Orthostatic intolerance

Orthostatic intolerance can be classified as acute OI and chronic OI.{{citation needed|date=June 2021}}

Patients who have acute OI usually manifest the disorder by a temporary loss of consciousness and posture, with rapid recovery (simple faints, or syncope), as well as remaining conscious during their loss of posture. This is different from a syncope caused by cardiac problems because the triggers for the fainting spell (standing, heat, emotion) and identifiable prodromal symptoms (nausea, blurred vision, headache) are known. As Dr. Julian M. Stewart, an expert in OI from New York Medical College states, "Many syncopal patients have no intercurrent illness; between faints, they are well."

Symptoms:{{cite web | title = Orthostatic Intolerance | author = Julian M. Stewart | publisher = New York Medical College | url = http://www.nymc.edu/fhp/centers/syncope/orthostatic_intolerance.htm | access-date = 2007-08-20 | archive-url = https://web.archive.org/web/20070806053841/http://nymc.edu/fhp/centers/syncope/orthostatic_intolerance.htm | archive-date = 2007-08-06 | url-status = dead }}

• Altered vision (blurred vision, "white outs"/gray outs, black outs, double vision)
• Anxiety
• Exercise intolerance
• Fatigue
• Headache
• Heart palpitations, as the heart races to compensate for the falling blood pressure
• Hyperpnea or sensation of difficulty breathing or swallowing (see also hyperventilation syndrome)
• Lightheadedness
• Sweating
• Tremulousness
• Weakness

A classic manifestation of acute OI is a soldier who faints after standing rigidly at attention for an extended period of time.

Patients with chronic orthostatic intolerance have symptoms on most or all days. Their symptoms may include most of the symptoms of acute OI, plus:

• Nausea
• Neurocognitive deficits, such as attention problems
• Pallor
• Sensitivity to heat
• Sleep problems
• Other vasomotor symptoms{{Cite journal |date=2023-06-30 |title=Orthostatic Intolerance: Background, Pathophysiology, Etiology |url=https://emedicine.medscape.com/article/902155-overview}}

Symptoms of OI are triggered by:

• An upright posture for long periods (e.g. standing in line, standing in a shower, or even sitting at a desk)
• A warm environment (e.g. hot summer weather, a hot crowded room, a hot shower or bath, after exercise)
• Emotionally stressful events (seeing blood or gory scenes, being scared or anxious)
• Return from an extended stay in space, when the body is not yet readapted to gravity{{cite journal |last1=Joyner |first1=Michael J. |last2=Masuki |first2=Shizue |title=POTS versus deconditioning: the same or different? |journal=Clinical Autonomic Research |date=December 2008 |volume=18 |issue=6 |pages=300–307 |doi=10.1007/s10286-008-0487-7 |pmid=18704621 |pmc=3770293 }}
• Extended bedrest
• Inadequate fluid and salt intake
• Concussion{{Cite journal |last=Pertab |first=Jon L. |last2=Merkley |first2=Tricia L. |last3=Cramond |first3=Alex J. |last4=Cramond |first4=Kelly |last5=Paxton |first5=Holly |last6=Wu |first6=Trevor |date=2018 |title=Concussion and the autonomic nervous system: An introduction to the field and the results of a systematic review |url=https://pubmed.ncbi.nlm.nih.gov/29660949/ |journal=NeuroRehabilitation |volume=42 |issue=4 |pages=397–427 |doi=10.3233/NRE-172298 |issn=1878-6448 |pmc=6027940 |pmid=29660949}}

Many patients go undiagnosed or misdiagnosed and either untreated or treated for other disorders. Current tests for OI (tilt table test, NASA Lean Test,{{Cite journal |last1=Lee |first1=Jihyun |last2=Vernon |first2=Suzanne D. |last3=Jeys |first3=Patricia |last4=Ali |first4=Weam |last5=Campos |first5=Andrea |last6=Unutmaz |first6=Derya |last7=Yellman |first7=Brayden |last8=Bateman |first8=Lucinda |date=2020-08-15 |title=Hemodynamics during the 10-minute NASA Lean Test: evidence of circulatory decompensation in a subset of ME/CFS patients |journal=Journal of Translational Medicine |volume=18 |issue=1 |pages=314 |doi=10.1186/s12967-020-02481-y |issn=1479-5876 |pmc=7429890 |pmid=32799889 |doi-access=free }} adapted Autonomic Profile (aAP),{{Cite journal |last1=M |first1=Sivan |last2=J |first2=Corrado |last3=C |first3=Mathias |date=2022-08-08 |title=The adapted Autonomic Profile (aAP) home-based test for the evaluation of neuro-cardiovascular autonomic dysfunction |url=https://acnr.co.uk/articles/the-adapted-autonomic-profile-aap-home-based-test-for-the-evaluation-of-neuro-cardiovascular-autonomic-dysfunction/ |journal=Advances in Clinical Neuroscience and Rehabilitation |language=en-GB |doi=10.47795/qkbu6715|doi-access=free }} autonomic assessment, and vascular integrity) can also specify and simplify treatment. Patients with dysautonomia symptoms can be referred to a cardiologist, neurologist, or even a gastroenterologist for treatment and management.{{Cite web | url=http://www.dynainc.org/living/finding-right-doctor | title=Finding the Right Doctor for You | date=9 August 2011 }}{{cite web |url=https://www.medicalnewstoday.com/articles/76785 |title = Dysautonomia: Symptoms, types, and treatment| date=16 December 2021 }}

Most patients experience an improvement of their symptoms, but for some, OI can be gravely disabling and can be progressive in nature, particularly if it is caused by an underlying condition that is deteriorating. The ways in which symptoms present themselves vary greatly from patient to patient; as a result, individualized treatment plans are necessary.{{cite web | title = National Dysautonomia Research Foundation | publisher = National Dysautonomia Research Foundation (NDRF) | url = http://www.ndrf.org/orthostat.htm | access-date = 2007-08-21}}

OI is treated pharmacologically and non-pharmacologically. Treatment does not cure OI; rather, it controls symptoms.{{citation needed|date=June 2021}}

Physicians who specialize in treating OI agree that the single most important treatment is drinking more than 2 liters (8 cups) of fluids each day. A steady, large supply of water or other fluids reduces most, and for some patients all, of the major symptoms of this condition. Typically, patients fare best when they drink a glass of water no less frequently than every two hours during the day, instead of drinking a large quantity of water at a single point in the day.

For most severe cases and some milder cases, a combination of medications is used. Individual responses to different medications vary widely, and a drug that dramatically improves one patient's symptoms may make another patient's symptoms much worse. Medications focus on three main issues:

Medications that increase blood volume:

• Fludrocortisone (Florinef)
• Erythropoietin
• Hormonal contraception

Medications that inhibit acetylcholinesterase:

• Pyridostigmine

Medications that improve vasoconstriction:

• Stimulants: (e.g., Ritalin or Dexedrine)
• Midodrine (ProAmatine)
• Ephedrine and pseudoephedrine (Sudafed)
• Theophylline (low-dose)
• Selective serotonin reuptake inhibitors (SSRIs - Prozac, Zoloft, and Paxil)

Behavioral changes that patients with OI can make are:

• Avoiding triggers such as prolonged sitting, quiet standing, warm environments, or vasodilating medications
• Using postural maneuvers and pressure garments
• Treating co-existing medical conditions
• Increasing fluid and salt intake
• Physical therapy and exercise

A notable person with OI is Greg Page, founding member and original lead singer of the Australian children's music group The Wiggles. Due to being diagnosed with this illness, Page left the group in late 2006, and was replaced by his understudy, Sam Moran.{{cite web |title=Greg Page leaves the Wiggles |url=http://www.thewiggles.com.au/au/mediacentre/news/31 |url-status=dead |archive-url=https://web.archive.org/web/20070928023000/http://www.thewiggles.com.au/au/mediacentre/news/31 |archive-date=2007-09-28 |access-date=2007-08-21 |publisher=The Wiggles Home Page}}{{cite news | last = Maddox | first = Greg | title = Life without a skivvie | publisher = The Sydney Morning Herald Online | url = http://www.smh.com.au/news/entertainment/people/yellow-wiggle-keen-to-perform-again/2008/11/28/1227491826882.html | access-date = 2008-11-29}} Two years later in late 2008, he went on to create his own fund for OI to help fund research into this then-little known disorder.{{Cite web | url=http://www.bakeridi.edu.au/support/greg_page_fund/ |title = Orthostatic Intolerance}} Page recovered enough to temporarily return to The Wiggles in early 2012 to help with the transition to the next generation of Wiggles, after which he again left the group at the end of 2012 and was replaced by Emma Watkins and again by Tsehay Hawkins.{{cite news| url=http://www.news.com.au/entertainment/original-yellow-wiggle-greg-page-gets-his-skivvy-back/story-e6frfmq9-1226247238549/ | work=The Daily Telegraph | title=Original Yellow Wiggle Greg Page gets his skivvy back | date=2012-01-18}}

• Orthostatic hypertension
• Orthostatic hypotension
• Postural orthostatic tachycardia syndrome (POTS)
• Vasovagal response

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{{Autonomic diseases}}

Category:Vascular diseases

Category:Peripheral nervous system disorders

Category:Sensitivities