Deterioration of Olfaction and Gustation As a Consequence of Total Laryngectomy

Introdution: After total laryngectomy the absence of a nasal airflow results in a decrease in olfaction and perception of flavors. Materials and Methods: Odor perception was assessed in 63 laryngectomized patients with two different olfactory tests. The methods used by patients to smell were observed during olfactory testing. Patients' judgment about their olfaction and gustation was assessed by means of a structured questionnaire, semistructured interview, and self-rating. Results: Based on the results of the olfactory tests, patients were categorized as “smellers” and “nonsmellers.” Approximately one third of the patients were able to smell the odorous substances used in the olfactory tests. The smellers more often used a variety of methods to smell than the nonsmellers (P > .002); in most patients the method consisted of active use of facial muscles. Patients appeared well able to judge their own odor perception. Compared with the smellers, the nonsmellers judged their odor perception as worse (P > .003) and reported a more severe decrease in gustation after the operation (P > .033). The results of this study in laryngectomized patients confirm the interrelation between olfaction and gustation: the nonsmellers reported a poorer gustation and a more severe decrease in gustation and appetite than both the smellers and a reference group of elderly persons (P > .05). Patients who reported a deterioration of olfaction and gustation tended to experience negative consequences such as the inability to smell smoke, leaking gas, or agreeable odors. Conclusion: Olfaction and odor-related flavor sensation are seriously deteriorated after total laryngectomy.     

Clinical usefulness of smell identification test card: Open Essence

Since the Odor Stick Identification Test for Japanese (OSIT-J) has proved clinically useful in Japan, the Open Essence (OE) smell identification test card has been developed to amend OSIT-J deficits. To determine its clinical effectiveness, we administered the OE to 93 Japanese subjects reporting olfactory dysfunction. They scored their olfactory dysfunction on levels one to five, i.e., normal to anosmic, using the Japan Rhinologic Society Self-Administered Odor Questionnaire (SAOQ) and the visual analog scale (VAS). They also took the Japanese standard olfactory test (T & T olfactometry) and intravenous olfactometry (Alinamin test). Opinions on the OE and OSIT-J were recorded from those previously administered the OSIT-J and testers familiar with OSIT-J administration. The OE took 5.1+/- 1.6 minutes to administer. Scores correlated significantly for the OE, self-reported olfactory function, SAOQ, VAS, T & T olfactometry recognition threshold, and Alinamin latency and duration time. Subjects and testers reported the OE to be easier, shorter, more interesting, and more convenient, indicating its utility in clinical olfactory dysfunction evaluation and its convenience for both subjects and testers.     

Retronasal and orthonasal olfactory ability after laryngectomy

OBJECTIVE: To characterize orthonasal and retronasal olfactory ability in patients who have had a total laryngectomy (TL). DESIGN: Prospective psychophysical evaluation of orthonasal and retronasal olfactory function. SETTING: Academic center outpatient clinic. PATIENTS: Volunteer sample of 36 subjects who underwent laryngectomy 0.5 to 25.0 years after TL (median, 3.5 years) and 36 age-, sex-, and smoking history-matched controls. MAIN OUTCOME MEASURES: Scores on established psychophysical tests of orthonasal and retronasal olfaction and self-rating scores of smell assessed with a visual analog scale. RESULTS: Assessment of orthonasal olfactory ability yielded a mean composite score of 4.3 (maximum score, 7) for the TL group and 5.3 for the control group (P = .002). Evaluation of retronasal olfactory ability resulted in a mean score of 11.0 (maximum score, 20) for the TL group vs 14.3 for the control group (P<.001). The mean self-rating scores of smell were 2.9 and 6.6 (maximum score, 10) for the TL and control groups, respectively (P<.001). Self-ratings of smell positively correlated with orthonasal (r(S) = 0.42; P<.001) and retronasal (r(S) = 0.50; P<.001) olfactory ability. CONCLUSIONS: Laryngectomy is associated with measurable decreases in olfactory function that are also subjectively perceived. Quantification of decrements in orthonasal and retronasal olfactory function can be used to characterize the severity of hyposmia and to assess the potential for, and efficacy of, olfactory rehabilitation. Although self-assessment with a simple visual analog scale successfully identifies many laryngectomy patients who have objective evidence of olfactory dysfunction, further investigation is necessary to evaluate and compare its validity and reliability with other available survey instruments that purport to measure olfaction.     

Usability of intravenous thiamine injection test compared with odor stick identification test for Japanese patients with severe traumatic brain injury

ObjectiveOlfactory dysfunction is often observed after severe traumatic brain injury (sTBI). Its diagnosis is difficult because patients with sTBI have a communication disability following impaired consciousness and communication disorder. The intravenous thiamine injection (IT) test is one of the representative diagnostic examinations to identify dysfunction, and it is often used in medical certification for liability insurance of automobiles in Japan because it could be judged by a simple reaction. However, the extent of usefulness of the IT test in the diagnosis of olfactory dysfunction in patients with sTBI is unknown. In this study, we validated the usability of the IT test and compared the results with those of the odor stick identification test for the Japanese (OSIT-J) to evaluate the sensitivity of the IT test in patients with sTBI.MethodsThe study enrolled 205 subjects, including 10 healthy volunteers and 195 patients with sTBI. First, we examined olfactory dysfunction in sTBI patients using OSIT-J. Subsequently, we performed the IT test among patients with olfactory dysfunction.ResultsIn the first part, 41 subjects, including 10 healthy volunteers, were examined by using the OSIT-J test. As a result, 28 patients were diagnosed with olfactory dysfunction (90.3%, p < 0.0001), including anosmia and parosmia, compared with healthy volunteers. Among the 12 odors, garlic odor was easily recognized for patients with olfactory dysfunction. As a consequence of the IT test for 11 patients with olfactory dysfunction, four patients recognized thiamine odor, and seven patients did not. All four patients could recognize the garlic odor of OSIT-J, but 2 of the seven patients could recognize the garlic odor of OSIT-J, suggesting that the thiamine odor is linked to garlic odor (p = 0.046), but not always. The detection rate of olfactory dysfunction through the IT test was 36.4%.ConclusionOur data showed that garlic odor, which is similar to thiamine odor, was easily recognizable for patients with sTBI. However, the IT test might overlook the diagnosis of olfactory dysfunction because it only identifies one odor. In addition, thiamine frequently induces angialgia. We should pay attention to the overconfidence of the IT test for patients with sTBI.     

Potential oscillation elicited by i.v. olfaction and its applicability as an objective clinical olfaction test

OBJECTIVE: Alinamin has long been applied in Japan for testing i.v. olfaction and to diagnose olfactory disorders. The test is subjective, each subject being asked about the presence or absence of olfaction. The credibility of the answers is highly questionable in some cases; as a result, the reliability of the test is poor. Recent studies demonstrated an induced electric potential in the scalp during i.v. olfactory testing. Some patients complain of the pain of the injection during i.v. olfactory testing; therefore, the effect of this pain must be considered with respect to measurement of the i.v. olfaction-elicited potential (IVOP). MATERIAL AND METHODS: This investigation involved 179 subjects with various olfaction levels. Each subject received an Alinamin injection; the elicited potential amplitude was compared before and after the injection and the increasing ratio (IR) was computed. Gender, age, level of olfactory disorder, the presence or absence of olfaction and the presence or absence of the pain of injection were considered as factors affecting IR. RESULTS: IR showed significant increases in groups characterized by the presence of olfaction as well as in groups reporting pain of injection. The test subjects were further divided into four groups based on their olfaction and pain of injection patterns as follows: Group A, no smell and no pain; Group B, smell and no pain; Group C, no smell and pain; and Group D, smell and pain. Subjects exhibiting no recognizable olfaction or pain of injection (Group A) revealed no increase in IVOP following injection. Subjects with either recognizable olfaction or pain of injection (Groups B and C) exhibited a slight increase in IVOP following injection. Subjects with both noticeable olfaction and pain of injection (Group D) demonstrated a significant increase in IVOP following the injection with a very high value of IR (>2). Furthermore, there were significant differences between the four groups in terms of IR level, with the exception of Groups B and C. CONCLUSIONS: Olfaction is largely involved with the generation of IVOP. However, pain resulting from injection of Alinamin is considered to be a significant factor. IVOP showed significant effectiveness for diagnosing olfactory disorders in cases who did not experience pain of injection.     

Self-ratings of olfactory function reflect odor annoyance rather than olfactory acuity

Objective/Hypothesis: Self‐ratings of olfactory function often correlates poorly with results of objective smell tests. We explored these ratings relative to self‐rating of odor annoyance, to odor identification ability, and to mean perceived intensity of odors, and estimated relative genetic and environmental contributions to these traits. Participants and Methods: A total of 1,311 individual twins from the general population (62% females and 38% males, aged 10–83 years, mean age 29 years) including 191 monozygous and 343 dizygous complete twin pairs from Australia, Denmark, Finland, and the United Kingdom rated their sense of smell and annoyance caused by ambient smells (e.g., smells of foods) using seven categories, and performed odor identification and evaluation task for six scratch‐and‐sniff odor stimuli. Results: The self‐rating of olfactory function correlated with the self‐rating of odor annoyance (r = 0.30) but neither correlated with the odor identification score. Quantitative genetic modeling revealed no unambiguously significant genetic contribution to variation in any of the studied traits. Conclusion: The results suggest that environmental rather than genetic factors modify the self‐rating of olfactory function and support earlier findings of discrepancy between subjective and objective measures of olfactory function. In addition, the results imply that the self‐rating of olfactory function arises from experienced odor annoyance rather than from actual olfactory acuity.     

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.     

A case report on congenital anosmia

We report 2 cases of congenital anosmia, in a 13-year-old girl and the other in a 10-year-old boy. They reported having no concept of "smell". The girl has no complications but the boy has congenital microphthalmia and is completely blind. They showed scale-out results on both T & T olfactometry and intravenous Alinamin test. Brain MRI detected hypoplasia or lack of the olfactory bulbs, tracts, and olfactory sulci in the frontal lobe of the brain in both patients. Neither had endocrinal dysfunction. In the boy, we biopsied the nasal mucosa in the olfactory cleft and found it had no olfactory epithelial cells at all. We found MRI to be the most useful imaging for diagnosing congenital olfactory disturbance.     

Comparison of open essence scent identification test card and conventional olfaction tests

Japan's medical insurance covers only the intravenous olfaction test, which is invasive and painful, and the T&T olfactometry recognition threshold test, which is not commonly used. The alternative open essence (OE) test recently developed and has shown clinical utility. Using a cross-over technique, we compared the OE test to other olfaction tests, administering it to 122 Japanese subjects diagnosed with olfactory dysfunction. Subjects scored olfactory function using the visual analog scale (VAS) and the Japan Rhinologic Society Self-Administered Odor Questionnaire (SAOQ). They also took the Japanese standard olfactory test (T&T olfactometry) and intravenous olfactometry (Alinamin test). Statistically significant correlations were seen among scores, the OE, SAOQ, VAS, T&T olfactometry recognition threshold, and Alinamin test, further indicating the OE test's clinical olfactory function evaluation. Menthol should, however, be eliminated from the OE formulation lineup due to its strong carry-over effect.     

Smell and taste in drug addicts

The main objective of this study was to establish the degree of influence of various illicit drugs, taken into the body in different ways, on the senses of smell and taste. Other possible factors, that might have caused disturbances in normal functioning of both senses, were outlined. The studied group consisted of 48 drug addicts, between the age of 16 and 48 years, addicted to various illicit drugs for several years. Olfactory testing included two methods. First quantitative method described by Elsberg and Levy, modified by Pruszewicz, was used to establish the smell detection threshold. Then the University of Pennsylvania Smell Identification Test was used as a method for odor identification. The sense of taste was tested with the use of method described by Krarup and modified by Pruszewicz. The results showed disturbances in olfactory performance (combined in both method) in 52.1% of all drug abusers, and 16.7% of them were diagnosed with ageusia when the sense of taste was tested. The route of administration of illicit drugs proved to be a statistically significant factor that might have caused disturbances of smell perception and identification in the study group. Drug abusers who were taking drugs intravenously and those who smoked and inhaled various drugs had the most significant olfactory problems. Both means for assessing smell function were statistically compared and the results showed that approximately 75% of drug users with olfactory disturbances had olfactory problems in both tests.     

Estimation of smell sense rehabilitation in patients after total laryngectomy

The loss of sense of smell significantly decreases a quality of life after total laryngectomy. That is why this problem should be considered within a complex rehabilitation of laryngectomized patients. The smell exercises ought to start parallely to the speech rehabilitation. The aim of our study was to estimate the efficacy of smell rehabilitation after total laryngectomy. 59 persons after total laryngectomy attending the fourteen days long rehabilitation camp were examined. All the patients had the examination of three smells identification (lemon, mint and anise) made before the beginning of exercises. All the persons had also the efficacy of air aspiration through the nose measured. The control examination of those parameters was conducted after fourteen days of exercises of making the negative pressure in the throat and nasopharynx directing the air flow into the olfactory area of the nose. We confirmed a statistically significant differences between the smell identification and the force of aspiration before and after rehabilitation. We confirmed that patient's age and the time from laryngectomy have the influence into the efficacy of smell rehabilitation.     

Olfactory changes at threshold and suprathreshold levels following septoplasty with partial inferior turbinectomy

Partial inferior turbinectomy with septoplasty is routinely carried out for airway obstruction. However, its effects on the sense of smell have not been systematically evaluated. The aim of this prospective study was to evaluate the influence of septoplasty with partial inferior turbinectomy on threshold and suprathreshold olfactory acuity. The subjects were 30 patients undergoing septoplasty including partial inferior turbinectomy. Olfactory function was determined by the "Sniffin' Sticks," which allow the assessment of odor thresholds, odor discrimination, and odor identification. The patients rated both olfactory function and nasal airflow using visual analog scales. Nasal airflow was measured by anterior rhinomanometry. Multivariate analyses of variance for repeated measures were used to analyze the results before and after surgery (mean interval, 9.1 weeks). After operation, 87% of the patients had increased airflow, 80% had improved olfactory function in terms of odor identification, and in 70% odor discrimination was found to be improved - but only 54% had improved olfactory function in terms of odor thresholds. Surgery increased ratings of nasal airflow in 93%, and those of olfactory function in 77% (p < .001). Similarly, bilateral inspiratory nasal flow increased (p < .001) and olfactory function was improved (p < .001) after surgical treatment. However, this increase was most pronounced for suprathreshold tests, while it was moderate for odor thresholds (interaction "surgery" x "olfactory test," p = .001). The present investigation suggests that septoplasty in combination with inferior turbinectomy has a beneficial effect on olfaction, mainly on suprathreshold olfactory functions. This effect may be partly due to interactions between the increased perception of nasal airflow and cognitive factors involved in olfactory sensitivity. According to the present results and data from the literature, a moderate decrease of olfactory function appears to occur in as many as 20% of patients. However, anosmia seems to be an extremely rare complication of septoplasty and partial turbinectomy.     

The effect of human olfactory biopsy on olfaction: A preliminary report

Normal human olfactory function is subject to a wide variety of factors. Although biopsy of human olfactory neuroepithelium has been reported by several researchers, there are no studies which have evaluated the effect of this procedure on olfactory function. In this retrospective study, we sought to determine if tissue removal from the olfactory cleft has an adverse influence on the sense of smell. Nineteen subjects underwent bilateral olfactory testing and subsequent endoscopic olfactory mucosal biopsy. All subjects were retested 6 weeks to 1 year after olfactory neuroepithelial biopsy. No statistical difference was found between olfactory tests performed before or after biopsy. These data suggest that biopsy of human olfactory neuroepithelium has no discernible adverse effect on the ability to smell.     

Changes of pressure and humidity affect olfactory function

The present study aimed at investigating the question whether olfactory function changes in relation to barometric pressure and humidity. Using climate chambers, odor threshold and discrimination for butanol were tested in 75 healthy volunteers under hypobaric and hyperbaric, and different humidity conditions. Among other effects, olfactory sensitivity at threshold level, but not suprathreshold odor discrimination, was impaired in a hypobaric compared to a hyperbaric milieu, and thresholds were lower in humid, compared to relatively dry conditions. In conclusion, environmental conditions modulate the sense of smell, and may, consecutively, influence results from olfactory tests.     

Olfactory mucosa histological findings in laryngectomees

After total laryngectomy, the patients often report immediate and marked olfactory deficit. The aim of this study was to determine whether hyposmia in laryngectomees reflects olfactory epithelial damage. Ten laryngectomized patients and ten rhinologically normal subjects were subjected to olfactory testing, after which histological examination of biopsied olfactory mucosa was performed. Olfactory testing in laryngectomees revealed a marked reduction in odor perception. Histological examination of olfactory mucosa specimens showed that in laryngectomees some neuroepithelial structural features were comparable with those found in normal subjects. However, additional signs of damage were also observed, consisting mainly of various degrees of epithelial degeneration, above and beyond those that are characteristic of physiological epithelium turnover. These different degenerative features consisted of severe damage to the neuroepithelium, culminating in complete topical loss. Bowman's glands were also observed to be involved in the degenerative process. Laryngectomy-induced hyposmia seems to be correlated with the almost complete loss of nasal airflow due to the disconnection between the upper and lower airways, which prevents odor molecules from reaching the olfactory area, together with degenerative phenomena, which affect the neuroepithelium, and consequent failure in neurosensorial performance.     

Clinical significance of results from olfactory testing

BACKGROUND: Although widely used in healthy subjects and patients with olfactory loss, the significance of changes of scores from validated olfactory tests is unknown. AIM AND METHODS: The aim of the present study was to relate the self-assigned changes of olfactory function in terms of "better," "unchanged," and "worse" in patients with smell disorders with the results from olfactory testing by means of a validated test set. Olfactory function of 83 anosmic or hyposmic patients (40 women, 43 men; age 12-84 yr) was tested on two occasions (mean interval 136 days, minimum 7 days, maximum 6.7 yr). Olfactory function was assessed using a validated technique ("Sniffin' Sticks"). This test consists of three subtests, one for odor threshold (T), odor discrimination (D), and odor identification (I), with possible results ranging up to 16 points each. From the sum of the results from the three subtests a composite "TDI" score was obtained. RESULTS: Forty-four patients indicated an improvement of olfactory function, whereas 39 patients reported no change. No subject reported deterioration of olfactory sensitivity. Subjects assigned to group BETTER had higher TDI scores in the second olfactory tests than subjects assigned to the group UNCHANGED, both in absolute terms and as compared with the first olfactory test (effect "test occasion" by "self-assessed improvement," P < .001). There was no significant difference between groups with respect to age and sex (P = .99 and .84, respectively). Logistic regression showed that more than 60% of the subjects reported an improvement of olfactory sensitivity when the TDI score increased by 5.5 points. CONCLUSION: We show that there is a statistically significant relation between measured and perceived improvement of olfactory function in patients who first presented with the diagnosis of anosmia or hyposmia. The results indicate that improved olfactory function in patients with olfactory deficiency is perceived as such in everyday life and is quantitatively related to an improvement in the composite TDI score of the "Sniffin' Sticks" olfactory test battery. This is the basis for the application of a specific therapy for olfactory loss because of a possible gain in quality of life for the patients.     

Rehabilitation of olfaction after laryngectomy by means of a nasal airflow-inducing maneuver: the "polite yawning" technique

OBJECTIVE: To develop a nasal airflow-inducing maneuver and apply it in the olfactory rehabilitation of patients who have undergone laryngectomy. DESIGN: Intervention study; before-and-after trial. SETTING: National cancer center. PATIENTS: Forty-four patients who underwent laryngectomy; 34 men and 10 women; mean age, 64 years (range, 42-80 years); mean time since surgery, 6 years (range, 8 months to 18 years). INTERVENTION: In a prospective clinical intervention study, we assessed the effectiveness of a nasal airflow-inducing maneuver ("polite yawning," ie, yawning with closed lips). Speech therapists trained the patients in the maneuver, and its effectiveness in inducing nasal airflow was checked with digital and water manometers. MAIN OUTCOME MEASURES: Olfactory acuity was assessed before and after the intervention by means of an odor detection test and a structured questionnaire concerning olfaction, taste, and appetite. Patients were categorized as "smellers" and "nonsmellers" on the basis of the results of the odor detection test and the present odor perception scale derived from the questionnaire. RESULTS: The nasal airflow-inducing maneuver could be taught to all patients, mostly in only one 30-minute therapy session. Fifteen of the 33 patients in the pretreatment nonsmeller category converted to smellers, for a success rate of 46% (P<.001). CONCLUSION: The nasal airflow-inducing maneuver (the "polite yawning" technique) allowed almost half of the patients to recover their sense of smell.     

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.     

Long-term results of olfaction rehabilitation using the nasal airflow-inducing ("polite yawning") maneuver after total laryngectomy

OBJECTIVES: To study the long-term results of the nasal airflow-inducing maneuver (NAIM) as an olfaction rehabilitation tool after laryngectomy and to investigate the effectiveness of a new, simpler odor detection test (ODT) called the smell disk test (SDT), or Zürcher Geruchstest. DESIGN: Intervention study. SETTINGS: National cancer center. PATIENTS: Forty-one laryngectomees who received olfaction rehabilitation training with the NAIM 4 months to 2 years earlier. This so-called polite yawning maneuver creates an "underpressure" in the oral cavity, which, in turn, generates a nasal airflow that enables odor molecules to again reach the olfactory epithelium. MAIN OUTCOME MEASURES: Olfaction acuity testing with a standard ODT, along with a questionnaire, providing a subjective olfaction score (present odor perception scale [POPS]), and the SDT, as well as assessment of the patients' correct execution of the NAIM by speech-language pathologists on video recordings made during odor testing and long-term assessment of olfaction acuity. RESULTS: The correlation between the previously used ODT-POPS combination and the SDT was kappa = 0.56 (P<.001). Based on these results, we preferred to use the much simpler SDT instead of the laborious combination of the ODT-POPS. Based on the SDT results, 19 (46%) of the 41 laryngectomees were "smellers" and could be considered normosmic. There was a significant relationship (P =.03) between the patient's correct execution of the NAIM and whether or not the laryngectomee was a smeller according to the SDT. CONCLUSIONS: The effectiveness of the NAIM, or so-called polite yawning technique, for the rehabilitation of olfaction in individuals who have undergone total laryngectomy was reconfirmed. Long-term olfaction rehabilitation was achieved in about 50% of the patients, but more intensified training may be needed to increase the percentage of successfully rehabilitated individuals. The SDT is an effective and simple test for the assessment of olfaction acuity after laryngectomy.     

A study on the frequency of olfactory dysfunction

OBJECTIVES/HYPOTHESIS: Goals of the study were to evaluate the frequency of olfactory dysfunction in a large representative population without sinonasal complaints and to investigate the extent to which general pathological conditions, medications, and aging influence olfaction. STUDY DESIGN: Prospective. METHODS: Results based on an odor identification test ("Sniffin' Sticks") were reported from 1240 subjects. The subjects presented themselves to an otorhinolaryngology outpatient clinic with relatively mild and transitory complaints unrelated to the upper airways. A detailed otorhinolaryngological examination in combination with a standardized interview further ascertained that these patients had no rhinological problems or symptoms relating to sinonasal disease. RESULTS: Apart from the confirmation of the effects of age, gender, and certain otorhinolaryngological diseases on the sense of smell, the study results revealed that certain general diseases (liver diseases, nonotolaryngological cancers) appear to influence olfactory function, whereas other diseases or disorders have little or no impact on olfaction (hypertension, cardiovascular problems). CONCLUSION: The data in the study revealed that olfactory dysfunction among subjects under 65 years of age is more frequent than previously reported.