Transient global amnesia
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225818940
2008-07-15T15:29:55Z
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[[WP:UNDO|Undid]] revision 222338300 by [[Special:Contributions/61.17.222.181|61.17.222.181]] ([[User talk:61.17.222.181|talk]])
{{Infobox_Disease |
Name = {{PAGENAME}} |
Image = |
Caption = |
DiseasesDB = 13251 |
ICD10 = {{ICD10|G|45|4|g|40}} |
ICD9 = {{ICD9|437.7}} |
ICDO = |
OMIM = |
MedlinePlus = |
eMedicineSubj = neuro |
eMedicineTopic = 380 |
MeshID = D020236 |
}}
'''Transient global amnesia''' (TGA), is an anxiety-producing temporary loss of [[short-term memory]]. Typically, patients will not be able to remember events for the past few hours, and not be able to retain new information for more than a few minutes. Patients will suffer the effects of TGA for up to 24 hours, after which symptoms resolve. Worldwide, its incidence is approximately 2.9–10/100 000 cases per year. <ref>Quinette P, Guillery-Girard B , Dayan J , et al. ''What does transient global amnesia really mean? Review of the literature and thorough study of 142 cases''. Brain 2006;129 (Part 7) :1640–58.</ref>
==Differential diagnosis==
TGA is differentiated from [[stroke]] by the lack of [[tingling]], peripheral limb involvement, [[speech impairment]], and inability to walk. It is differentiated from [[subarachnoid hemorrhage]] from the lack of headache. <ref>Monzani V, Rovellini A , Schinco G , et al. Transient global amnesia or subarachnoid haemorrhage? Clinical and laboratory findings in a particular type of acute global amnesia. Eur J Emerg Med 2000;7:291–3.</ref>
==Presentation==
TGA does produce an inability to assimilate certain, generally current or recent, details while social skills and memories of distant past events or trivia is maintained.
The requirements for TGA include: <ref>Hodges JR, Warlow CP ''Syndromes of transient amnesia: towards a classification; a study of 153 cases.'' Neurosurg Psychiatry 1990;53:834–43</ref>
* The attack was witnessed and reported as being a definite loss of recent memory ([[anterograde amnesia]]).
* There was an absence of clouding of consciousness.
* There were no focal neurological signs or deficits during or after the attack.
* There were no features of [[epilepsy]], and the patient did not have any recent head injury or active epilepsy
* The attack resolved within 24 hours
==Causes==
The underlying cause of TGA is unclear. One current hypothesis is that TGA may be due to venous congestion of the brain <ref> Lewis SL. ''Aetiology of transient global amnesia.'' Lancet.1998;352:397-399..</ref>, leading to [[ischemia]] of structures involved with memory, such as the [[hippocampus]].<ref> Chung CP, Hsu H , Chao A , et al.'' Detection of intracranial venous reflux in patients of transient global amnesia.'' Neurology 2006;66:1873–7.</ref> This may be triggered by performing a [[Valsalva maneuver]] in the context of various precipitating events such as immersion in cold water, sexual activity, severe emotional stress and vigorous exertion.<ref>{{cite web |url=http://www.med.ucla.edu/modules/wfsection/article.php?articleid=38 |title=UCLA Department of Medicine - wfsection-Transient Global Amnesia |accessdate=2007-07-25 |format= |work=}}</ref> <ref>Moreno-Lugris XC, Martinez-Alvarez J , Branas F , et al. ''Transient global amnesia. Case–control study of 24 cases.'' Rev Neurol 1996;24:554–7.</ref>
==Prognosis==
The prognosis of TGA is very good. It does not affect mortality and has a small recurrence rate.
<blockquote>
"The most important part of management after diagnosis is looking after the psychological needs of the patient and his or her relatives. Seeing a once competent and healthy partner, sibling or parent become incapable of remembering what was said only a minute ago is very distressing, and hence it is often the relatives who will require reassurance." <ref name="TGA">{{cite journal| journal=Emerg Med J| author=Magnus Harrison and Mark Williams
|title=The diagnosis and management of transient global amnesia in the emergency department |volume=24 |pages=444–445 |year=2007 |doi=10.1136/emj.2007.046565}}</ref>
</blockquote>
==See also==
* [[Amnesia]]
==References==
<references/>
{{CNS diseases of the nervous system}}
[[pl:Przejściowa amnezja globalna]]
[[Category: Memory disorders]]