| Abstract: | To assess the degree to which the olfactory deficit associatedwith laryngectomy is simply due to the loss of nasal airflow,17 laryngectomees were fitted with a device (larynx bypass)which allowed them to produce approximately normal sniffs. Detectionthresholds were determined for two odorants, vanillin (reportedlyexcites only the olfactory nerve) and ammonia (a strong trigeminalirritant). Without the bypass nine patients detected neitherodorant. The others, who could manoeuver somewhat more vigorousnasal airflows, detected the odorants but only half had ‘normal’thresholds. In this latter group there was a tendency for decreasingdetection thresholds with increasing postoperative years. Withthe bypass all 17 patients achieved ‘normal’ ammoniathresholds whereas 10 achieved ‘normal’ vanillinthresholds. Thus, the loss of nasal airflow is a major contributorto the olfactory deficit of laryngectomy, and it may be theonly contributor for trigeminal irritants like ammonia. On theother hand, for non-trigeminal stimuli like vanillin other factorsseem to be involved. |
