MS is a disease of the central nervous system that disrupts communication between the brain and other parts of the body. The severity of the disease and its symptoms vary from person to person. The cause of MS is unknown and although there are treatments that can slow disease progression, at this time there is no known cure.
What It Is:
MS is a chronic disease of the brain, spinal cord and optic nerves. Three factors appear to have an influence on developing MS: genetic predisposition, environmental factors such a geographical location, and a trigger, such a virus.
How It Manifests:
The “cable” of the nerve that connects one nerve cell with another, the axon, is coated with a substance made of protein and fat called myelin. This enhances the conduction of electricity down the axon. MS produces injury in the central nervous system when the immune system mistakenly attacks myelin. Areas of myelin damage are known as plaques, or lesions, and these eventually fill in with scar tissue.
The name multiple sclerosis means “many scars.” MS can also cause destruction of the entire nerve. The damage from lesions disrupts the transmission of nerve impulses from the central nervous system to the rest of the body causing a variety of symptoms.
“Types” of MS
In the past, MS was commonly divided into four separate forms or “types” of the disease. Today we think of MS as one distinct disease, with different symptoms from person to person, but also changing manifestations over the course of the lifetime of a single patient. There is still debate as to how distinct or different these forms of MS are from each other, but it’s nonetheless useful to look at these four categories as a way to explain how MS manifests at different stages in different people.
Clinically Isolated Syndrome (CIS) refers to essentially the first outward, clinical signs of the disease, or the first relapse. Commonly this is between the ages of 20 to 45, but may be younger or older. Typical symptoms might be numbness, or visual disturbance such as optic neuritis. An individual after this first attack may already fulfill formal criteria for a diagnosis of MS based on the symptoms and lab tests, but if not, we simply call it a CIS. Over time, if a patient has more clinical symptoms, and/or new changes on MRI scans, they would then fulfill formal diagnostic criteria for MS. If a person never experiences another exacerbation, or their MS does not progress or get worse over time, this singular event is said to be CIS. Most patients however will eventually experience another exacerbation, in which case they fulfill criteria for a formal diagnosis of MS.
Relapsing-Remitting MS (RRMS) is diagnosed in someone when they have a second attack and/or new changes on MRIs over time. Typically, these would affect different parts of the CNS, and then an individual would formally fulfill criteria for MS. Up to 85% of people diagnosed with MS have relapses when diagnosed. For most with RRMS, relapses and new MRI changes are most common when they are younger, and risk of new relapses diminishes with age.
Secondary Progressive MS (SPMS) manifests about 10-15 years, on average, after a diagnosis of RRMS. Some (but not all) will begin to more overtly show signs of slowly worsening symptoms unrelated to, or in addition to, relapses. This may be manifested especially with greater walking and cognitive problems, and is called SPMS. Men, and especially those with very active relapses when first diagnosed, are at higher risk of developing SPMS. We now recognize that CIS, RRMS, and SPMS are all “relapsing” forms of MS. This is relevant to treatment, as younger patients with active disease with recent relapses or new scan changes are more likely to benefit from present MS meds, regardless of whether this is called RRMS or SPMS.
Primary Progressive MS (PPMS) is diagnosed when someone has a steady progression of MS symptoms that is not preceded by relapses. Average age of onset is similar to those with SPMS, about 40-45. Followed long enough, a minority of those with PPMS could have a relapse.
Common MS Symptoms
Symptoms vary greatly from patient to patient, and can change in severity and occurrence over time. Some of the most common MS symptoms often include (among many others):
- Numbness and tingling
- Muscle stiffness (spasticity)
- Difficulty walking (ataxia)
- Vision problems
- Heat sensitivity
- Dizziness and vertigo
- Problems with coordination and balance
- Bladder and/or bowel problems
- Cognitive problems
- Mood problems
- Sexual problems
Many MS patients experience “quiet” periods when the disease is relatively dormant, but they may still be coping with one or a number of symptoms that aren’t apparent to the outside world. These patients can also have periods where the disease is quite active, known as exacerbations. During exacerbations, symptoms can be more pronounced, but usually subside and sometimes go away entirely soon after an exacerbation. Other patients may not experience dormant periods, and instead live with constant symptoms or a progressive worsening of the disease. MS can sometimes lead to disability, depending on a multitude of factors.
Every case of MS is different and every patient’s experience is unique. No person experiences the same symptoms in the same way, making MS a particularly difficult experience to explain or relate to others. At the Rocky Mountain MS Center, our focus is on treating the disease early and effectively with the aim of halting disease progression and maximizing the lifelong brain health of MS patients.
Who Gets It:
MS is most commonly diagnosed in young adults. Eighty percent of MS patients develop MS between the ages of 16 and 45. Women are more frequently diagnosed with MS by around 3 to 1. MS is a significant cause of disability in younger adults.
The worldwide prevalence is around 2.7 million, and the National MS Society estimated in 2017 that nearly 1 million Americans are living with the disease. In Colorado, we estimate that one in about 550 people have MS.
How It’s Treated:
It’s only been since 1993 that medications have been available to treat MS. Today there are dozens of agents approved by the FDA for the treatment of MS, but these drugs are only partially effective. Research efforts to improve MS treatment are ongoing, and much of that research is being done by the RMMSC right here in Colorado. An encouraging new frontier is exploring potential strategies for neuroprotection and neurorepair.