Olfactory function in patients with and without temporal lobe resection.

Objectives: The study aimed to assess olfactory function in patients with temporal lobe epilepsy before and after resection of temporal lobe structures and especially addressed the question whether there are any significant olfactory differences as a function of side of epileptic focus or resection.

Materials And Methods: Thirteen pre- and 22 postoperative patients and 35 age- and sex-matched healthy controls underwent olfactory testing by means of the Sniffin' Sticks testing device (comprehensive measurement of threshold, discrimination, and identification abilities).

Results: Patients with unilateral epileptic focus but without temporal lobe resection tended to have impaired identification abilities only compared to the healthy controls. There were no significant differences in olfactory function on the side of the epileptic focus compared to the non-affected side. However, the patients after temporal lobe resection presented with significantly impaired bilateral discrimination and identification abilities compared to the healthy controls and with lower olfactory scores on the side of the lesion compared to the non-lesioned side.

Conclusions: Olfactory function is only partially impaired preoperatively and will deteriorate further after the partial resection on the side of the lesion.