What is multiple sclerosis?
Multiple sclerosis is a progressive autoimmune disease and the most common neurological disease diagnosed in young adults. Researchers believe multiple sclerosis occurs when the body’s own immune system attacks the central nervous system. Commonly called MS, the disease generally gets worse with time and can cause significant nerve damage.
The progression and severity of multiple sclerosis varies greatly among individuals. The severity of multiple sclerosis ranges from mild to severe and disabling, and it can result in muscle weakness, loss of balance, and difficulty walking.
In some cases, multiple sclerosis can lead to serious complications, such as choking and paralysis. Early diagnosis and medical care can help manage and control symptoms and minimize complications of multiple sclerosis.
What are some conditions related to multiple sclerosis?
Conditions related to MS include:
- Acute disseminated encephalomyelitis: A rare but short-lived condition marked by severe inflammation that causes demyelination and MS symptoms. It often follows a bacterial or viral infection.
- Balo’s disease: A rare and rapidly progressive disease with a different pattern of brain demyelination than MS; may develop shortly after an infection.
- HTLV-I associated myelopathy: A progressive spinal cord disease marked by leg weakness and spasticity and other symptoms; occurs in about 2% of people infected with HTLV-1 (human T-cell leukemia virus type 1).
- Neuromyelitis optica: A relapsing-remitting disease that targets the optic nerve, spinal cord, and sometimes the brain. An autoimmune-mediated attack damages specific nervous system cells and causes demyelination.
- Schilder's disease: A rare and progressive disorder with demyelination of the central nervous system and MS symptoms. Schilder’s is a variant of MS that often follows an infection.
- Transverse myelitis: A rare neurologic condition marked by inflammation and demyelination across one level of the spinal cord. It often develops after an infection.
What are the symptoms of multiple sclerosis?
The symptoms of multiple sclerosis result from inflammation, swelling, and lesions on the myelin, a fatty material that covers and insulates the nerve cells in the central nervous system. Myelin greatly improves the transmission speed of nerve impulses without decay of the nerve signal. Loss of myelin leads to abnormal transmission of electrical impulses through the central nervous system and difficulties with motor skills, cognition and sensation.
Symptoms of multiple sclerosis generally appear between the ages of 20 and 40 years. Symptoms are unpredictable and can vary greatly. In the early stages of the disease, symptoms come and go. People with multiple sclerosis can also experience periods of remission, in which symptoms disappear, and periods of relapse, in which symptoms reappear. Symptoms may worsen during relapses.
Symptoms of multiple sclerosis include:
- Abnormal sensations in the extremities, such as tingling, burning or numbness
- Bowel and bladder problems, such as constipation and incontinence
- Hearing and vision loss
- Mental difficulties, such as problems with judgment, memory and concentration
- Muscle spasms
- Muscle weakness and difficulty moving arms and legs
- Problems with balance, coordination and walking
- Sexual dysfunction
- Trembling or tremors
- Worsening of symptoms with increased body temperature
What causes multiple sclerosis?
The causes of multiple sclerosis (MS) are not well understood. Researchers believe that the body’s immune system begins to attack the nervous system, specifically the myelin of nerve fibers. Myelin is a fatty material that covers and insulates the nerve fibers in the central nervous system (CNS). Healthy myelin is vital to the normal, rapid movement of electrical impulses through the nerve pathways.
In MS, patches of myelin in the brain and spinal cord become inflamed; this causes swelling and lesions (scleroses, or scars). Damage to the nerve fibers disrupts normal transmission of electrical impulses and affects how your brain and body communicate. MS symptoms occur with increasing loss of myelin (demyelination) and damage to the fibers and cells themselves, creating more lesions in the CNS. Progressive nerve loss leads to disability.
Experts believe the immune system-mediated damage of myelin is triggered by a combination of genetic factors and environmental elements, such as exposure to a virus. Sometimes it’s a case of biological 'mistaken identity.' This occurs when circulating antibodies meant to destroy viruses inaccurately target myelin because it has a similar molecular ‘fingerprint’.
Who gets multiple sclerosis?
Recent research estimates 1 million people in the United States have MS. Most people are 20 to 40 years old when symptoms start, but younger and older people can develop it. The primary progressive form of MS most often occurs in people older than 40.
Data on the exact incidence of MS in specific populations is lacking because MS is not common—an individual’s risk of developing MS is 1 in 750 to 1,000. However, research studies highlight some significant factors for who gets MS:
- Family history: People who have a first-degree family member (parent or sibling) with MS have a 20- to 40-fold higher risk of developing it compared to individuals without an affected first-degree relative.
- Gender: Women (biologically female) have a three-fold higher risk of developing MS than biological males.
- Ethnicity: MS affects White Americans more than Black and Hispanic Americans in the United States.
- Location: MS prevalence increases with distance from the equator, although the reason for this geographic difference is not clear.
What are the risk factors for multiple sclerosis?
A number of factors are linked to an increased risk of developing multiple sclerosis. Some risk factors include:
- Environmental factors including increasing distance from equator, low vitamin D levels in the blood, smoking, and obesity
- Female biological sex
- Family history of multiple sclerosis
- Genetic factors, including chance variations in some 200 different genes linked to an increased risk of MS. The identical twin of a sibling with MS has about a 30% chance of developing it. Specific sequences in HLA-DRB1 and IL7R genes are strong risk factors.
- History of autoimmune disorders
- History of infections, such as Epstein-Barr virus and hepatitis B virus
In general, the most widely held view is that a non-genetic factor, such as an infection, triggers MS in a person with a genetic risk for developing it.
How are you diagnosed with multiple sclerosis?
There is no single or series of tests that return a ‘positive’ MS result. It is a clinical diagnosis, which means the neurologist diagnoses it after considering a variety of factors. A high likelihood or proof that a patient has MS involves a comprehensive neurologic evaluation, blood tests, MRI, and possibly cerebrospinal fluid analysis.
A formal MS diagnosis requires all these criteria:
- Central nervous system damage in at least two separate areas
- Damage at different points in time
- Exclusion of other diagnoses, such as Lyme disease
What are the different forms of multiple sclerosis?
Doctors base their diagnosis of different MS types, or disease courses, on patient symptoms and clinical evidence of brain lesions by MRI (magnetic resonance imaging).
Disease courses include:
- Clinically isolated syndrome: A patient is diagnosed with CIS upon the first episode of MS symptoms lasting at least 24 hours, with or without MS-like brain lesions on MRI. A person with lesions is more likely to develop MS.
- Relapsing-remitting multiple sclerosis: Affecting 80 to 85% of patients initially diagnosed with MS, periods of acute symptom flares (relapses) and disease remission characterize RRMS.
- Secondary-progressive multiple sclerosis: SPMS develops after RRMS, usually within 35 years of initial diagnosis, but the transition occurs earlier when RRMS is not well controlled or treated. It is marked by a significant increase in disability. MS symptoms are more severe and debilitating, with or without periods of relapse and remission.
- Primary-progressive multiple sclerosis: Affecting 5 to 15% of patients at initial diagnosis, steadily worsening MS symptoms and increasing disability characterize PPMS. It does not follow the more classic RRMS pattern with acute exacerbations.
As of 2014, clinicians replaced the former disease course known as progressive-relapsing multiple sclerosis with the PPMS classification.
How is multiple sclerosis treated?
There is no cure for multiple sclerosis. However, the disease can be managed and the symptoms controlled to various degrees of success with an individualized, multifaceted approach that includes medications and other therapies.
Treatment plans are geared toward managing your symptoms and suppressing the body’s immune response, which experts believe is the root of multiple sclerosis.
People with mild cases of multiple sclerosis may need or choose to have little or no treatment. However, all people with the disease are encouraged to keep their bodies as strong and healthy as possible by:
- Avoiding excessive heat and exercise
- Avoiding fatigue and stress
- Eating a well-balanced diet
- Engaging in regular, moderate exercise
- Maintaining a healthy weight
Medications for multiple sclerosis
Specific treatment strategies, including which drug is prescribed when and for how long, depend on patient benefits and drug risks (side effects) as well as physician preference and clinical expertise. For people whose symptoms are moderate to severe, treatment may include any of the following medications:
- Beta interferons, which can reduce the number of episodes of symptoms and slow progression of the disease
- Corticosteroids, which can help minimize the intensity of symptoms
- Intravenous biologic therapies, which can inhibit the abnormal immune response and reduce the rate of MS relapses
- Muscle relaxers, which can reduce muscle spasms
- Novantrone, which can be used for severe or advanced multiple sclerosis
Other treatments and therapies for multiple sclerosis
- Equipment to help maintain independence, such as walkers, canes and braces
- Exercise programs
- Occupational therapy
- Physical therapy
- Speech therapy
Some complementary treatments may help some people to better deal with multiple sclerosis and its treatments. These treatments, sometimes referred to as alternative therapies, are used in conjunction with traditional medical treatments. Complementary treatments are not meant to substitute for traditional medical care. Be sure to notify your doctor if you are taking nutritional supplements or homeopathic (nonprescription) remedies as they may interact with the prescribed medical therapy.
Complementary treatments may include:
- Massage therapy
- Nutritional dietary supplements, herbal remedies, tea beverages, and similar products
What are the possible complications of multiple sclerosis?
In some cases, complications of multiple sclerosis can be severely disabling.
Complications of multiple sclerosis include:
- Adverse effects of multiple sclerosis treatment
- Choking because of problems chewing and swallowing
- Hearing loss
- Loss of balance and falls
- Painful muscle spasms
- Permanent physical disability
- Problems with memory and other mental functions
- Sexual dysfunction
- Speech difficulties
- Vision loss
Can you die from multiple sclerosis?
Although MS symptoms and disability are not a direct cause of death, complications from the disease can be fatal. Overall, multiple sclerosis life expectancy is shortened by 7 to 14 years compared to people without the disease. About 50% of MS patients die from MS-related causes, according to a review of many studies. A recent study from Norway finds that people with MS have a three-fold higher mortality rate than the general population.
New studies of large patient populations are necessary to understand factors affecting MS prognosis and survival, including disease and disability severity, age at transition from RRMS (relapsing-remitting multiple sclerosis) to SPMS (secondary-progressive multiple sclerosis), treatment, symptom control, and coexisting conditions, among other factors. In particular, smoking and vascular conditions increase disability and mortality risk.
How does multiple sclerosis affect quality of life?
The unpredictable nature and disability of MS makes living with the disease difficult. Health-related quality of life (HRQoL) represents the degree of impact of physical and mental well-being, treatment strategies, and disability on quality of life for people with MS. It is based on patients’ answers to a standardized MS questionnaire. MS reduces HRQoL values compared to the general population.
Not surprisingly, disability is the strongest factor for lower values, according to a Canadian study on patients with relapsing MS. Patient-reported depression, anxiety, fatigue, and coexisting medical conditions (in this order) also have a negative impact.
MS-caused disabilities and conditions associated with lower quality of life include:
- Cognitive problems, including poor concentration and problem solving
- Fatigue, which is tied to depression
- Inability to walk unassisted (e.g., with a cane)
- Pain, which may be due to causes other than MS, such as arthritis
Research and awareness of multiple sclerosis
As part of the 21st Century Cures Act, the Centers for Disease Control and Prevention launched the National Neurological Conditions and Surveillance initiative to collect data on multiple sclerosis. A better understanding of MS causes and risk factors, including possible environmental and viral triggers, will help with prevention and cure strategies.
MS Awareness week occurs in March, and World MS Day is in May.