Editing Conversion disorder (section)

==Diagnosis==
===Definition===
[[File:Conversion Disorder Image.jpg|thumb|219x219px|Analysis of Conversion Disorder in Symptomatic Patients ]]
Conversion disorder is now partly contained under [[Functional neurologic disorder|functional neurological symptom disorder]] (FNsD). In cases of conversion disorder, there is a psychological stressor.

The diagnostic criteria for functional neurologic symptom disorder, as set out in DSM-5, are:

{{ordered list|list_style_type=lower-alpha
| The patient has at least one symptom of altered voluntary motor or sensory function.
| Clinical findings provide evidence of incompatibility between the symptom and recognised neurological or medical conditions.
| The symptom or deficit is not better explained by another medical or mental disorder.
| The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.
}}
'''Specify type of symptom or deficit as:'''
* With weakness or paralysis
* With abnormal movement (e.g. tremor, [[dystonic]] movement, [[myoclonus]], gait disorder)
* With swallowing symptoms
* With speech symptoms (e.g. [[dysphonia]], slurred speech)
* With attacks or seizures
* With amnesia or memory loss
* With special sensory loss symptoms (e.g. visual blindness, olfactory loss, or hearing disturbance)
* With mixed symptoms.
'''Specify if:'''
* Acute episode: symptoms present for less than six months
* Persistent: symptoms present for six months or more.<ref>{{Cite web|url = http://bestpractice.bmj.com/best-practice/monograph/989/diagnosis/criteria.html|title = Conversion and somatic symptom disorders|access-date = 25 November 2015}}</ref>
'''Specify if:'''
* Psychological stressor (conversion disorder)
* No psychological stressor ([[functional neurological symptom disorder|functional neurologic symptom disorder]])

===Exclusion of neurological disease===

Conversion disorder presents with symptoms that typically resemble a [[neurological disorder]] such as [[stroke]], [[multiple sclerosis]], [[epilepsy]], [[hypokalemic periodic paralysis]], or [[narcolepsy]]. The neurologist must carefully exclude neurological disease, through examination and appropriate investigations.<ref name="Stone_2005">{{cite journal |vauthors=Stone J, Carson A, Sharpe M | title = Functional symptoms and signs in neurology: assessment and diagnosis | journal = J. Neurol. Neurosurg. Psychiatry | volume = 76 | pages = i2–12 | year = 2005 | issue = Suppl 1 | pmid = 15718217 | pmc = 1765681 | doi = 10.1136/jnnp.2004.061655 }}</ref> However, it is not uncommon for patients with neurological disease to also have conversion disorder.<ref name="pmid1469401">{{cite journal | author = Eames P | title = Hysteria following brain injury | journal = J. Neurol. Neurosurg. Psychiatry | volume = 55 | issue = 11 | pages = 1046–53 | year = 1992 | pmid = 1469401 | pmc = 1015291 | doi = 10.1136/jnnp.55.11.1046}}</ref>

In excluding neurological disease, the neurologist has traditionally relied partly on the presence of positive signs of conversion disorder (i.e., certain aspects of the presentation that were thought to be rare in neurological disease but common in conversion disorder). The validity of many of these signs has been questioned by a study showing that they also occur in neurological disease.<ref name="pmid3760849">{{cite journal |vauthors=Gould R, Miller BL, Goldberg MA, Benson DF | title = The validity of hysterical signs and symptoms | journal = J. Nerv. Ment. Dis. | volume = 174 | issue = 10 | pages = 593–7 | year = 1986 | pmid = 3760849 | doi = 10.1097/00005053-198610000-00003| s2cid = 38888726 }}</ref> One such symptom, for example, is ''la belle indifférence'', described in DSM-IV as "a relative lack of concern about the nature or implications of the symptoms". In a 2006 study, no evidence was found that patients with [[functional symptom]]s are any more likely to exhibit this than patients with a confirmed organic disease.<ref name="pmid16507959">{{cite journal |vauthors=Stone J, Smyth R, Carson A, Warlow C, Sharpe M | title = La belle indifférence in conversion symptoms and hysteria: systematic review | journal = Br J Psychiatry | volume = 188 | pages = 204–9 | year = 2006 | pmid = 16507959 | doi = 10.1192/bjp.188.3.204 | doi-access = free }}</ref> In the DSM-5, ''la belle indifférence'' was removed as a diagnostic criterion.

Another feature thought to be important was that symptoms tended to be more severe on the non-dominant, usually left side of the body. There have been a number of theories about this, such as the relative involvement of cerebral hemispheres in emotional processing, or more simply, that it was "easier" to live with a functional deficit on the non-dominant side. However, a literature review of 121 studies established that this was not true, with [[publication bias]] the most likely explanation for this commonly held view.<ref name="pmid12397155">{{cite journal |vauthors=Stone J, Sharpe M, Carson A, Lewis SC, Thomas B, Goldbeck R, Warlow CP | title = Are functional motor and sensory symptoms really more frequent on the left? A systematic review | journal = J. Neurol. Neurosurg. Psychiatry | volume = 73 | issue = 5 | pages = 578–81 | year = 2002 | pmid = 12397155 | pmc = 1738113 | doi = 10.1136/jnnp.73.5.578}}</ref> Although agitation is often assumed to be a positive sign of conversion disorder, release of [[epinephrine]] is a well-demonstrated cause of paralysis from [[hypokalemic periodic paralysis]].<ref>{{cite web|url=https://www.uni-ulm.de/fileadmin/website_uni_ulm/med.inst.040/Dokumente/owner.html |title=Segal MM, Jurkat-Rott K, Levitt J, Lehmann-Horn F, Hypokalemic periodic paralysis—an owner's manual |publisher=Uni-ulm.de |date=2009-06-05 |access-date=2013-11-30}}</ref>

Misdiagnosis does sometimes occur. In a highly influential<ref name="pmid14286998">{{cite journal | author = Slater E | title = Diagnosis of Hysteria | journal = Br Med J | volume = 1 | issue = 5447 | pages = 1395–9 | year = 1965 | pmid = 14286998 | pmc = 2166300 | doi = 10.1136/bmj.1.5447.1395}}</ref> study from the 1960s, [[Eliot Slater]] demonstrated that misdiagnoses had occurred in one third of his 112 patients with conversion disorder.<ref name="pmid5857619">{{cite journal |vauthors=Slater ET, Glithero E | title = A follow-up of patients diagnosed as suffering from "hysteria" | journal = J Psychosom Res | volume = 9 | issue = 1 | pages = 9–13 | year = 1965 | pmid = 5857619 | doi = 10.1016/0022-3999(65)90004-8}}</ref> Later authors have argued that the paper was flawed.<ref name="ReferenceB">{{cite journal|year=2005|title=Eliot Slater's myth of the non-existence of hysteria|journal=J R Soc Med|volume=98|issue=12|pages=547–8|doi=10.1177/014107680509801214|pmc=1299341|pmid=16319432|vauthors=Stone J, Warlow C, Carson A, Sharpe M}}</ref><ref>Ron M, "The Prognosis of Hysteria" In P. Halligan, C. Bass, J. Marshall (Eds.) Hysterical Conversion: clinical and theoretical perspectives (pp. 73–87). Oxford: Oxford University Press.</ref> A 2005 meta-analysis has shown that misdiagnosis rates since that paper was published are around four percent, the same as for other neurological diseases.<ref name="Stone_2005"/>

===Psychological mechanism===

The psychological mechanism of conversion can be the most difficult aspect of a conversion disorder diagnosis. Even if there is a clear antecedent trauma or other possible psychological trigger, it is still not clear exactly how this gives rise to the symptoms observed. Patients with medically unexplained neurological symptoms may not have any psychological stressor, hence the use of the term "functional neurological symptom disorder" in the DSM-5, as opposed to "conversion disorder", and the DSM-5's removal of the need for a psychological trigger. The change of name in the DSM-5 also came with a change of criteria. There was a removal of connection to sexual functioning as well as relation to any other medical condition. There was also an added connection to social and occupational functioning.<ref>Kanaan, R.A.A. (2022).</ref>