Multiple sclerosis or MS is thought to be a neuroinflammatory disease meaning that the immune system of the individual attacks the protective membrane called the Myelin Sheath that covers the axon of the neurons similar to electrical wire insulation. Damage to Myelin Sheaths interrupts the communication between the brain and the rest of the body.
There are two different types of cells that are responsible for myelinating or insulating the neurons:
- The first type of cell are the Oligodendrocytes that are responsible for myelinating the axons of the Central Nervous system or the CNS, which consists of the Brain, Spinal Cord and optic nerves.
- The Schwann cells are the second types of cells which are responsible for myelinating the Peripheral Nervous System or the PNS, which consists of the nerves and ganglia outside of the brain and spinal cord. The main function of the PNS is to connect the CNS to the limbs and other organs.
Risk factors for Multiple Sclerosis:
There are several factors that may increase the risk of developing MS:
- Age. MS can occur at any age, but most commonly affects people between the ages of 15 and 60.
- Sex. Women are about twice as likely as men are to develop MS.
- Family history. If one of the parents or siblings of the individual has had MS, they are at higher risk of developing the disease.
- Certain infections. A variety of viruses have been linked to MS, including Epstein-Barr virus, which causes infectious mononucleosis.
- Race. White people, specially those of Northern European descent, are at highest risk of developing MS.
- Cold climate. MS is far more common in countries with cold climates, including southern Canada, northern United States, New Zealand, southeastern Australia and Europe.
- Sunlight and vitamin D. A number of studies have suggested that people who spend more time in the sun and those with relatively high levels of vitamin D are less likely to develop MS. Researchers believe that vitamin D may help regulate the immune system in ways that reduce the risk of MS.
Certain autoimmune diseases. Individuals who have other autoimmune disorders such as thyroid disease, type 1 diabetes or inflammatory bowel disease such as Ulcerative colitis or Crohn’s disease, have a slightly higher risk of developing MS.
- Smoking. Smokers who experience an initial event of symptoms that may signal MS are more likely than nonsmokers to develop a second event that confirms relapsing-remitting MS.
Signs and Symptoms of Multiple Sclerosis:
Because symptoms come and go in the majority of people with MS, the presence of symptoms is called an attack. Recovery from symptoms is referred to as remission, whereas a return of symptoms is called a relapse. This form of MS is therefore called relapsing-remitting MS, in contrast to a more slowly developing form called primary progressive MS. Progressive MS can also be a second stage of the illness that follows years of relapsing-remitting symptoms.
The symptoms include:
- Vision problems such as blurred or double vision,
- Optic neuritis, which causes pain in the eye and a rapid loss of vision,
- Internuclear Ophthalmoplegia, which is a gaze disorder in which the affected eye shows impairment of adduction,
- Weak or stiff muscles, often with painful muscle spasms,
- Tingling or numbness in the arms, legs, trunk or face,
- Trigeminal neuralgia, a chronic pain condition that affects the trigeminal or 5th cranial nerve, which causes a sudden, severe, and stabbing pain that can be triggered by vibration or contact with cheek (such as when shaving, washing the face or applying make up) as well as eating, talking or being exposed to the wind,
- Clumsiness and difficulty staying balanced when walking,
- Slurred speech,
- Bladder control problems, either inability to control the bladder or urgency,
MS may also lead to:
- Mental or physical fatigue which accompanies the above symptoms during an attack,
- Mood changes such as depression or euphoria,
- Inability to concentrate or to multitask effectively,
- Difficulty making decisions and planning.
Diagnosis of Multiple Sclerosis:
Multiple sclerosis is typically diagnosed based on the presenting signs and symptoms, in combination with supporting medical imaging and laboratory testing.
In order to diagnose MS we can do:
- Blood tests, to help rule out infectious or inflammatory diseases with symptoms similar to MS.
- MRI is used to generate images of the brain and/or spinal cord. Then a special dye or contrast agent is injected into a vein and the MRI is repeated. In regions with active inflammation in MS, there is disruption of the blood-brain barrier and the dye will leak into the active MS lesion, which can be seen on the MRI.
- Evoked potential tests may also be done, which uses electrodes on the skin and painless electrical signals to measure how quickly and accurately the nervous system responds to stimulation.
- Lumbar puncture or a “spinal tap” may be done to obtain a sample of cerebrospinal fluid or CSF. The CSF is then tested for oligoclonal bands of IgG antibodies on electrophoresis, which are inflammation markers found in 75–85% of people with MS.
Treatment and Drugs for Multiple Sclerosis:
There is still no cure for MS, but there are treatments for initial attacks, medications and therapies to improve symptoms, and recently developed drugs to slow the worsening of the disease.
- During symptomatic attacks, administration of high doses of intravenous corticosteroids, is the usual therapy.
DRUGS THAT PREVENT RELAPSE AND PROGRESSION:
- Interferon beta
- Glatiramer acetate
POSSIBLE CURE IN THE FUTURE:
- Stem cell transplantation: It is also important to mention that based on a new published study, patients with MS who took part in the cutting-edge stem cell study are still in remission years later. Researchers found that more than 86% of the patients remained relapse free after 3 years, and nearly 91% showed no sign of disease progression. Read more on this study here.
References for Multiple Sclerosis: