Multiple sclerosis (MS) is an autoimmune disease that affects the brain and spinal cord. An autoimmune disorder or disease is a condition that occurs when the immune system mistakenly attacks and destroys components within its own body, disrupting proper function and responses. There are more than 80 different types of autoimmune disorders. The initial cause of autoimmunity is unknown, but has been thought to be associated with a defected gene or virus. Environmental factors may also play a role in why autoimmune disorders occur.
Depending on the severity of progress, symptoms of multiple sclerosis can include weakness, tingling, numbness, blurred vision, and stiffness of musculature, loss of balance, problems with coordination of precise movements, difficulty concentrating, and urinary problems. There is no cure for multiple sclerosis, but treatment can ease the worsening of symptoms. The earlier the detection, the more effective the treatment can be, and therefore improved quality of life.
MS develops due to damage of the myelin sheath, the protective covering and insulator surrounding nerve cells (neurons). Inflammation is the primary cause of damage. The body’s natural immune response is to attack cells it senses as foreign, undesirable invaders, which creates inflammation. However, with the autoimmune disorder making it difficult to detect the difference, they instead attack indigenous cells.
The peripheral nervous system (PNS) is the arrangement of nerves around the body, and the central nervous system (CNS) is the collection of nerves inside the brain and the spinal cord. The central nervous system collects information and instructs the rest of the body to move muscles. Each nerve transmits a signal through a system of electrical impulses and chemical signals. Myelin protects the outside of the nerve cell, and keeps the electrical impulses inside the cells so they do not dissipate energy outside the cells, but rather keep all the electricity in the right place and direction. Think of the electrical wiring in your home, needing to be properly grounded and insulated in order to work properly and safely. When the myelin degrades with MS the signals malfunction. They slow down or stop altogether.
It can be difficult for doctors to monitor MS because it can be unpredictable. Neurologists use magnetic resonance imaging (MRI) to precisely review inflammation in the deep parts of the brain and spinal cord. An MRI is considered the best test to view the shrinkage and scarring caused by multiple sclerosis. However, it is not clear how early exactly these changes have occurred in the disease, and whether they accurately reflect ongoing damage on an MRI. Therefore, scientists have been trying to find additional tests or scans that can be helpful in detecting continuing changes associated with MS.
Optical Coherence Tomography (OCT) is a noninvasive imaging technique used to obtain high resolution cross-sectional images of the retina using light. OCT has been shown to be clinically useful for imaging selected macular diseases like age-related macular degeneration, and retinal inflammatory diseases. OCT has the capability of measuring the thickness of the lining at the back of the eye, the retina. This is essential in charting the progress of glaucoma and other diseases of the optic nerve. This scan can also assist in detecting the germination of MS because the optic nerve does not have a myelinated sheath. Therefore, scientists indicate that the development of MS can be observed much earlier using this technique, based on a Johns Hopkins based study of 40 MS patients.
The five minute OCT exam is more economical, costing a fraction of what an MRI does, and takes up much less work space. Aside from being more expensive and uncomfortable, an MRI can be misleading since brain inflammation, another symptom of the disease, can skew brain volume readings. Also, the brain begins shrinking relatively late in the progression of the disease. An MRI isn’t as good at detecting the disease in its early stages, when treatments are most effective. OCT scans look directly at the thickness, and therefore health, of the optic nerve, which is affected early on in the disease, often before the patient suffers permanent brain damage.