Document resource
Transient global amnesia (TGA) is a clinical syndrome characterised by acute-onset reversible anterograde and shrinking retrograde memory dysfunction, often accompanied by repetitive questioning, with preservation of other cognitive and neurological functions. Episodes typically resolve within 24 hours 1 and occur in otherwise healthy adults with a mean age of onset between 60 and 65 years, with no significant sex predilection. Precipitating factors are frequently identified and include physical or emotional stress, Valsalva manoeuvres, sexual activity and acute illness, suggesting a possible link to transient venous congestion or metabolic stress in the hippocampus, particularly the CA1 region (Sommer sector) of the hippocampal cornu ammonis.2 3 Hippocampal CA1 neurons are exquisitely sensitive to metabolic and ischaemic insults, and this unique susceptibility underlies the transient memory impairment seen in transient global amnesia.2