As mentioned previously, patients can register information, but retentive memory ability is dramatically affected. If a patient is young or has repeated attacks, then the possibility of seizure or even migraine is higher. Precipitants of TGA frequently include physical exertion, overwhelming emotional stress, pain, cold-water exposure, sexual intercourse, and a Valsalva maneuver. It is important to always consider the effects of drugs. For instance, sedative-hypnotic medications either over the counter or prescribed for sleep, especially if used in conjunction with a transatlantic flight, or premedication with midazolam for medical procedures may cause similar symptoms.
Excessive alcohol can cause a blackout phenomenon.
Hence, any history of drug related amnesia may help clarify mitigating causes. If any lateralizing or focal findings are noted on the exam, then the diagnosis of TGA should be questioned. The exact mechanism that produces TGA is unclear. The most compelling evidence in favor of migraine is that patients who suffer from a TGA event have a slightly higher incidence of a previous migraine. However, patients with TGA rarely report an associated headache.