Olfactory function in HIV-positive subjects

The aim of this study was to reinvestigate previous reports of chemosensory dysfunction in HIV-positive subjects. Odor thresholds, odor discrimination and odor identification were assessed using the Sniffin' Sticks test battery. Seventy-four HIV-positive patients were tested. According to CDC criteria, 38 subjects were classified as stage A, 10 as stage B and 26 as stage C. None of the subjects exhibited severe cognitive impairment. Compared to normative data all subjects had normal odor identification and discrimination. However, odor thresholds were well below the median of a normal population. There were no significant differences between stage A, B or C subjects. This may be interpreted as indicating that olfactory dysfunction is among the primary deficits of HIV infection and occurs independently of disease stage. These results confirm previous work suggesting that odor thresholds are elevated early in HIV infection whereas a decline in identification and discrimination abilities is correlated with reduced cognitive abilities.     

Olfactory function in chronic renal failure

BACKGROUND: Patients with chronic renal failure (CRF) show a high prevalence of poor nutritional state so that dietary treatment becomes a significant part of the therapeutic regimen. Because smell plays an important role in nutrition, this study aimed to investigate olfactory function in CRF patients. METHODS: A total of 64 CRF patients were investigated. Forty-nine of them were treated with hemodialysis, 15 CRF patients were not dialysis dependent. For comparison we examined 15 healthy subjects. Olfactory function was assessed for odor discrimination, odor identification, and butanol odor thresholds. RESULTS: Olfactory loss was found in 56% of the patients, with 3 functional anosmics and 33 hyposmics. CRF had specific effects on individual tests of olfactory function. Elevated odor thresholds werefound in 11% of patients, 38% of patients had reduced odor discrimination, and 48% of patients exhibited deficits in odor identification. Results of psychological tests (Mini-Mental State Examination and Trail-Making Test) correlated with results from odor identification (p < 0.01) and discrimination (p < 0.01) but not with odor thresholds. CONCLUSIONS: The ability to discriminate and identify odors was found severely impaired whereas odor thresholds were similar to what is seen in the general population. Consequently, CRF patients should be counseled with regard to the possibility of reduced chemosensory functions.     

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.     

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.     

原发性帕金森病患者嗅觉功能临床分析

目的 分析原发性帕金森病患者嗅球体积、嗅沟深度与嗅觉功能的相关性.方法 选取2011年1月至2013年12月天津市环湖医院原发性帕金森病患者(测试组)及无运动障碍的健康受试者(对照组)各100例,应用T&T嗅觉测试法检查所有受试者的嗅觉功能,并行嗅球体积、嗅沟深度的MRI检查及测量.对测试组进行H-Y分期、统一帕金森病评分量表(UPDRS)、左右肢体功能评分、简易精神状态检查表(MMSE)及蒙特利尔认知评估表(MoCA)检查.以SPSS 13.0软件进行统计学分析.结果 测试组T&T嗅觉识别阈分数为(3.0±0.3)分,明显高于对照组的(1.3±0.2)分,差异有统计学意义(t=2.537,P＜0.01),测试组、对照组男女嗅觉识别阈差异无统计学意义(t值分别为0.893、1.184,P值均＞0.05).测试组左右两侧嗅球体积[分别为(34.25 ±5.14)、(35.79±5.28)mm3]及平均嗅球体积[(35.28±5.21) mm3]均明显小于对照组[分别为(47.38±6.47)、(47.75 ±6.51)、(47.53±6.49)mm3],差异有统计学意义(t值分别为2.876、2.747、2.798,P值均＜0.01).测试组与对照组左右两侧嗅沟深度及平均嗅沟深度差异无统计学意义(t值分别为0.914、0.987、0.951,P值均＞0.05).测试组及对照组嗅觉识别阈与平均嗅球体积呈负相关趋势(r值分别为-0.537、-0.526,P值均＜0.05),与平均嗅沟深度无关(r值分别为-0.142,-0.157,P值均＞0.05).测试组平均嗅球体积与UPDRSⅢ、UPDRS总评分及H-Y分期具有相关趋势(r值分别为0.312、-0.419、-0.358,P值均＜0.05),与病程无相关性(r=-0.089,P＞0.05).结论 原发性帕金森病患者嗅球体积减小,嗅沟深度不变;其嗅觉功能与嗅球体积具有相关性,与嗅沟深度无关;其嗅觉减退的程度与疾病的严重程度具有一致性,与疾病的病程无关.     

Olfactory and gustatory function in irritable bowel syndrome

Irritable bowel syndrome (IBS) is the most common, functional disorder diagnosed by gastroenterologists. It is still unclear whether IBS has a central etiology, e.g., hyperreactivity of the brain, or a peripheral etiology, e.g., stimulation of olfactory/gustatory receptors on enterochromaffin cells, followed by serotonin release and changed gut motility. Testing the odor identification (ID), odor discrimination (DIS) and odor threshold (THR) as well as the total taste and the taste qualities “sweet”, “sour”, “salty” and “bitter” should be of help for determining the etiology. To our knowledge, this is the first study investigating the olfactory/gustatory function in IBS patients. The olfactory/gustatory function of 43 patients (32 women, 11 men) suffering from IBS as defined by the ROME III criteria was investigated by means of validated tests (Sniffin’ Sticks and taste strips). Compared to normative data, scores of THR were decreased and scores of ID and DIS were increased in IBS patients. Additionally, when compared to normative data, there was no difference in the taste function of IBS patients. Assuming that THR reflects more the peripheral olfactory function, whereas ID and DIS are influenced by central activity, and that taste did not differ in IBS patients compared to normative data, this supports the idea of a central etiology of IBS.     

Olfactory function and nasal nitric oxide.

OBJECTIVE: To determine the relationship between nasal nitric oxide (nNO) concentration and its influence on olfactory function. SETTING: Tertiary otolaryngology care centre. PARTICIPANTS: Sixty-four patients suffering from chronic rhinosinusitis and 20 healthy subjects participated. STUDY DESIGN: Prospective study. OUTCOME MEASURES: The nNO concentration was measured by chemiluminescence and olfactory thresholds were measured with the phenyl ethanol threshold of the Sniffin' Sticks. In chronic rhinosinusitis patients this measure was done preoperatively and 3 months after endoscopic sinus surgery. RESULTS: Healthy subjects had significantly higher nNO concentrations and better olfactory thresholds compared to the chronic rhinosinusitis patients, both before and after those had undergone sinus surgery. Olfactory thresholds and nNO concentrations remained unchanged after surgery in the chronic rhinosinusitis group. In the chronic rhinosinusitis group, nNO concentrations correlated positively with the olfactory threshold preoperatively (P < 0.0001) and 3 months after surgery (P < 0.05). In the control group, nNO production did not correlate with the olfactory thresholds (P > 0.05). CONCLUSION: Olfactory function and nNO concentration correlate in chronic rhinosinusitis patients but not in healthy subjects. This suggests that both parameters do rather not directly influence each other but it might be the inflammatory processes found in chronic rhinosinusitis that affects olfaction and nNO. Nasal nitric oxide produced by the paranasal sinuses seems not to directly influence olfactory function.     

Olfactory function following late repair of choanal atresia

Results of olfactory function tests (threshold determination and odor identification) in three cases of bilateral and one case of unilateral choanal atresia are reported. All four patients underwent successful repair of choanal atresia at relatively advanced ages (8 to 31 years). Test results showed that patients who had suffered from bilateral atresia had permanent olfactory deficits, while the patient who had suffered from unilateral atresia appeared to have normal olfactory acuity. Although these results should be interpreted with caution due to the small number of cases examined, they suggest the possibility that early sensory exposure might be needed for the normal development of central olfactory functions in analogy to the visual system.     

深圳小学高年级学生嗅觉功能的初步调查及与成绩的相关性初探

目的 探讨SniffinSticks在儿童嗅觉功能检查中的应用可行性。 方法 2015年4月至7月采用SniffinSticks法检测嗅觉正常的深圳某小学五、六年级小学生共70名,比较嗅觉评分与期末考试各科成绩的相互关联,探讨嗅觉记忆与学习能力的可能联系。 结果 选取对象中五年级30名,男17名,女13名;六年级40名,男22名,女18名。70名学生的SniffinSticks正常参考值是:气味阈值(OT):10.95±2.7,气味辨别值(OD):12.92±1.0,气味鉴别值(OI):13.74±1.6;嗅觉功能总分(TDI):37.54±2.2。男女间OT、OD、OI、TDI值差异无统计学意义,五、六年级间OT、OD、OI、TDI值差异亦无统计学意义。OT、TDI与英语成绩呈负相关(P<0.01)。 结论 SniffinSticks嗅觉检测方法能被较大儿童理解和接受,可用于儿童嗅觉测试。高年级男女学生嗅觉功能差异无统计学意义。     

慢性鼻-鼻窦炎患者嗅觉功能和嗅觉标记蛋白的研究

目的 探讨慢性鼻-鼻窦炎患者嗅觉功能障碍的发病机制和嗅觉标记蛋白(olfactionmarker protein,OMP)在嗅觉黏膜中的表达及意义。方法 对55例慢性鼻-鼻窦炎和11例对照组患者用T＆T嗅觉计定量检查法进行嗅觉功能主观检测,并应用免疫组化技术检测其嗅黏膜嗅觉标记蛋白的表达和分布。结果 慢性鼻-鼻窦炎患者主诉有嗅觉障碍者为50.9％(28/55),经主观嗅觉功能检测嗅觉障碍者为85.5％(47/55);对照组患者主诉有嗅觉障碍者为9.09％(1/11),经主观嗅觉功能检测嗅觉障碍者为18.2％(2/11),差异有显著性(x2=9.86,P<0.01)。对两组嗅黏膜进行OMP免疫组化染色显示:OMP存在于嗅黏膜的嗅细胞和微绒毛细胞中,OMP染色细胞数随嗅觉障碍程度加重而逐渐减少或消失。结论 慢性鼻-鼻窦炎患者嗅觉障碍的主要原因是嗅黏膜中嗅细胞的减少、萎缩和退化所导致的对嗅素的不能察觉和认识。     

Olfactory function in patients with ischemic stroke: a pilot study

The aim of this pilot study was to investigate olfactory function in unselected, cooperative patients with ischemic stroke and to gain information about olfactory perception in patients with distinct stroke localizations. Three ischemic stroke patients underwent olfactory testing using the Sniffin’ Sticks test and olfactory event-related potentials recording. All stroke patients were found to be normosmic or only slightly hyposmic when using a psychophysical testing device with age-adjusted norms. No responses or longer latencies on the affected side were found, however, when recording evoked potentials. This seems to argue for the idea that on the affected side it is often possible to document the objective lesion although the subjective perception of the patient appears normal.     

慢性鼻-鼻窦炎患者嗅觉功能和嗅觉标记蛋白的研究

OBJECTIVE: To study the pathogenesis of dysosphresia in patients with chronic sinusitis, to discuss the expression and significance of olfaction marker protein in olfactory mucosa. METHODS: There were 55 cases with chronic sinusitis in the experimental group, and 11 cases in the control. All of them were first tested by subjective method, and then the olfactory marker protein in olfactory mucosa was examined by the method of immunohistochemistry. Tissue sections were observed under optical microscope. RESULTS: The ratio of dysosphresia in patients with chronic sinusitis was 50.9% (28/55), while by subjective olfactory test, it was 85.5% (47/55). The ratio of dysosphresia in control patients was 9.09% (1/11), by subjective olfactory test, it was 18.2% (2/11). Olfactory marker protein was identified in the olfactory cells and microrillar cells by histochemical and immunohistochemical technique (S-P method). CONCLUSIONS: The main cause of dysosphresia in patients with chronic sinusitis is the decrease, atrophy and degeneration of the olfactory cells, which lead to the failure of olfactus perception and recognition.     

Olfactory function following nasal surgery: a 1-year follow-up

Olfactory dysfunction is a frequent symptom of nasal and sinunasal disease. Many of these patients undergo nasal sinus or nasal septum surgery. In this study, we evaluated the benefit of nasal surgery on olfactory function over a period of 12 months. Patients included in this study underwent either nasal sinus or nasal septum surgery. All patients were tested for olfactory function using the “Sniffin’ sticks” 16 item odor identification test. In addition, patients were asked to rate their nasal patency as well as their olfactory function at each visit. 157 patients were tested 3.5 months after surgery and 52 patients were tested again 12 months after surgery. Olfactory function improved significantly 3.5 months after surgery in patients, who received nasal sinus surgery; no significant increase was found in patients treated with nasal septum surgery. At the 12-month follow-up, the increase in olfactory function over all patients just missed statistical significance. Individually, however, 19% of the patients exhibited improvement after 3.5 months and 17% after 12 months. These numbers increased in patients with rhinosinusitis with nasal polyps, who exhibited improvement of 30% after 3.5 months, and 32% after 12 months. Nasal sinus surgery produced an increase in measured olfactory function, but not nasal septum surgery. This increase appeared to be stable over the examined period of 12 months.     

Olfactory ability as a function of nasal air flow volume in laryngectomees

This study tested a number of hypotheses concerning the interrelationships between the olfactory abilities and the volume of nasal airflow in laryngectomees. Data were collected from 25 laryngectomees and 25 control subjects and comprised the following: 1) Odor threshold and identification test results. In the threshold test, an 11-step aqueous dilution series of butanol was used. In the odor identification tests, 14 common odorants were used. 2) Measurement of nasal air flow volume in liters per minute. For olfaction and airflow, the laryngectomees' measurements were made under two conditions: 1) using unassisted airflow through the nose, and 2) using a laryngeal bypass that linked the stoma to the mouth and allowed airflow through the nose. The major findings showed that among laryngectomees olfactory abilities depend on nasal airflow. It is concluded that laryngectomees have intact olfactory mechanisms that function normally when adequate airflow volume is provided.     

Olfactory function and olfactory bulb volume in patients with postinfectious olfactory loss

OBJECTIVE: The study aimed to investigate whether the degree of postinfectious olfactory loss is reflected in volume of the olfactory bulb (OB). STUDY DESIGN: Retrospective study of 26 patients with postinfectious olfactory loss. MATERIALS AND METHODS: Olfactory function was assessed with the "Sniffin' Sticks" test kit, and the magnetic resonance imaging study focused on OB volume and the olfactory sulcus. RESULTS: The study revealed that 1) OB volume varies with regard to olfactory function, 2) OB volume decreases with duration of olfactory loss, and 3) patients with parosmia had smaller OB volumes than patients who did not report such smell distortions, although their overall olfactory function was not significantly different from each other. CONCLUSION: The study emphasizes that OB volume is a gauge of olfactory function.     

Olfactory function following open rhinoplasty: A 6-month follow-up study

Background

To assess the importance of different information pathways for patients undergoing elective ENT surgery (General Practitioner, Specialist consultation, pre assessment clinic and consent process as well as printed information material and non medical sources) and to correlate their relative importance with patient and doctor factors

Methods – Patients

Cross – sectional questionnaire survey 226 consecutive patients undergoing elective non-oncological otolaryngology procedures at a District General Hospital between May and August 2004

Results

Overall patients were moderately satisfied with the information they received prior to surgery (score 63/100). Although they were generally satisfied with the quality of information they received at their outpatient consultation and at the preadmission clinic, they were less satisfied with the quality of information provided by their GPs and by the quality of self – obtained information. Most importantly, linear regression modeling showed that the overall level of information could be predicted by three factors: The quality of written information received at the hospital, the quality of self-obtained information and the information provided by the specialist at the time of listing for surgery. While patient's education level was correlated with the information process, the age and gender of the patient as well as the grade of the doctor at the outpatients were not associated with his overall levels of satisfaction.

Conclusion

Although the impact of the initial outpatient consultation for patients undergoing elective surgery can not be over emphasized, written information provided at the hospital as well as patient – initiated, parallel information pathways are at least as important: It is our duty to recognize them and use them for the patient's advantage.     

Olfactory bulb volume and olfactory function after radiotherapy in patients with nasopharyngeal cancer

Objective

Radiotherapy is the primary method of treatment for nasopharyngeal cancer (NPC) and many side effects were reported in patients receiving radiation to this area. This study was conducted to evaluate the long-term effects of radiotherapy following NPC on olfactory bulb (OB) volume and olfactory function.

Methods

Twenty-four patients with NPC who received radiotherapy at least 12 months ago were recruited. Fourteen healthy subjects with similar demographical characteristics were recruited as the healthy control group. All volunteers were subjected to a nasoendoscopical examination, and abnormalities that could potentially cause olfactory dysfunction were the exclusion criteria from the study. An experienced radiologist segmented the MRI coronal, axial and sagittal slices manually for three-dimensional OB volume measurement in a blinded manner. Olfactory function was assessed using the Connecticut Chemosensory Clinical Research Center (CCCRC) test, and average score (0: worst, 7: best) was calculated as the total CCCRC olfactory score.

Results

The mean CCCRC score was 5.5 ± 1.1 for the nasopharyngeal cancer patients, whereas the mean score of healthy control group was 6.4 ± 0.4. There was a significant difference in the olfactory scores (p = 0.003). The mean OB volume in the NPC group was 46.7 ± 12.1 mm³. Among the patients with NPC, the cisplatin receiving group had a mean OB volume of 47.2 mm³, whereas the cisplatin + docetaxel receiving group had a mean OB volume of 46.5 mm³, and they were similar. The MRI measurement of the healthy control group was 58.6 ± 13.8 mm³. The OB volumes of the healthy control group were significantly higher (p < 0.05).

Conclusion

Radiotherapy following nasopharyngeal cancer results in a diminished OB volume and deteriorated olfactory function. Chemosensory olfactory dysfunction might be a contributing factor to lack of appetite, cancer cachexia and consequent lowered quality of life in NPC patients.