Retro-and orthonasal olfactory function in relation to olfactory bulb volume in patients with hypogonadotrophic hypogonadism

Braz J Otorhinolaryngol. 2018;84(5):630---637 Brazilian Journal of OTORHINOLARYNGOLOGY www.bjorl.org ORIGINAL ARTICLE Retro- and orthonasal olfactory function in relation to olfactory bulb volume in patients with hypogonadotrophic hypogonadism夽 Murat Salihoglu a,∗ , Onuralp Kurt a , Seyid Ahmet Ay b , Kamil Baskoy b , Aytug Altundag c , Muzaffer Saglam d , Ferhat Deniz b , Hakan Tekeli e , Arif Yonem b , Thomas Hummel f a GATA Haydarpasa Training Hospital, Department of Otorhinolaryngology, Istanbul, Turkey GATA Haydarpasa Training Hospital, Department of Endocrinology and Metabolism, Istanbul, Turkey c Istanbul Surgical Hospital, Department of Otorhinolaryngology, Istanbul, Turkey d GATA Haydarpasa Training Hospital, Department of Radiology, Istanbul, Turkey e GATA Haydarpasa Training Hospital, Department of Neurology, Istanbul, Turkey f University of Dresden Medical School, Smell & Taste Interdisciplina Center, Department of Otorhinolaryngology, Dresden, Germany b Received 26 March 2017; accepted 31 July 2017 Available online 24 August 2017 KEYWORDS Olfaction; Gustatory function; Hypogonadotropic hypogonadism; Olfactory bulb Abstract Introduction: Idiopathic hypogonadotrophic hypogonadism with an olfactory deficit is defined as Kallmann syndrome and is distinct from normosmic idiopathic hypogonadotrophic hypogonadism. Objective: Because olfactory perception not only consists of orthonasally gained impressions but also involves retronasal olfactory function, in this study we decided to comprehensively evaluate both retronasal and orthonasal olfaction in patients with idiopathic hypogonadotrophic hypogonadism. Methods: This case-control study included 31 controls and 45 idiopathic hypogonadotrophic hypogonadism patients. All participants whose olfactory and taste functions were evaluated with orthonasal olfaction (discrimination, identification and threshold), retronasal olfaction, taste function and olfactory bulb volume measurement. The patients were separated into three groups according to orthonasal olfaction: anosmic idiopathic hypogonadotrophic hypogonadism, hyposmic idiopathic hypogonadotrophic hypogonadism and normosmic idiopathic hypogonadotrophic hypogonadism. 夽 Please cite this article as: Salihoglu M, Kurt O, Ay SA, Baskoy K, Altundag A, Saglam M, et al. Retro- and orthonasal olfactory function in relation to olfactory bulb volume in patients with hypogonadotrophic hypogonadism. Braz J Otorhinolaryngol. 2018;84:630---37. ∗ Corresponding author. E-mail: (M. Salihoglu). Peer Review under the responsibility of Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. https://doi.org/10.1016/j.bjorl.2017.07.009 1808-8694/© 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). Olfactory function in hypogonadotrophic hypogonadism 631 Results: Discrimination, identification and threshold scores of patients with Kallmann syndrome were significantly lower than controls. Threshold scores of patients with normosmic idiopathic hypogonadotrophic hypogonadism. were significantly lower than those of controls, but discrimination and identification scores were not significantly different. Retronasal olfaction was reduced only in the anosmic idiopathic hypogonadotrophic hypogonadism group compared to controls. Identification of bitter, sweet, sour, and salty tastes was not significantly different when compared between the anosmic, hyposmic, and normosmic idiopathic hypogonadotrophic hypogonadism groups and controls. Olfactory bulb volume was lower bilaterally in all patient groups when compared with controls. The olfactory bulb volume of both sides was found to be significantly correlated with threshold, discrimination and identification scores in idiopathic hypogonadotrophic hypogonadism patients. Conclusion: 1) There were no significant differences in gustatory function between controls and idiopathic hypogonadotrophic hypogonadism patients; 2) retronasal olfaction was reduced only in anosmic patients but not in orthonasally hyposmic participants, possibly indicating presence of effective compensatory mechanisms; 3) olfactory bulb volumes were highly correlated with olfaction scores in the hypogonadotrophic hypogonadism group. The current results indicate a continuum from anosmia to normosmia in idiopathic hypogonadotrophic hypogonadism patients. © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. This is an open access article under the CC BY license (http:// creativecommons.org/licenses/by/4.0/). PALAVRAS-CHAVE Olfato; Função gustativa; Hipogonadismo hipogonadotrófico; Bulbo olfatório Função olfativa retro e ortonasal em relação ao volume do bulbo olfatório em pacientes com hipogonadismo hipogonadotrófico Resumo Introdução: O hipogonadismo hipogonadotrófico idiopático com déficit olfatório é definido com síndrome de Kallmann e é distinto de hipogonadismo hipogonadotrófico idiopático normósmico. Objetivo: Pelo fato de a percepção olfativa não apenas consistir em impressões obtidas ortonasalmente, mas também envolver a função olfativa retronasal, neste estudo decidimos avaliar de maneira abrangente o olfato retronasal e ortonasal em pacientes com hipogonadismo hipogonadotrófico idiopático. Método: Este estudo caso-controle incluiu 31 controles e 45 pacientes com hipogonadismo hipogonadotrófico idiopático. Todos os participantes tiveram as funções olfativas e de paladar avaliadas com olfação ortonasal (discriminação, identificação e limiar), olfação retronasal, função do paladar e medida do volume do bulbo olfatório. Os pacientes foram separados em três grupos de acordo com a olfação ortonasal: hipogonadismo hipogonadotrófico idiopático anósmico, hipogonadismo hipogonadotrófico idiopático hipósmico e hipogonadismo hipogonadotrófico idiopático normósmico. Resultados: Os escores de discriminação, identificação e limiar de pacientes com síndrome de Kallmann foram significativamente menores do que os controles. Os escores dos limiares de pacientes com hipogonadismo hipogonadotrófico idiopático foram significativamente menores do que os dos controles, mas os escores de discriminação e identificação não foram significativamente diferentes. A olfação retronasal foi reduzida apenas no grupo hipogonadismo hipogonadotrófico idiopático anósmico em comparação com os controles. A identificação de gostos amargos, doces, azedos e salgados não foi significativamente diferente quando comparada entre os grupos e controles de hipogonadismo hipogonadotrófico idiopático anósmicos, hipósmicos e normósmicos. O volume do bulbo olfatório foi menor bilateralmente em todos os grupos de pacientes quando comparado com os controles. O volume do bulbo olfatório de ambos os lados foi significativamente correlacionado com os escores de limiar, discriminação,id (...truncated)