Multiple Sclerosis: Causes, Symptoms, Risk Factors, Complications, Diagnosis, Treatments
Multiple sclerosis is a demyelinating disease of the central nervous system, which includes the brain and the spinal cord. Myelin sheath is a protective fat-containing layer that surrounds the nerve cells and allows the transmission of the electrical impulses.
In multiple sclerosis, demyelination occurs when the immune system inappropriately attacks and damages the myelin sheaths that surround the nerve cells. Due to this damage the communication between the neurons breakdown and leads sensory and cognitive problems.
- What is Multiple Sclerosis?
- Types of Multiple Sclerosis:
- What Causes Multiple Sclerosis?
- Symptoms of Multiple Sclerosis:
- Risk Factors for Multiple Sclerosis:
- Complications of Multiple Sclerosis:
- Diagnosis of Multiple Sclerosis:
- Treatment for Multiple Sclerosis:
What is Multiple Sclerosis?
Multiple sclerosis is a permanent, long-lasting, immune-mediated disease that affects the brain, spinal cord, and the optic nerves of the eye and results in serious disability.
Types of Multiple Sclerosis:
Depending upon the severity of the condition multiple sclerosis is of four types, they are:
Relapsing-remitting Multiple Sclerosis:
Relapsing-remitting multiple sclerosis is the common type and eight out of every ten patients are diagnosed with this type of multiple sclerosis. The individuals usually experience the symptoms that respond, resolve and relapse without warning. The severity of attacks and the degree of recovery is different in different patients.
Primary Progressive Multiple Sclerosis:
Primary progressive multiple sclerosis is a condition in which the symptoms get worse gradually. This type of multiple sclerosis is without episodes of remission or improvement of symptoms. It usually affects 10% of the population having multiple sclerosis.
Secondary Progressive Multiple Sclerosis:
Secondary progressive multiple sclerosis mostly affects the individuals who had relapsing-remitting multiple sclerosis for several years. This type of multiple sclerosis usually develops 10 to 20 years after the diagnosis of relapsing-remitting multiple sclerosis. Secondary progressive multiple sclerosis is difficult to treat and manage.
Progressive-relapsing Multiple Sclerosis:
Progressive-relapsing multiple sclerosis is a rare condition that occurs when the patient experience symptoms very rapidly over time with episodes of remission.
What Causes Multiple Sclerosis?
Multiple sclerosis is an autoimmune disease, which occurs when the body’s immune system attacks its own healthy tissues. In multiple sclerosis the immune system breakdown and destroys the myelin sheath. Due to this damage, the communication between the neurons is lost and leads to nerve damage. The exact cause for the malfunction of the immune system is still unknown, but certain evidence shows that environmental and genetic factors may contribute to multiple sclerosis.
Symptoms of Multiple Sclerosis:
The symptoms of multiple sclerosis are based on the area of affected nerve fiber and vary from one person to another person. The common symptoms of multiple sclerosis include:
- Visual disturbances, such as vision loss or double vision
- Numbness or weakness in the limbs
- Difficulty in walking
- Muscles stiffness
- Muscle spasm
- Fatigue (severe weakness)
- Tremors (unsteady and involuntary movements of the body)
- Vertigo (sensation of spinning)
- Slurred speech
- Bladder incontinence (involuntary urination due to loss of bladder control)
Risk Factors for Multiple Sclerosis:
Factors that increase the risk of multiple sclerosis include:
- Age: Multiple sclerosis can develop at any age but the risk increases between the ages of 15 and 60 years.
- Gender: Females are at higher risk of multiple sclerosis as compared to males due to the presence of estrogen (the hormone responsible for development and regulation of female reproductive system).
- Family history: Individuals having a family history of multiple sclerosis are at increased risk.
- Infections: Infections caused due to certain viruses, such as Epstein-Barr virus increase the risk of multiple sclerosis.
- Race: White people from the Northern European origin are at increased risk of developing multiple sclerosis than compared with Asian, African or Native American origin.
- Geography: The risk of multiple sclerosis is more in individuals living in certain countries that are away from equator due to the lack of sunlight and vitamin D.
- Auto-immune disorders: Individuals having autoimmune diseases, such as type-1 diabetes, lupus, and rheumatoid arthritis are at increased risk of multiple sclerosis.
- Smoking: Smoking is a modifiable risk factor that increases and influences the risk of multiple sclerosis and its progression.
Complications of Multiple Sclerosis:
Multiple sclerosis causes widespread nerve injury, which may lead to severe complications, such as:
- Sexual dysfunction
- Bowel and bladder dysfunction
- Nocturia (abnormal and excessive urination during nights)
- Lung problems
- Osteoporosis ( weakened and brittle bones due to decreased bone density)
- Cognitive problems, such as trouble in concentrating and solving problems
Diagnosis of Multiple Sclerosis:
The doctor initiates the diagnosis by reviewing the family history, medical history and signs and symptoms of the individuals. The diagnosis mainly focuses on ruling out other conditions, which may have similar symptoms.
The doctor recommends certain tests, such as:
A neurological examination is done to evaluate the functioning of the brain, spinal cord, and other nerves. This examination is done to check:
- Changes in the vision
- Eye movement
- Balance and coordination
Evoked Potential Test:
Evoked potential test is performed to record the electrical signals produced by the nervous system. This test uses visual stimuli or electrical stimuli to assess the visual pattern. This test is used to determine the time taken by the brain to receive messages.
Lumbar puncture is performed under the influence of local anesthetic. In this procedure, a sample of spinal fluid (fluid, which surrounds the brain and spinal cord) is collected from the spine and is examined. This sample reveals abnormalities in the antibodies that are associated with multiple sclerosis.
A blood test is done for ruling out other condition with similar symptoms, such as neuromyelitis optica (a rare condition that affects spinal cord and nerves of eyes).
Magnetic Resonance Imaging (MRI):
An MRI is a non-invasive procedure that creates detailed images of the brain. In multiple sclerosis, an MRI reveals the damaged myelin sheath in the brain and spinal cord.
Treatment for Multiple Sclerosis:
Multiple sclerosis does not have a complete cure. The treatment mainly focuses on reducing the symptoms and slowing the progression of the disease. The treatment options for multiple sclerosis include:
- Beta interferons, such as interferon beta-1a and interferon beta-1b are the common drugs recommended in the treatment of multiple sclerosis. These drugs are prescribed to reduce the severity and frequency of the symptoms.
- Glatiramer is an immunomodulatory agent that prevents the immune system from attacking the myelin sheath that protects the nerves.
- Ocrelizumab is a monoclonal antibody used for treating relapse-remitting and primary progressive forms of multiple sclerosis.
- Glatiramer acetate is an immunomodulatory agent that blocks the attack of the immune system on the myelin sheath.
- Natalizumab is a monoclonal antibody that prevents the entry of damaged immune cells in the brain and spinal cord by blocking the movement of damaged immune cells in the bloodstream.
- Corticosteroids are prescribed to reduce the nerve inflammation and to prevent the attacks of multiple sclerosis.
Other drugs, such as dimethyl fumarate, fingolimod, teriflunomide, and alemtuzumab are also prescribed to reduce the risk of recurrence.