Defining and diagnosing multiple sclerosis is a notoriously difficult task due to the lack of a single test for the condition.
At present, nobody knows precisely what causes this disease of the central nervous system. Its severity ranges dramatically from relatively benign cases to the devastatingly disabling, bringing partial or complete paralysis to the body.
According to the National Institutes of Health (NIH), somewhere between 250,000 and 350,000 people in the US have been diagnosed with multiple sclerosis (MS). Because the Centers for Disease Control and Prevention (CDC) do not require physicians to report new diagnoses of the disease, the prevalence of MS can only be estimated.
In addition, many symptoms of the condition are invisible. MS is a notoriously difficult disease to diagnose, and so many people must live with their chronic disease untreated until doctors can rule out all other possibilities.
This week is National MS Awareness Week in the US. For this Spotlight feature, we will be taking a look at this complex and elusive condition in an attempt to pin down precisely what makes it such a mysterious and difficult disease to contend with.
What is MS?
MS is a whereby the body's immune system targets its own central nervous system - the brain, spinal cord and optic nerves. At present, the precise target that the immune system attacks - the antigen - is unknown, leading experts to regard MS as "immune-mediated" rather than an "autoimmune" disease.
When MS attacks the central nervous system, a fatty substance that protects the nerve fibers called myelin is damaged, along with the nerve fibers themselves. After becoming damaged, myelin forms scar tissue, in a process known as sclerosis.
The damage to the myelin and nerve fibers leads to the disruption and interruption of electrical signals being transmitted throughout the central nervous system, and it is this effect that MS has on the nerve impulses that produces the symptoms of the disease.
People with MS can experience a wide range of symptoms. The National MS Society (NMSS) emphasize the point that no two people have exactly the same MS symptoms, and each person's symptoms can change or fluctuate over time.
Due to the role the central nervous system has in the body, many areas can be affected by the disease. Common symptoms include fatigue, walking difficulties, vision problems, bladder problems, pain and cognitive changes.
One thing that many of these symptoms have in common is that they can be described as "invisible symptoms." In the video below, Rosalind Kalb, PhD, from the NMSS, discusses the effect of these symptoms and some of the challenges they present:
Due to the presence of invisible symptoms, some people with MS may appear to be much healthier than they are. Others might not be aware of symptoms they are inwardly struggling with, and, therefore, might have unreasonable expectations of the person with MS.
Another element of the disease that alters people's expectations is that MS has several different disease courses that have been identified - ways in which the disease presents itself and develops over time. The NMSS describe the following:
- Relapsing-remitting (RRMS) - around 85% of people with MS are believed to have this form, characterized by clearly defined flare-ups (relapses) of worsening symptoms, followed by periods of partial or complete recovery (remissions). During remission periods, no disease progression is apparent
- Secondary-progressive (SPMS) - many people transition to this form of the disease, whereby MS begins to progress more steadily, with or without periods of remission
- Primary-progressive (PPMS) - around 10% of people are believed to have this form of MS, characterized by neurologic function steadily worsening over time. While there may be temporary improvements from time to time, there are no distinct relapses or remissions
- Progressive-relapsing (PRMS) - the least common disease course, whereby MS is characterized by steadily worsening neurologic function with occasional relapses occurring from time to time. In PRMS, the disease continues to progress without remissions.
A clear line of communication between individuals and their physicians is vital. Symptoms such as fatigue can also occur as a result of other conditions, such as interrupted sleep due to sleep apnea. People with MS must be wary when a new symptom presents; it is important to discuss symptoms with a health care professional rather than simply attributing it to MS.
The prospect of an MS diagnosis can be a daunting one, and not just because of the symptoms that can potentially be experienced. At present, there is no known cure for MS, although studies often claim to offer hope.
Rewiring the immune system?
In the UK, The Telegraph reported that a "'miracle' stem cell therapy reverses multiple sclerosis." For the study, published in JAMA, doctors used chemotherapy to "knock out" parts of the immune system that were not working properly and then rebuild them using stem cells from the patient's blood.
Could stem cells be used to "reboot" the immune system of people with MS?
The article reporting on the study describes wheelchair-bound patients able to walk again and blind patients having their vision restored. These are dream results for many MS patients. However, the British National Health Service (NHS) were swift to put the story in perspective.
Although improvements were made in the levels of disability experienced by almost 64% of the study participants, the study was limited by only focusing on one form of MS - RRMS - and by not including a control group in the investigation. As a result, the researchers cannot be certain that these improvements are attributable to the treatment.
"These preliminary findings from this uncontrolled study require randomized trials," the authors of the study write, in acknowledgment of the study's limitations.
"It's also worth noting that not everyone will be able to tolerate the aggressive chemotherapy used," add the NHS on their Choices website, "and that the technique did not work for people with more severe or longstanding MS (over 10 years)."
This example serves to illustrate that there is still a great deal of work that needs to be carried out before patients can look forward to definitive treatment for this chronic illness. The presence of different courses of MS also means that levels of treatment available vary depending on what form of MS a person has.
Dr. Annette Langer-Gould, a research scientist and neurologist at Kaiser Permanente in Pasadena, CA, described to Medical News Today the current situation regarding MS treatment in the US:
"We have highly effective immunomodulatory treatments for relapsing, nonprogressive MS, somewhat effective treatments for relapsing progressive MS, but, unfortunately, progressive, nonrelapsing MS is a neurodegenerative process more similar to Alzheimer's disease and Parkinson's disease than to relapsing forms of MS."
For patients with progressive MS that does not relapse, the focus is a proactive management of symptoms to maximize function and quality of life. "This takes more time and energy on the part of the physician and patient, and a multidisciplinary approach often with the help of a social worker, primary care physician, physical and occupational therapy and urology," she explained.
Dr. Langer-Gould also drew MNT's attention to the categorization of the disease courses of MS. In contrast to the four defined courses described by the NMSS, Dr. Langer-Gould said that newer terms were being used:
"The subtypes of MS are relapsing, nonprogressive MS, relapsing progressive MS and progressive, nonrelapsing MS. The older terms - primary or secondary progressive MS, chronic progressive MS - are terms that are no longer being used because they confuse general neurologists and patients and don't really help guide care."
While experts have previously accepted that MS is more prevalent among white people than black people, a recent study has refuted this claim.
MS is a disease that appears to be constantly redefined the more that researchers and experts find out about it. The way in which the disease is dealt with has changed greatly in a short period, and as more is discovered, we can expect the way MS is treated and discussed to continue changing.
A study from Kaiser Permanente examining the electronic health records of over 3.5 million members in Southern California suggested that MS is more common in black women than in white women. These findings directly contrast with what had previously been established: that black people were less susceptible to the disease.
Conflicting findings arising from studies such as this demonstrate the level of mystery that surrounds MS. Experts believe that the development of MS is influenced by environmental factors, exposure to infectious microbes and genetic factors, but as yet they have not been able to pin the disease down precisely.
Such uncertainty is also present in the diagnosis of MS. As symptoms of the disease can vary so greatly, it can take a considerable amount of time before a patient is successfully diagnosed.
"Recognizing patients who are at high risk of early disability (or imminent risk of disability) and getting these individuals on the optimal treatment plan is the biggest challenge general neurologists face today," suggested Dr. Langer-Gould.
As new forms of treatment for the management of MS symptoms have been discovered, the need for quick diagnosis has changed. When there was no effective treatment for highly aggressive MS, being able to identify people with this form of the disease was less critical.
"Now we are lucky that we do have such highly effective medications (natalizumab and fingolimod and in some instances rituximab as well), but timely identification of the individuals who need these treatments remains a critical barrier," Dr. Langer-Gould explained.
Invisible symptoms, invisible disease?
Unfortunately, such treatments do not come cheap in the US. "The other big challenge for many Americans with MS is the astronomical rise in prices of the MS medications, including treatments that are not particularly effective," Dr. Langer-Gould told us. "For many people their co-pay is far more than they can afford."
She suggests that action needs to be taken, with patient advocacy groups working alongside Congress in order to help bring affordable medications to the market while simultaneously controlling the rising costs of medication.
Another aspect of MS that the government could help with is tracking the disease on an epidemiological level. As mentioned earlier in this article, physicians are not required to report to a central database whenever a new diagnosis is made.
A lack of reporting in combination with difficulties in diagnosis and classifying cases of MS - there is no standard method for testing or identifying the disease - means that all epidemiological numbers are estimated and contributes to the lack of certainty surrounding the disease.
Keeping a centralized record of the number of MS cases in some way would certainly help scientists attempting to track the incidence and prevalence of the disease, and could contribute toward helping determine what causes MS.
MS is one of the most complex diseases that an individual can experience. Due to this fact, it is important that awareness of the condition is raised. For more information, take a look at the NMSS information on what can be done to raise awareness or the MNT Knowledge Center page about the condition.