We have observed a falsely lateralizing mesial temporal [C-11]-flumazenil b
inding asymmetry in three patients who had temporal lobe epilepsy (TLE) wit
h normal hippocampal volumes. This abnormality was not detected 3 months la
ter in two of the patients who underwent a second PET study. We conclude th
at transient and falsely lateralizing changes of flumazenil binding might o
ccur in patients with TLE and no hippocampal sclerosis.