What is multiple sclerosis?
Multiple sclerosis is also known as MS, and it is classified as a disease of the myelin. Specifically, it is classified as a demyelinating disease: these types of diseases are autoimmune diseases because the patient’s immune system decides to attack the myelin surrounding the nerve cells. By doing so, the nerves end up becoming exposed. Like some types of infectious diseases such as herpes, it has both periods of remission (i.e. the symptoms disappear and the patient becomes relatively healthy) and relapsing (the symptoms reappear). There is also a subset of MS known as Marburg MS, which I’ll discuss in more detail later on.
What purpose does myelin serve?
Myelin is the material which covers the axons along the nerve at alternating points with the nodes of Ranvier. Myelin acts like an insulator: it helps to speed up the electrical impulses sent to and from the brain. If were to compare the electrical impulse sent along a nerve to a more familiar analogy, the myelin would help to convert an internet connection from dial-up to broadband. This happens because, as I mentioned in Structure of a Neuron, the electrical signal ‘skips’ from one Node of Ranvier to the next over each section of the myelin, rather than travelling all the way down the axon, which would take a considerable amount of time.
Who does MS most affect?
MS can affect people of all ages, however it tends to affect women more than men and it most commonly starts in adults below 50 years of age. As the disease progresses, there are less periods of remission/relapse, however the symptoms generally get worse. Like many other diseases, MS is far more likely to happen in someone who has an immediate family member (i.e. a parent or sibling) affected by the disease. Identical twins have a one in four chance of developing MS, but in fraternal twins, the risk is around the same as the rest of the population.
What does MS appear like?
MS is a disease of the white matter of the brain, and is distinguishable by the presence of plaques, which are often spotted within the brain stem and the ventricles. These plaques are not the same as the fatty atherosclerotic plaques in arteries nor the plaque that can develop on your teeth. There are three stages in which the plaques can be present: an active plaque, an inactive plaque and a shadow plaque. You can tell when an MS plaque is active by the presence of myelin debris in the area where the immune system is attacking, and there may also be white cells such as macrophages (or eating machines, as I like to call them), lymphocytes and monocytes present. If MS is in one of its inactive phases (i.e. when the patient is in remission), the white cells that trigger inflammation disappear, and the myelin debris is no longer seen. There are also shadow plaques, which are characterized by thinned out myelin sheaths: it is uncertain whether this indicates the myelin attempting to regenerate or whether it is being lost.
What are the symptoms of MS?
The symptoms of MS can vary significantly depending on where in the brain the plaques are located, but the most common signs include disruption of the eye movements and ataxia (loss of the ability to control your own body movements). If the plaques end up in the spine, both the motor and sensory nerves can be affected. There are many symptoms that can be attributed to MS, and they include the following:
- Heat sensitivity
- Memory loss
- Urinary incontinence
- Loss of cognitive function
How is MS diagnosed?
MS is somewhat difficult to diagnose, due to its wide range of symptoms. Therefore, other conditions which can trigger the same symptoms must first be ruled out through differential diagnosis. There is no gold standard test within a lab to point out MS, hence several tests must be conducted. Such tests include:
- MRI (magnetic resonance imaging) to detect the presence of plaques and demyelination
- CSF (cerebrospinal fluid) examination: in MS the protein level is elevated
- Discovery of oligoclonal bands within the CSF
Can MS be cured/treated?
Unfortunately, MS at the moment is incurable, but the symptoms can be managed to a degree via several types of treatment. These treatments help to reduce the rate of the attacks and also to shorten the duration of the attacks when they flare up. Such treatments include:
- Subcutaneous injections
- Steroids to reduce inflammation
- Disposable pads to treat incontinence
- Change of diet
- Special exercises through physiotherapy, occupational therapy and/or chiro
- Having appointments with a neuropsychologist
- Sleep medication
- Acupuncture and massage therapies
- Meditation and yoga
What is Marburg MS?
Marburg MS was discovered by Otto Marburg, who is pictured alongside, and it is the MS equivalent of metastatic cancer: it is both relatively aggressive and the prognosis of the patient is relatively grim compared to a patient diagnosed with regular MS. Patients with regular MS can survive for decades, but patients with Marburg MS have an average survival rate of a few days and may only survive for up to a couple of months after the initial attack. Thankfully, compared to regular MS, this condition is relatively rare.
What are the symptoms of Marburg MS?
Marburg MS has similar symptoms to regular MS, but they appear and attack far more severely.
How is Marburg MS treated?
There are multiple medications that can be used to help treat Marburg MS, they include the following:
- Immunosuppressive agents
- Interferons (help to modify the immune response)
- Stem cell transplant
- Mitoxantone (chemotherapy drug)