Editing Multiple sclerosis (section)

==Disease course==
=== Prodromal phase ===
MS may have a [[prodromal]] phase in the years leading up to its manifestation, characterized by psychiatric issues, cognitive impairment, and increased use of healthcare.<ref name="Makhani2021Prodrome">{{cite journal | vauthors = Makhani N, Tremlett H | title = The multiple sclerosis prodrome | journal = Nature Reviews. Neurology | volume = 17 | issue = 8 | pages = 515–521 | date = August 2021 | pmid = 34155379 | pmc = 8324569 | doi = 10.1038/s41582-021-00519-3 }}</ref><ref name="Marrie2019_Prodrome">{{cite journal | vauthors = Marrie RA | title = Mounting evidence for a multiple sclerosis prodrome | journal = Nature Reviews. Neurology | volume = 15 | issue = 12 | pages = 689–690 | date = December 2019 | pmid = 31654040 | doi = 10.1038/s41582-019-0283-0 | s2cid = 204887642 }}</ref>

===Onset===
85% of cases begin as a [[clinically isolated syndrome]] (CIS) over a number of days with 45% having motor or sensory problems, 20% having [[optic neuritis]],<ref name="Petzold_2022" /> and 10% having symptoms related to [[brainstem]] dysfunction, while the remaining 25% have more than one of the aforementioned difficulties.<ref name="Tsang20112">{{cite journal |vauthors=Tsang BK, Macdonell R |date=December 2011 |title=Multiple sclerosis- diagnosis, management and prognosis |journal=Australian Family Physician |volume=40 |issue=12 |pages=948–955 |pmid=22146321}}</ref> With optic neuritis as the most common presenting symptom, people with MS notice sub-acute loss of vision, often associated with pain worsening on eye movement, and reduced color vision. Early diagnosis of MS-associated optic neuritis helps timely initiation of targeted treatments. However, it is crucial to adhere to established diagnostic criteria when treating optic neuritis due to the broad range of alternative causes, such as [[neuromyelitis optica]] spectrum disorder (NMOSD), and other autoimmune or infectious conditions. The course of symptoms occurs in two main patterns initially: either as episodes of sudden worsening that last a few days to months (called [[relapse]]s, exacerbations, bouts, attacks, or flare-ups) followed by improvement (85% of cases) or as a gradual worsening over time without periods of recovery (10–15% of cases).<ref name=Milo2010 /> A combination of these two patterns may also occur<ref name="pmid8780061" /> or people may start in a relapsing and remitting course that then becomes progressive later on.<ref name=Milo2010 />

===Relapses===
Relapses are usually unpredictable, occurring without warning.<ref name="pmid1897097722"/> Exacerbations rarely occur more frequently than twice per year.<ref name="pmid1897097722"/> Some relapses, however, are preceded by common triggers and they occur more frequently during spring and summer.<ref name="pmid168043312">{{cite journal | vauthors = Tataru N, Vidal C, Decavel P, Berger E, Rumbach L | title = Limited impact of the summer heat wave in France (2003) on hospital admissions and relapses for multiple sclerosis | journal = Neuroepidemiology | volume = 27 | issue = 1 | pages = 28–32 | year = 2006 | pmid = 16804331 | doi = 10.1159/000094233 | s2cid = 20870484 }}</ref> Similarly, viral infections such as the [[common cold]], [[influenza]], or [[gastroenteritis]] increase their risk.<ref name="pmid1897097722"/> [[Stress (medicine)|Stress]] may also trigger an attack.<ref name="pmid17439878">{{cite journal | vauthors = Heesen C, Mohr DC, Huitinga I, Bergh FT, Gaab J, Otte C, Gold SM | title = Stress regulation in multiple sclerosis: current issues and concepts | journal = Multiple Sclerosis | volume = 13 | issue = 2 | pages = 143–148 | date = March 2007 | pmid = 17439878 | doi = 10.1177/1352458506070772 | s2cid = 8262595 }}</ref>

Many events do not affect rates of relapse requiring hospitalization including [[vaccination]],<ref>{{cite journal | vauthors = Confavreux C, Suissa S, Saddier P, Bourdès V, Vukusic S | title = Vaccinations and the risk of relapse in multiple sclerosis. Vaccines in Multiple Sclerosis Study Group | journal = The New England Journal of Medicine | volume = 344 | issue = 5 | pages = 319–326 | date = February 2001 | pmid = 11172162 | doi = 10.1056/NEJM200102013440501 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Grimaldi L, Papeix C, Hamon Y, Buchard A, Moride Y, Benichou J, Duchemin T, Abenhaim L | title = Vaccines and the Risk of Hospitalization for Multiple Sclerosis Flare-Ups | journal = JAMA Neurology | volume = 80 | issue = 10 | pages = 1098–1104 | date = October 2023 | pmid = 37669073 | pmc = 10481324 | doi = 10.1001/jamaneurol.2023.2968 }}</ref> [[breast feeding]],<ref name="pmid1897097722"/> physical trauma,<ref name="pmid112053612">{{cite journal | vauthors = Martinelli V | title = Trauma, stress and multiple sclerosis | journal = Neurological Sciences | volume = 21 | issue = 4 Suppl 2 | pages = S849–S852 | year = 2000 | pmid = 11205361 | doi = 10.1007/s100720070024 | s2cid = 2376078 }}</ref> and [[Uhthoff's phenomenon]].<ref name="pmid168043312"/>

===Pregnancy===
Many women with MS [[pre-existing disease in pregnancy|who become pregnant]] experience lower symptoms during pregnancy.<ref>{{cite journal | vauthors = Dobson R, Dassan P, Roberts M, Giovannoni G, Nelson-Piercy C, Brex PA | title = UK consensus on pregnancy in multiple sclerosis: 'Association of British Neurologists' guidelines | journal = Practical Neurology | volume = 19 | issue = 2 | pages = 106–114 | date = April 2019 | pmid = 30612100 | doi = 10.1136/practneurol-2018-002060 }}</ref><ref name="Varytė-2020">{{cite journal | vauthors = Varytė G, Zakarevičienė J, Ramašauskaitė D, Laužikienė D, Arlauskienė A | title = Pregnancy and Multiple Sclerosis: An Update on the Disease Modifying Treatment Strategy and a Review of Pregnancy's Impact on Disease Activity | journal = Medicina | volume = 56 | issue = 2 | page = 49 | date = January 2020 | pmid = 31973138 | pmc = 7074401 | doi = 10.3390/medicina56020049 | doi-access = free }}</ref><ref>{{cite web |title=Pregnancy, birth, breastfeeding and MS |url=https://www.mssociety.org.uk/about-ms/what-is-ms/women-and-ms/pregnancy-and-birth |website=Multiple Sclerosis Society |access-date=8 April 2024 |archive-date=8 April 2024 |archive-url=https://web.archive.org/web/20240408181959/https://www.mssociety.org.uk/about-ms/what-is-ms/women-and-ms/pregnancy-and-birth |url-status=live }}</ref> During the first months after delivery, the risk increases.<ref name="pmid1897097722"/> Overall, pregnancy does not seem to influence long-term disability.<ref name="pmid1897097722"/>