Abstracts

Research work on olfactory capability (birhinal) has shown recognition, threshold and memory (Carrol et al, 1993) alterations in MTLE patients. Nevertheless, there are no reports on unirhinal studies in Mexican population. Objective: Study on the unirhinal and birhinal olfactory capabilities applying standard olfactory tests in our laboratory on recognition, discrimination, threshold and memory of healthy adults and patients with MTLE diagnosis. We evaluated 15 patients (7 women and 8 men) in pair-wise comparisons to a control group (60 women and 40 men) of the same age, educational background and minimental test results. Results: The results showed significant differences in the identification and recognition tests. We used four odors: rose, orange, cinnamon and lime. MTLE patients showed a decrease (p<0.05, 2 test) using the left, then the right and then both nostrils for the rose odor. However, the cinnamon, orange and lime odors were identified in a lesser proportion when using the left nostril (p<0.05). As discriminating difficulty was raised (nard/jasmine similar scents) the patients showed a lower discriminating capability regardless of the evaluating method (unirhinal/birhinal) in comparison to the control group (P<0.05, 2 test). When the olfactory threshold was evaluated using the coffee odor, we found that the left nostril showed a higher threshold when compared to the right nostril in TLE patients. When we evaluated using both nostrils, the differences in the concentrations were significantly higher in the patients (2.98X10-5) than in the control group (8.2X10-6).In the olfactory memory analysis we observed that the control group memorized an unfamiliar odor for two weeks; whereas the TLE patients for three weeks. The decrease in the olfactory capability when using the left nostril may suggest impairment of the left lobe which would show why they cannot label an odor or that the impairment of the right lobe makes them identify an odor as an isolated known entity;In the discrimination tests, patients showed a lesser olfactory capability when using the left nostril. Carroll & Richardson (1993) found that the right TLE patients lose their olfactory short-term which may explain the patients difficulty to remember an unfamiliar odor such as that of nards. These findings might be caused by the impairment of the structures related with olfactory functions such as the piriform cortex, hippocampus and entorinal cortex due to TLE. Conclusion: These results showed that there is an olfactory dysfunction in TLE patients. Further studies are currently being performed to evaluate the diagnostic value regarding localization, lateralization and prognosis of MTL seizures.