Multiple Sclerosis – Symptoms and Causes

ByJanis Updated

Understanding Multiple Sclerosis

Multiple sclerosis (MS) is a condition in which the immune system attacks the protective covering of nerve cells in the brain, optic nerve, and spinal cord. This covering, called the myelin sheath, works like insulation on electrical wires.

When damaged, it slows or blocks nerve signals. The name โ€œmultiple sclerosisโ€ refers to the multiple scars (lesions) left behind by repeated immune attacks.

While the body tries to repair the damage, the process is often incomplete, leading to permanent nerve deterioration over time.

When parts of the brain or spinal cord are damaged by MS, nerve cells in those areas die faster than in normal areas. This process happens slowly, typically over decades, and often appears as gradual walking difficulty over several years.

People with MS experience different symptoms depending on which nerve fibers are affected. The disease impacts each person uniquely based on where the damage occurs and how severe it is.

MS can develop at any age, but most commonly appears in people between 20 and 40 years old. Women are about three times more likely than men to develop relapsing-remitting MS.

The risk for MS in the general population is about 0.5%, while those with a parent or sibling with MS have about a 1% risk.

Several factors may increase MS risk, including:

  • Low vitamin D levels
  • Limited sunlight exposure
  • Being overweight
  • Smoking
  • Certain infections (especially Epstein-Barr virus)
  • Living in northern or southern latitudes
  • European ancestry
  • Having other autoimmune conditions

Types of Multiple Sclerosis

MS is classified into different types based on how symptoms progress and how often relapses occur:

Relapsing-Remitting MS (RRMS)

This is the most common form, affecting about 85% of people initially diagnosed with MS. People with RRMS experience:

  • Clear attacks (relapses) of new or worsening symptoms
  • Symptoms that develop over 24โ€“48 hours
  • Relapses lasting days to weeks
  • Recovery periods (remissions) between attacks
  • Remissions that can last months or years with no new symptoms
  • 80โ€“100% improvement after each relapse

Common symptoms during RRMS relapses include:

  • Vision loss in one eye
  • Weakness in an arm or leg
  • Numbness or tingling sensations
  • Balance problems

Secondary Progressive MS (SPMS)

Many people with RRMS eventually transition to SPMS, characterized by:

  • Steady worsening of symptoms
  • Fewer or no relapses
  • Gradual progression rather than sudden attacks
  • Continued deterioration of neurological function

Primary Progressive MS (PPMS)

About 15% of people with MS have PPMS, which features:

  • Gradual, steady worsening from the beginning
  • No distinct relapses or remissions
  • Slower progression than other forms
  • More common in people diagnosed after age 40

Progressive Relapsing MS (PRMS)

This rare form shows:

  • Progressive disease from the start
  • Clear relapses with or without recovery
  • Continued progression between relapses

Signs and Symptoms

Multiple sclerosis (MS) affects people differently. Symptoms can change over time as different nerve fibers become damaged. Some people experience mild symptoms while others face more severe challenges.

Common MS symptoms include:

  • Numbness or tingling sensations
  • Electric-shock feelings when bending the neck (Lhermitte’s sign)
  • Poor coordination
  • Walking difficulties or inability to walk
  • Muscle weakness
  • Vision problems:
    • Partial or complete vision loss (usually in one eye)
    • Pain during eye movement
    • Double vision
    • Blurry vision
  • Dizziness and vertigo (feeling that you or your surroundings are spinning)
  • Sexual, bowel, and bladder problems
  • Extreme tiredness
  • Slurred speech
  • Memory and thinking difficulties
  • Mood changes

It’s important to note that small increases in body temperature can temporarily make MS symptoms worse. These are called pseudorelapses, not true disease flare-ups.

When to Get Medical Help

Contact your healthcare provider if you experience any concerning symptoms. Early diagnosis and treatment may help slow disease progression and manage symptoms effectively.

Causes

The exact cause of multiple sclerosis remains unknown. MS is believed to be an immune-mediated disease where a person’s immune system mistakenly attacks their own body tissues.

In MS, the immune system attacks and damages myelin, the protective fatty covering of nerve fibers in the brain and spinal cord. This myelin functions similarly to insulation around electrical wires.

When myelin becomes damaged, nerve signals travel more slowly or may be completely blocked. Scientists aren’t entirely sure why MS develops in certain individuals but not others.

Research suggests that a combination of factors likely contributes to the disease:

  • Genetic Factors: Family history can increase risk.
  • Environmental Triggers: May include certain viral infections, vitamin D deficiency, and geographic location.
  • Immune System Abnormalities: Overactive or misdirected immune responses.

Risk Factors

Multiple sclerosis (MS) can affect people of different backgrounds, but certain factors may increase the chance of developing this condition:

Age and Sex

While MS can develop at any age, it most commonly begins between ages 20 and 40. Women face a two- to three-times higher risk of developing relapsing-remitting MS compared to men.

Genetic Factors

Having a parent or sibling with MS raises your risk. Your racial background also plays a role:

  • Highest Risk: White individuals, especially those with Northern European ancestry.
  • Lower Risk: People of Asian, African, or Native American descent.

Recent research suggests MS may be more common among Black and Hispanic young adults than previously recognized.

Environmental Influences

  • Geographic Location: MS occurs more frequently in temperate climates. (Canada, the northern United States, New Zealand, southeastern Australia, and Europe).
  • Vitamin D Levels: Lower vitamin D levels and reduced sun exposure are linked to a higher MS risk.
  • Birth Month: May affect risk due to the mother’s sun exposure during pregnancy.

Health Conditions

  • Infections: Several viruses show connections to MS, particularly Epstein-Barr virus (which causes infectious mononucleosis).
  • Obesity: Being obese, especially during childhood, increases risk.
  • Other Autoimmune Diseases: Having conditions like thyroid disease, pernicious anemia, psoriasis, type 1 diabetes, or inflammatory bowel disease slightly raises MS risk.

Lifestyle Factors

  • Smoking: Smokers face a higher risk of developing relapsing-remitting MS

Emerging Research Areas

  • Gut Microbiome: People with MS may have different gut bacteria compositions than those without the condition, though further research is needed to understand this relationship fully

Complications

Multiple sclerosis can cause various health issues beyond its main symptoms. People with MS may experience:

  • Emotional changes. Including depression, anxiety, or mood swings
  • Muscle problems. Such as stiffness or spasms
  • Seizures (though these rarely occur)
  • Weakness or paralysis. These usually affect the arms or legs.
  • Problems with daily functions. Including bladder control, bowel movements, and sexual activity
  • Cognitive Difficulties. Affecting thinking skills and memory

These complications can significantly impact quality of life.


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Health Writer

Janis's areas of expertise include nutrition, exercise, stress management, and mental health. She is passionate about educating and empowering people to take control of their health and make positive changes that can last a lifetime. Janis believes that small, sustainable changes are the key to long-term success, and she works with her clients to develop personalized plans that fit their individual needs and lifestyles.