Transient Global Amnesia: Difference between revisions

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== Introduction ==
== Introduction ==
Transient global amnesia (TGA) is a clinical syndrome, usually occurring in those over 50, with as yet unknown etiology. TGA is transient in nature, with an acute onset and resolves within a twenty four hours.  It is often preceded by such events as very strenuous, migraines, high-stress, or sexual intercourse.<ref name=":0">Nehring SM, Spurling BC, Kumar A. [https://www.ncbi.nlm.nih.gov/books/NBK442001/ Transient global amnesia]. InStatPearls [Internet] 2022 Jul 31. StatPearls Publishing.Available:https://www.ncbi.nlm.nih.gov/books/NBK442001/ (accessed 31.3.2023)</ref>   
[[File:Transiente globale Amnesie MRT DWI axial.png|thumb|TGA MRI. Punctiform diffusion disturbances in the hippocampus on the left.]]
Transient global [[amnesia]] (TGA) is a clinical syndrome, usually occurring in those over 50, with as yet unknown etiology. TGA is transient in nature, with an acute onset and resolves within a twenty four hours.  It is often preceded by such events as very strenuous, migraines, high-stress, or sexual intercourse.<ref name=":0">Nehring SM, Spurling BC, Kumar A. [https://www.ncbi.nlm.nih.gov/books/NBK442001/ Transient global amnesia]. InStatPearls [Internet] 2022 Jul 31. StatPearls Publishing.Available:https://www.ncbi.nlm.nih.gov/books/NBK442001/ (accessed 31.3.2023)</ref>   


== Pathophysiology ==
== Pathophysiology ==
TGAs are thought to begin in the hippocampus. The region of the hippocampus is an area were blood drains in the brain and is  vulnerable to impact from various metabolic stresses. When changes are seen here they are found MRI around 2 days post event after symptoms have gone. <ref>Enzinger C, Thimary F, Kapeller P, Ropele S, Schmidt R, Ebner F, Fazekas F. [https://www.ahajournals.org/doi/10.1161/STROKEAHA.107.508655 Transient global amnesia: diffusion-weighted imaging lesions and cerebrovascular disease.] Stroke. 2008 Aug 1;39(8):2219-25.Available:https://www.ahajournals.org/doi/10.1161/STROKEAHA.107.508655 (accessed 31.3.2023)</ref><ref name=":0" />
TGAs are thought to begin in the [[hippocampus]]. The region of the hippocampus is an area were blood drains in the [[Brain Anatomy|brain]] and is  vulnerable to impact from various metabolic stresses. When changes are seen here they are found on [[MRI Scans|MRI]] around 2 days post event, after symptoms have resolved. <ref>Enzinger C, Thimary F, Kapeller P, Ropele S, Schmidt R, Ebner F, Fazekas F. [https://www.ahajournals.org/doi/10.1161/STROKEAHA.107.508655 Transient global amnesia: diffusion-weighted imaging lesions and cerebrovascular disease.] Stroke. 2008 Aug 1;39(8):2219-25.Available:https://www.ahajournals.org/doi/10.1161/STROKEAHA.107.508655 (accessed 31.3.2023)</ref><ref name=":0" />


== Risk Factors ==
== Risk Factors ==
The clearest risk factor is age, with people over 50 have a greater risk. Male and female have the same risk.
The clearest risk factor is age, with people over 50 have a greater risk. Male and female have the same risk.
* Research shows that approximately 12% of clients may experience recurrence, this risk further increasing if there is a history of migraine, depression, or sexual intercourse before the TGA episode.
* Research shows that approximately 12% of clients may experience recurrence, this risk further increasing if there is a history of [[Migraine Headache|migraine]], [[depression]], or sexual intercourse before the TGA episode.
* Those with a history migraines have x 2 the risk, and those with depression are nat x 4 the risk of having a TGA episode.
* Those with a history migraines have x 2 the risk, and those with depression are at x 4 the risk of having a TGA episode.
* Recurrence rates are not known but studies suggest it is between 2.9% and 22.8%.<ref>Hernández MA, Arena JE, Alessandro L, Allegri RF, Calandri IL. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647817/ Transient Global Amnesia Recurrence: Prevalence and Risk Factor Meta-analysis.] Neurology: Clinical Practice. 2022 Aug 1;12(4):e35-48.Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647817/<nowiki/>(accessed 31.3.2023)</ref>
* Recurrence rates are not known but studies suggest it is between 2.9% and 22.8%.<ref>Hernández MA, Arena JE, Alessandro L, Allegri RF, Calandri IL. [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647817/ Transient Global Amnesia Recurrence: Prevalence and Risk Factor Meta-analysis.] Neurology: Clinical Practice. 2022 Aug 1;12(4):e35-48.Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647817/<nowiki/>(accessed 31.3.2023)</ref>
* History of a stroke or epilepsy are not risk factors.
* History of a [[stroke]] or [[epilepsy]] are not risk factors.


== Presentation ==
== Presentation ==
TGA presents neurologically dramatically and may cause great concern to both patient and clinician. Anterograde and partial retrograde amnesia with a duration of less than 24 hours without no lasting symptoms are the hallmarks of TGA. Semantic memory is less affected than episodic, and most cases memories resolve within a few hours.<ref>Miller TD, Butler CR. [https://pn.bmj.com/content/22/3/201 Acute-onset amnesia: transient global amnesia and other causes]. Practical Neurology. 2022 Jun 1;22(3):201-8.Available:https://pn.bmj.com/content/22/3/201 (accessed 31.3.2023)</ref> Usually the person will be unable to create new memories, and repetitively make questions, usually the same question like "What am I doing here?" or "How did we get here?".
TGA presents neurologically dramatically and may cause great concern to both patient and clinician. Anterograde and partial retrograde amnesia with a duration of less than 24 hours without no lasting symptoms are the hallmarks of TGA. Semantic [[memory]] is less affected than episodic, and most cases memories resolve within a few hours.<ref>Miller TD, Butler CR. [https://pn.bmj.com/content/22/3/201 Acute-onset amnesia: transient global amnesia and other causes]. Practical Neurology. 2022 Jun 1;22(3):201-8.Available:https://pn.bmj.com/content/22/3/201 (accessed 31.3.2023)</ref> Usually the person will be unable to create new memories, and repetitively asks questions, usually the same question like "What am I doing here?" or "How did we get here?".


== Differential Diagnosis ==
== Differential Diagnosis ==
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== Treatment ==
== Treatment ==
No treatment is undertaken, and the condition completely resolves in 24 hours.
No treatment is undertaken, and the condition completely resolves in 24 hours.
*x
or
#numbered list
#x
== References  ==
== References  ==


<references />
<references />
[[Category:Neurological - Conditions]]
[[Category:Neurology]]
[[Category:Older People/Geriatrics - Conditions]]
[[Category:Older People/Geriatrics]]
[[Category:Brain]]

Latest revision as of 08:01, 31 March 2023

Original Editor - Lucinda hampton

Top Contributors - Lucinda hampton  

Introduction[edit | edit source]

TGA MRI. Punctiform diffusion disturbances in the hippocampus on the left.

Transient global amnesia (TGA) is a clinical syndrome, usually occurring in those over 50, with as yet unknown etiology. TGA is transient in nature, with an acute onset and resolves within a twenty four hours. It is often preceded by such events as very strenuous, migraines, high-stress, or sexual intercourse.[1]

Pathophysiology[edit | edit source]

TGAs are thought to begin in the hippocampus. The region of the hippocampus is an area were blood drains in the brain and is vulnerable to impact from various metabolic stresses. When changes are seen here they are found on MRI around 2 days post event, after symptoms have resolved. [2][1]

Risk Factors[edit | edit source]

The clearest risk factor is age, with people over 50 have a greater risk. Male and female have the same risk.

  • Research shows that approximately 12% of clients may experience recurrence, this risk further increasing if there is a history of migraine, depression, or sexual intercourse before the TGA episode.
  • Those with a history migraines have x 2 the risk, and those with depression are at x 4 the risk of having a TGA episode.
  • Recurrence rates are not known but studies suggest it is between 2.9% and 22.8%.[3]
  • History of a stroke or epilepsy are not risk factors.

Presentation[edit | edit source]

TGA presents neurologically dramatically and may cause great concern to both patient and clinician. Anterograde and partial retrograde amnesia with a duration of less than 24 hours without no lasting symptoms are the hallmarks of TGA. Semantic memory is less affected than episodic, and most cases memories resolve within a few hours.[4] Usually the person will be unable to create new memories, and repetitively asks questions, usually the same question like "What am I doing here?" or "How did we get here?".

Differential Diagnosis[edit | edit source]

Most important to rule out stroke. Other diagnoses include:

  • transient epileptic amnesia
  • psychogenic amnesia
  • drug-related amnesia
  • post-traumatic amnesia[5]

Treatment[edit | edit source]

No treatment is undertaken, and the condition completely resolves in 24 hours.

References[edit | edit source]

  1. 1.0 1.1 Nehring SM, Spurling BC, Kumar A. Transient global amnesia. InStatPearls [Internet] 2022 Jul 31. StatPearls Publishing.Available:https://www.ncbi.nlm.nih.gov/books/NBK442001/ (accessed 31.3.2023)
  2. Enzinger C, Thimary F, Kapeller P, Ropele S, Schmidt R, Ebner F, Fazekas F. Transient global amnesia: diffusion-weighted imaging lesions and cerebrovascular disease. Stroke. 2008 Aug 1;39(8):2219-25.Available:https://www.ahajournals.org/doi/10.1161/STROKEAHA.107.508655 (accessed 31.3.2023)
  3. Hernández MA, Arena JE, Alessandro L, Allegri RF, Calandri IL. Transient Global Amnesia Recurrence: Prevalence and Risk Factor Meta-analysis. Neurology: Clinical Practice. 2022 Aug 1;12(4):e35-48.Available: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9647817/(accessed 31.3.2023)
  4. Miller TD, Butler CR. Acute-onset amnesia: transient global amnesia and other causes. Practical Neurology. 2022 Jun 1;22(3):201-8.Available:https://pn.bmj.com/content/22/3/201 (accessed 31.3.2023)
  5. Radiopedia Transient Global Amnesia Available:https://radiopaedia.org/articles/transient-global-amnesia (accessed 31.34.2023)