Recording of the human electro-olfactogram

Electro-olfactograms (EOG) are electrical potentials of the olfactory epithelium that occur in response to olfactory stimulation. The EOG represents the sum of generator potentials of olfactory receptor neurons. While this response has been used extensively in animal research, there are only a handful of papers describing the properties of the human EOG. In addition to a discussion of methodological issues related to the EOG, this review summarizes the characteristics and uses of these recordings. Among other results, EOGs have been used to provide evidence for the dominant role of the central nervous system in olfactory desensitization, for the functional characterization of the olfactory epithelium, the specific topographical distribution of olfactory receptors, or the expression of olfactory receptor neurons in response to exposure to odorants, and the characterization of certain odorants as olfactory receptor antagonists. In conclusion, in combination with nasal endoscopy and air-dilution olfactometry, the EOG is a unique part of a large array of techniques used to provide a complete picture of the processing of olfactory information in humans.     

Sex differences in cognitive and symptom profiles in children with high functioning autism spectrum disorders

Although a small number of studies have investigated sex differences in the associated features of high-functioning autism spectrum disorders (HFASDs), they have failed to provide consistent findings. We sought to examine sex differences in 5–9-year-old females and males with HFASDs within a narrow range of ages before adolescence in order to identify the noticeable autistic profile of females compared to males. Using the Japanese version of the Wechsler Intelligence Scale for Children-Third Edition (WISC-III) and the Childhood Autism Rating Scale-Tokyo Version (CARS-TV), 20 females with HFASDs were compared with 26 males with HFASDs. Although females and males with HFASDs share similar cognitive profiles in WISC-III, females demonstrated a different symptom profile from males in CARS-TV. Although the female subjects scored significantly lower than the male subjects on “Body Use,” “Object Use,” and “Activity Level,” female subjects scored significantly higher than males on “Taste, Smell, and Touch Response and Use” in the CARS-TV. This finding can be useful for the early identification of females with HFASDs who have typically been underdiagnosed. Future research should focus on elucidating the possible behavioral, neurological, and genetic links to these sex differences.     

药物治疗慢性鼻-鼻窦炎嗅觉障碍的疗效观察

目的 观察药物治疗慢性鼻-鼻窦炎嗅觉障碍的疗效。方法 对本院2006年1月～2008年8月26例慢性鼻-鼻窦炎（不伴鼻息肉）嗅觉障碍患者进行回顾性分析。减充血剂、抗炎、抗感染、黏液促排药物治疗20例,在此基础上给予全身激素及营养神经治疗5例,全身激素、营养神经及抗病毒治疗1例。治疗前后行嗅觉测试、鼻窦CT和鼻内镜检查。结果 本组26患者中24例治愈,治愈率92.00％,平均治疗时间25.64d。结论 以嗅觉障碍为主诉的慢性鼻-鼻窦炎,根据病因,选择正确的治疗方案,可获满意治疗效果。     

The influence of narcolepsy on olfactory function: a review

IntroductionNarcolepsy is a sleep disorder associated with loss of hypocretin cells characterized by irrepressible need to sleep, often accompanied by cataplexy, sleep fragmentation, hypnagogical and hypnopompic hallucinations, and sleep paralysis. It is also correlated with alterations in the sleep–wake cycle, dysautonomia, olfactory dysfunction, and eating disorders.MethodsThis is a review about influence of narcolepsy on human olfaction. Pubmed, Embase, Ovid and Cochrane databases were searched for articles on the evaluation of olfactory function in narcoleptic patients including terms as narcolepsy, olfaction disorder, amongst others.ResultsSeven articles met the inclusion criteria. In five of them, the olfaction of narcoleptic patients was diminished in comparison with healthy control groups. The diagnosis of narcolepsy relates to worse performance in olfactory tests.Experimental researches showed that hypocretin and hypocretin receptors are present in the olfactory system, and this neuropeptide may have a role on olfactory sensitivity and on the olfactory modulation. The cause of hyposmia appears to be multifactorial. Among them, it stands out the hypocretin deficiency, therefore, that seems to be involved in the olfactory impairment in narcoleptic patients.     

Effects of smell loss (hyposmia) on salt usage

ObjectiveSmell loss (hyposmia) inhibits flavor perception and influences food intake. To compensate for flavor loss, some patients with hyposmia appear to increase salt usage. The purpose of this study was to compare self-reported salt usage in patients with hyposmia with that in normal volunteers.MethodsSalt usage was compared in 56 patients with hyposmia but with normal taste function with that in 27 normal volunteers. Salt usage was formulated with respect to 1) a standard quantitative salt intake scale, 2) salt addition related to food intake, 3) intake of foods and beverages with high salt content, and 4) salt intake related to presence or absence of hypertension.ResultsEighteen (32%) of the 56 patients self-reported increased salt usage; they were labeled “increased users.” The other 38 hyposmic patients (68%) did not report increased salt usage; they were labeled “non-changers.” Increased users estimated their salt usage rose an average 2.8 times that experienced before their hyposmia onset. They also reported adding salt to their food before tasting it and ate more highly salted foods than did the non-changers. Salt usage was not increased further among increased users with hypertension but was increased further among non-changers with hypertension.ConclusionsSalt usage is increased among some patients with hyposmia presumably to enhance flavor perception to compensate for diminished flavor perception related to loss of smell.     

Olfactory Dysfunction and Olfactory Bulb Volume Reduction in Patients with Leprosy

To ascertain the level and rate of olfactory dysfunction in patients with leprosy and to determine whether olfactory bulb volume is affected by the pathophysiology. Olfactory bulb (OB) volume, measured using magnetic resonance imaging (MRI), was compared in 15 patients with leprosy and 15 healthy controls. All of the participants were evaluated using a detailed history to identify the probable causes of the smell dysfunction. Those who had a disease other than leprosy that may have caused the smell dysfunction were excluded from the study. OB volumes were calculated by manually tracing the OB on coronal sections. Orthonasal olfaction testing was used to assess smell function. The orthonasal olfaction testing indicated that all patients with leprosy were anosmic or severely hyposmic. The smell function test indicated that the OB volume of the patient group was significantly lower than that of the control group. No within-group difference was detected between right and left OB volume in either group. The patients in the leprosy group were severely hyposmic or anosmic and their olfactory bulb volume was significantly lower than that of the control group. To our knowledge, this study is the first to show a reduction in olfactory bulb volume among leprosy patients.     

Sniffin' Sticks嗅觉心理物理测试方法的临床应用

目的 建立Sniffin' Sticks检查的中国人正常参考值,探讨其在我国临床应用的可行性.方法 2007年至2013年于首都医科大学附属北京同仁医院体检科,任意选取健康志愿者105例作为健康对照组,任意选取同期该院耳鼻咽喉头颈外科门诊嗅觉障碍患者165例作为试验组,其中嗅觉功能减退组92例,嗅觉功能丧失组73例.对270例受试者又分别分为青年组(＜ 35岁)、中年组(～55岁)和老年组(＞55岁)3个亚组,分别采用Sniffin' Sticks和T&T方法进行嗅觉功能检查.以SPSS12.0统计软件对数据结果进行分析.结果 Sniffin' Sticks正常参考值是:青年组TDI值(气味阈值T、气味辨别阈值D和气味识别阈值I,三项得分之和)＞30.12,中年组TDI值＞27.37,老年组TDI值＞20.43;健康对照组TDI平均((x-)±s)值为32.12±3.95,嗅觉功能减退组TDI平均值17.52±10.37,嗅觉功能丧失组TDI平均值3.56±3.49.嗅觉功能减退和嗅觉功能丧失组和健康对照组按照青年、中年和老年各亚组分别比较,TDI值、阈值、辨别阈和识别阈差异均有统计学意义(青年组:FTDI=125.136,FT=49.454,FD=89.037,FI=39.888,P值均为0.000;中年组:FTDI=190.240,FT=128.374,FD=174.122,FI=178.945,P值均为0.000;老年组:FTDI=72.992,FT=26.599,FD=77.119,FI=88.107,P值均为0.000).T&T嗅觉识别阈结果显示,健康对照组平均值为-1.00±0.98,嗅觉功能减退组为2.27 ±2.01,嗅觉功能丧失组为5.89±0.14.嗅觉功能减退和丧失组与健康对照组按照青年、中年和老年各亚组分组比较差异均有统计学意义(F青年=158.144,F中年=247.695,F老年=70.579,P值均为0.000).Sniffin' Sticks检查结果中的TDI值与T＆T嗅觉识别阈值呈负相关(r=-0.927,P＜0.01).T&T识别阈值与Sniffin' Sticks阈值呈负相关(rT=-0.846,P＜0.01);与辨别阈呈负相关(rD=-0.908,P＜0.01);与识别阈呈负相关(rI=-0.864,P＜0.01).结论 Sniffin' Sticks嗅觉检测方法均能很好地区分嗅觉功能正常、减退和丧失,其测试结果与T&T测试存在一致性,Sniffin' Sticks方法能多方面评价受试者的嗅觉功能状态,可以在中国人群中使用.