Transient global amnesia will obviously present with acute memory loss and temporarily affected cognition. There is no other pertinent organ involvement unless there is an underlying organic cause like brain tumor or hepatic cancer on chemotherapy. The following signs and symptoms can present in patients with transient global amnesia:

• Acute memory loss 
• Ability to recall self-identity despite memory impairment
• Normal cognition (e.g. recognize familiar objects and names)
• No pertinent sign that leads to an organic brain lesion
• Transient disorder of no more than 24 hours
• Gradual return of memory
• No medical history of seizure and epilepsy

• Falling

  What caused me to fall into a dark, blank pit remains a mystery months later. I had suffered no traumas, physical or emotional. It just happened and then went away. [blog.aarp.org]

• Unconsciousness

  When Michael Thomas Boatwright, 61, was found unconscious in a Palm Springs, California, motel on February 28, no one would have ever expected what happened next. [thedailybeast.com]

• Sweating

  At the age of 17, she started to complain lipothymic episodes, characterized by generalized asthenia, profuse sweating, blurred vision, and feeling of air starvation, with a spontaneous recovery. [journals.lww.com]

  Complete 14-point review of systems was negative including fever, headache, visual changes, and loss of consciousness, automatisms, night sweats, rashes, and insect bites. Vital signs were normal. [omicsgroup.org]

  The most common physical symptoms include: Panics Sweats Racing heartbeat Stomach upset Headache If the physical problems are not reported at the time of memory loss, patients are not likely to report them again as they are unlikely to remember them at [primehealthchannel.com]

  She reported having no lightheadedness, weakness, generalized sweating or a fainting sensation during the spell. She was visiting La Paz, Bolivia, a city located at high altitude in the Andes Mountains of South America. [webmedcentral.com]

  I opened my eyes with a start, breathing heavily, my pyjamas drenched in sweat. I must have had a nightmare, I told myself. But as my eyes came into focus, cold fear gripped my belly – I realised I had no idea where I was; my nightmare was real. [independent.co.uk]

• Night Sweats

  Complete 14-point review of systems was negative including fever, headache, visual changes, and loss of consciousness, automatisms, night sweats, rashes, and insect bites. Vital signs were normal. [omicsgroup.org]

• Eruptions

  Otherwise, most dreams are psychological in nature and nothing but eruptions of the mind. [spiritualresearchfoundation.org]

• Insect Bite

  Complete 14-point review of systems was negative including fever, headache, visual changes, and loss of consciousness, automatisms, night sweats, rashes, and insect bites. Vital signs were normal. [omicsgroup.org]

• Suggestibility

  Various etiological mechanisms have been suggested to account for this complication, but no consensus has been reached yet. [ncbi.nlm.nih.gov]

  FLAIR sequence showing periventricular white matter abnormalities suggestive of demyelination (C, D). [em-consulte.com]

• Anxiety Disorder

  Tags: delusions, hippocampus, neurobiology, Transient global amnesia Category : Anxiety Disorders, Behavioral and Cognitive Neurology, Case Report, Cognition, Dementia, Medical Issues, Neurologic Systems and Symptoms, Neurology, Past Articles, Psychiatry [innovationscns.com]

  Psychiatric disease was defined as having “a diagnosis of depression or anxiety disorder” or having received “treatment with specific drugs for at least 3 months”. [ncbi.nlm.nih.gov]

• Amnesia

  amnesia, psychogenic fugue state, retrograde amnesia, soap opera, soap opera amnesia, transient global amnesia, Wernike's encephalopathy [mmcneuro.wordpress.com]

  Transient Global Amnesia (TGA) is the complete inability to formulate new memory. Suddenly, new memories no longer register in the victim's mind, a condition known as anterograde amnesia. [spacedoc.com]

  Stroke morbidity is not increased in patients with transient global amnesia, and the risk of a recurrent attack of transient global amnesia within five years ranges from 3 to 20 percent. [aafp.org]

  Transient global amnesia and stroke. Eur Neurol. 1988 ; 28 :106-110. Crossref Medline Google Scholar 33 Fisher CM. Whiplash amnesia. Neurology. 1982 ; 32 :667-668. Crossref Medline Google Scholar 34 Fisher CM. Concussion amnesia. [stroke.ahajournals.org]

  Abstract We prospectively identified patients with transient global amnesia in an urban population of 163,000. In 1982, 16 patients experienced their first transient global amnesia. [doi.org]

• Confusion

  They may be confused about time and place but are usually not confused about the identity of other people. They can provide coherent answers to questions that do not depend on memory. [merckmanuals.com]

  A 61-year-old man suffered an episode of transient confusion and anterograde amnesia after a Valsalva-related manoeuvre. [ncbi.nlm.nih.gov]

  A 62 y/o female with no significant past medical history, presented with confusion, disorientation and short- term memory loss for approximately one hour prior to arrival in the Emergency Department (ED). [omicsgroup.org]

• Headache

  However, he returned with right leg weakness and complained of a thunderclap headache. [ncbi.nlm.nih.gov]

  Lane RJM, Davies PTG Modified Valsava test differentiates primary from secondary cough headache. J Headache Pain (2013) 14:31 15. Jacome DE, Stamm M Malignant cough headache. Headache (2004) 44:259-261 16. [webmedcentral.com]

  Patients who have a history of migraines and headaches are more likely to get TGA as some people report getting terrible head pains related to orgasms, called coital headaches. [web.archive.org]

• Memory Impairment

  Baclofen-induced amnesia in rodents is a reliable model of memory impairment. In contrast, baclofen-induced memory impairment in humans is uncommon. Baclofen- associated transient global amnesia has not previously been reported. [ncbi.nlm.nih.gov]

  […] of memory impairment observed. [clinicaltrials.gov]

• Perseveration

  Our patient is a 64-year-old white man with a previous history of myocarditis from borreliosis who developed sudden-onset confusional state with perseverations and repetition of the same questions during a funeral for his brother-in-law. [ncbi.nlm.nih.gov]

  The perseveration-consolidation hypothesis: Mueller and Pilzecker, 1900. Brain Research Bulletin. 1999; 50 445-446 18 Melo T P, Ferro J M, Ferro H. Transient global amnesia. A case control study. [dx.doi.org]

  Due to the sudden-onset of symptoms, anxiety is common, and it is typical for patients to perseverate, asking the same questions repeatedly- often with similar gestures and vocal intonation [ 1, 3, 6 ]. [omicsgroup.org]

Patients are evaluated extensively on neurologic examination to rule out organic brain disorders like stroke, concussion, and seizure that can mimic the signs of transient global amnesia. Cognitive test of judgment and memory may also be applied routinely. These imaging test will confirm brain pathology like tumors, impaired blood circulation and electrical activity:

• Electroencephalogram (EEG): These records the brain electrical activity from electrode to the scalp of the head. This test can detect the abnormal patterns of brainwave activity in seizure disorder [10].
• Magnetic Resonance Imaging (MRI): This imaging technique can reveal masses or circulatory problems in the brain matter.
• Computed Tomography (CT) Scan: CT scans may demonstrate brain tumors and vascular pathology. It may also demonstrate an old infarct or a past brain hemorrhage in those with past history of stroke. 

• Epileptiform Activity

  EEG showed a nonspecific temporal lobe abnormality with no epileptiform activity. [omicsgroup.org]

• Ischemic Changes

  There were no chronic white matter ischemic changes. EEG showed a nonspecific temporal lobe abnormality with no epileptiform activity. [omicsgroup.org]

  This method of imaging allows detection of hyperacute ischemic change. [emedicine.medscape.com]

Transient global amnesia requires no treatment. The amnesia resolves on its own with no known side effects.

The prognosis for transient global amnesia is generally good. Loss of memory is usually short-lived and lasts within 24 hours from the attack. The state of amnesia may improve upon resolution but recent memory lost during the attack may never be remembered by the patients. The recurrence rate for the disorder is only 5-25% which are usually found in migraine and seizure cases. Transient global amnesia does not increase the likelihood of cerebrovascular disease like stroke.

Complications

Transient global amnesia has no direct medical complication. However, patients who undergo the episode may feel anxious because of the fear of recurrence or the fear of a more serious underlying neurologic disease like brain tumor may be at play. A strong emotional support or an encompassing psychotherapy may allay the anxiety which may lead to depression if left unchecked.

The exact etiology of transient global amnesia is still unclear. There has been some strong correlation with the occurrence of migraines but direct linkage is still not well-established. The following common events has been observed to trigger attacks of transient global amnesia:

• Strenuous physical activity
• Sudden immersion to cold or warm water
• Mild head concussion
• After sexual intercourse
• Acute emotional distress
• Medical procedures (e.g. angiography and endoscopy) 
• Withdrawal from medications like beta-blockers [1]
• Anti-phospholipid therapy [2]
• Brain tumor and infection
• Radiation therapy
• Chemotherapy
• Migraine 
• Brain surgery

In the United States, the current incidence of transient global amnesia reaches 5.2 cases per 100,000 population. However, elderly people beyond age 50 years old may reach a case specific incidence rating of up to 23.5 cases per 100,000 annually [3]. Internationally, studies in Alcoi, Spain has a lower incidence of 2.9 cases per 100,000 citizens [4].

The Italians in Belluno were noted to have a higher incidence reaching up to 10 cases of transient global amnesia out of 100,000 population [5]. Although attacks of transient global amnesia rarely recurs, studies have shown that it may reach a recurrence rate of up to 24% in one lifetime.

There are no observable racial and sexual predilection of the disease across all cultures. Transient global amnesia typically occurs at the age of fifty years old. Females usually incurs transient memory loss following an emotional distress, or severe anxiety, while male counterparts succumbs to transient amnesia following a strenuous physical activities like sports.

The definite pathophysiology of transient global amnesia remains unclear up to this point. However, advances in neurology research and real-time imaging techniques have elucidated some plausible theories on occurrence and pathology. Real time positron emission tomography (PET) and diffuse weighted magnetic resonance imaging (DWI) have demonstrated a transient ischemia in the brain regions of the thalamus and the mesial temporal structures involved in memory processing.

However, DWI may have a lower yield in picking up transient global amnesia when performed early in its course [6]. Other studies reveal that minute lesions of the hippocampus as revealed by DWI has been associated with transient global amnesia [7].

Other dominant theories suggest the role of edema and the spreading depression in the left frontal cortex of the brain contribute to the transient memory loss [8]. Single photon emission computed tomography (SPECT) has demonstrated real time hypoperfusion of the cerebral mater coincides with the transient global amnesia attacks [9]. In the same way, cerebellar hypoperfusion may also give out similar transient neurologic deficits.

There is no modifiable lifestyle approach to prevent transient global amnesia.

Transient global amnesia (TGA) is clinical disease characterized by a sudden loss of memory which lasts temporarily that is not a part of any organic neurologic illnesses like cerebrovascular disease (stroke) or epilepsy.

Transient global amnesia injures memory loss of recent memory or events that happens within hours (within 24 hours) from the attack. Immediate memory recall and distant memory are usually preserved during the paroxysmal attacks of memory loss. Attacks of transient global amnesia may be short and fleeting and may rarely recur in patients.

Definition

Transient global amnesia is a temporary loss of memory that resolves within 24 hours. This disorder is not serious and is not associated with any brain pathology.

Cause

The exact cause is unknown but it is associated with conditions like emotional outbreak and strenuous physical activity. 

Symptoms

Paroxysmal or transient loss of recent memory that resolves within 24 hours. The past memory are preserved in all cases.

Diagnosis

A meticulous history taking and interview of witnesses may suggests the diagnosis of transient global amnesia. Imaging techniques and electroencephalogram can rule out other organic causes like stroke, tumor or seizure disorders.

Treatment and follow-up

No treatment is required for it resolves spontaneously. Recurrence is relatively rare.

1. Saura D, Peñafiel P, Morales A, Albert L, Martínez F, de la Morena G. Transient global amnesia after dobutamine--atropine stress echocardiography. Eur J Echocardiogr. Jul 2008; 9(4):567-8.
2. Zardi EM, Zardi DM, Lazarevic Z, Santucci S, D'Errico F, Afeltra A, Tonioni S. Transient global amnesia as the first symptom of primary antiphospholipid syndrome: a case report. Int J Immunopathol Pharmacol. 2012; 25(1):275-80 (ISSN: 0394-6320)
3. Miller JW, Petersen RC, Metter EJ, et al. Transient global amnesia: clinical characteristics and prognosis.Neurology. May 1987; 37(5):733-7. 
4. Matias-Guiu J, Blanquer J, Falip R, et al. Incidence of transient global amnesia in a Alcoi (Spain). Acta Neurol Scand. Aug 1992; 86(2):221.
5. Lauria G, Gentile M, Fassetta G, et al. Incidence of transient global amnesia in the Belluno province, Italy: 1985 through 1995. Results of a community-based study. Acta Neurol Scand. May 1997; 95(5):303-10.
6. Ahn S, Kim W, Lee YS, Kim WY, Lee JH, Oh BJ, Lim KS. Transient global amnesia: seven years of experience with diffusion-weighted imaging in an emergency department. Eur Neurol. 2011; 65(3):123-8 (ISSN: 1421-9913)
7. Liang JF, Shen AL, Lin SK. Bilateral hippocampal abnormalities on diffusion-weighted MRI in transient global amnesia: report of a case. Acta Neurol Taiwan. Jun 2009; 18(2):127-9.
8. Strupp M, Bruning R, Wu RH, et al. Diffusion-weighted MRI in transient global amnesia: elevated signal intensity in the left mesial temporal lobe in 7 of 10 patients. Ann Neurol. Feb 1998; 43(2):164-70.
9. Yamane Y, Ishii K, Shimizu K, Sofue K, Yoshikawa T, Miyamoto N, et al. Global cerebral hypoperfusion in a patient with transient global amnesia. J Comput Assist Tomogr. May-Jun 2008; 32(3):415-7.
10. Cabrera-Naranjo F; Saiz-Diaz RA; Gonzalez-Hernandez A; de la Pena-Mayor P; Gonzalez de la Aleja J. Usefulness of electroencephalograms in evaluating transient global amnesia .Rev Neurol. 2012; 55(2):81-6 (ISSN: 1576-6578)