Association of olfactory and cognitive function test scores with hippocampal and amygdalar grey matter volume: a cross-sectional study.

Few population-based studies including younger adults have examined the potential of olfactory function tests to capture the degree of atrophy in memory-associated brain regions, which cannot be adequately explained by cognitive function tests screening for cognitive impairment. This population-based study investigated associations between high-resolution olfactory test data with few odours and grey matter volumes (GMVs) of the left and right hippocampi, amygdala, parahippocampi, and olfactory cortex, while accounting for differences in cognitive decline, in 1444 participants (aged 31-91 years). Regression analyses included intracranial volume (ICV)-normalised GMVs of eight memory-related regions as objective variables and age, sex, education duration, smoking history, olfaction test score, and the Montreal Cognitive Assessment-Japanese version (MoCA-J) score as explanatory variables. Significant relationships were found between olfactory test scores and ICV-normalised GMVs of the left and right hippocampi and left amygdala (p = 0.020, 0.024, and 0.028, respectively), adjusting for the MoCA-J score. The olfactory test score was significantly related to the right amygdalar GMV (p = 0.020) in older adults (age ≥ 65 years). These associations remained significant after applying Benjamini-Hochberg multiple testing correction (false discovery rate < 0.1). Therefore, olfactory and cognitive function tests may efficiently capture the degree of atrophy in the hippocampi and amygdala, especially in older adults.

Reply to Lee, S.Y. Comment on "Matsuo et al. Impact of Olfactory Change on Postoperative Body Weight Loss in Patients with Gastric Cancer after Gastrectomy. Nutrients 2024, 16, 851".

Dr [...].

Comment on Matsuo et al. Impact of Olfactory Change on Postoperative Body Weight Loss in Patients with Gastric Cancer after Gastrectomy. Nutrients 2024, 16, 851.

I read with interest the paper by Matsuo et al [...].

A Review of the Role of Estrogens in Olfaction, Sleep and Glymphatic Functionality in Relation to Sex Disparity in Alzheimer's Disease.

Several risk factors contribute to the development of Alzheimer's disease (AD), including genetics, metabolic health, cardiovascular history, and diet. It has been observed that women appear to face a higher risk of developing AD. Among the various hypotheses surrounding the gender disparity in AD, one pertains to the potential neuroprotective properties of estrogen. Compared to men, women are believed to be more susceptible to neuropathology due to the significant decline in circulating estrogen levels following menopause. Studies have shown, however, that estrogen replacement therapies in post-menopausal women do not consistently reduce the risk of AD. While menopause and estrogen levels are potential factors in the elevated incidence rates of AD among women, this review highlights the possible roles estrogen has in other pathways that may also contribute to the sex disparity observed in AD such as olfaction, sleep, and glymphatic functionality.

Screening olfaction under dupilumab in chronic rhinosinusitis with nasal polyps.

BACKGROUND: Chronic rhinosinusitis with nasal polyps (CRSwNP) frequently leads to olfactory dysfunction. This study aimed to assess the impact of dupilumab on CRSwNP patients, focusing on olfactory outcomes and potential correlations with other clinical factors. METHODS: CRSwNP patients eligible for dupilumab therapy received subcutaneous Dupixent® injections every two weeks (300mg/2ml dupilumab). The 12-item Sniffin' Sticks Test (SST-12), fractional exhaled nitric oxide (FeNO) and Nasal Polyp Score (NPS) were assessed at baseline and after one, three, and six months. Patients also completed the Sino-Nasal Outcome Test (SNOT-22) weekly. RESULTS: 26 CRSwNP patients were included. After one month, dupilumab led to substantial reductions in FeNO, SNOT scores, andNPS, whereas SST-12 scores improved significantly only after three months. A shift toward normosmia occurred, with 81% achieving normosmia after six months, and a drop in anosmia prevalence to 9.5%. Significant negative correlations between olfaction (SST-12) and polyp severity (NPS) at baseline and after six months were found, while no significant correlations were observed between SST-12 and FeNO or SNOT scores. Age did not correlate with olfaction. CONCLUSIONS: Dupilumab demonstrated efficacy in restoring olfaction in CRSwNP patients. Reaching normosmia in over 80% ofpatients after six months of treatment underscores the drug's effectiveness in managing this challenging symptom.

Precision detection of select human lung cancer biomarkers and cell lines using honeybee olfactory neural circuitry as a novel gas sensor.

Human breath contains biomarkers (odorants) that can be targeted for early disease detection. It is well known that honeybees have a keen sense of smell and can detect a wide variety of odors at low concentrations. Here, we employ honeybee olfactory neuronal circuitry to classify human lung cancer volatile biomarkers at different concentrations and their mixtures at concentration ranges relevant to biomarkers in human breath from parts-per-billion to parts-per-trillion. We also validated this brain-based sensing technology by detecting human non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cell lines using the 'smell' of the cell cultures. Different lung cancer biomarkers evoked distinct spiking response dynamics in the honeybee antennal lobe neurons indicating that those neurons encoded biomarker-specific information. By investigating lung cancer biomarker-evoked population neuronal responses from the honeybee antennal lobe, we classified individual human lung cancer biomarkers successfully (88% success rate). When we mixed six lung cancer biomarkers at different concentrations to create 'synthetic lung cancer' vs. 'synthetic healthy' human breath, honeybee population neuronal responses were able to classify those complex breath mixtures reliably with exceedingly high accuracy (93-100% success rate with a leave-one-trial-out classification method). Finally, we employed this sensor to detect human NSCLC and SCLC cell lines and we demonstrated that honeybee brain olfactory neurons could distinguish between lung cancer vs. healthy cell lines and could differentiate between different NSCLC and SCLC cell lines successfully (82% classification success rate). These results indicate that the honeybee olfactory system can be used as a sensitive biological gas sensor to detect human lung cancer.

Role of iRhom2 in Olfaction: Implications for Odorant Receptor Regulation and Activity-Dependent Adaptation.

The cell surface metalloprotease ADAM17 (a disintegrin and metalloprotease 17) and its binding partners iRhom2 and iRhom1 (inactive Rhomboid-like proteins 1 and 2) modulate cell-cell interactions by mediating the release of membrane proteins such as TNFα (Tumor necrosis factor α) and EGFR (Epidermal growth factor receptor) ligands from the cell surface. Most cell types express both iRhoms, though myeloid cells exclusively express iRhom2, and iRhom1 is the main iRhom in the mouse brain. Here, we report that iRhom2 is uniquely expressed in olfactory sensory neurons (OSNs), highly specialized cells expressing one olfactory receptor (OR) from a repertoire of more than a thousand OR genes in mice. iRhom2-/- mice had no evident morphological defects in the olfactory epithelium (OE), yet RNAseq analysis revealed differential expression of a small subset of ORs. Notably, while the majority of ORs remain unaffected in iRhom2-/- OE, OSNs expressing ORs that are enriched in iRhom2-/- OE showed fewer gene expression changes upon odor environmental changes than the majority of OSNs. Moreover, we discovered an inverse correlation between the expression of iRhom2 compared to OSN activity genes and that odor exposure negatively regulates iRhom2 expression. Given that ORs are specialized G-protein coupled receptors (GPCRs) and many GPCRs activate iRhom2/ADAM17, we investigated if ORs could activate iRhom2/ADAM17. Activation of an olfactory receptor that is ectopically expressed in keratinocytes (OR2AT4) by its agonist Sandalore leads to ERK1/2 phosphorylation, likely via an iRhom2/ADAM17-dependent pathway. Taken together, these findings point to a mechanism by which odor stimulation of OSNs activates iRhom2/ADAM17 catalytic activity, resulting in downstream transcriptional changes to the OR repertoire and activity genes, and driving a negative feedback loop to downregulate iRhom2 expression.

Performance of a cost-effective olfactory test to evaluate hyposmia in Parkinson's disease patients.

BACKGROUND: Parkinson's disease (PD) causes motor and non-motor symptoms such as hyposmia, which is evaluated through olfactory tests in the clinical practice. OBJECTIVE: To assess the feasibility of using the modified Connecticut Chemosensory Clinical Research Center (mCCCRC) olfactory test and to compare its performance with the Sniffin' Sticks-12 (SS-12, Burghart Messtechnik GmbH, Wedel, Germany) test. METHODS: A transversal case-control study in which the patients were divided into the PD group (PDG) and the control group (CG). The cost and difficulty in handling substances to produce the mCCCRC test kits were evaluated. Sociodemographic characteristics, smoking habits, past coronavirus disease 2019 (COVID-19) infections, self-perception of odor sense, and cognition through the Montreal Cognitive Assessment (MoCA) were also evaluated. The PDG was scored by part III of the Unified Parkinson's Disease Rating Scale (UPDRS-III) and the Hoehn and Yahr Scale (H&Y) scale. Correlations were assessed through the Spearman rank correlation coefficient test (ρ, or rho). RESULTS: The mCCCRC test was easily manufactured and handled at a cost ten times lower compared with the SS-12. The groups (PDG: n = 34; CG: n = 38) were similar in terms of age, sex, level of schooling, smoking habits, and history of COVID-19. The tests results showed moderate correlation (rho = 0.65; p < 0.0001). The CG presented better cognitive performance and scored better in both tests (p < 0.0001). There was a tendency for a negative correlation with age, but good correlation with the MoCA (p = 0.0029). The results of the PDG group showed no correlation with olfactory results and motor performance or disease duration. The self-perception of hyposmia was low in both groups. CONCLUSION: The mCCCRC is an easy-to-apply and inexpensive method that demonstrated a similar performance to that of the SS-12 in evaluating olfaction in PD patients and healthy controls.

ANTECEDENTES: A doença de Parkinson (DP) cursa com sintomas motores e não motores como a hiposmia, que é avaliada por diferentes testes olfativos na prática clínica. OBJETIVO: Avaliar a viabilidade do teste olfatório Connecticut Chemosensory Clinical Research Center modificado (mCCCRC) e compará-la à do teste Sniffin' Sticks-12 (SS-12, Burghart Messtechnik GmbH, Wedel, Alemanha). MéTODOS: Estudo transversal de caso-controle em que os pacientes foram divididos no grupo DP (GDP) e no grupo controle (GC). O custo e as dificuldades no manuseio das substâncias necessárias para a produção dos kits do teste mCCCRC foram avaliados. Características sociodemográficas, tabagismo, histórico de infecção por doença do coronavírus 2019 (coronavírus disease 2019, COVID-19, em inglês), autopercepção do olfato e cognição pelo Montreal Cognitive Assessment (MoCA) também foram avaliados. O GDP foi avaliado pela parte III da Unified Parkinson's Disease Rating Scale (UPDRS-III) e pela escala de Hoehn and Yahr (H&Y). As correlações utilizaram o teste do coeficiente de correlação de postos de Spearman (ρ, ou rho). RESULTADOS: O mCCCRC foi facilmente poroduzido e manipulado com custo dez vezes inferior ao do SS-12. Os grupos (GDP: n = 34; GC: n = 38) eram similares em termos de idade, sexo, escolaridade, tabagismo e histórico de COVID-19. Os resultados obtidos em ambos os testes mostraram excelente correlação (rho = 0.65; p < 0.0001). O GC teve um desempenho cognitivo melhor e pontuou melhor nos dois testes (p < 0.0001). Houve uma tendência a uma correlação negativa com a idade, mas boa correlação com a pontuação no MoCA (p = 0.0029). Os resultados olfativos do GDP não mostraram correlação com desempenho motor ou duração da doença. A autopercepção de hiposmia foi baixa em ambos os grupos. CONCLUSãO: O mCCCRC é um teste de fácil aplicação, baixo custo, e apresentou um desempenho semelhante ao do SS-12 na avaliação olfativa de pacientes com DP e controles saudáveis.

Effects of Radiation on Olfactory Function in Head and Neck Malignancy.

OBJECTIVES: Olfactory dysfunction is an overlooked adverse effect of radiation therapy. This study is designed to find the effect of radiation therapy on olfactory function in head and neck malignancy excluding tumors of nose and nasopharynx and correlate the olfactory changes with the radiotherapy dose. METHOD: This prospective observational study was done over a 2-year period in 34 participants with head and neck malignancies who underwent radiation therapy (RT). The participants olfaction was evaluated subjectively with Italian Nose Obstruction Symptom Evaluation (I-NOSE) scale and objectively by a modified I-Smell test which included an olfactory identification score and an olfactory threshold score at 5 time points. The beginning of RT (T0), at 2 weeks of RT(T1), end of RT (T2), 1 month follow-up (T3), and 3-month follow-up (T4). The near maximum dose to the nasal cavity (D2%) and mean dose to the nasal cavity (Dmean) were calculated for all participants and correlated with olfactory function. RESULTS: A total of 34 patients with head neck malignancy were recruited. The median I-NOSE score reached maximum at the end of radiation and decreased to baseline at 3 months follow-up (P < .001). The olfactory identification score, olfactory threshold score, and median combined olfactory score showed a significant decrease at the end of radiation therapy compared to Pre-radiation therapy values. There was a significant but incomplete recovery in the 3-month follow-up period (P < .001). CONCLUSION: There was a significant deterioration in quality of life for olfaction, olfactory identification, and olfactory threshold at the completion of radiotherapy. At 3 months follow-up, though there was no complete recovery of olfaction, it did not have an adverse effect on the quality of life.

Type 2 and Non-type 2 Inflammation in the Upper Airways: Cellular and Molecular Alterations in Olfactory Neuroepithelium Cell Populations.

PURPOSE OF REVIEW: Neurogenesis occurring in the olfactory epithelium is critical to continuously replace olfactory neurons to maintain olfactory function, but is impaired during chronic type 2 and non-type 2 inflammation of the upper airways. In this review, we describe the neurobiology of olfaction and the olfactory alterations in chronic rhinosinusitis with nasal polyps (type 2 inflammation) and post-viral acute rhinosinusitis (non-type 2 inflammation), highlighting the role of immune response attenuating olfactory neurogenesis as a possibly mechanism for the loss of smell in these diseases. RECENT FINDINGS: Several studies have provided relevant insights into the role of basal stem cells as direct participants in the progression of chronic inflammation identifying a functional switch away from a neuro-regenerative phenotype to one contributing to immune defense, a process that induces a deficient replacement of olfactory neurons. The interaction between olfactory stem cells and immune system might critically underlie ongoing loss of smell in type 2 and non-type 2 inflammatory upper airway diseases. In this review, we describe the neurobiology of olfaction and the olfactory alterations in type 2 and non-type 2 inflammatory upper airway diseases, highlighting the role of immune response attenuating olfactory neurogenesis, as a possibly mechanism for the lack of loss of smell recovery.

Effect of preservation versus resection of turbinate on olfactory function in endoscopic trans-nasal trans-sphenoidal pituitary surgery: a systematic review and meta-analysis.

BACKGROUND: Utilizing endoscopes in surgery offers advantages and concerns, including potential nasal function impacts. Hyposmia following Transseptal Transsphenoidal hypophysectomy ranges from 0% to 2.2%. Debates persist about managing the M.T. in endoscopic sinus surgery due to its impact on nasal function. While preservation is recommended for sinonasal health, debates continue, as certain cases require resection. Our meta-analysis aims to compare turbinate resection and preservation effects on olfactory function. METHODS: We searched five electronic databases to collect all relevant studies. Records were screened for eligibility. Data were extracted from the included studies independently. Our continuous outcomes were pooled as standardized mean difference with 95% CI. Statistical analyses was done by RevMan. RESULTS: Our meta-analysis included four studies involving 235 patients (81 males). Evaluating changes in olfaction scores, two one-month studies (82 patients) revealed no significant difference between preservation and resection groups (Std.MD = 0.05[-0.39, 0.50], p = 0.81). For three-month assessments (146 patients), SNOT tests indicated no significant difference (Std.MD = 0.21, 95% CI[-0.11, 0.54], p = 0.20). Two studies used other tests on 70 patients at three months, yielding no significant difference (Std.MD = 0.13, 95% CI [-0.35, 0.62], p = 0.59). Two six-month studies (72 patients) similarly found no significant difference (Std.MD = 0.09, 95% CI [-0.39, 0.56], p = 0.72). CONCLUSION: Our meta-analysis involving 235 patients examined olfaction score changes over various time frames in trans-nasal trans-sphenoidal pituitary surgeries. No significant differences were observed between turbinate preservation and resection groups at one month, three months, or six months post-surgery.

Persistent COVID-19 parosmia and olfactory loss post olfactory training: randomized clinical trial comparing central and peripheral-acting therapeutics.

PURPOSE: Although COVID-19 anosmia is often transient, patients with persistent olfactory dysfunction (pOD) can experience refractory parosmia and diminished smell. This study evaluated four putative therapies for parosmia in patients with chronic COVID-19 olfactory impairment. METHODS: After screening nasal endoscopy, 85 patients (49 female, 58%) with pOD and treatment-refractory parosmia were randomized to: (1) ultramicronized palmitoylethanolamide and luteolin + olfactory training (OT) (umPEALUT group, n = 17), (2) alpha-lipoic acid + OT (ALA group, n = 21), (3) umPEALUT + ALA + OT (combination group, n = 28), or 4) olfactory training (OT) alone (control group, n = 23). Olfactory function was assessed at baseline (T0) and 6 months (T1) using a parosmia questionnaire and Sniffin' Sticks test of odor threshold, detection, and identification (TDI). Analyses included one-way ANOVA for numeric data and Chi-Square analyses for nominal data on parosmia. RESULTS: The umPEALUT group had the largest improvement in TDI scores (21.8 ± 9.4 to 29.7 ± 7.5) followed by the combination group (19.6 ± 6.29 to 27.5 ± 2.7), both p < 0.01. The control and ALA groups had no significant change. Patients in the combination and umPEALUT groups had significantly improved TDI scores compared to ALA and control groups (p < 0.001). Rates of parosmia resolution after 6 months were reported at 96% for combination, 65% for control, 53% for umPEALUT and 29% for ALA (p < 0.001). All treatment regimens were well-tolerated. CONCLUSIONS: umPEALUT and OT, with or without ALA, was associated with improvement in TDI scores and parosmia, whereas OT alone or OT with ALA were associated with little benefit.

A method for detecting spatiotemporal patterns of cancer biomarkers-evoked activity using radial basis function network extracted time-domain features from calcium imaging data.

BACKGROUND: Two-photon calcium imaging is widely used to study the odor-evoked glomerular activity in the dorsal olfactory bulb of macrosmatic animals. The nonstationary character of activated patterns sets a limit on the use of a traditional image processing approaches. NEW METHOD: The developed method makes it possible to automatically map cancer biomarkers-activated glomeruli in the rat dorsal olfactory bulb. We interpolated fluorescence intensity of calcium dynamics based on the Gaussian RBF network and synthesized the physiological fluorescence model of the receptive glomerular field. RESULTS: The experiments on 5 rats confirmed the correctness of the developed approach. Patterns evoked by the 6-methyl-5-hepten-2-one (stomach cancer biomarker) and benzene (lung cancer biomarker) were correctly identified. COMPARISON WITH EXISTING METHODS: The proposed method was compared with the nonnegative matrix factorization method and with the method based on computer vision algorithms. The developed approach showed better accuracy in experiments and provided the mathematical models of the odor-evoked patterns synthesis. These models can be used to generate synthetic images of odor-evoked glomerular activity and thus to overcome the problem of small experimental data collected in calcium imaging. CONCLUSIONS: The proposed method should be considered part of the toolkit for fully automatic analysis of calcium imaging-based studies. Currently available methodology is not able to use breath biomarkers to reliably discriminate between cancer patients and healthy controls. Nevertheless, the effective identification of the spatial patterns of cancer biomarkers-evoked glomerular activity can serve as the foundation for highly sensitive biohybrid systems for cancer screening.

Does vaping affect the taste and smell perception? An exploratory study with New Zealand young adults.

OBJECTIVE: The study aimed to assess potential effects of vaping on individual taste and smell perception in a sample of young adult New Zealanders. DESIGN: This cross-sectional study measured taste and smell perception using intensity and hedonic ratings to two olfactory (i.e., vanillin, methional) and two gustatory stimuli (i.e., sucrose, monosodium glutamate), representing sweet and savoury flavours. Detection sensitivities to sucrose and vanillin were also assessed using a forced choice detection paradigm aligned with the signal detection framework. MANCOVAs were employed to compare sensory perception between groups based on vaping use frequency. Additional regression analyses were conducted to identify potential predictors of intensity and hedonic sensory ratings. SETTING: Participants were recruited from the University of Otago student population and surrounding neighbourhoods of Dunedin, New Zealand in 2023. PARTICIPANTS: The study included 213 university students (98 vapers and 115 non-vapers) RESULTS: We found a significant difference in hedonic ratings for vanillin, indicating a stronger preference among non-vapers. However, no other differences between the two groups were significant. Notably, the use of tobacco and mint flavours were emerged as significant predictors for hedonic responses to the savoury smell and sweet taste stimulus, respectively. No significant differences were observed between groups in the ability to detect weak stimuli. CONCLUSIONS: Our findings suggest that vape use, particularly with specific flavours, may be associated with alterations in hedonic responses to smells. This finding may have potential implications for how vaping affects on food preferences and dietary choices.

Mepolizumab improves sense of smell in severe chronic rhinosinusitis with nasal polyps: SYNAPSE.

BACKGROUND: Loss of smell is one of the most bothersome and difficult-to-treat symptoms in patients with severe chronic rhinosinusitis with nasal polyps (CRSwNP). METHODOLOGY: SYNAPSE was a 52-week Phase III study of 4-weekly mepolizumab (100 mg subcutaneously) plus standard of care in adults with severe bilateral CRSwNP. This post hoc analysis assessed changes from baseline to study end in loss of smell visual analogue scale (VAS) symptom score, in patients stratified by several baseline clinical characteristics. SinoNasal Outcomes Test (SNOT)-22 sense of smell/taste item and University of Pennsylvania Smell Identification Test (UPSIT) scores were also assessed. RESULTS: SYNAPSE enrolled 407 patients (mepolizumab=206; placebo=201) with impaired sense of smell at baseline. Improvements from baseline to study end in loss of smell VAS score were greater with mepolizumab versus placebo (treatment difference: -0.37) and most notable in patients with fewer or more recent prior surgeries (treatment difference: 1 vs 2 vs more than 2 prior surgeries,-1.29 vs -0.23 vs -0.07; =3 years since last surgery, -.89 vs 0.22). Approximately 25% of patients had baseline UPSIT scoresavailable; among those scoring =19 by study end. The SNOT-22 sense of smell/taste item score improved with mepolizumab versus placebo. CONCLUSIONS: Mepolizumab treatment improved patients' perceived sense of smell, as measured by loss of smell VAS score and SNOT-22 sense of smell/taste item score in patients with severe refractory CRSwNP.

Chronic rhinosinusitis and olfaction after highly effective modulator therapy: The role of individual sinus inflammation.

KEY POINTS: Individual sinus opacification (ISO) is measurable via a convolutional neural network approach. ISO decreased through 2 years after highly effective modulator therapy was initiated. In adults with cystic fibrosis, ISO did not correlate with quality of life or olfaction.

Trigeminal function in patients with COVID-associated olfactory loss.

PURPOSE: Olfactory dysfunction (OD) can be a long-term consequence of various viral infections, including COVID-19. Dysfunction includes hyposmia/anosmia and parosmia (odor distortions). Interactions of the virus with the olfactory nerve have been extensively researched, but little is known about the interactions of the intranasal trigeminal nerve system in modulating this sensory loss. METHODS: We investigated intranasal trigeminal function across COVID-19 OD patients with and without parosmia compared to normosmic controls, to determine whether (1) post-viral hyposmia and/or (2) post-viral hyposmia with parosmia is associated with altered trigeminal function. OD patients (n = 27) were tested for olfactory function using the extended Sniffin' Sticks olfactory test and for trigeminal function through three methods-odor lateralization, subjective ratings of nasal patency, and ammonium vapor pain intensity ratings. This group was subsequently compared to controls, normosmic subjects (n = 15). RESULTS: Our findings revealed that post-COVID OD patients without parosmia experienced decreased sensitivity in ammonium vapor pain intensity ratings and odor lateralization scores-but similar nasal patency ratings-compared to normosmic controls. There were no significant differences in trigeminal function between OD patients with and without parosmia. CONCLUSIONS: Based on our results, we conclude that the trigeminal nerve dysfunction may partially explain post-viral OD, but does not seem to be a major factor in the generation of parosmia pathophysiology.

International clinical assessment of smell: An international, cross-sectional survey of current practice in the assessment of olfaction.

OBJECTIVES: Olfactory dysfunction (OD) is common and carries significant personal and societal burden. Accurate assessment is necessary for good clinical and research practice but is highly dependent on the assessment technique used. Current practice with regards to UK/international clinical assessment is unknown. We aimed to capture current clinical practice, with reference to contemporaneously available guidelines. We further aimed to compare UK to international practice. DESIGN: Anonymous online questionnaire with cross-sectional non-probability sampling. Subgroup analysis according to subspeciality training in rhinology ('rhinologists' and 'non-rhinologists') was performed, with geographical comparisons only made according to subgroup. PARTICIPANTS: ENT surgeons who assess olfaction. RESULTS: Responses were received from 465 clinicians (217 from UK and 17 countries total). Country-specific response rate varied, with the lowest rate being obtained from Japan (1.4%) and highest from Greece (72.5%). Most UK clinicians do not perform psychophysical smell testing during any of the presented clinical scenarios-though rhinologists did so more often than non-rhinologists. The most frequent barriers to testing related to service provision (e.g., time/funding limitations). Whilst there was variability in practice, in general, international respondents performed psychophysical testing more frequently than those from the UK. Approximately 3/4 of all respondents said they would like to receive training in psychophysical smell testing. Patient reported outcome measures were infrequently used in the UK/internationally. More UK respondents performed diagnostic MRI scanning than international respondents. CONCLUSIONS: To our knowledge, this is the most comprehensive UK-based, and only international survey of clinical practice in the assessment of OD. We present recommendations to improve practice, including increased education and funding for psychophysical smell testing. We hope this will promote accurate and reliable olfactory assessment, as is the accepted standard in other sensory systems.

Evaluación del olfato en pacientes operados por adenoma hipofisario con acceso transesfenoidal en el Instituto de Neurocirugía Dr. Asenjo / Olfactory evaluation in patients operated for pituitary adenoma with transsphenoidal access at the Instituto de Neurocirugía Dr. Asenjo

Introducción: El olfato tiene una gran importancia en la calidad de vida. Los accesos quirúrgicos selares pueden realizarse por vía transcraneal, transeptal y transnasal, y pueden generar hiposmia al incluir resecciones que afectan a la mucosa olfatoria. Objetivo: Determinar la existencia de alteración persistente en el olfato ocasionado por los accesos quirúrgicos transeptal y transnasal en pacientes operados por adenoma hipofisiario en el Instituto de Neurocirugía Dr. Asenjo. Material y Método: Estudio prospectivo de cohorte con comparación de resultados olfatorios ("sniffin' sticks" versión extendida) y encuesta SNOT-22 pre y poscirugía por adenoma hipofisiario por vía transeptal o transnasal. Se utilizaron medidas estadísticas de comparación de pruebas pareadas paramétricas y no paramétricas según las características de las variables evaluadas. Resultados: Se reclutaron 60 pacientes, completando el seguimiento 39. En 21 se realizó acceso transeptal y en 18 transnasal. Al analizar el total de pacientes y por cada técnica quirúrgica, no hubo diferencias significativas en los puntajes del "sniffin' sticks" versión extendida y tampoco en SNOT-22. Conclusión: La literatura describe incidencia de hiposmia posoperatoria muy variable, entre 0% y 88%, con mediciones subjetivas y objetivas. Existe una predilección por la técnica endoscópica a nivel internacional, por lo que cuenta con estudios de mejor calidad. A nivel nacional existen dos estudios previos que han encontrado tasas de hiposmia posoperatoria de 10% y 14%. En este estudio no hubo diferencias significativas en los puntajes obtenidos en la prueba de olfato entre el pre y posoperatorio.

Introduction: Olfaction is of great importance in quality of life. Surgical accesses to the sellar region can be performed by transcranial, transseptal, and transnasal routes, which can generate hyposmia when including resections that affect the olfactory mucosa. Aim: To determine the existence of persistent alteration in olfaction caused by transseptal and transnasal surgical accesses in patients operated for pituitary adenoma at the Instituto de Neurocirugía Dr. Asenjo. Material and Method: Prospective cohort study with comparison of olfactory results ("sniffin' sticks" extended version) and SNOT-22 survey pre and post transseptal or transnasal surgery for pituitary adenoma. Parametric and non-parametric paired test comparison statistics were used according to the characteristics of the variables evaluated. Results: 60 patients were recruited and 39 completed follow-up. 21 patients underwent transseptal access and 18 underwent transnasal access. When analyzing the total number of patients and for each surgical technique, there were no significant differences in the scores obtained in the "sniffin' sticks" extended version and neither for the SNOT-22. Conclusion: The literature describes a highly variable incidence of postoperative hyposmia, between 0% and 88%, with subjective and objective measurements. There is a predilection for the endoscopic technique at an international level, which is why it has better quality studies. At the national level there are two previous studies that have found postoperative hyposmia rates of 10% and 14%. In this study there were no significant differences in the scores obtained between pre and postoperative olfaction test.