BACKGROUND: Olfactory loss is a challenging clinical problem with few proven therapeutic options. Early experimental results with olfactory training suggest that this novel therapy may be an effective intervention for olfactory dysfunction of multiple etiologies. The aim of this study was to systematically review currently available studies that assess the efficacy and outcomes of olfactory training in patients with olfactory loss. METHODS: A comprehensive systematic literature review was performed with the assistance of a reference librarian using the PubMed, PsycInfo, Google Scholar, EMBASE, and Proquest databases. Eligible studies were extracted based on defined inclusion criteria and the effect of olfactory training on objective olfactory function was evaluated qualitatively and by meta-analysis. RESULTS: A total of 10 studies with 639 patients were identified and systematically reviewed. Sufficient data for meta-analysis was available for 3 studies. Patients receiving olfactory training experienced a statistically significant improvement in the Threshold, Discrimination, Identification (TDI) score compared to control patients (mean difference [MD] 3.77; 95% confidence interval [CI], 2.28 to 5.26). Improvement in olfactory function was observed in discrimination (MD 1.92; 95% CI, 1.13 to 2.71) and identification (MD 1.61; 95% CI, 0.55 to 2.68), but not in olfactory thresholds (MD -0.01; 95% CI, -0.42 to 0.39). CONCLUSION: Olfactory training is a promising modality for the treatment of olfactory dysfunction. Results of this systematic review and meta-analysis suggest that it may be an effective treatment for olfactory dysfunction due to multiple etiologies. Additional high-quality studies are needed to define indications, outcomes, and duration of therapy for this novel therapy.
BACKGROUND:Olfactory loss is a challenging clinical problem with few proven therapeutic options. Early experimental results with olfactory training suggest that this novel therapy may be an effective intervention for olfactory dysfunction of multiple etiologies. The aim of this study was to systematically review currently available studies that assess the efficacy and outcomes of olfactory training in patients with olfactory loss. METHODS: A comprehensive systematic literature review was performed with the assistance of a reference librarian using the PubMed, PsycInfo, Google Scholar, EMBASE, and Proquest databases. Eligible studies were extracted based on defined inclusion criteria and the effect of olfactory training on objective olfactory function was evaluated qualitatively and by meta-analysis. RESULTS: A total of 10 studies with 639 patients were identified and systematically reviewed. Sufficient data for meta-analysis was available for 3 studies. Patients receiving olfactory training experienced a statistically significant improvement in the Threshold, Discrimination, Identification (TDI) score compared to control patients (mean difference [MD] 3.77; 95% confidence interval [CI], 2.28 to 5.26). Improvement in olfactory function was observed in discrimination (MD 1.92; 95% CI, 1.13 to 2.71) and identification (MD 1.61; 95% CI, 0.55 to 2.68), but not in olfactory thresholds (MD -0.01; 95% CI, -0.42 to 0.39). CONCLUSION: Olfactory training is a promising modality for the treatment of olfactory dysfunction. Results of this systematic review and meta-analysis suggest that it may be an effective treatment for olfactory dysfunction due to multiple etiologies. Additional high-quality studies are needed to define indications, outcomes, and duration of therapy for this novel therapy.
Authors: Antje Haehner; Clara Tosch; Martin Wolz; Lisa Klingelhoefer; Mareike Fauser; Alexander Storch; Heinz Reichmann; Thomas Hummel Journal: PLoS One Date: 2013-04-17 Impact factor: 3.240
Authors: Samuel N Helman; Jonah Adler; Aria Jafari; Sasha Bennett; Jackson R Vuncannon; Ashley C Cozart; Sarah K Wise; Merin E Kuruvilla; Joshua M Levy Journal: Allergy Asthma Proc Date: 2022-03-01 Impact factor: 2.587
Authors: Katie E Webster; Lisa O'Byrne; Samuel MacKeith; Carl Philpott; Claire Hopkins; Martin J Burton Journal: Cochrane Database Syst Rev Date: 2022-09-05
Authors: Lisa O'Byrne; Katie E Webster; Samuel MacKeith; Carl Philpott; Claire Hopkins; Martin J Burton Journal: Cochrane Database Syst Rev Date: 2022-09-05
Authors: Carol H Yan; Aakanksha Rathor; Kaelyn Krook; Yifei Ma; Melissa R Rotella; Robert L Dodd; Peter H Hwang; Jayakar V Nayak; Nelson M Oyesiku; John M DelGaudio; Joshua M Levy; Justin Wise; Sarah K Wise; Zara M Patel Journal: Neurosurgery Date: 2020-08-01 Impact factor: 4.654
Authors: Katie E Webster; Lisa O'Byrne; Samuel MacKeith; Carl Philpott; Claire Hopkins; Martin J Burton Journal: Cochrane Database Syst Rev Date: 2021-07-22
Authors: Lisa O'Byrne; Katie E Webster; Samuel MacKeith; Carl Philpott; Claire Hopkins; Martin J Burton Journal: Cochrane Database Syst Rev Date: 2021-07-22