Diagnostic features of Transient Epileptic Amnesia (TEA):
(1) history of recurrent episodes of transient amnesia
(2) cognitive functions other than memory must be judged intact during a typical episode by a reliable witness.
(3) evidence of underlying partial epilepsy
The period covered by amnesia may involve a period from hours to a few years. The transient amnesia may affect:
(1) antegrade memory
(2) retrograde memory
(3) both
Evidence of underlying partial epilepsy involves 1 or more of the following:
(1) reproducible epileptiform discharges on EEG
(2) co-occurrence of other seizure types (if concurrent onset or close association with episodes of transient amnesia suggests a connection)
(3) a clear-cut response to anticonvulsant therapy (with abolition or definite reduction in frequency of amnesic episodes)
Other features of TEA:
(1) tends to occur in older adults, usually males
(2) patients often give a history of heart disease
(3) commonly occur upon waking from sleep
(4) average of 3 episodes per year (TGA only rarely recurs within 1 year)
(5) may affect verbal and nonverbal memory (TGA affects verbal memory more selectively)