The Answer to Dr. Shafer's Neuro Dilemma

by Bob Stuntz


From the last post: 

A 57 y/o male presents to the ED with a chief complaint of sudden loss of memory. His wife reports that when he awoke this morning he was his normal self, had coffee and ate breakfast but while his wife was showering he suddenly told her that he felt “weird”. His wife realized that he had forgotten everything that had happened not only this morning but also the night prior and was very tearful and frightened which is unlike his normal personality.  Last night he drank four beers which he usually does every weekend. His wife denies any trauma, or LOC, slurred speech or weakness. His only medical problem is hypertension. He has no significant family history, does not smoke and denies any illicit drug use. On physical examination, initially on arrival to the department he was only oriented to self but after an hour on he began to remember events from the night prior and became oriented to time and place. He was noted to persistently have trouble making new memories as he scored 0/3 when asked to recall three objects and was also noted to occasionally ask the same questions multiple times.  He can easily remember past events such as his first car and his birthday. Cranial nerves are intact, he has normal sensory and muscle strength in all four extremities bilaterally, normal finger to nose testing and also has a normal gait. The rest of the physical exam is unremarkable

1) At this time, what testing should be performed?

Answer: No further testing is needed. 

2) What is your diagnosis?

Answer: Transient Global Amnesia

3) What is the prognosis for this diagnosis?

Excellent prognosis.  The attack typically resolves in 24 hours

Transient global amnesia(TGA) is a rare condition where there is a sudden, temporary episode of memory loss that cannot be attributed to a neurologic condition such as epilepsy or stroke. Patients do not have any focal neurologic findings before or after the attack and there is no history of recent head injury; however, 1/3 of patients have an identifiable precipitating event.   Females are more likely to have an emotional precipitating event while in men the precipitating event is likely to involve physical exertion. The deficit is in short-term memory and ability to make new memories resulting in speech perseverance. Long-term memory remains intact as demonstrated in our clinical case where our patient was able to recall things such as his birthday and his first car. During the event the patient is aware of their amnesia because their consciousness is not effect often leading to anxiety. In one study, 11% of patients exhibited “emotionalism” (as our case patient experienced) and 14% “fear dying”. The average duration lasts between 2-8 hours and per diagnostic criteria resolves within 24 hours making this a rather benign disorder. The cause of TGA remains unknown at this time and about 6% of patients experience a relapse of TGA per year. These patient’s are not at an increased risk for stroke and management of these patients is simply reassurance and time. 

Resources:

1) Miller, J. W.; Petersen, R; Metter, E; Millikan, C; Yanagihara, T (1987).”Transient global amnesia: Clinical characteristics and prognosis”. Neurology 37 (5): 733–7. 

2) Quinette, P.; Guillery-Girard, B; Dayan, J; De La Sayette, V; Marquis, S; Viader, F; Desgranges, B; Eustache, F (2006). “What does transient global amnesia really mean? Review of the literature and thorough study of 142 cases”. Brain 129 (Pt 7): 1640–58. 

3) Pantoni; Bertini, E; Lamassa, M; Pracucci, G; Inzitari, D (2005). “Clinical features, risk factors, and prognosis in transient global amnesia: a follow-up study”. European Journal of Neurology 12 (5): 350–6