ISCHEMIC STROKE / STROKE MIMICS

• transient global amnesia (TGA) is a sudden, temporary (lasting < 24h) episode of memory loss with the absence of other neurological signs that can’t be attributed to more common neurological conditions, such as epilepsy or stroke
• TGA is mostly non-recurrent
• can be triggered by intense emotional experiences
• annual incidence ~ 5–11  per 100,000 people in the general population, with a higher prevalence in individuals over 50 years of age
• TGA is considered a benign disorder; recurrences are relatively uncommon (12–19%), and it is not associated with an increased risk of stroke  [Mangla, 2013]

Clinical presentation

• sudden onset of memory loss, verified by a witness, duration < 24 h (mostly 3-6 h, rarely > 12h), usually with the gradual return of memory
  • anterograde amnesia
    • inability to form new memories and to recall recent past events
      
    • a common feature includes repetitive questioning, typically asking the same questions (“How did we get here?”, “What am I doing here?”)
  • retrograde amnesia
    • inability to recall events that immediately preceded the memory loss
• retention of personal identity despite memory loss
• normal cognition, such as the ability to recognize and name familiar objects and follow simple directions
• the patient may be slightly restless and anxious, but adequately given the situation
• absence of focal neurological deficits (hemiparesis, involuntary movements, problems with speech, apraxia, etc.)
• no evidence of seizures during the amnestic episode and no history of active epilepsy

• transient global amnesia is associated with dysfunction in the medial part of the temporal lobes, particularly the hippocampus, is observed
• the exact etiology and etiopathogenesis have not yet been clearly elucidated
  • spreading depression or transient vasospasms are considered
• inconsistent MR DWI findings highlight ambiguities regarding the etiology – some DWI studies yield negative results, while others show images resembling stroke  [Bartsch, 2007]
  • punctuate hyperintensity on DWI, hypointense on ADC map with normalization of ADC signal occurring within ten days
  • however, it remains unclear whether these patients do not actually have TGA syndrome
• it is necessary to exclude TGA syndrome (stroke/TIA, epileptic seizure or nonconvulsive status epilepticus, and metabolic disorders)

Diagnostic evaluation

• exclusion of TGA syndrome (stroke, epilepsy, and other stroke mimics)
• TGA is not associated with an increased risk of ischemic stroke  [Mangla, 2013]

• no specific treatment is needed for true TGA
  
• supportive care includes ensuring patient safety, keeping the patient calm, and monitoring their vital signs
• treatment of TGA syndrome depends on its etiology (antiseizure medications, antiplatelet therapy, lifestyle modifications, etc.)

• patients who experience TGA should have temporary check-ups with a neurologist or general practitioner to monitor their condition