OBJECTIVE: Olfactory and trigeminal systems interact and contribute to the perception of odorants. This study was aimed at investigating the effect of local anesthesia on olfaction. METHODS: One percent of tetracaine on a cotton swab was applied intranasally at three different locations in 20 volunteers and 4% of lidocaine was applied to the olfactory cleft in a head-down position. Before and after anesthesia, self-assessment, psychometric testing and olfactory event-related potentials [OERPs, using H(2)S and phenyl ethyl alcohol (PEA)], and chemosomatosensory event-related potentials (CSSERPs, using CO(2)) were examined. RESULTS: Anesthesia at all four locations significantly lowered the perceived self-assessment of olfaction, while using the cotton swab only anesthesia in the middle meatus elevated threshold (P = 0.020), lowered discrimination (P = 0.015), and prolonged OERP (PEA, P = 0.008; H(2)S, P = 0.016), as well as CSSERPs latencies (CO(2), P = 0.020). However, complete temporary anosmia was only achieved after applying 4% lidocaine into the olfactory cleft. CONCLUSIONS: Intranasal anesthesia applied with a swab reduced self-assessment of olfaction but was unable to produce anosmia. Psychometric test results were concordant with changes in chemosensory event-related potentials. SIGNIFICANCE: Temporary anosmia is technically difficult to achieve but could be demonstrated for the first time using local anesthesia. Even though anesthesia influences self-assessment, measurable olfactory function can remain unchanged.
OBJECTIVE: Olfactory and trigeminal systems interact and contribute to the perception of odorants. This study was aimed at investigating the effect of local anesthesia on olfaction. METHODS: One percent of tetracaine on a cotton swab was applied intranasally at three different locations in 20 volunteers and 4% of lidocaine was applied to the olfactory cleft in a head-down position. Before and after anesthesia, self-assessment, psychometric testing and olfactory event-related potentials [OERPs, using H(2)S and phenyl ethyl alcohol (PEA)], and chemosomatosensory event-related potentials (CSSERPs, using CO(2)) were examined. RESULTS: Anesthesia at all four locations significantly lowered the perceived self-assessment of olfaction, while using the cotton swab only anesthesia in the middle meatus elevated threshold (P = 0.020), lowered discrimination (P = 0.015), and prolonged OERP (PEA, P = 0.008; H(2)S, P = 0.016), as well as CSSERPs latencies (CO(2), P = 0.020). However, complete temporary anosmia was only achieved after applying 4% lidocaine into the olfactory cleft. CONCLUSIONS: Intranasal anesthesia applied with a swab reduced self-assessment of olfaction but was unable to produce anosmia. Psychometric test results were concordant with changes in chemosensory event-related potentials. SIGNIFICANCE: Temporary anosmia is technically difficult to achieve but could be demonstrated for the first time using local anesthesia. Even though anesthesia influences self-assessment, measurable olfactory function can remain unchanged.
Authors: Anna Oleszkiewicz; Timo Schultheiss; Valentin A Schriever; Jana Linke; Mandy Cuevas; Antje Hähner; Thomas Hummel Journal: Eur Arch Otorhinolaryngol Date: 2018-05-09 Impact factor: 2.503
Authors: Gerold Besser; David T Liu; Bertold Renner; Thomas Hummel; Christian A Mueller Journal: Int Forum Allergy Rhinol Date: 2020-03-26 Impact factor: 3.858