and adjust plans as needed, as energy levels can fluctuate day to day. Counseling and therapy can provide valuable coping strategies.
Ongoing Research: Scientists are actively engaged in research to deepen our understanding of MS, develop more effective treatments, and ultimately find a cure.

By taking a proactive and holistic approach to managing MS, focusing on medical care, lifestyle adjustments, and emotional well-being, individuals with MS can live full and meaningful lives. For further information and resources, please explore more videos and resources at mayoclinic.org. We wish you the best in your journey to understanding and managing multiple sclerosis.