55 year old man presents to ED in the presence of his son after becoming confused at the supermarket whilst doing his morning shopping.
No memory of why he was shopping, no memory of being in the supermarket or how he arrived there.
Unable to remember drive to the hospital, unable to recall names of team.
repeated attempts to orientate to time and place. “whats going on bro?”
no other change in cognition. preservation of longer term memory.
denies drug use, no History of epilepsy, migraines, head injury.
Normal neurological exam.
Throughout the time in the department the patient would catch the eye of staff who they knew before the episode wave and say “bro, whats going on?”
Bloods showed no abnormalities.
This constellation of symptoms is consistent with a diagnosis of:
Transient global amnesia.
Diagnosis of exclusion.
Rapid lost of antegrade memory.
Repeated attempts to orientate themselves. often with a repetitive manner.
No change in level of consciousness.
lasting less than 24 hours.
Clinicians report perseveration as the predominant feature. Many can remember the specific mannerism of the TGA patients they have seen.
Rare condition: incidence in those over the age of 50 being: 20-30/100,000 per year
The cause of TGA is unknown but a number of hypotheses exist with migraines, epilepsy being initially linked but then more recently discounted. A vascular hypothesis is another disputed possible cause. With this number of possible causes being postulated it’s pretty clear we are unsure of the cause. This is likely due to TGA being a syndrome with multiple causes leading to hippocampal dysfunction.
The most comforting feature of TGA is that patients with “pure” TGA eg: only memory impairment which resolves they have a normal mortality and morbidity and a low chance of further events.
Patient was admitted to the ward for observation, symptoms improved with return of normal memory within 8 hours at which time he stopped waving. No memory of events of the day.