Importance of unilateral examination in olfactometry

Hyposmia, the decreased sense of smell, and anosmia, the loss of sense of smell, may be unilateral or bilateral. If the olfactory acuity examined by means of bilateral test is normal, olfactory disorders are not found; unilateral examination is therefore necessary for definite evaluation of olfactory acuity. As evidence, 7 cases out of 94 patients with chronic rhinosinusitis and 6 cases out of 12 patients who received the surgery of anterior cranial fossa showed definite different olfactory threshold between nasal cavities, and there were no patients who recognized the diminished sense of smell in spite of unilateral high olfactory threshold. Additionally, we have experienced that a patient with brain tumor was diagnosed by the help of unilateral olfactory test. We thus strongly recommend the unilateral olfactometry as a method for simple and reliable test in clinical measurement of the sense of smell.     

Comparison of diagnostic findings using different olfactory test methods

OBJECTIVE: To quantify discrepancies in the diagnosis of olfactory function that might exist when comparing results obtained from centers using different methods of olfactory testing. STUDY DESIGN: Prospective study of 50 healthy adult volunteers and 25 adult patients with olfactory complaints. METHODS: Two test methods, the Connecticut Chemosensory Clinical Research Center (CCCRC) test widely used in the United States, and the Jet Stream Olfactometer (JSO) test used in Japan, were used to measure and categorize the diagnostic level of olfactory function (normosmia, mild hyposmia, moderate hyposmia, severe hyposmia, anosmia). Olfactory function was measured separately for each nostril. RESULTS: There was a significant correlation (rs = 0.788, P < .01, n = 150 nostrils) between diagnostic categories assigned by the CCCRC and JSO test methods. Diagnostic categories were identical for 66.7% of the nostrils tested, and in only 7.3% of the cases did the results differ by more than one category. For the anosmic and normosmic categories, test results were in agreement 91.7% of the time, whereas for the hyposmic categories (mild, moderate, and severe) results were in agreement only 22.2% of the time. CONCLUSIONS: Our results demonstrate that when comparing clinical or research data obtained from centers using different olfactory test methods, subjects with diagnoses of anosmia or normosmia may be more reliably compared than those with different levels of hyposmia.     

单侧突发性聋与椎基底动脉影像学特征的相关性研究

目的 探讨单侧突发性聋(简称突聋)与椎基底动脉影像学特征间的关系。 方法 收集2014-2018年在山西医科大学第一医院被诊断为单耳突聋,且临床检验及影像学资料完整的患者175例,分析其听力损失侧别及程度与椎动脉、基底动脉特点间的关系。 结果 椎动脉(χ2=8.031,P=0.045)及基底动脉(χ2=5.091,P=0.034)狭窄/弯曲与听力损失侧别有关。听力损失预测因素的单变量分析结果显示,左侧听力损失患者与右侧(OR=2.89,95%CI为1.77~2.77,P=0.036)及双侧椎动脉狭窄/迂曲(OR=4.43,95%CI为1.49~13.23,P=0.008)有关,无基底动脉狭窄/迂曲与右侧听力损失(OR=0.31,95%CI为0.11~0.90,P=0.030)相关,其他因素无统计学意义。年龄和性别匹配的多变量分析结果显示,右侧椎动脉狭窄/迂曲与左耳听力损失有关(OR=2.83,95%CI为1.05~7.67,P=0.040)。患者基底动脉狭窄/迂曲与否与听力损失程度不存在统计学差异(χ2=3.339,P=0.068)。突聋患者听力损失的程度与椎动脉(χ2=3.897,P=0.273)及基底动脉(χ2=3.339,P=0.068)的影像学特征无关。 结论 在突聋患者中,听力损失的侧向性与椎基底动脉是否狭窄/迂曲有关,右侧椎动脉狭窄/迂曲与左耳听力损失有关。     

Hearing impairment in patients with acoustic neuroma—analysis by electrocochleography

Objective: In patients with acoustic neuroma, the site and severity of hearing impairment are important in discussing surgical approaches. Since the effectiveness of conventional auditory psychological testing is limited, we studied objectively hearing impairment of the cochlea and the cochlear nerve due to the tumor. Methods: Electrocochleography (ECochG) was carried out in 21 patients with acoustic neuroma. Cochlear microphonic potential (CM) and action potential (AP) in ECochG evoked with clicks and short tone bursts were recorded through a transtympanic needle electrode technique. Cochlear function was studied using the detection thresholds of CM, and cochlear nerve involvement was analyzed by differences between AP and CM detection thresholds. Results: The 1 kHz CM detection threshold was elevated in 17 (81.0%) of 21 patients indicating cochlear impairment. Of seven patients with normal hearing or mild sensorineural hearing loss in pure tone audiometry, three had a slightly elevated CM detection threshold. Of five patients with pronounced pure tone levels, four showed a CM response and were thought to have mild cochlear dysfunction. Cochlear nerve impairment was confirmed in three of four patients with well-developed CM based on elevated AP detection thresholds. Three patients had CM response but no AP response, suggesting severe cochlear nerve impairment. Conclusion: Disorders of the cochlea and the cochlear nerve can be evaluated with ECochG AP and CM measurement. The findings of ECochG are thought to be important information to judge hearing prognosis, thereby enhancing its clinical utility.     

慢性鼻-鼻窦炎伴鼻息肉患者组织嗜酸性粒细胞与嗅觉功能障碍的相关性研究

目的 探讨慢性鼻-鼻窦炎伴鼻息肉(CRSwNP)患者术后组织嗜酸性粒细胞与嗅觉功能障碍的相关性。 方法 回顾性选择2016年7月至2018年7月CRSwNP行鼻内镜鼻窦手术(ESS)治疗的120例患者。通过视觉模拟评分(VAS)和Lund-Kennedy评分了解患者病情;术后取筛窦黏膜组织进行嗜酸性粒细胞计数。通过Sniffin'Sticks测试和化学感觉事件相关电位(CSERP)来评估嗅觉功能。Spearman相关分析用以了解嗜酸性粒细胞计数与Sniffin'Sticks测试和CSERP参数之间的关系及VAS评分和CSERP的相关性。 结果 调整协变量(年龄、性别、饮酒、吸烟、过敏性鼻炎、哮喘、术后时间和Lund-Kennedy评分)后的相关性分析结果与未调整协变量的结果一致。组织嗜酸性粒细胞计数与阈值评分相关(r=-0.460,P=0.012);组织嗜酸性粒细胞计数与苯乙醇(N1:r=0.471,P=0.010; P2:r=-0.487,P=0.007)及乙醇(N1:r=-0.516,P=0.008; P2:r=-0.590,P=0.002)刺激产生的CSERP峰值潜伏期N1和P2相关;但与CSERP振幅均无明显相关(P>0.05)。苯乙醇刺激产生的阈值评分和CSERP峰值潜伏期N1之间存在明显负相关(r=-0.560,P<0.001)。乙醇刺激产生的CSERP潜伏期与症状VAS评分存在明显负相关(r=-0.400,P=0.005)。 结论 CRSwNP患者鼻术后组织嗜酸性粒细胞增多与术后嗅觉功能障碍明显相关,且三叉神经的敏感性可能与组织嗜酸性粒细胞增多相关,鼻黏膜炎症可同时影响嗅神经及三叉神经的功能。     

Study on difference in olfactory response in dysosmia patients

Using 1952 dysosmia patients, we studied the difference in olfactory response to 5 types of odorous substances used in the standard olfactory acuity test in Japan--beta-phenyl ethyl alcohol, methyl cyclopentenolone, isovaleric acid, gamma-undecalactone, and scatol. Olfactory dysfunctions included 887 patients with chronic paranasal sinusitis, 255 with allergic rhinitis, 326 with common cold sequela, 77 with complications from head injuries, 28 with drug-induced dysosmia, 39 with congenital dysosmia, 257 with dysosmia of unknown etiology, and 83 miscellaneous. The standard olfactory acuity test before treatment indicated that 82 patients detected only one odor within the detection threshold and 157 within the recognition threshold; 40 responded only to isovaleric acid at the detection threshold and 101 at the recognition threshold. Both figures were significantly greater than those who responded to other odors (p < 0.01). No specific trends were noted in etiologies of dysosmia that allowed smelling of isovaleric acid only either at the detection or recognition threshold. Among those whose olfactory thresholds were judged to be scaled out against all 5 odorous substances, 552 were rated as scaled out at the detection threshold and 630 at the recognition threshold. During post treatment, 33 scaled out at the detection threshold and 32 scaled out at the recognition threshold improved enough to smell 1 type of odor. Of these, 15 scaled out at the detection threshold and 13 scaled out at the recognition threshold became able to smell only isovaleric acid. Those becoming able to smell only isovaleric acid either at the detection or recognition threshold, significantly outnumbered those becoming able to smell other odors (p < 0.01). No outstanding cause of dysosmia was seen in those able to smell isovaleric acid. This data indicates that olfactory function for detecting isovaleric acid is relatively resistant to disease and is most likely to be restored. The difference in olfactory response of patients with olfactory dysfunction such as those above may be due to variations in the number of olfactory receptor proteins for specific odors within olfactory cells or different responses to the type of molecules of odor-emitting substances.     

Barcelona Smell Test - 24 (BAST-24): validation and smell characteristics in the healthy Spanish population

OBJECTIVES: Smell tests for clinical use have been developed in different countries, but no single test has gained general acceptance. The objectives of the study were to evaluate the smell outcomes in a Spanish population. METHODS: A prospective study on healthy volunteers (n = 120) without olfactory disturbances was performed. The volunteers were differentiated by gender, age, and smoking habit groups. We used a new olfactory test, the Barcelona Smell Test 24 (BAST-24) that consists of 24 odours scoring smell detection, identification, and forced choice. RESULTS: Volunteers showed the highest scores on smell detection for both 1st (99%) and 5th cranial nerve (98%) odours. Spontaneous smell identification (54.7% and 59.3%) and forced choice (72.2% and 42.6%) scores were lower than those of smell detection, for both 1st and 5th cranial nerves respectively. On smell identification, volunteers scored higher in the left than in the right nostril. Females had better smell identification for both 1st and 5th cranial nerves (62.8%, 66.7%) than males (50.3%, 58.8%). Non-smokers had higher scores (65%) than smokers (59%) on smell identification for the 5th CN. CONCLUSIONS: For smell identification, females, non-smokers, and left nostril had higher scores than males, smokers, and right nostril respectively. BAST-24 is a good and reliable method to test the olfactory function in the clinical practice.     

Olfactory function evaluated by SPECT

Few articles on neuroimaging techniques in the study of central and peripheral olfactory pathways are present in the literature. By Single Photon Emission Computed Tomography (SPECT), cortical perfusion increment after sensorial stimulation can be evaluated objectively. In the present research, 10 healthy adults underwent SPECT by CER.TO.96 cerebral tomograph, before and after olfactory stimulation with lavender-water. A variable degree of cortical activation was detected in all patients. Gyrus rectus (+24.5%), orbito-frontal cortex (right +26.6%, left +25.6%), and superior temporal (right +9.9%, left +5.5%) cortical areas were always activated. A slight perfusion increase was present in middle temporal (right +3.2%, left +2.1%) and parieto-occipital (right +0.4%, left +2%) regions. Five patients affected by posttraumatic anosmia were also investigated: they showed a perfusion increment markedly inferior to 0.5% in every olfactory area. SPECT is a rather diffused, easily performed technique which yields objective semi-quantitative information on brain perfusion. Hence, it can be regarded as a promising contribution in the fields of smell neurophysiology, clinical olfactometry, and medicolegal queries.     

Magnetic resonance imaging for diagnosis of congenital anosmia

Magnetic Resonance Imaging (MRI) was performed on 9 patients who lacked a sense of smell since birth. Seven of them, including two patients with Kallmann syndrome, exhibited abnormality of the olfactory bulb, olfactory tract, olfactory sulcus, or rectus gyrus, with some variation among patients in type and degree of abnormality. The other two patients exhibited normal olfactory pathway morphology, and for them the possibility of acquired sensorineural anosmia could not be ruled out. MRI is useful for determining whether patients with congenital anosmia have olfactory pathway anomalies. Many patients with congenital anosmia and hypoplasty or aplasty of the olfactory pathway nevertheless had no gonadal or endocrinological disorders.     

单侧特发性声带麻痹神经电刺激治疗后即刻疗效初步观察

目的 探讨单侧特发性声带麻痹喉返神经/喉上神经电刺激治疗后即刻对主观声音改变、声学参数以及动态喉镜观察结果的影响.方法 选取诊断为单侧特发性声带麻痹的患者,回顾性收集其行喉肌电图检查并同期行神经电刺激治疗前后的动态喉镜及嗓音分析检查结果,分析检查及治疗前后主观声音改变,声学参数(jitter、shimmer、DSI、M...     

Validation study of the "Sniffin' Sticks" olfactory test in a British population: a preliminary communication

Clin. Otolaryngol. 2012, 37 , 23–27 Objective: The ‘Sniffin’ Sticks’ olfactory test contains pen‐like odour dispensing devices which are used to assess olfactory threshold, discrimination and identification. Odour identification is strongly dependent on familiarity with the odours and has an important cultural component which has limited the usefulness of other validated tests. The ‘Sniffin’ Sticks’ test was developed in Germany and is validated in other countries but not in the UK. This study aims to validate the applicability of ‘Sniffin’ Sticks’ in a local population. Design: Prospective controlled study. Setting: Rhinology or olfactory disorder clinic. Participants: About 82 subjects, 33 healthy volunteers with a reported normal sense of smell, and 49 patients with an impaired sense of smell presenting either at a rhinology or an olfactory disorder clinic. Each subject’s olfactory function was assessed using the ‘Sniffin’ Sticks’ test with a maximum score of 48. Main outcome measures: Threshold, discrimination and identification scores along with the combined olfactory score. Results: The mean age of the subjects tested was 46.7 years; 46 female and 36 male. In the patient group 36 were hyposmic and 13 anosmic. In the healthy volunteers group all subjects were normosmic. In the control group the mean combined olfactory score was 34.5 (±2.5). The mean combined score in the patients group was 20.8 (±7.4). Odour threshold scores were 3.7(±2.8) for patients (hyposmics and anomics) and 8.3(±1.8) for controls. In the identification test the controls mean score was 13.6 (±1.2) for while the patients’ mean score was 8.6 (±3.5). Conclusions: In our sample of the local population the combined olfactory and odour identification scores for healthy volunteers and patients with olfactory disorders are comparable with the normative data published on large samples of European populations. However, modification of a few of the distracters is recommended for British patients based on our findings.     

Olfactory function in patients with chronic rhinosinusitis before and after functional endoscopic sinus surgery

BACKGROUND: The olfactory loss in patients with chronic rhinosinusitis has been measured by different methods. However, the results have been variable and it is not clear whether functional endoscopic sinus surgery (FESS) significantly improves olfactory function. This study was performed to evaluate the influences of FESS on olfactory function in patients with chronic rhinosinusitis using three different types of olfactory tests. METHODS: Seventy patients with chronic rhinosinusitis were administered the University of Pennsylvania Smell Identification Test (UPSIT), a single staircase phenyl ethyl alcohol odor detection threshold test (STT), and a short-term odor memory/discrimination test a day before and 6 months after FESS. A questionnaire inquiring about the patients' self-perception of olfactory function was administered also. Independent ratings of the severity of chronic rhinosinusitis before FESS were established from CT scans. RESULTS: Fifty-two (74.3%) of the patients reported that their olfactory function was impaired before surgery, and 68.6% of the patients reported impaired olfactory function after surgery, a difference that was not significant. No meaningful changes in any of the olfactory test scores were noted 6 or more months after FESS. Preoperatively, small correlations between CT scores and the symptom scores (r = 0.278; p = 0.024), threshold scores (r = -0.27; p = 0.031), and UPSIT scores (r = -0.36; p = 0.003) were observed. CONCLUSION: In patients with severe rhinosinusitis, FESS had little impact on the ability to smell, regardless of the method for assessing smell function. Subtle associations between olfactory function and the severity of chronic rhinosinusitis determined by CT were observed, however, preoperatively. The olfactory test measures were correlated with one another both pre- and postoperatively.     

Evaluation of the efficacy of the ‘nasal airflow‐inducing manoeuvre’ for smell rehabilitation in laryngectomees by means of the Sniffin′ Sticks test

Clin. Otolaryngol. 2011, 36 , 17–23 Objective: To determine the efficacy of the nasal airflow‐inducing manoeuvre (NAIM) as a method for olfactory rehabilitation in laryngectomees by the means of the Sniffin′ Sticks test. Study design: Prospective open interventional trial. Setting: Tertiary academic hospital. Participants: Thirty‐seven patients after laryngectomy have been screened and 25 patients have been included into the study. The participant’s sense of smell was tested with the Sniffin′ Sticks test before and after learning the nasal airflow inducing manoeuvre. The individual level of threshold, discrimination and identification (TDI) was determined and the individual threshold, discrimination and identification score was used to classify the patients as being anosmic, hyposmic or normosmic. Main outcome measures: The primary endpoint was the change of the threshold, discrimination and identification score before and after learning the nasal airflow inducing manoeuvre. The secondary endpoint was a change in the diagnostic group (normosmic, hyposmic and anosmic) after learning of the nasal airflow inducing manoeuvre. Results: There was a statistically significant increase in the total threshold, discrimination and identification score (P < 0.001) and the three sub‐scores (P ≤ 0.02) before and after the learning of the nasal airflow inducing manoeuvre. Patients gained seven points on average in the threshold, discrimination and identification score. Twenty of 25 patients showed an increase of five or more point in the threshold, discrimination and identification score. In the classification of the smell ability, 15 of 25 patients showed a change to a higher class (hyposmic to normosmic or from anosmic to hyposmic or normosmic). Conclusion: The nasal airflow inducing manoeuvre is a method for the successful rehabilitation of the sense of smell in laryngectomees. The evaluation with the Sniffin′ Sticks tests showed a clinically relevant increase of olfaction in 80% of patients. The teaching of the nasal airflow inducing manoeuvre should be included in post‐laryngectomy rehabilitation programmes.     

Amount of airflow required for olfactory perception in laryngectomees: a prospective interventional study

Clin. Otolaryngol. 2012, 37 , 28–34 Objectives: To determine minimum airflow rate required for olfactory stimulation in successfully rehabilitated laryngectomised patients after learning the polite yawning technique (PYT) and to confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re‐established. Design: Prospective open interventional trial. Setting: Tertiary academic hospital. Participants: The study population comprised 100 laryngectomised patients. The control group consisted of 100 non‐laryngectomised patients of similar age and sex. Rhinomanometry was used to measure air flow in the right and left nostrils, respectively, while the Smell Diskettes Olfaction test (SDOT) was used to test each individual’s sense of smell. Main outcome measures: The primary endpoint was increasing the airflow, while the secondary endpoint was improvement in the Smell Diskettes Olfaction test score after learning the polite yawning technique. Results: The difference in the Smell Diskettes Olfaction test results before and after introducing the polite yawning technique was statistically significant (F = 53.077; P < 0.001). The number of accurately identified odours increased with each measurement. There was a significant difference among rhinomanometric measurements of airflow through the right (F = 65.002; P < 0.001) and left nostrils (F = 75.465; P < 0.001). Nasal airflow improved with each measurement. The minimum airflow required for olfactory stimulation in successfully rehabilitated patients was approximately 60 cm³/s. The control group had considerably better airflow in both nostrils than the laryngectomised group. The difference between the total number of rehabilitated (normosmic) patients (48%) in the laringectomised group and normosmic participants (56%) in the control group (z = 1.132; P = 0.129) was not statistically significant. Conclusion: The number of odours identified by laryngectomised patients increased with the volume of nasal airflow. The number of patients with rehabilitated olfactory function approximated the percentage of normosmic individuals in the non‐laryngectomised population. These findings confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re‐established.     

Does iron deficiency anemia affect olfactory function?

Conclusion This study found a negative effect of IDA on olfactory function. IDA leads to a reduction in olfactory function, and decreases in hemoglobin levels result in further reduction in olfactory function. Objective This study examined the effects of iron-deficiency anemia (IDA) on olfactory function. Method The study enrolled 50 IDA patients and 50 healthy subjects. Olfactory function was evaluated using the Sniffin’ Sticks olfactory test. The diagnosis of IDA was made according to World Health Organization (WHO) criteria. Results Patients with IDA had a significantly lower threshold, discrimination, and identification (TDI) value, and a lower threshold compared with the control group. However, there were no significant differences between the groups in terms of smell selectivity values.     

Nine cases of piriform sinus fistula with acute suppurative thyroiditis

Objective: Acute suppurative thyroiditis is a disease of an infection originated from the piriform sinus via congenital fistula. The purposes of this study are the establishment of accurate and necessary examinations for the diagnosis and necessary treatment for complete remission of this disease. Methods: We reported nine cases with acute suppurative thyroiditis who were treated by operation. Preoperative examinations and operative procedures for nine cases were investigated. Results: A congenital fistula was detected in seven of nine patients preoperatively, and in all seven patients, the fistula was detected during the operation. Serum thyroglobulin was elevated in four of five patients who were examined the serum level. Ultrasonogram was performed in eight cases, and localized swelling of the thyroid lobe was observed in all cases. No inflammatory recurrence was observed in eight cases, and recurrence was observed in one case where complete fistelectomy was not performed. Conclusion: Measurements of serum thyroglobulin, ultrasonography, and pharyngoesophagography were useful in the diagnosis of acute suppurative thyroiditis. Complete removal of the fistula with or without affected thyroid lobe is necessary to prevent recurrent suppuration.     

Sense of smell in long-standing nasal polyposis.

An impaired sense of smell is a common complaint in patients with nasal polyposis, and hyposmia is usually attributed to obstruction of the nasal airways. The duration of nasal polyposis and nasal surgery may also affect olfaction. It has been shown that aging and chronic rhinitis both impair olfaction. The aim of our study was to evaluate the sense of smell in patients who had had nasal polyposisfor at least 20 years. The olfactory threshold was assessed with a commercially available odor detection threshold test. The threshold of 19 (46%) of 41 patients was greater than the age-related upper 95% reference limit. In a forward stepwise multiple regression analysis of all the polyposis patients, the degree of opacity of ethmoidal sinuses seen in computed tomography (CT), polyposis visible in anterior rhinoscopy, total nasal resistance, and gender had a significant association with olfactory threshold.     

Assessment the long-term effects of septoplasty surgery on olfactory function

Objectives: This research aimed to evaluate pre-operatively and post-operatively the olfactory function of patients who had undergone surgery in our clinic for chronic nasal blockage via the Connecticut Chemosensory Clinical Research Center (CCCRC) smell test.

Method: Thirty-seven patients (24 females, 13 males) were enrolled in this study. All had undergone surgery in our clinic due to chronic nasal blockage (not for smell dysfunction), having been diagnosed with septal deviation in conjunction with concha bullosa and/or inferior turbinate hypertrophy. This is a prospective study without a control group. The mean age was 33.74?±?8.98 (range =19–54). All of the operations were performed under general anesthesia. CCCRC smell tests were performed on every patient before the operation and at post-operative 1st week, 6th week, 6th month, and 1st year.

Results: In this study, we found that septoplasty, in conjunction with middle concha surgery and/or inferior concha radiofrequency, did not affect the olfactory function negatively.

Conclusion: Although nasal surgery has the potential to affect the smell function negatively, it was found that olfactory function was not affected after the surgery during a considerably long follow-up period. Moreover, an improvement in smell function was detected at post-operative 6th month and 1st year.     

Clinical observations on parosmia]

We reviewed the clinical records of 15 patients with parosmia examined in our department from April 1987 to September 1990. Seven (29.2%) of 24 patients with olfactory disturbance caused by traumatic injury complained of parosmia. Eight (23.2%) of 34 patients with olfactory disturbance caused by influenza also showed parosmia. The incidence of parosmia between two groups was not statistically significant (p greater than 0.05). Parosmia was observed in none of 42 patients with olfactory disturbance caused by nasal-paranasal diseases. All patients (n:15) always perceived odors as unpleasent. Twelve of them had spontaneous parosmia, and three patients recognized the unpleasant smell when an odor came. In comparison with the auditory system, we speculated that spontaneous parosmia resembles tinnitus. The cause of tinnitus is recognized as a disturbance of the auditory nerve (the first order neuron). Tinnitus is rare in patients with conductive hearing loss, and cases of olfactory disturbance of the "respiratory dysosmia" did not complain of parosmia. Post-traumatic olfactory disturbance is caused by transection of the fila olfactoria, which is part of an olfactory neuron, while post-inflammatory olfactory disturbance is caused by damage to olfactory receptor cells. Furthermore, the fact that the incidence of parosmia between the two groups was not statistically significant suggests the same etiological mechanism in receptor cells. We consider that parosmia is caused by damage to olfactory sensory neurons.     

Olfactory function following nasal surgery

Objective/Hypothesis: This prospective study aimed to investigate predictors of nasal surgery in terms of olfactory function. Study Design: Prospective study. Methods: A total of 775 patients were included in this prospective study (482 men, 293 women; age range 10–81 years, mean age 41 years, standard deviation = 15.3 y). Prior to surgery, patients received a detailed otorhinolaryngologic examination including nasal endoscopy. Olfactory function was assessed with a standardized odor identification test (“Sniffin' Sticks”). In 356 patients, olfactory function was retested 4 months after surgery (63–339 days after surgery; mean 128 days, standard deviation = 29 days); 206 of these patients received sinus surgery, while 150 received surgery involving the septum. Results: Using a conservative definition of change of olfactory function, following sinus surgery, improvement of the sense of smell was found in 23%, no change was seen in 68%, and decreased function was seen in 9% of the patients; in patients with septum surgery, improvement was seen in 13%, no change in 81%, and decreased function in 7%. Patients exhibiting a postoperative decrease of olfactory function had significantly higher preoperative olfactory scores than patients who experienced improvement. In terms of the sense of smell, nasal surgery produced the highest success rates in patients with eosinophilia and a high degree of polyposis. Neither age nor sex had a major impact on the outcome of surgery in terms of olfactory function. Conclusions: These results in a large group of patients confirm previous work. Apart from apparent success in 13 to 23% of patients, there is also a small but significant group of patients (7 to 9%) in whom olfactory function decreases after surgery. Because this decrease was mostly found in patients with relatively good preoperative olfactory function, this group should receive specific attention when counseling patients about the potential risks of nasal surgery.