Multiple sclerosis (MS) is an autoimmune disease for which there is no known cure. Its main characteristic is that it causes weakness in various parts of the body. It also affects vision and generates fatigue and lack of balance. There is no specific protocol for the diagnosis of multiple sclerosis, this is a conclusion that the doctor or specialist will come to, based on many factors.
“MS is one of the most common causes of non-traumatic disability among young and middle-aged adults. Direct MS-related healthcare costs are estimated to be more than $10 billion annually in the United States. As symptoms of MS are extremely variable and often quite subtle, diagnosis and management have been greatly enhanced by the use of magnetic resonance imaging (MRI). Therapies that target inflammation and slow progression of disease are available; therefore, early diagnosis and treatment are important in limiting the impact of this potentially devastating disease. Complementary approaches such as symptom management and healthy lifestyle practices also have an important role in MS care.”1
“The exact cause of MS is unknown, and symptoms vary greatly from one person to another and for any one person over time. Most people afflicted with MS have a normal or near-normal life expectancy, and the majority of people with the disease do not become severely disabled. Although there is still no cure for MS, various strategies are available to modify the disease course, treat exacerbations (also known as relapses, attacks, or flare-ups), manage symptoms, and improve physical function and safety. In combination, these treatments are designed to enhance the quality of life for people living with MS. An individual’s treatment needs are best identified in an ongoing collaboration between a knowledgeable physician and other members of the treatment team. Of the approximately 400,000 Americans who have MS:
- Most are diagnosed between the ages of 20 and 50 years.
- Roughly 5% are diagnosed before age 21 years (early onset).
- Approximately 9.4% are diagnosed after age 50 years (late onset).
- An estimated 2 to 3 times as many women as men have MS.”2
“Multiple sclerosis is an inflammatory demyelinating disease affecting the central nervous system (CNS), thought to result from the interaction of genetic and environmental factors that remain only partially understood. The pathogenesis of multiple sclerosis is also complex and incompletely understood, but the major principles underlying the disease seem to be inflammation and neurodegeneration. The previous classification scheme relied on the idea of the existence of distinct phenotypes dominated by either underlying inflammatory (relapsing-remitting) or neurodegenerative (progressive) disease. Research has since demonstrated that axonal and neuronal loss actually begins at the earliest stages of the disease process, resulting in cognitive impairment and other early disability. In addition, it is possible for patients with a more progressive clinical phenotype to have evidence of ongoing inflammatory activity either through clinical relapses or new MRI lesions. These distinctions are important on the clinical level as they influence treatment considerations, payer reimbursement, and eligibility for clinical trials. The classification scheme has therefore been recently revised to incorporate these principles.”3
“There are no biological markers for MS. Today, the diagnosis is made from clinical findings, lesions identified on magnetic resonance imaging (MRI), presence of oligoclonal bands and/ or high levels of immunoglobulin G (IgG) in the cerebrospinal fluid (CSF), as described in the revised McDonald criteria in 2010.2 The most commonly presented form of MS is relapsing and remitting. In this, neurological symptoms or lesions are followed by periods of clinical improvement or latency. On the other hand, the progressive form can present either at the beginning of the disease (primary progressive), or after years of the relapsing-remitting form (secondary progressive).3 Despite these known diagnostic criteria, there is difficulty in establishing the diagnosis of MS and its onset is usually neglected since these initial symptoms may resolve spontaneously. This situation leads to delayed diagnosis, which consequently delays the treatment and has a negative impact regarding the speed of progression of the disease, and its prognosis.4 Thus, knowledge of the initial manifestations of MS has great epidemiological value, since it can contribute towards decreasing the time between MS onset and treatment, and may slow the progression of the disease.”4
Diagnosis of Multiple Sclerosis
The diagnosis of multiple sclerosis (MS) is a long process in which other similar diseases are discarded and then specific clinical tests are made. This diagnosis is complex, given that the symptoms of this disease are suggestive. Likewise, it is a pathology in which the manifestations can vary significantly from one patient to another. For this reason, the diagnosis of multiple sclerosis does not depend only on one test as with other diseases. Usually, a discarding process is carried out before arriving at a definitive diagnosis and commonly requires the concurrence of several medical disciplines simultaneously.
“The diagnosis of MS is primary clinical and is dependent on the demonstration of neurologic signs and symptoms subsequent to white matter lesions. To distinguish MS from other conditions with similar neurologic manifestations, several criteria including McDonald criteria have been proposed. These criteria depend on the demonstration of lesions disseminated in time and space to exclude alternative diagnoses. The requirement for such dissemination of lesions is achieved with adjuvant laboratory tests and imaging, including magnetic resonance imaging (MRI) of brain and spinal cord, cerebrospinal fluid analysis, and functional assays of the nervous system. The McDonald criteria, which combine these paraclinical assessments with clinical examination, are the most commonly used diagnostic approach. Currently, the diagnosis of MS depends largely on the results of MRI examination. Using gadolinium as a contrast agent to highlight active plaques, MRI allows detecting plaques that are ongoing to destruction of the BBB, and also those not associated with neurological symptoms at the time of the assessment. Therefore, relapsing remitting MS can be diagnosed earliest after a single relapse with an MRI scan showing gadolinium-enhancing and non-enhancing lesions disseminated in space.”5
Generic Symptoms of Multiple Sclerosis
The first element to take into account for the diagnosis of multiple sclerosis is the presence of generic symptoms. These are: double or blurred vision, motor coordination difficulties, loss of balance, cognitive issues, tingling or numbness and weakness of the leg or arm. The symptoms mentioned occur in almost half of patients with multiple sclerosis. However, the other half experience very mild manifestations or none at all. Likewise, it is possible that the following symptoms may appear
- Burning sensation in the body
- Urinary urgency, frequent urination and / or difficulties to empty the bladder completely
- Sexual dysfunction
- Difficulties when speaking and nasal pronunciation
Clinical Symptoms and Course of the Disease
“MS typically presents with abrupt onset of focal or multifocal neurological symptoms over minutes to hours. The actual deficits can be quite variable, but commonly include sensory disturbances, unilateral painless loss of vision, double vision, weakness of limbs, unsteadiness of gait, and bowel or bladder symptoms. The symptoms can be localized to a single plaque or multiple concurrent plaques of demyelination. A relapsing and remitting course (in 80-85 percent of patients) is characterized by isolated “attacks” of acute onset of such focal deficits followed by complete or partial resolution over 6-8 weeks. While at the onset of the disease there is no worsening of symptoms between attacks, subsets of patients eventually experience progression of neurological deficits between attacks (termed secondary progressive MS). In contrast to the relapsing and remitting course, a smaller group of patients follows a gradually progressive clinical course termed primary progressive MS.
While MS is generally not considered a fatal disease and is associated with only a small change in average life expectancy, the course of the disease in individual patients is quite variable and difficult to predict. By the time patients are 15 years into the course of disease, 20 percent are bedbound, 20 percent require some form of assistance for mobility and 60 percent are ambulatory without aid. Isolated sensory symptoms, long interval between relapses, and a normal initial MRI are predictive of a good prognosis.”6
The diagnosis of multiple sclerosis is based mainly on a detailed study of the clinical history and a neurological examination to detect any anomalies of the nervous system. It is also relatively common for other specialized tests to be ordered, although this is not always necessary. The tests that are usually prescribed by the doctor include:
- Blood test: It helps detect other diseases similar to multiple sclerosis.
- Lumbar puncture: It consists in the extraction of a sample of cerebrospinal fluid to analyze it, while searching for the presence of some antibodies that are typical of the disease. It also helps discard other pathologies.
- Magnetic resonance: This test reveals lesions in the brain and spinal cord which are areas of multiple sclerosis affectation. If they are present, it is said that the disease is in an active stage.
- Proof of evoked potentials: This test records the electrical signals produced by the nervous system against certain stimuli. These can be visual or motor and they measure the speed with which information is transmitted by the nervous system.
In most cases, all of the above elements allow the diagnosis of multiple sclerosis with a certain degree of reliability. However, there are also cases in which a definitive conclusion is not reached. If this happens, what is done is to periodically control the patient and repeat the tests after a certain amount of time.
(1) Hersh, C. M., & Fox, R. J. Definition and Disease Course. Available online at http://www.clevelandclinicmeded.com/medicalpubs/diseasemanagement/neurology/multiple_sclerosis/
(2) Theodorou, A. A., Johnson, K. M., Ruf, S., Szychowski, J. A., & AAS, B. (2010). Prescription utilization by multiple sclerosis patients in the United States. American Journal of Pharmacy. Available online at https://www.ajpb.com/journals/ajpb/2010/vol2_no2/drugtrends_2-2
(3) Sand, I. K. (2015). Classification, diagnosis, and differential diagnosis of multiple sclerosis. Current opinion in neurology, 28(3), 193-205. Available online at https://pdfs.semanticscholar.org/0745/4b05de78a7d1feb1e4514e8767e0947c712c.pdf
(4) Cavenaghi, V. B., Dobrianskyj, F. M., Olival, G. S. D., Carneiro, R. P. C. D., & Tilbery, C. P. (2017). Characterization of the first symptoms of multiple sclerosis in a Brazilian center: cross-sectional study. Sao Paulo Medical Journal, 135(3), 222-225. Available online at https://arxiv.org/ftp/arxiv/papers/1804/1804.03282.pdf
(5) Huang, W. J., Chen, W. W., & Zhang, X. (2017). Multiple sclerosis: pathology, diagnosis and treatments. Experimental and therapeutic medicine, 13(6), 3163-3166. Available online at https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5450788/
(6) Ganguly, K. (2006). The diagnosis of multiple sclerosis. AMA Journal of Ethics, 8(2), 93-96. Available online at https://journalofethics.ama-assn.org/article/diagnosis-multiple-sclerosis/2006-02