olfaction

Extended endoscopic sinus surgery (EESS) can reduce the recurrence rate of chronic rhinosinusitis (CRS). The purpose of this study was to investigate the effect of the application of modified “protective middle turbinate-EESS” (mEESS) on patients with CRS with nasal polyps (CRSwNP) and allergic rhinitis (AR). Forty-three patients with CRSwNP and AR were classified into 2 groups, the mEESS group (n=23) and the functional endoscopic sinus surgery (FESS) group (n=20), and were followed up for 6 months and 1 year after surgery. The disease severity was assessed by the Lund-Mackay score, the Lund-Kennedy score, and the visual analog scale (VAS) score. The patency rate of the frontal sinus was evaluated by endoscopy. Patient satisfaction was also followed up. No preoperative differences or postoperative complications were found between the 2 groups. The VAS score and Lund-Kennedy score of the 2 groups were lower at 6 months and 1 year after surgery. The olfactory function of the mEESS group was significantly better than that of the FESS group at 6 months post-operative. The patency rate of the frontal sinus orifice in the mEESS group was significantly higher than that in the FESS group at 6 months and 1 year post-operative. Patient satisfaction in the mEESS group was relatively higher than that in the FESS group. mEESS improves frontal sinus drainage, olfactory sense, and patient satisfaction in the short term.

Olfactory system is a vital sensory system in mammals, giving them the ability to connect with their environment. Anosmia, or the complete loss of olfaction ability, which could be caused by injuries, is an interesting topic for inspectors with the aim of diagnosing patients. Sniffing test is currently utilized to examine if an individual is suffering from anosmia; however, functional Magnetic Resonance Imaging (fMRI) provides unique information about the structure and function of the different areas of the human brain, and therefore this noninvasive method could be used as a tool to locate the olfactory-related regions of the brain.

In this study, by recruiting 31 healthy and anosmic individuals, we investigated the neural Blood Oxygenation Level Dependent (BOLD) responses in the olfactory cortices following two odor stimuli, rose and eucalyptus, by using a 3T MR scanner.

Comparing the two groups, we observed a network of brain areas being more active in normal individuals when smelling the odors. In addition, a number of brain areas also showed an activation decline during the odor stimuli, which is hypothesized as a resource allocation deactivation.

This study illustrated alterations in the brain activity between normal individuals and anosmic patients when smelling odors, and could potentially help for a better anosmia diagnosis in the future.

Many infinite theories have been suggested to explain memory loss in neurodegenerative diseases. However, there are clear data that iron-containing neurofibrillary networks can cause neuron death and erase the memory of neurons, just like black holes in space.

Ths study aimed to investigate the electromagnetic properties of iron-loaded neurofibrillary networks formed in the hippocampus as a result of damage to the olfactory nerves, just like black holes in space, as well as whether they cause neuron death and memory loss.

All rats were tested with star maze performance before, 3 weeks, and 3 months after surgery. The data used in the study were obtained from the subjects in the experimental groups who had been followed up for 3 months with control (GI; n = 5), SHAM (GII; n = 5) with only frontal burr hole, and study (GIII; n = 15) animals with olfactory bulb lesion. All rats were tested with star maze performance before, 3 weeks, and 3 months after surgery. The olfactory bulbs and hippocampus of subjects were examined by stereological methods. Olfactory bulb volumes, degenerated neuron densities of the hippocampus, and numbers of hippocampal black holes were estimated quantitatively, and results were statistically analyzed by a 1-way analysis of variance (ANOVA). The properties of black holes in the brains and the universe were compared theoretically.

The mean olfactory bulb volumes, degenerated neuron density, and black holes of the hippocampus were estimated as 4.43 ± 0.22 mm3, 42 ± 9 mm3, and 3 ± 1 mm3 in GI, 4.01 ± 0.19 mm3, 257 ± 78 mm3, and 11 ± 3 mm3 in GII, and 2.4 ± 0.8 mm3, 1675 ± 119 mm3, and 34 ± 7 mm3 in GIII. All animals were tested with star maze performance before, 3 weeks, and 3 months after surgery. Latency, distance, speed, and path efficiency values of all animals were detected. The more diminished olfactory bulb volume (P < 0.00001) causes more apoptotic neurons and black holes in the hippocampus (P < 0.0001) and more memory loss in olfactory bulb lesion (OBL)-applied animals (P < 0.005).

Hippocampal black holes, which are similar to black holes in terms of their formation processes, may be responsible for neuronal losses and memory erasures in the brain by acting like black holes in space. These amyloid plaques, which cause neuron death and memory loss, will be called data-deleting amyloid black holes (DADA-Black Holes) in the paper.

Psychophysical tests are typically used for clinical assessment of human smelling function. Given that olfactory identification is linked to the regional culture, the main aim of this study was to provide the comprehensive “sniffin’ sticks” olfactory test, culturally adapted on the Iranian population as well as to examine the discriminatory power of this test between normal people and patients with olfactory disorder.

This cross-sectional study consisted of 3 steps. A total of 200 healthy people were recruited to determine odor familiarity (using Likert- scale) for the first step. In the second step, based on the original sniffin’ sticks test and odor familiarity, 16 odor items were selected. Odor modification was performed and the identification part of the sniffin’ sticks test was created. Then, 99 patients with olfactory disorders and 214 healthy participants were tested using the Iranian sniffin’ sticks test (Ir-SST). After 2 to 4 weeks, participants were reexamined and test reliability was evaluated by using a Pearson correlation coefficient test. 

The Ir-SST showed that scores of patients with smell loss were significantly lower than normosmic participants (13.6 ± 5.24 vs 34.3 ± 3.41, P < 0.001). The sensitivity (95.2%) and specificity (93.5%) of the test were also found to be high. Test-retest reliability was as follows: composite score: r = 0.8; odor identification: r = 0.83; odor threshold: r = 0.77; and odor discrimination test: r = 0.56; P < 0.001.

The results suggest that the Ir-SST can be effectively adapted to the Iranian population. The current study validates that the sniffinchr('39') sticks olfactory test is applicable as a useful screening tool for comprehensive assessment of olfactory function in an Iranian population.

Laryngeal cancer is one of the most common head and neck cancers for which total laryngectomy is the preferred treatment in advanced stages. Major disabilities of this surgical procedure include loss of voice and nasal function, swallowing difficulties, and psychological consequences.

This study aimed to investigate the effect of the Polite Yawning technique on olfactory quality in patients undergoing total laryngectomy.

In this cross-sectional study, after total laryngectomy, the patients with olfactory dysfunction were enrolled and the quality of olfaction was evaluated by the Quick Odor Detection test before and after receiving the Nasal Airflow Inducing Maneuver technique training. Statistical analysis was performed using SPSS 21 software by the Wilcoxon or McNemar’s test. The significance level was considered for P ≤ 0.05.

A total of 40 patients were evaluated. The mean age was 55.98 ± 6.27 years. Eighty-five percent of the patients were male (n = 34). The difficulty score in learning maneuvering was 2.5 ± 1.3, and 90% had no problem with learning it. Before maneuver, none of the patients had normal olfaction and had hyposmia mostly (n = 32, 80%). Immediately after the maneuver, there was a sensation of smell in all patients and the rate of hyposmia in patients was reduced to 65% (P = 0.008). Normal olfactory status was reported in half of the patients one month after the maneuver (21 patients, 52.5%, P = 0.0001), and there was a sense of smell in all patients (P = 0.0001).

The results proved that olfactory quality can be rehabilitated after laryngectomy by the nasal airflow-inducing maneuver (the “Polite Yawning” technique). It is a patient-friendly method; however, a single training session is probably insufficient and most patients may need more training sessions.

Sniffin’ Sticks smell identification test is a tool used for evaluation of olfactory function but the results are culture-dependent. It relies on the subject’s familiarity to the odorant and descriptors. This study aims to develop the Malaysian version of Sniffin’ Sticks smell identification test suitable for local population usage.

  The odorant descriptors and distractors of the original version of Sniffin’ Sticks were translated into Malay language. It was then tested for familiarity and identifiability in 30 normosmic subjects. The descriptors were replaced until the familiarity of all descriptors and identification rates of odorants achieved ≥ 70%. The validity of the new cultural-adapted version was tested in 60 hypo-anosmic subjects and 60 normosmic subjects with Student t-test. The test-retest reliability was evaluated after two weeks with interclass correlation.

Two odorant descriptors and nine distractors achieved familiarity <70% (13.3% - 66.7%) and were replaced. Another three culturally inappropriate distractors were also replaced. The mean score among the healthy subjects was significantly higher than the subject with smell dysfunction [13.7 (1.12) and 7.3 (3.42); t= 7.24 (df= 34.23), P<0.001]. The coefficient of correlation (r) between test and retest scores was 0.93 (P<0.001).

The cultural adapted Malaysian version of Sniffin’ Sticks smell identification test is valid and has high test-retest reliability. This is the first smell identification test validated in Malaysia. It is effective for evaluation of olfactory function in local population.

The occurrence of anosmia/hyposmia during novel Coronavirus disease 2019 (COVID-19) may indicate a relationship between coincidence of olfactory dysfunction and coronavirus disease 2019 (COVID-19). This study aimed to assess the frequency of self-reported anosmia/hyposmia during COVID-19 epidemic in Iran.

This population-based cross sectional study was performed through an online questionnaire from March 12 to 17, 2020. Cases from all provinces of Iran voluntarily participated in this study. Patients completed a 33-item patient-reported online questionnaire, including smell and taste dysfunction and their comorbidities, along with their basic characteristics and past medical histories. The inclusion criteria were self-reported anosmia/hyposmia during the past 4 weeks, from the start of COVID-19 epidemic in Iran.

A total of 10 069 participants aged 32.5±8.6 (7-78) years took part in this study, of them 71.13% women and 81.68% nonsmokers completed the online questionnaire. The correlation between the number of olfactory disorders and reported COVID-19 patients in all provinces up to March 17, 2020 was highly significant (Spearman correlation coefficient = 0.87, P< 0.001). A sudden onset of olfactory dysfunction was reported in 76.24% of the participations and persistent anosmia in 60.90% from the start of COVID-19 epidemic. In addition, 80.38% of participants reported concomitant olfactory and gustatory dysfunctions.

An outbreak of olfactory dysfunction occurred in Iran during the COVID-19 epidemic. The exact mechanisms by which anosmia/hyposmia occurred in patients with COVID-19 call for further investigations.