What is Multiple Sclerosis?
Multiple Sclerosis (MS) in a demyelinating disorder, causing the insulating cover (myelin) of neurons in the brain and spinal cord to become damaged. In 2015, the World Health Organisation estimated that approximately 2.3 million people globally were affected by MS, making it the most common immune disorder that targets the central nervous system[1].
The myelin sheath is the fatty material that coats and protects neurons, enabling communication between the brain and the rest of the body. In patients with Multiple Sclerosis, the body’s own immune system attacks and destroys myelin, which leaves nerve cells unprotected. As a result, the messages the nerves try to send are delayed or misinterpreted. Myelin is lost in multiple areas, resulting in scarring and lesions in the brain (sclerosis). These lesions commonly affect the white matter (the tissue made up of myelinated axons which affects learning, brain function and coordinates communication between brain regions) in the optic nerve, brain stem, basal ganglia (a midbrain structure that facilitates control of movement, eye movements, cognition and emotion) and the spinal cord. These lesions can be seen on a magnetic resonance imaging (MRI) scan.
Symptoms and Types of MS
Symptoms of Multiple Sclerosis include weakness and fatigue, vision problems, bladder and bowel problems, pain, problems with memory and thinking, and problems with balance and coordination. Patients can also experience a worsening of symptoms when the body is overheated, known as Uhthoff’s phenomenon.
There are several phenotypes of MS, which impact the prognosis and treatment of patients. Patients normally first experience a neurological event suggestive of MS known as Clinically Isolated Syndrome (CIS). This first event lasts at least 24 hours[2].
The most common phenotype is Relapsing-Remitting Multiple Sclerosis (RRMS), with 85% of patients with MS having this specific type[3]. Patients with RRMS have periods of remission from symptoms for a few months of years before experiencing unpredictable relapses.
65% of patients experiencing RRMS will eventually develop Secondary-Progressive Multiple Sclerosis (SPMS). SPMS patients experience a steadier neurological decline and worsening of symptoms, and periods of remission grow shorter or no longer occur.
10% of patients with MS are diagnosed with Primary-Progressive Multiple Sclerosis (PPMS), meaning they experience a steady worsening of symptoms from the beginning without periods of relapse and remission.
Treatment Options
Although there is no known cure for Multiple Sclerosis, treatments and therapies have been developed to treat symptoms and slow the progression of the disorder. As a first-line of treatment, patients with Relapsing-Remitting MS are often treated with medications called beta interferons or glatiramer acetates, which reduce relapses by approximately 30%[4]. However, about 30% of patients show no improvement from beta interferons, so the second-line of treatment is medications known as Natalizumab and Mitoxantrone. These medications are more effective in reducing the symptoms and progression of MS, but they are related to dangerous side effects[5]. More advanced forms of MS are harder to treat, with Natalizumab and Mitoxantrone being moderately effective at reducing symptoms over a two year period[6].
Neurorehabilitation is also used to treat MS patients, and treatment such as speech therapy and physiotherapy can help to manage patients’ symptoms[7][8]. Because MS can cause a variety of symptoms, it is important that patients are treated individually depending on how they present. For example, patients with bladder problems may be prescribed drugs to control urinary urgency or use be catheterised[9], and patients with neuropsychiatric symptoms such as depression and anxiety may be treated with antidepressant drugs or cognitive behavioural therapy.
Research is currently being undertaken to develop new treatments for MS. Recent research has found that stem cell therapy may be successful in treating patients with relapsing-remitting MS[10]. In an international study, patients were first treated with cytotoxic therapy (chemotherapy) to inhibit cell division and cause immune cells to die, and were then givin a stem cell transplant to “reboot” their immune system. The results found patients showed quantitative and qualitative changes in T cells (a type of lymphocyte which plays a central role in the immune response). Patients reported a complete absence of symptoms following transplantation, however more research needs to be done in this area before it becomes a recognised treatment of multiple sclerosis.
References:
[1]World Health Organization (2008). Atlas: Multiple Sclerosis Resources in the World 2008. Geneva: World Health Organization, 15–16.
[2]Kappos, L., Polman, C,H., Freedman, M.S., (2006). Treatment with interferon beta-1b delays conversion to clinically definite and McDonald MS in patients with clinically isolated syndromes.Neurology, 67, 1242-1249
[3]Hooper, K. (2011) Managing Progressive MS.New York, NY: National Multiple Sclerosis Society;.
[4]Compston, A., Coles, A. (2008). Multiple sclerosis. Lancet, 372(9648): 1502–17.
[5]Comi, G. (2009). Treatment of multiple sclerosis: role of natalizumab. Neurol. Sci. 30. 2(2), 155–8.
[6]Martinelli Boneschi, F., Vacchi, L., Rovaris, M., Capra, R., Comi, G. (2013). Mitoxantrone for multiple sclerosis. The Cochrane Database of Systematic Reviews. 5 (5).
[7]Solari, A., Filippini, G., Gasco, P. (1999). Physical rehabilitation has a positive effect on disability in multiple sclerosis patients. Neurology. 52(1), 57–62.
[8]Merson, R.M., Rolnick, M.I. (1998). Speech-language pathology and dysphagia in multiple sclerosis. Physical Medicine and Rehabilitation Clinics of North America. 9(3), 631–41
[9]The National Collaborating Centre for Chronic Conditions (UK) (2004). Diagnosis and treatment of specific impairments. Multiple sclerosis: national clinical guideline for diagnosis and management in primary and secondary care. NICE Clinical Guidelines. 8. London: Royal College of Physicians (UK). 87–132.
[10]Snowden, J. A., Sharrack, B., Akil, M., Kiely, D. G., Lobo, A., Kazmi, M., … Lindsay, J. O. (2018). Autologous haematopoietic stem cell transplantation (aHSCT) for severe resistant autoimmune and inflammatory diseases - a guide for the generalist. Clinical medicine (London, England), 18(4), 329–334. doi:10.7861/clinmedicine.18-4-329
Kommentare