name: Multiple Sclerosis
creation_date: '2025-12-04T16:57:31Z'
updated_date: '2026-02-16T20:19:38Z'
category: Neurological Disorder
parents:
- Autoimmune Disorder
prevalence:
- population: Global
  percentage: 0.1
  evidence:
  - reference: PMID:30679040
    reference_title: "Global, regional, and national burden of multiple sclerosis 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016."
    supports: WRONG_STATEMENT
    snippet: In 2016, there were 2 221 188 prevalent cases of multiple sclerosis ... globally, which corresponded to a 10·4% ... increase in the age-standardised prevalence since 1990
    explanation: The statement claims that the global prevalence of multiple sclerosis is 0.1%, but the literature indicates that the prevalence is much higher.
  - reference: PMID:37059571
    reference_title: "Incidence and prevalence of multiple sclerosis in China and other Asian countries."
    supports: WRONG_STATEMENT
    snippet: Prevalence rates in countries with predominantly white populations are considerably higher and have increased over time, reaching 115 cases/100,000 population in 2015.
    explanation: The statement's percentage is incorrect as prevalence rates in various populations are much higher than 0.1%.
progression:
- phase: Relapsing-Remitting
  notes: Characterized by periods of neurological symptoms (relapses) followed by periods of partial or complete recovery (remissions).
  evidence:
  - reference: PMID:25997994
    reference_title: "Multiple Sclerosis Relapses: Epidemiology, Outcomes and Management. A Systematic Review."
    supports: SUPPORT
    snippet: Relapses (episodic exacerbations of neurological signs or symptoms) are a defining feature of relapsing-remitting multiple sclerosis (MS), the most prevalent MS phenotype.
    explanation: The abstract clearly states that relapses are a defining feature of relapsing-remitting MS, supporting the statement about periods of neurological symptoms followed by partial or complete recovery.
  - reference: PMID:34006674
    reference_title: "[Relapsing-Remitting Multiple Sclerosis]."
    supports: PARTIAL
    snippet: The relapsing-remitting type is a major clinical course in MS.
    explanation: This reference confirms that the relapsing-remitting type is a major clinical course in MS, aligning with the statement about periods of relapses and remissions.
  - reference: PMID:31971066
    reference_title: "Recovery of cognitive function after relapse in multiple sclerosis."
    supports: PARTIAL
    snippet: Cognitive impairment is common in multiple sclerosis (MS) but its manifestation as acute disease activity is underappreciated... In RG patients, SDMT declined from 55.2 to 44.6 at relapse and recovered to 51.7.
    explanation: This study highlights cognitive function decline during relapses and subsequent recovery, supporting the characterization of MS by periods of neurological symptoms followed by recovery.
- phase: Secondary Progressive
  notes: Following an initial relapsing-remitting phase, there is a progressive worsening of neurological function over time.
  evidence:
  - reference: PMID:16545751
    reference_title: "Secondary progressive multiple sclerosis: current knowledge and future challenges."
    supports: SUPPORT
    snippet: The secondary progressive phase of multiple sclerosis (MS), which is characterised by a steady accrual of fixed disability after an initial relapsing remitting course, is not clearly understood.
    explanation: The reference describes secondary progressive MS as a phase that follows an initial relapsing-remitting course and is characterized by progressive worsening of neurological function.
  - reference: PMID:20946934
    reference_title: "Mechanisms of neuronal dysfunction and degeneration in multiple sclerosis."
    supports: SUPPORT
    snippet: This transforms into a disease of continuous and irreversible neurological decline by the sixth or seventh decade.
    explanation: The reference supports the statement by describing the transition from an initial phase with reversible episodes to a phase of continuous and irreversible neurological decline.
  - reference: PMID:24722325
    reference_title: "Relapsing and progressive forms of multiple sclerosis: insights from pathology."
    supports: SUPPORT
    snippet: The predominant clinical disease course of multiple sclerosis starts with reversible episodes of neurological disability, which transforms into progressive neurological decline.
    explanation: The reference supports the statement by describing the progression from relapsing episodes to a phase of progressive neurological decline.
- phase: Primary Progressive
  notes: A gradual progression of disability from onset without early relapses and remissions.
  evidence:
  - reference: PMID:33578205
    reference_title: "Definitions of primary-progressive multiple sclerosis trajectories by rate of clinical disability progression."
    supports: PARTIAL
    snippet: Patients with primary progressive multiple sclerosis (PPMS) vary in the rate of disability progression.
    explanation: The statement describes a gradual progression of disability from onset without early relapses and remissions, which aligns with the characteristics of primary progressive MS (PPMS).
  - reference: PMID:35977131
    reference_title: "Multiple Sclerosis: A Primary Care Perspective."
    supports: PARTIAL
    snippet: Types of MS include relapsing-remitting (most common), secondary progressive, and primary progressive.
    explanation: This reference supports the classification of MS into types, including primary progressive MS, which is characterized by a gradual progression of disability from onset without early relapses and remissions.
  - reference: PMID:29157397
    reference_title: "Progressive Forms of Multiple Sclerosis: Distinct Entity or Age-Dependent Phenomena."
    supports: PARTIAL
    snippet: Subclinical activity in radiologically isolated syndrome evolving to primary-progressive MS is mostly indistinguishable from relapsing-remitting MS evolving to secondary-progressive MS.
    explanation: This reference supports the concept of primary progressive MS, which involves a gradual progression of disability without the early relapses and remissions seen in relapsing-remitting MS.
- phase: Progressive-Relapsing
  notes: Progressive disability from onset with occasional acute relapses.
  evidence:
  - reference: PMID:37068931
    reference_title: "Disability accrual in primary and secondary progressive multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: 'BACKGROUND: Some studies comparing primary and secondary progressive multiple sclerosis (PPMS, SPMS) report similar ages at onset of the progressive phase and similar rates of subsequent disability accrual. Others report later onset and/or faster accrual in SPMS.'
    explanation: The reference discusses primary and secondary progressive multiple sclerosis but does not mention progressive-relapsing multiple sclerosis (PRMS).
  - reference: PMID:17884680
    reference_title: "Primary-progressive multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: About 10-15% of patients with multiple sclerosis (MS) present with gradually increasing neurological disability, a disorder known as primary-progressive multiple sclerosis (PPMS).
    explanation: This reference focuses on primary-progressive multiple sclerosis (PPMS) and does not address progressive-relapsing multiple sclerosis (PRMS).
  - reference: PMID:31397221
    reference_title: "Risk of secondary progressive multiple sclerosis: A longitudinal study."
    supports: NO_EVIDENCE
    snippet: 'BACKGROUND: The risk factors for conversion from relapsing-remitting to secondary progressive multiple sclerosis remain highly contested.'
    explanation: The reference discusses the transition from relapsing-remitting to secondary progressive multiple sclerosis but does not mention progressive-relapsing multiple sclerosis (PRMS).
  - reference: PMID:11207871
    reference_title: "Late-onset multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Late-onset MS was defined as the first presentation of clinical symptoms after the age of 50 years.
    explanation: The reference discusses late-onset multiple sclerosis but does not specifically address progressive-relapsing multiple sclerosis (PRMS).
  - reference: PMID:24722325
    reference_title: "Relapsing and progressive forms of multiple sclerosis: insights from pathology."
    supports: NO_EVIDENCE
    snippet: The clinical course of multiple sclerosis is variable, and the disease can be classified into relapsing and progressive phases.
    explanation: The reference distinguishes between relapsing and progressive phases of multiple sclerosis but does not specifically mention progressive-relapsing multiple sclerosis (PRMS).
pathophysiology:
- name: Demyelination
  description: The immune system attacks and destroys myelin, the protective sheath around nerve fibers, disrupting nerve signal transmission.
  downstream:
  - target: Neurological Disability
    description: Autoimmune demyelination and neuronal loss lead to progressive neurological disability.
    evidence:
    - reference: PMID:40636815
      reference_title: "Multiple sclerosis: 2024 update."
      supports: SUPPORT
      snippet: Multiple sclerosis (MS) is a complex immune-mediated disease that leads to neurological disability
      explanation: This 2024 review explicitly states the causal relationship between the immune-mediated (autoimmune) nature of MS and neurological disability.
  cell_types:
  - preferred_term: Oligodendrocyte
    term:
      id: CL:0000128
      label: oligodendrocyte
  - preferred_term: T cell
    term:
      id: CL:0000084
      label: T cell
  - preferred_term: B cell
    term:
      id: CL:0000236
      label: B cell
  - preferred_term: Microglial cell
    term:
      id: CL:0000129
      label: microglial cell
  - preferred_term: Astrocyte
    term:
      id: CL:0000127
      label: astrocyte
  - preferred_term: CD4-positive, alpha-beta T cell
    term:
      id: CL:0000624
      label: CD4-positive, alpha-beta T cell
  biological_processes:
  - preferred_term: Antigen processing and presentation of peptide antigen via MHC class II
    term:
      id: GO:0002495
      label: antigen processing and presentation of peptide antigen via MHC class II
  - preferred_term: T cell activation
    term:
      id: GO:0042110
      label: T cell activation
  - preferred_term: Cytokine-mediated signaling pathway
    term:
      id: GO:0019221
      label: cytokine-mediated signaling pathway
  - preferred_term: Complement activation
    term:
      id: GO:0006956
      label: complement activation
  - preferred_term: Myelination
    term:
      id: GO:0042552
      label: myelination
  locations:
  - preferred_term: Central nervous system
    term:
      id: UBERON:0001017
      label: central nervous system
  - preferred_term: Meninges
    term:
      id: UBERON:0002360
      label: meninx
  - preferred_term: White matter
    term:
      id: UBERON:0002316
      label: white matter
  - preferred_term: Gray matter
    term:
      id: UBERON:0002020
      label: gray matter
  - preferred_term: Brain
    term:
      id: UBERON:0000955
      label: brain
  - preferred_term: Spinal cord
    term:
      id: UBERON:0002240
      label: spinal cord
  evidence:
  - reference: PMID:24507511
    reference_title: "Immune regulation of multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is considered a prototype inflammatory autoimmune disorder of the central nervous system (CNS)... These autoreactive lymphocytes can migrate to the CNS where they become reactivated upon encountering their target antigen, initiating an autoimmune inflammatory attack. This ultimately leads to demyelination and axonal damage.
    explanation: The literature supports that MS involves the immune system attacking myelin in the CNS, leading to demyelination. It specifically mentions the role of autoreactive lymphocytes, which include T and B lymphocytes.
  - reference: PMID:19847447
    reference_title: "Oligodendrocytes: biology and pathology."
    supports: PARTIAL
    snippet: Oligodendrocytes are the myelinating cells of the central nervous system (CNS)... we will lay out the different pathways leading to oligodendrocyte and myelin loss in human CNS diseases...
    explanation: The literature supports the involvement of oligodendrocytes in myelination and their loss in CNS diseases like MS, which leads to demyelination.
  - reference: PMID:36889543
    reference_title: "Schwann Cell Remyelination in the Multiple Sclerosis Central Nervous System."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating disease... CNS myelin is normally produced by oligodendroglial cells.
    explanation: The literature supports that MS is a demyelinating disease affecting the CNS, with oligodendrocytes being the cells responsible for myelin production.
  - reference: PMID:37629092
    reference_title: "Alterations of Oligodendrocyte and Myelin Energy Metabolism in Multiple Sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is a complex autoimmune disease of the central nervous system (CNS), characterized by demyelination and neurodegeneration. Oligodendrocytes play a vital role in maintaining the integrity of myelin... However, in MS, oligodendrocytes become dysfunctional, leading to myelin damage and axonal degeneration.
    explanation: The literature supports that MS involves demyelination and neurodegeneration in the CNS, with oligodendrocytes playing a crucial role in this process.
  - reference: PMID:15727225
    reference_title: "Lessons from the neuropathology of atypical forms of multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is characterized by multiple demyelinated inflammatory lesions disseminated in the central nervous system (CNS)... different mechanisms of demyelination, such as T-cell/macrophage-mediated demyelination, antibody/complement-mediated demyelination, and primary damage of the oligodendrocyte have been observed in individual MS patients.
    explanation: The literature supports that MS involves demyelination in the CNS and mentions the role of T-cells and oligodendrocytes in this process.
  - reference: PMID:21425268
    reference_title: "Targeting oligodendrocyte protection and remyelination in multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis is an inflammatory demyelinating disease of the brain and spinal cord with a presumed autoimmune etiology... Approaches that directly protect myelin-producing oligodendrocytes and enhance remyelination may improve long-term outcomes...
    explanation: The literature supports that MS is an autoimmune disease causing demyelination in the CNS, involving oligodendrocytes.
  - reference: PMID:28674983
    reference_title: "Multiple Sclerosis: Basic and Clinical."
    supports: SUPPORT
    snippet: MS is a chronic inflammatory disease of the central nervous system caused by aberrant immune activation resulting in damage to myelin sheaths within the brain and spinal cord and axonal loss
    explanation: The literature supports that MS involves immune activation leading to damage of myelin sheaths in the CNS.
  - reference: PMID:17548563
    reference_title: "Pathogenesis of myelin/oligodendrocyte damage in multiple sclerosis."
    supports: SUPPORT
    snippet: Substantial evidence supports autoimmune activity as the etiologic mechanism underlying multiple sclerosis (MS)... Both the innate and the adaptive arms of the immune system are involved in the aberrant response to several antigens associated with the myelin sheath and oligodendrocytes (OGCs)...
    explanation: The literature supports that MS is an autoimmune disease involving the immune system's attack on myelin and oligodendrocytes in the CNS.
  - reference: PMID:24507514
    reference_title: "Demyelination in multiple sclerosis."
    supports: SUPPORT
    snippet: This review, focused on demyelination in multiple sclerosis, is divided in two parts. The first part addresses the many and not exclusive mechanisms leading to demyelination in the central nervous system... the influence of a primary immune response against myelin antigen(s), with a diversity of potential targets.
    explanation: The literature supports that MS involves immune responses against myelin antigens leading to demyelination in the CNS.
- name: Axonal Damage
  description: Along with demyelination, damage to the axons themselves contributes to the permanent neurological deficits.
  evidence:
  - reference: PMID:21425267
    reference_title: "Axonal damage in multiple sclerosis."
    supports: SUPPORT
    snippet: Here, we review distinct, but not mutually exclusive, mechanisms of pathogenesis of axonal damage in multiple sclerosis patients that are either consequent to long-term demyelination or independent from it.
    explanation: The article discusses axonal damage as a significant factor in the pathogenesis of multiple sclerosis, supporting the statement that axonal damage contributes to permanent neurological deficits.
  - reference: PMID:17115075
    reference_title: "Axonal conduction and injury in multiple sclerosis: the role of sodium channels."
    supports: SUPPORT
    snippet: Recent studies have implicated specific sodium channel isoforms as having an important role in several aspects of the pathophysiology of MS, including the restoration of impulse conduction after demyelination, axonal degeneration and the mistuning of Purkinje neurons that leads to cerebellar dysfunction.
    explanation: The article mentions axonal degeneration as part of the pathophysiology of MS, supporting the statement that axonal damage contributes to permanent neurological deficits.
  - reference: PMID:25159125
    reference_title: "Axonal degeneration in multiple sclerosis: can we predict and prevent permanent disability?"
    supports: SUPPORT
    snippet: Axonal degeneration is a major determinant of permanent neurological impairment during multiple sclerosis (MS).
    explanation: The article directly states that axonal degeneration is a major determinant of permanent neurological impairment in MS, which supports the statement.
  - reference: PMID:31760649
    reference_title: "Roads to Formation of Normal Myelin Structure and Pathological Myelin Structure."
    supports: SUPPORT
    snippet: Demyelination and axonal damage are responsible for neurological deficits in demyelinating diseases including multiple sclerosis (MS), an inflammatory demyelinating disease of the central nervous system.
    explanation: The article explicitly mentions that both demyelination and axonal damage are responsible for neurological deficits in MS, supporting the statement.
  - reference: PMID:17884680
    reference_title: "Primary-progressive multiple sclerosis."
    supports: SUPPORT
    snippet: Although neuroaxonal degeneration seems to underlie PPMS, the pathogenesis and the extent to which immune-mediated mechanisms operate is unclear.
    explanation: The article discusses neuroaxonal degeneration as underlying primary-progressive multiple sclerosis (PPMS), which supports the statement.
- name: Th1/Th17-Mediated Neuroinflammation
  description: MS immunopathology is mediated by myelin-reactive CD4+ T cells of Th1 and Th17 lineage. Th17 cells produce IL-17, IL-22, and other proinflammatory cytokines that disrupt blood-brain barrier tight junction proteins and recruit neutrophils into the CNS. The IL-23/IL-17 axis amplifies neuroinflammation.
  biological_processes:
  - preferred_term: T-helper 17 type immune response
    term:
      id: GO:0072538
      label: T-helper 17 type immune response
  - preferred_term: Inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
  cell_types:
  - preferred_term: T-helper 17 cell
    term:
      id: CL:0000899
      label: T-helper 17 cell
  - preferred_term: T-helper 1 cell
    term:
      id: CL:0000545
      label: T-helper 1 cell
  downstream:
  - target: Inflammatory Lesions
    description: Autoreactive Th17 cells migrate through the BBB and drive focal demyelinating lesion formation.
  evidence:
  - reference: PMID:32801039
    reference_title: "The role of TH17 cells in multiple sclerosis: Therapeutic implications."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS) where immunopathology is thought to be mediated by myelin-reactive CD4+ T helper (TH) cells. The TH cells most commonly implicated in the pathogenesis of the disease are of TH1 and TH17 lineage, which are defined by the production of interferon-γ and interleukin-17, respectively.
    explanation: Directly establishes TH1 and TH17 cells as the key drivers of MS immunopathology.
  - reference: PMID:21338381
    reference_title: "Th17 cell, the new player of neuroinflammatory process in multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis (MS) is an autoimmune disease characterized by recurrent episodes of demyelination and axonal lesion mediated by CD4(+) T cells with a proinflammatory Th1 and Th17 phenotype, macrophages, and soluble inflammatory mediators.
    explanation: Confirms Th1 and Th17 phenotypes as mediators of MS demyelination and axonal damage.
  - reference: PMID:21338381
    reference_title: "Th17 cell, the new player of neuroinflammatory process in multiple sclerosis."
    supports: SUPPORT
    snippet: Autoreactive Th17 cells can migrate through the BBB by the production of cytokines such as IL-17 and IL-22, which disrupt tight junction proteins in the central nervous system (CNS) endothelial cells.
    explanation: Describes the mechanism by which Th17 cells cross the BBB via IL-17 and IL-22 disruption of tight junctions.
- name: Inflammatory Lesions
  description: Immune cells crossing the blood-brain barrier create focal areas of inflammation in the central nervous system.
  biological_processes:
  - preferred_term: Inflammatory response
    term:
      id: GO:0006954
      label: inflammatory response
  cell_types:
  - preferred_term: T cell
    term:
      id: CL:0000084
      label: T cell
  - preferred_term: Macrophage
    term:
      id: CL:0000235
      label: macrophage
  evidence:
  - reference: PMID:21550344
    reference_title: "How do immune cells overcome the blood-brain barrier in multiple sclerosis?"
    supports: SUPPORT
    snippet: Leukocyte entry into the CNS is nonetheless an early event in multiple sclerosis (MS), an inflammatory disorder of the CNS... Immune cells of MS subjects express inflammatory cytokines, reactive oxygen species (ROS) and enzymes that can facilitate their migration to the CNS by influencing BBB function, either directly or indirectly.
    explanation: This reference supports the statement that immune cells cross the blood-brain barrier and create inflammation in the central nervous system.
  - reference: PMID:34440810
    reference_title: "What Guides Peripheral Immune Cells into the Central Nervous System?"
    supports: SUPPORT
    snippet: During this early stage of the disease, leukocytes cross the blood-brain barrier to drive the formation of focal demyelinating plaques.
    explanation: This reference directly supports the statement by mentioning that leukocytes cross the blood-brain barrier and drive the formation of focal demyelinating plaques, which are inflammatory lesions.
  - reference: PMID:30407467
    reference_title: "[Actualidades en la inmunopatología de la esclerosis múltiple]."
    supports: SUPPORT
    snippet: Neuroinflammation is triggered when peripheral leukocytes migrate to the central nervous system and release cytokines such as interleukins 1 and 6 (IL-1 and 6) and tumor necrosis factor (TNF), which act on dwelling cells.
    explanation: This reference supports the statement by explaining that peripheral leukocytes migrate to the CNS and trigger neuroinflammation.
  - reference: PMID:29515568
    reference_title: "The Role of Astrocytes in Multiple Sclerosis."
    supports: SUPPORT
    snippet: Astrocytes are now recognized to be early and highly active players during lesion formation and key for providing peripheral immune cells access to the central nervous system.
    explanation: This reference supports the statement by mentioning the role of astrocytes in providing access for peripheral immune cells to the CNS, contributing to lesion formation.
phenotypes:
- category: Neurologic
  name: Muscle Weakness
  frequency: FREQUENT
  evidence:
  - reference: PMID:23897142
    reference_title: "[Acute muscle weakness: differential diagnoses]."
    supports: NO_EVIDENCE
    snippet: Acute muscle weakness, a common disorder in pediatrics, can occur from impairment of any part of the motor unit, including the upper motor neuron, lower motor neuron, peripheral nerve, neuromuscular junction or muscle.
    explanation: The reference mentions muscle weakness as a common disorder, which supports the statement that muscle weakness is frequent in neurological conditions like multiple sclerosis.
  - reference: PMID:32120056
    reference_title: "Ghost spasticity in multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Spasticity is the velocity-dependent hypertonia frequently encountered in patients affected by Upper Motor Neuron Syndrome.
    explanation: While the primary focus is on spasticity, the study involves patients with multiple sclerosis, implying that muscle-related issues, including weakness, are frequent.
  - reference: PMID:26863109
    reference_title: "Disability and Fatigue Can Be Objectively Measured in Multiple Sclerosis."
    supports: PARTIAL
    snippet: Hip mROM was extremely sensitive in measuring lower limb motor impairment, being correlated with muscle strength and also altered in patients without clinically detectable disability.
    explanation: The study shows that lower limb motor impairment, which includes muscle weakness, is a frequent symptom in multiple sclerosis patients.
  - reference: PMID:15228757
    reference_title: "Central nervous system atrophy and clinical status in multiple sclerosis."
    supports: PARTIAL
    snippet: Cross-sectional studies have demonstrated a moderate but significant correlation between brain or spinal cord atrophy and physical disability in patients with MS.
    explanation: Physical disability in multiple sclerosis patients often includes muscle weakness, supporting the statement.
  - reference: PMID:10101582
    reference_title: "Spasticity, ataxia and fatigue in multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Chief among these symptoms, both in relation to their frequency and their impact on the patient, are spasticity, ataxia and fatigue.
    explanation: While muscle weakness is not directly mentioned, spasticity and ataxia are related symptoms, supporting the frequency of muscle-related issues in multiple sclerosis.
  phenotype_term:
    preferred_term: Muscle weakness
    term:
      id: HP:0001324
      label: Muscle weakness
- category: Neurologic
  name: Vision Problems
  frequency: FREQUENT
  notes: Including optic neuritis and double vision.
  evidence:
  - reference: PMID:15664543
    reference_title: "The neuro-ophthalmology of multiple sclerosis."
    supports: SUPPORT
    snippet: The commonness of visual sensory and eye movement abnormalities in MS highlights the importance of understanding the principles addressed in this review.
    explanation: This reference discusses the frequent occurrence of visual sensory and eye movement abnormalities in multiple sclerosis, supporting the statement that vision problems, including optic neuritis and double vision, are frequent in MS.
  - reference: PMID:32981685
    reference_title: "Vision Problems in Multiple Sclerosis."
    supports: PARTIAL
    snippet: Vision Problems in Multiple Sclerosis.
    explanation: The title of this reference directly indicates that vision problems are a recognized issue in multiple sclerosis, supporting the statement.
  - reference: PMID:34939452
    reference_title: "Ocular manifestations of multiple sclerosis in patients from three countries: A Web-based survey."
    supports: PARTIAL
    snippet: The first ocular crisis or clinical debut of MS is characterized by slow and progressive visual impairment, increasing and adding to other ocular manifestations during its evolutionary course.
    explanation: This reference confirms the frequent occurrence of visual impairment in multiple sclerosis, supporting the statement that vision problems are frequent in MS.
- category: Neurologic
  name: Fatigue
  frequency: VERY_FREQUENT
  diagnostic: true
  evidence:
  - reference: PMID:3355400
    reference_title: "Fatigue in multiple sclerosis."
    supports: SUPPORT
    snippet: Fatigue is a frequent symptom in multiple sclerosis (MS) that can interfere with a patient's daily functioning.
    explanation: The abstract explicitly states that fatigue is a frequent symptom in multiple sclerosis, supporting the statement.
  - reference: PMID:26195047
    reference_title: "Relation of quantitative visual and neurologic outcomes to fatigue in multiple sclerosis."
    supports: PARTIAL
    snippet: The relation of fatigue in multiple sclerosis (MS) to the visual system, an emerging structural and functional surrogate in MS, has not been well established.
    explanation: The abstract discusses the relationship between fatigue and MS, implicitly supporting the statement that fatigue is a frequent symptom.
  phenotype_term:
    preferred_term: Fatigue
    term:
      id: HP:0012378
      label: Fatigue
- category: Neurologic
  name: Gait and Balance Issues
  frequency: FREQUENT
  evidence:
  - reference: PMID:30482317
    reference_title: "Balance, gait, and falls in multiple sclerosis."
    supports: PARTIAL
    snippet: MS is characterized by clinical symptoms resulting from lesions in the brain, spinal cord, or optic nerves that can affect balance, gait, and fall risk.
    explanation: The reference clearly states that MS affects balance and gait, indicating that these issues are frequent in individuals with MS.
  - reference: PMID:38141562
    reference_title: "Smartphone-based gait assessment for multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple Sclerosis causes gait alteration, even in the early stages of the disease.
    explanation: This reference supports the statement by indicating that gait issues occur even in the early stages of MS.
  - reference: PMID:35174869
    reference_title: "Intensive Circuit Class Therapy in Patients with Relapsing-Remitting Multiple Sclerosis."
    supports: PARTIAL
    snippet: Intensive circuit class therapy is an effective therapeutic approach for improving gait and balance problems in patients with MS.
    explanation: This reference supports the statement by mentioning the effectiveness of therapy in addressing frequent gait and balance issues in MS patients.
  - reference: PMID:23153835
    reference_title: "Gait variability and disability in multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Gait variability is clinically relevant in some populations, but there is limited documentation of gait variability in persons with multiple sclerosis (MS).
    explanation: This reference supports the statement by discussing the clinical relevance of gait variability in MS patients.
- category: Neurologic
  name: Spasticity
  frequency: FREQUENT
  evidence:
  - reference: PMID:22721362
    reference_title: "[Editorial. Spasticity in multiple sclerosis]."
    supports: PARTIAL
    snippet: Spasticity in multiple sclerosis
    explanation: The title of the article directly mentions spasticity in the context of multiple sclerosis.
  - reference: PMID:35977131
    reference_title: "Multiple Sclerosis: A Primary Care Perspective."
    supports: NO_EVIDENCE
    snippet: Symptoms of MS depend on the areas of neuronal involvement. Common symptoms include sensory disturbances, motor weakness, impaired gait, incoordination, optic neuritis, and Lhermitte sign.
    explanation: The abstract mentions various symptoms of MS, though it does not explicitly mention spasticity. This reference is not included as it does not provide clear evidence for spasticity being a frequent symptom of MS.
  - reference: PMID:30286958
    reference_title: "Common Etiologies of Upper Extremity Spasticity."
    supports: PARTIAL
    snippet: The most common causes leading to spasticity include stroke, traumatic brain injury, multiple sclerosis, spinal cord injury, and cerebral palsy.
    explanation: The abstract clearly states that multiple sclerosis is a common cause of spasticity.
  - reference: PMID:32120056
    reference_title: "Ghost spasticity in multiple sclerosis."
    supports: PARTIAL
    snippet: Spasticity is the velocity-dependent hypertonia frequently encountered in patients affected by Upper Motor Neuron Syndrome.
    explanation: The abstract discusses spasticity in the context of multiple sclerosis, indicating it is a frequent symptom.
  - reference: PMID:10101582
    reference_title: "Spasticity, ataxia and fatigue in multiple sclerosis."
    supports: SUPPORT
    snippet: Chief among these symptoms, both in relation to their frequency and their impact on the patient, are spasticity, ataxia and fatigue.
    explanation: The abstract explicitly states that spasticity is a frequent symptom in multiple sclerosis.
  - reference: PMID:22612755
    reference_title: "Management of spasticity in progressive multiple sclerosis: efficacy of repeated intrathecal triamcinolone acetonide administration."
    supports: SUPPORT
    snippet: Spasticity is one of the most common symptoms.
    explanation: The abstract clearly states that spasticity is one of the most common symptoms of multiple sclerosis.
  - reference: PMID:20586738
    reference_title: "Clinical assessment and management of spasticity: a review."
    supports: PARTIAL
    snippet: Spasticity is a sign of upper motor neurone lesion, which can be located in the cerebrum or the spinal cord, and be caused by stroke, multiple sclerosis, spinal cord injury, brain injury, cerebral paresis, or other neurological conditions.
    explanation: The abstract mentions multiple sclerosis as a cause of spasticity, supporting the statement.
  - reference: PMID:26611270
    reference_title: "Country break-out session highlights."
    supports: PARTIAL
    snippet: Individuals with multiple sclerosis (MS) spasticity present a wide range of symptoms and disability levels that are frequently challenging to manage.
    explanation: The abstract discusses the challenges of managing spasticity in multiple sclerosis patients, indicating it is a frequent symptom.
  - reference: PMID:30626509
    reference_title: "Special Considerations and Assessment in Patients with Multiple Sclerosis."
    supports: PARTIAL
    snippet: Spasticity in patients with multiple sclerosis can be debilitating and detrimental to the function and quality of life of patients.
    explanation: The abstract discusses the impact of spasticity on multiple sclerosis patients, indicating it is a frequent symptom.
  phenotype_term:
    preferred_term: Spasticity
    term:
      id: HP:0001257
      label: Spasticity
- category: Neurologic
  name: Cognitive Impairment
  frequency: FREQUENT
  notes: Difficulties with memory, attention, and information processing.
  evidence:
  - reference: PMID:37379870
    reference_title: "Cognitive impairment in multiple sclerosis: \"classic\" knowledge and recent acquisitions."
    supports: SUPPORT
    snippet: Multiple sclerosis causes motor, sensory, cerebellar, and autonomic dysfunctions, as well as cognitive and psychoemotional impairment. The most frequently compromised cognitive domains are complex attention/information processing, memory, executive and visuospatial functions.
    explanation: The literature confirms that cognitive impairment, including difficulties with memory, attention, and information processing, is a frequent neurological symptom in multiple sclerosis.
  - reference: PMID:27207446
    reference_title: "Information processing speed in multiple sclerosis: Past, present, and future."
    supports: SUPPORT
    snippet: Information processing speed (IPS) is a prevalent cognitive impairment in multiple sclerosis (MS).
    explanation: The literature specifically highlights information processing speed as a prevalent cognitive impairment in MS, supporting the statement.
  - reference: PMID:37031630
    reference_title: "Do cardiovascular disease comorbidities affect the cognitive function of Multiple Sclerosis patients?"
    supports: SUPPORT
    snippet: Cognitive impairment is a core symptom of multiple sclerosis, leading to disability in 40-70% of patients. The most common cognitive domains affected by MS are information processing speed, complex attention, executive functions and less frequently, episodic declarative memory.
    explanation: The literature confirms that cognitive impairment is a frequent symptom of MS, affecting information processing, attention, and memory.
  phenotype_term:
    preferred_term: Cognitive Impairment
    term:
      id: HP:0100543
      label: Cognitive impairment
- category: Neurologic
  name: Bladder and Bowel Dysfunction
  frequency: COMMON
  evidence:
  - reference: PMID:7707085
    reference_title: "Prevalence of bowel dysfunction in patients with multiple sclerosis and bladder dysfunction."
    supports: SUPPORT
    snippet: Urinary dysfunction is common in cases of multiple sclerosis (MS)... A total of 52% currently had at least one bowel symptom.
    explanation: The study indicates that both bladder and bowel dysfunction are common in MS patients.
  - reference: PMID:37084150
    reference_title: "Autonomic nervous system disorders in multiple sclerosis."
    supports: PARTIAL
    snippet: Manifestations of MS in the ANS include urological, sexual, gastrointestinal, cardiovascular, and thermoregulatory disorders...
    explanation: The literature confirms that urological (bladder) and gastrointestinal (bowel) disorders are common manifestations of MS.
  - reference: PMID:20955903
    reference_title: "Review of neurologic diseases for the urologist."
    supports: PARTIAL
    snippet: This article reviews the neurologic conditions associated with a high prevalence of bladder dysfunction...
    explanation: The review highlights the high prevalence of bladder dysfunction in neurologic conditions, including MS.
  - reference: PMID:24314685
    reference_title: "Bladder management in multiple sclerosis."
    supports: PARTIAL
    snippet: This article reviews the basic principles and therapeutic options in the management of the neurogenic bladder due to multiple sclerosis (MS)...
    explanation: The article confirms that bladder dysfunction is a common issue in MS patients.
- category: Neurologic
  name: Sensory Disturbances
  frequency: FREQUENT
  notes: Numbness or tingling in limbs.
  evidence:
  - reference: PMID:2602337
    reference_title: "Weakness, numbness, tingling and multiple sclerosis."
    supports: SUPPORT
    snippet: Multiple sclerosis is the most common serious neurological disease in young patients but it is not the only cause of paraesthesiae. Such sensory symptoms occur frequently and reflect a variety of underlying conditions.
    explanation: The literature indicates that sensory symptoms such as numbness or tingling occur frequently in multiple sclerosis patients.
  - reference: PMID:33296981
    reference_title: "A longitudinal study of symptom botheration in Multiple Sclerosis."
    supports: PARTIAL
    snippet: Small but significant increases during followup were seen in dexterity, bladder, vision, and pain domains, while significant decreases were seen in anxiety and sensory domains.
    explanation: The study shows that sensory symptoms are commonly affected in MS patients.
  - reference: PMID:38795594
    reference_title: "Relationship between sensation and balance and gait in multiple sclerosis patients with mild disability."
    supports: SUPPORT
    snippet: Patients with Multiple Sclerosis (PwMS) often experience sensory, balance, and gait problems.
    explanation: The literature supports that sensory disturbances are frequent in MS patients.
  - reference: PMID:10554672
    reference_title: "Sensory-motor and genito-sphincter dysfunctions in multiple sclerosis."
    supports: SUPPORT
    snippet: Among the symptoms, sensory-motor disorders and genito-sphincter dysfunctions are some of the more disabling.
    explanation: Sensory disturbances are listed as common and disabling symptoms in MS patients.
  - reference: PMID:10408718
    reference_title: "Sensory symptoms of multiple sclerosis: a hidden reservoir of morbidity."
    supports: SUPPORT
    snippet: Sensory symptoms were more common in MS patients than in controls, and differed in severity and quality.
    explanation: Sensory symptoms, including numbness or tingling, are reported as frequent in MS patients.
- category: Neurologic
  name: Ataxia
  frequency: FREQUENT
  notes: Lack of voluntary coordination of muscle movements; cerebellar dysfunction
  phenotype_term:
    preferred_term: Ataxia
    term:
      id: HP:0001251
      label: Ataxia
- category: Neurologic
  name: Optic Neuritis
  frequency: FREQUENT
  notes: Inflammation of the optic nerve causing visual impairment or loss
  phenotype_term:
    preferred_term: Optic neuritis
    term:
      id: HP:0100653
      label: Optic neuritis
- category: Neurologic
  name: Dysesthesia
  frequency: FREQUENT
  notes: Abnormal unpleasant sensations such as burning or prickling
  phenotype_term:
    preferred_term: Dysesthesia
    term:
      id: HP:0012534
      label: Dysesthesia
biochemical:
- name: Oligoclonal Bands
  presence: Positive
  context: Detected in cerebrospinal fluid during lumbar puncture.
  evidence:
  - reference: PMID:31031747
    reference_title: "The Cerebrospinal Fluid in Multiple Sclerosis."
    supports: SUPPORT
    snippet: The hallmark of MS-specific changes in CSF is the detection of oligoclonal bands (OCB) which occur in the vast majority of MS patients.
    explanation: This reference reiterates that oligoclonal bands are a key diagnostic marker in the cerebrospinal fluid of multiple sclerosis patients.
  - reference: PMID:32408148
    reference_title: "From Baló's concentric sclerosis to multiple sclerosis: a series of 6 patients."
    supports: PARTIAL
    snippet: Oligoclonal bands were identified in 5/6 patients. After 7 years of follow-up, all patients achieved MS criteria with mild disability.
    explanation: This reference shows that oligoclonal bands were detected in the cerebrospinal fluid of patients who later met the criteria for multiple sclerosis.
  - reference: PMID:22919874
    reference_title: "Reibergram and oligoclonal bands in diagnosis of multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Immunoglobulin IgG in cerebrospinal fluid (CSF) can be detected in neurological diseasses (infections and inflammatory neurological diseases and in demyelinating diseases, like multiple sclerosis (MS))
    explanation: This reference supports the detection of oligoclonal bands in the cerebrospinal fluid of multiple sclerosis patients.
  - reference: PMID:29452342
    reference_title: "Neurofilament light chain and oligoclonal bands are prognostic biomarkers in radiologically isolated syndrome."
    supports: PARTIAL
    snippet: Neurofilament light chain levels and oligoclonal bands were independent risk factors for the development of clinically isolated syndrome (hazard ratio = 1.02, P = 0.019, and hazard ratio = 14.7, P = 0.012, respectively) and multiple sclerosis.
    explanation: This reference indicates that oligoclonal bands are present in the cerebrospinal fluid and are a risk factor for the development of multiple sclerosis.
diagnosis:
- name: MRI with Gadolinium Contrast
  presence: Positive
  notes: Used to identify areas of demyelination in the brain and spinal cord.
  evidence:
  - reference: PMID:25909791
    reference_title: "[Contrast agents in MRI-diagnosis of multiple sclerosis]."
    supports: SUPPORT
    snippet: Magnetic resonance imaging using contrast agents plays an important role in diagnosis and assessment of treatment efficacy in multiple sclerosis.
    explanation: The use of MRI with gadolinium contrast is highlighted as important for diagnosing and assessing treatment efficacy in multiple sclerosis, which involves identifying areas of demyelination.
  - reference: PMID:33872085
    reference_title: "Multiple sclerosis: prevalence of the 'central vein' sign in white matter lesions on gadolinium-enhanced susceptibility-weighted images."
    supports: SUPPORT
    snippet: Gadolinium-enhanced susceptibility-weighted imaging improves the detection rate of the central vein sign in multiple sclerosis lesions.
    explanation: This study demonstrates that gadolinium-enhanced MRI improves the detection of specific signs in multiple sclerosis lesions, which are related to demyelination.
  - reference: PMID:32388832
    reference_title: "Gadolinium enhancement on cranial MRI in multiple sclerosis is age dependent."
    supports: SUPPORT
    snippet: Gadolinium-enhancing lesions are a biomarker of inflammatory disease activity in MS.
    explanation: Gadolinium-enhancing lesions are used as a biomarker for inflammatory activity in MS, indicating areas of active demyelination.
  - reference: PMID:33780808
    reference_title: "Low-field portable brain MRI in CNS demyelinating disease."
    supports: PARTIAL
    snippet: These images demonstrate the ability to identify a solitary demyelinating lesion in early stage disease and cortical atrophy and chronic white matter changes in late stage disease.
    explanation: The use of MRI, including with gadolinium contrast, is shown to identify demyelinating lesions and other changes in the brain associated with multiple sclerosis.
  - reference: PMID:33901207
    reference_title: "Blood-brain barrier breakdown in non-enhancing multiple sclerosis lesions detected by 7-Tesla MP2RAGE ΔT1 mapping."
    supports: SUPPORT
    snippet: Measurement of the changes in T1 relaxation time caused by contrast on 7T MP2RAGE reveals clinically relevant evidence of BBB breakdown in NELs in MS.
    explanation: The study discusses how gadolinium contrast in MRI can reveal blood-brain barrier breakdown in multiple sclerosis lesions, which is associated with demyelination.
- name: Lumbar Puncture
  presence: Presence of oligoclonal bands in cerebrospinal fluid.
  evidence:
  - reference: PMID:35662071
    reference_title: "Repeated lumbar puncture in search of oligoclonal bands - What is the yield?"
    supports: PARTIAL
    snippet: Cerebrospinal fluid (CSF) oligoclonal bands (OCBs) are immunoglobulins that represent intrathecal synthesis during central nervous system infection or inflammation.
    explanation: This study confirms that the presence of oligoclonal bands in cerebrospinal fluid is relevant in the context of central nervous system conditions, including multiple sclerosis.
  - reference: PMID:38791450
    reference_title: "Multiple Sclerosis: From the Application of Oligoclonal Bands to Novel Potential Biomarkers."
    supports: SUPPORT
    snippet: Current diagnosis is based on the integration of clinical, imaging, and laboratory results, with the latter based on the presence of intrathecal IgG oligoclonal bands in the cerebrospinal fluid whose detection via isoelectric focusing followed by immunoblotting represents the gold standard.
    explanation: This study highlights that oligoclonal bands in cerebrospinal fluid are a gold standard in the laboratory diagnosis of multiple sclerosis.
  - reference: PMID:15557527
    reference_title: "CSF characteristics in early-onset multiple sclerosis."
    supports: SUPPORT
    snippet: CSF oligoclonal IgG supports the early diagnosis of MS in childhood with a sensitivity similar to adult-onset MS.
    explanation: The presence of oligoclonal bands in cerebrospinal fluid is noted to support the diagnosis of multiple sclerosis in both early-onset and adult-onset cases.
  - reference: PMID:29571849
    reference_title: "Oligoclonal bands and periventricular lesions in multiple sclerosis will not increase blood-brain barrier permeability."
    supports: PARTIAL
    snippet: OB and PVLs were associated each other, but they did not affect the clinical course or increased the BBB-permeability within MS patients.
    explanation: This study indicates that oligoclonal bands are associated with multiple sclerosis, although they do not necessarily affect the clinical course or blood-brain barrier permeability.
- name: Evoked Potentials
  presence: Delayed response times.
  notes: Tests that measure the electrical activity in the brain in response to stimuli.
  evidence:
  - reference: PMID:24314688
    reference_title: "Evoked potentials in multiple sclerosis."
    supports: SUPPORT
    snippet: The identification of an area of the central nervous system showing abnormal conduction was used to supplement the abnormal signs identified on the physical examination-thus identifying the 'multiple' in MS.
    explanation: The reference discusses the use of evoked potentials to identify areas of abnormal conduction in the CNS, which supports the statement about delayed response times in MS.
  - reference: PMID:35963325
    reference_title: "Transcranial direct current stimulation as a preventive treatment in multiple sclerosis? Preclinical evidence."
    supports: PARTIAL
    snippet: Optic nerve demyelination, associated with delay of visual evoked potentials (VEPs), is also observed prior to motor signs in the preclinical MS model Experimental Autoimmune Encephalomyelitis (EAE).
    explanation: This reference directly mentions that optic nerve demyelination in MS is associated with delays in visual evoked potentials, supporting the statement.
  - reference: PMID:8610486
    reference_title: "Tests of autonomic dysfunction in patients with multiple sclerosis."
    supports: PARTIAL
    snippet: The sensitivity of SSR and RRIV is high and compatible with that of visual and somatosensory evoked potentials.
    explanation: This reference discusses the use of various evoked potentials in MS and their sensitivity, implying the presence of delayed responses.
  - reference: PMID:7698890
    reference_title: "Serial evoked potentials in multiple sclerosis bouts. Relation to steroid treatment."
    supports: PARTIAL
    snippet: Evoked potentials may be useful for monitoring acute Multiple Sclerosis bouts and evaluating the effect of therapy.
    explanation: This reference supports the use of evoked potentials in monitoring MS, which implies the presence of delayed responses as part of the evaluation.
genetic:
- name: HLA-DRB1
  association: Risk Factor
  notes: Notably DRB1*15:01 allele; strongest genetic risk factor for MS
  evidence:
  - reference: PMID:28676141
    reference_title: "HLA-DRB1*15 association with multiple sclerosis is confirmed in a multigenerational Italian family."
    supports: SUPPORT
    snippet: HLA-DRB1*15 association with multiple sclerosis is confirmed in a multigenerational Italian family.
    explanation: The study confirms the association of the HLA-DRB1*15:01 allele with multiple sclerosis in a multigenerational family.
  - reference: PMID:27802296
    reference_title: "A Risk Score for Predicting Multiple Sclerosis."
    supports: PARTIAL
    snippet: Multiple sclerosis (MS) develops as a result of environmental influences on the genetically susceptible... Odds ratios for MS associated with each risk factor were derived from existing literature, and the log values of the odds ratios from each of the risk factors were combined in an additive model to provide an overall score.
    explanation: The study uses HLA-DRB1*1501 as a genetic risk factor in developing a risk score for MS, supporting the association of HLA-DRB1 with MS.
  - reference: PMID:21310812
    reference_title: "Genome-wide association studies in multiple sclerosis: lessons and future prospects."
    supports: SUPPORT
    snippet: A haplotype within the major histocompatibility region is the major risk factor for MS...
    explanation: The article mentions the major histocompatibility region as a significant risk factor for MS, which includes the HLA-DRB1 allele.
  - reference: PMID:25502788
    reference_title: "The Role of HLA in MS Susceptibility and Phenotype."
    supports: SUPPORT
    snippet: One of the most consistent findings in multiple sclerosis (MS) is that development of MS is linked with carriage of the class II human leucocyte antigen (HLA) molecule HLA-DRB1*15:01; around 60 % of Caucasian MS patients carry this allele compared to 25-30 % of ethnically matched healthy individuals.
    explanation: The chapter reviews the strong association between HLA-DRB1*15:01 and MS, supporting the statement.
- name: IL7R
  association: Risk Factor
  notes: Interleukin 7 receptor; involved in T cell homeostasis and immune regulation
  evidence:
  - reference: PMID:17660530
    reference_title: "Risk alleles for multiple sclerosis identified by a genomewide study."
    supports: SUPPORT
    snippet: Alleles of IL2RA and IL7RA and those in the HLA locus are identified as heritable risk factors for multiple sclerosis
    explanation: The first large-scale GWAS of multiple sclerosis identified IL7RA as a genome-wide significant susceptibility locus (P=2.94x10-7), establishing it as a heritable genetic risk factor for MS.
- name: IL2RA
  association: Risk Factor
  notes: Interleukin 2 receptor alpha chain; role in immune cell regulation
  evidence:
  - reference: PMID:17660530
    reference_title: "Risk alleles for multiple sclerosis identified by a genomewide study."
    supports: SUPPORT
    snippet: Alleles of IL2RA and IL7RA and those in the HLA locus are identified as heritable risk factors for multiple sclerosis
    explanation: The first large-scale GWAS of multiple sclerosis identified IL2RA as a genome-wide significant susceptibility locus (P=2.96x10-8), establishing it as a heritable genetic risk factor for MS.
- name: TYK2
  association: Risk Factor
  notes: Tyrosine kinase 2; involved in cytokine signaling pathways
- name: CD40
  association: Risk Factor
  notes: Costimulatory molecule on antigen presenting cells; involved in T and B cell interactions
- name: TNFRSF1A
  association: Risk Factor
  notes: TNF receptor superfamily member 1A; mediates inflammatory responses
- name: BACH2
  association: GWAS
  notes: Transcription factor regulating Treg/effector T cell balance and B cell class switching
- name: TNFAIP3
  association: GWAS
  notes: Encodes A20, a ubiquitin-editing enzyme that negatively regulates NF-kB signaling
- name: STAT3
  association: GWAS
  notes: Signal transducer mediating Th17 differentiation via JAK-STAT pathway
- name: IL10
  association: GWAS
  notes: Anti-inflammatory cytokine critical for immune tolerance
- name: CD28
  association: GWAS
  notes: T cell co-stimulatory receptor required for T cell activation
- name: EGR2
  association: GWAS
  notes: Transcription factor involved in T cell anergy and peripheral tolerance
- name: ETS1
  association: GWAS
  notes: Transcription factor regulating T and B cell development and immune cell differentiation
- name: IRF8
  association: GWAS
  notes: Interferon regulatory factor controlling myeloid cell development and type I interferon response
- name: SATB1
  association: GWAS
  notes: Chromatin organizer regulating T cell development and lineage commitment
- name: IKZF1
  association: GWAS
  notes: Ikaros transcription factor essential for lymphocyte development and differentiation
- name: REL
  association: GWAS
  notes: NF-kB subunit c-Rel controlling lymphocyte activation and survival
- name: PTPN22
  association: GWAS
  notes: Protein tyrosine phosphatase modulating T cell receptor signaling threshold
environmental:
- name: Vitamin D Deficiency
  effect: Increased risk
  evidence:
  - reference: PMID:20494325
    reference_title: "Vitamin D and multiple sclerosis."
    supports: PARTIAL
    snippet: Overall, the results of these studies support a protective effect of vitamin D, but there are uncertainties and many unanswered questions, including how vitamin D exerts a protective effect, how genetic variations modify the effect, and whether vitamin D can influence the course of MS progression.
    explanation: The abstract suggests that adequate vitamin D nutrition can contribute to the prevention of multiple sclerosis, implying that vitamin D deficiency increases the risk.
  - reference: PMID:22906614
    reference_title: "Risk factors for multiple sclerosis: decreased vitamin D level and remote Epstein-Barr virus infection in the pre-clinical phase of multiple sclerosis."
    supports: SUPPORT
    snippet: 'Risk factors for multiple sclerosis: decreased vitamin D level and remote Epstein-Barr virus infection in the pre-clinical phase of multiple sclerosis.'
    explanation: The title directly states that decreased vitamin D levels are a risk factor for multiple sclerosis.
  - reference: PMID:28757204
    reference_title: "Low-Frequency Synonymous Coding Variation in CYP2R1 Has Large Effects on Vitamin D Levels and Risk of Multiple Sclerosis."
    supports: PARTIAL
    snippet: We showed that heterozygote carriers of this low-frequency variant have an increased risk of vitamin D insufficiency... Individuals carrying one copy of this variant also had increased odds of multiple sclerosis...
    explanation: The study finds that individuals with a genetic variant that increases the risk of vitamin D insufficiency also have increased odds of developing multiple sclerosis.
  - reference: PMID:34510165
    reference_title: "Vitamin D status and its associations with clinical and laboratory parameters in patients with Addison's disease."
    supports: NO_EVIDENCE
    snippet: There is increasing evidence that several autoimmune diseases, as well as their activity, are associated with vitamin D (VD) deficiency.
    explanation: Although the study focuses on Addison's disease, it mentions the association between vitamin D deficiency and autoimmune diseases, which includes multiple sclerosis.
  exposure_term:
    preferred_term: Vitamin D exposure (deficiency)
    term:
      id: ECTO:9000133
      label: exposure to vitamin D
- name: Epstein-Barr Virus Infection
  effect: Increased risk
  evidence:
  - reference: PMID:35145009
    reference_title: "New Evidence for Epstein-Barr Virus Infection as a Cause of Multiple Sclerosis."
    supports: SUPPORT
    snippet: New Evidence for Epstein-Barr Virus Infection as a Cause of Multiple Sclerosis.
    explanation: The title of the reference directly supports the statement that Epstein-Barr Virus infection increases the risk of Multiple Sclerosis.
  - reference: PMID:24289836
    reference_title: "Environmental factors in multiple sclerosis."
    supports: SUPPORT
    snippet: The strongest known risk factor for MS is infection with Epstein-Barr virus (EBV). Compared with uninfected individuals, the hazard of developing MS is approximately 15-fold higher among individuals infected with EBV in childhood and about 30-fold higher among those infected with EBV in adolescence or later in life.
    explanation: The abstract provides strong evidence of a causal relation between EBV infection and increased MS risk.
  - reference: PMID:36669485
    reference_title: "Virus exposure and neurodegenerative disease risk across national biobanks."
    supports: SUPPORT
    snippet: With recent findings connecting the Epstein-Barr virus to an increased risk of multiple sclerosis... We also replicated the Epstein-Barr/multiple sclerosis association.
    explanation: The study confirms the association between Epstein-Barr Virus infection and an increased risk of Multiple Sclerosis.
  - reference: PMID:37804765
    reference_title: "Humoral response to Epstein-Barr virus in patients with multiple sclerosis treated with B cell depletion therapy."
    supports: SUPPORT
    snippet: Epstein-Barr virus (EBV) is a known risk factor for MS and seems to be a prerequisite for disease development.
    explanation: The abstract states that EBV is a known risk factor for MS, supporting the statement.
  - reference: PMID:21836034
    reference_title: "Epstein-Barr virus and multiple sclerosis."
    supports: SUPPORT
    snippet: There is strong evidence however that people with MS are more likely to report a past history of infectious mononucleosis (thought to represent initial EBV infection at an older age), and higher titres of EBV specific antibodies are associated with an increased risk of developing MS.
    explanation: The review highlights strong evidence linking EBV infection to an increased risk of MS.
  exposure_term:
    preferred_term: Epstein-Barr virus exposure
    term:
      id: ECTO:3000001
      label: exposure to virus
treatments:
- name: Disease-Modifying Therapies (DMTs)
  description: Medications that can slow the progression of the disease and reduce the frequency and severity of relapses.
  examples:
  - Interferon-beta
  - Glatiramer Acetate
  - Natalizumab
  - Fingolimod
  evidence:
  - reference: PMID:12894379
    reference_title: "Current disease-modifying therapies in multiple sclerosis."
    supports: SUPPORT
    snippet: In recent years, the usefulness of interferon beta and glatiramer acetate in the treatment of relapsing-remitting multiple sclerosis (RRMS) has been established.
    explanation: The reference confirms the efficacy of interferon beta and glatiramer acetate in treating RRMS, which aligns with the statement about DMTs reducing the frequency and severity of relapses.
  - reference: PMID:24494618
    reference_title: "Multiple sclerosis update."
    supports: SUPPORT
    snippet: Diseasemodifying drugs (DMDs) that reduce the frequency of relapses, development of brain lesions, and progression of disability are the standard of care for relapsing forms of MS, and the use of DMDs should be initiated as early as possible
    explanation: The reference supports the statement by indicating that DMDs reduce the frequency of relapses and progression of disability in MS.
  - reference: PMID:29921609
    reference_title: "Effects of multiple sclerosis disease-modifying therapies on employment measures using patient-reported data."
    supports: PARTIAL
    snippet: Those using the higher efficacy (category 3) DMTs, particularly fingolimod and natalizumab, reported significant increases in amount of work, work attendance and work productivity, suggesting they have important beneficial effects on work life in people with MS.
    explanation: The reference supports the statement by highlighting the beneficial effects of fingolimod and natalizumab on patients' work life, indirectly supporting their role in reducing the severity of relapses.
  - reference: PMID:27549763
    reference_title: "Disease modifying therapies for relapsing multiple sclerosis."
    supports: PARTIAL
    snippet: Disease modifying therapies (DMTs) approved for relapsing multiple sclerosis interfere with a variety of immunological mechanisms to reduce rates of relapse, accumulation of disease burden measured by magnetic resonance imaging (MRI), and decline in neurological function over the two to three year duration of typical randomized controlled trials.
    explanation: The reference supports the statement regarding the reduction of relapse rates and disease burden but notes that the benefits on long-term disability reduction are less clear.
  - reference: PMID:32560364
    reference_title: "Approved and Emerging Disease Modifying Therapies on Neurodegeneration in Multiple Sclerosis."
    supports: PARTIAL
    snippet: Several FDA-approved medications seek to alleviate disease progression by reducing the impact of such factors as demyelination and neurodegeneration.
    explanation: The reference supports the statement by indicating that FDA-approved medications aim to alleviate disease progression and reduce neurodegeneration, which aligns with the description of DMTs.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
- name: Symptomatic Treatments
  description: Range of therapies to manage symptoms like spasticity, pain, fatigue, and bladder issues.
  examples:
  - Muscle Relaxants
  - Physical Therapy
  - Pain Management
  evidence:
  - reference: PMID:9817541
    reference_title: "Multiple sclerosis: symptomatic therapies."
    supports: SUPPORT
    snippet: Management of symptoms, however, can help everyone with the disease. Several new therapies, including tizanidine, intrathecal baclofen, botulinum toxin injections, gabapentin, ondansitron, thalamic stimulation, and lamotrigine, increase our treatment options.
    explanation: This reference supports the statement by mentioning multiple therapies used to manage symptoms of multiple sclerosis, including muscle relaxants and other treatments.
  - reference: PMID:36807901
    reference_title: "Spasticity evaluation and management tools."
    supports: SUPPORT
    snippet: Therapeutic options exist for the treatment of spasticity along a broad spectrum from nonpharmacologic to interventional procedures. Treatment strategies may include exercise, physical agent modalities, oral medications, injections, pumps, and surgery.
    explanation: This reference supports the statement by outlining various therapeutic options for managing spasticity, which is a symptom of multiple sclerosis.
  - reference: PMID:15575796
    reference_title: "Exercise and multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: The pathophysiology of multiple sclerosis (MS) is characterised by fatigue, motor weakness, spasticity, poor balance, heat sensitivity and mental depression.
    explanation: This reference supports the statement by describing the range of symptoms in multiple sclerosis and mentioning exercise as a therapeutic strategy.
  - reference: PMID:12926840
    reference_title: "Reflexology treatment relieves symptoms of multiple sclerosis: a randomized controlled study."
    supports: PARTIAL
    snippet: Specific reflexology treatment was of benefit in alleviating motor; sensory and urinary symptoms in MS patients.
    explanation: This reference supports the statement by showing that reflexology can help manage symptoms like spasticity and bladder issues in multiple sclerosis patients.
  - reference: PMID:26611270
    reference_title: "Country break-out session highlights."
    supports: PARTIAL
    snippet: Individuals with multiple sclerosis (MS) spasticity present a wide range of symptoms and disability levels that are frequently challenging to manage.
    explanation: This reference supports the statement by discussing the challenges and management strategies for symptoms of multiple sclerosis, including spasticity.
  - reference: PMID:35102733
    reference_title: "Management of bladder dysfunction in multiple sclerosis: a systematic review and meta-analysis of studies regarding bladder rehabilitation."
    supports: SUPPORT
    snippet: The present study suggests the need of a specific therapeutic protocol, based on the degree of disability and symptom complexity in patients with MS-related neurogenic lower urinary tract dysfunction (NLUTD).
    explanation: This reference supports the statement by discussing the need for specific therapeutic protocols for managing bladder dysfunction in multiple sclerosis.
  - reference: PMID:22721366
    reference_title: "[Non-medicinal treatments of spasticity in multiple sclerosis]."
    supports: SUPPORT
    snippet: Non-medicinal treatments of spasticity may be proposed in patients with multiple sclerosis as either an adjunct to pharmacological treatments or the first line of treatment.
    explanation: This reference supports the statement by mentioning non-medicinal treatments for spasticity in multiple sclerosis.
  - reference: PMID:11898533
    reference_title: "Management of spasticity, pain, and paroxysmal phenomena in multiple sclerosis."
    supports: SUPPORT
    snippet: Among the more common symptoms is spasticity. Despite a lack of full knowledge of the physiology causing this phenomenon, successful treatments have been developed.
    explanation: This reference supports the statement by discussing the prevalence of spasticity in multiple sclerosis and the development of successful treatments.
  - reference: PMID:16168933
    reference_title: "Symptomatic therapy and neurorehabilitation in multiple sclerosis."
    supports: SUPPORT
    snippet: 'First, we review treatment of the main symptoms of MS: fatigue, bladder and bowel disturbances, sexual dysfunction, cognitive and affective disorders, and spasticity.'
    explanation: This reference supports the statement by reviewing the treatments for main symptoms of multiple sclerosis, including fatigue, bladder issues, and spasticity.
  - reference: PMID:26166264
    reference_title: "Effect of Sativex on spasticity-associated symptoms in patients with multiple sclerosis."
    supports: SUPPORT
    snippet: In this review, the effects of Sativex(®) oromucosal spray on symptoms and functional impairment associated with MS-related spasticity were examined
    explanation: This reference supports the statement by discussing the use of Sativex for managing symptoms associated with multiple sclerosis spasticity.
  treatment_term:
    preferred_term: supportive care
    term:
      id: MAXO:0000950
      label: supportive care
- name: Physical Therapy and Rehabilitation
  description: Exercise programs and physical therapy to maintain mobility, strength, and function.
  examples:
  - Exercise therapy
  - Gait training
  - Balance exercises
  treatment_term:
    preferred_term: physical therapy
    term:
      id: MAXO:0000011
      label: physical therapy
- name: Corticosteroids
  description: Used to reduce inflammation and speed recovery during acute exacerbations.
  examples:
  - Prednisone
  - Methylprednisolone
  evidence:
  - reference: PMID:17920542
    reference_title: "Corticosteroids for multiple sclerosis: I. Application for treating exacerbations."
    supports: SUPPORT
    snippet: The treatment of MS exacerbations with anti-inflammatory agents such as corticosteroids and adrenocorticotropic hormone has represented an established practice throughout the neurology community.
    explanation: The abstract clearly states that corticosteroids are used to treat MS exacerbations, which aligns with the statement that they are used to reduce inflammation and speed recovery during acute exacerbations.
  - reference: PMID:10073279
    reference_title: "Immunologic therapy of multiple sclerosis."
    supports: NO_EVIDENCE
    snippet: Three interferon beta preparations (Betaseron, Avonex, and Rebif) have shown efficacy in the treatment of relapsing-remitting multiple sclerosis (MS).
    explanation: Although this reference primarily discusses interferon beta preparations, it indirectly supports the use of other treatments like corticosteroids for MS exacerbations.
  - reference: PMID:3940867
    reference_title: "Evoked potentials in multiple sclerosis before and after high-dose methylprednisolone infusion."
    supports: NO_EVIDENCE
    snippet: There were no manifest changes of the evoked potentials parameters parallel to the clinical effect of high-dose therapy.
    explanation: This study did not find significant changes in evoked potentials with high-dose methylprednisolone, but it does not refute the use of corticosteroids for reducing inflammation and speeding recovery in MS exacerbations.
  treatment_term:
    preferred_term: pharmacotherapy
    term:
      id: MAXO:0000058
      label: pharmacotherapy
disease_term:
  preferred_term: multiple sclerosis
  term:
    id: MONDO:0005301
    label: multiple sclerosis
classifications:
  harrisons_chapter:
  - classification_value: nervous system disorder
  - classification_value: demyelinating disease
  - classification_value: autoimmune disease