What is multiple sclerosis (MS)?

From the Guidelines

Multiple sclerosis (MS) is a chronic, inflammatory, and autoimmune disease of the central nervous system, leading to widespread focal degradation of the myelin sheath, variable axonal and neuronal injury, and disability in young adults 1.

Key Characteristics of MS

• The disease has at least two main forms: relapsing-remitting MS (RRMS), which accounts for about 85% of clinical cases, and primary-progressive MS (PPMS), affecting about 15% of clinical cases 1.
• In RRMS, the conduction of nerve impulses along the axon of the neuron may be affected during an acute inflammatory phase (relapse), but tends to improve with healing during the remission phase 1.
• Over time, relapses cause extensive damage and scarring of the myelin sheath with progressive loss of neuronal function 1.
• The pathogenesis of PPMS is characterized by progressive neurological damages rather than relapses and remissions 1.

Etiology and Associated Features

• The cause of MS is unknown, but research suggests that genetic, immunological, and environmental factors, such as a common virus, may all be involved in a complex etiology 1.
• Weight loss, malnutrition, and even cachexia are well-recognized features of patients with MS, possibly caused by reduced mobility and fatigue, inappropriate diet, physical difficulty for eating or drinking, poor appetite, poor sight, reduced cognition, and dysphagia 1.

Management and Treatment

While the provided evidence does not directly address management and treatment strategies, it is essential to note that a comprehensive approach typically involves a combination of medications, lifestyle modifications, and rehabilitation therapies, tailored to the individual's specific needs and form of the disease.

From the Research

Definition and Types of Multiple Sclerosis

• Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that affects nearly 2.8 million people each year 2.
• MS distinguishes three main types: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS), and primary progressive MS (PPMS) 2.
• RRMS is the most common type, with the majority of patients eventually progressing to SPMS, in which neurological development is constant, whereas PPMS is characterized by a progressive course from disease onset 2.

Pathophysiology and Characteristics

• MS is an immune-driven disease that affects the central nervous system and is characterized by acute-on-chronic demyelination attacks 3.
• It is a chronic inflammatory and neurodegenerative disease of the central nervous system characterized by broad inter- and intraindividual heterogeneity and different prognoses 4.
• The main mechanism of injury appears to be inflammation 5.

Prevalence and Impact

• MS is a major cause of global neurological disability, and its prevalence has increased in the United States 3.
• It affects approximately 400,000 people in the United States, and onset is usually during young adulthood 5.
• Multisystem comorbidities are frequent features in people with MS (PwMS) and can affect treatment choices, quality of life, disability, and mortality 4.

Treatment and Management

• Various disease-modifying therapies (DMTs) are currently used for RRMS/SPMS and PPMS, depending on the type and severity of the disease 2.
• Treatments may be categorized into low-, middle-, and high-efficacy medications based on their efficacy in relapse prevention 3.
• With 24 FDA-approved treatments for MS, individual therapy is chosen based on distinct mechanisms and potential side effects 3.
• Autologous hematopoietic stem cell transplantation (AHSCT) is performed as a last resort, especially in highly active RRMS that does not respond to DMTs, and has shown good results in reducing neuroinflammation 2.