Olfactory dysfunction in chronic stroke patients.

BACKGROUND: The aim of the study was to investigate odor identification performance in patients one year after hospital admittance due to stroke. Predictors for olfactory dysfunction were investigated as well as self-reported olfactory function and pleasantness of olfactory items. METHODS: A 1-year prospective study was performed. Stroke location, classification and comorbidities were registered at hospital admission. One year after admission, olfactory function was assessed using standardized olfactory methods (screening for loss of detection sensitivity and an odor identification test). A group of matched controls was derived from a population-based study to compare odor identification performance between groups. Patients were asked for their personal judgment regarding their olfactory function and pleasantness of odorous items. In addition, global cognitive function and symptoms of depression were assessed. RESULTS: A total of 78 patients were enrolled (46 males, 32 females; mean age 68 years) of which 28.2% exhibited reduced olfactory function (hyposmia) and 15.4% exhibited loss of olfactory function (10.3% functional anosmia, 5.1% complete anosmia). Patients showed significantly lower olfactory performance compared to age- and sex-mated matched controls. Predictors of impaired olfactory function were age and NIHSS score. Self-reports indicated no significant differences between patients with normal olfactory function and those with reduced function. Yet, patients having an olfactory dysfunction rated odorous items as significantly less pleasant compared to patients without dysfunction. CONCLUSIONS: Olfactory dysfunction seems to occur frequently after stoke even one year after initial admission. The deficits seem to relate to hyposmia and functional anosmia, and less to a complete loss of smell sensitivity.

Even cognitively well-functioning adults are unaware of their olfactory dysfunction: Implications for ENT clinicians and researchers.

BACKGROUND: Past findings of an impact of cognitive impairment on awareness of olfactory dysfunction, and high prevalence of age-associated cognitive impairment motivated the present study of whether middle-aged and elderly adults are unaware of an olfactory dysfunction despite being carefully screened for cognitive impairment. METHODOLOGY: The sample included 203 Norwegian participants, aged 46-79 years, 134 women and 69 men, who underwent comprehensive neuropsychological assessment for screening of cognitive impairment. Subjective assessment of olfactory function ("How would you estimate your sense of smell?") was compared with outcome on objective assessment of olfactory function with the Scandinavian Odor Identification Test, which in the present study was shown to be valid for use on Norwegian populations. RESULTS: We found that 79% of this cognitively healthy sample with objectively assessed olfactory dysfunction reported normal olfactory function (57% of functionally anosmics reported normal function). In contrast, only 9% with objectively assessed normal olfactory function reported olfactory dysfunction. CONCLUSION: A large proportion of cognitively well-functioning middle-aged and elderly adults with an olfactory dysfunction are unaware of their dysfunction. The ENT physician who suspects that the sense of smell may be compromised should, in addition to an anamnesis, assess the patient`s olfactory function objectively.

Chemosensory interaction: acquired olfactory impairment is associated with decreased taste function.

Olfaction, taste and trigeminal function are three distinct modalities. However, in daily life they are often activated concomitantly. In health and disease, it has been shown that in two of these senses, the trigeminal and olfactory senses, modification of one sense leads to changes in the other sense and vice versa. The objective of the study was to investigate whether and (if so) how, the third modality, taste, is influenced by olfactory impairment. We tested 210 subjects with normal (n = 107) or impaired (n = 103) olfactory function for their taste identification capacities. Validated tests were used for olfactory and gustatory testing (Sniffin' Sticks, Taste Strips). In an additional experiment, healthy volunteers underwent reversible olfactory cleft obstruction to investigate short-time changes of gustatory function after olfactory alteration. Mean gustatory identification (taste strip score) for the subjects with impaired olfaction was 19.4 +/- 0.6 points and 22.9 +/- 0.5 points for those with normal olfactory function (t = 4.6, p < 0.001). The frequencies of both, smell and taste impairments interacted significantly (Chi(2), F = 16.4, p < 0.001), and olfactory and gustatory function correlated (r (210) = 0.30, p < 0.001). Neither age nor olfactory impairment cause effects interfered with this olfactory-gustatory interaction. In contrast, after short-lasting induced olfactory decrease, gustatory function remained unchanged. The present study suggests that longstanding impaired olfactory function is associated with decreased gustatory function. These findings seem to extend previously described mutual chemosensory interactions also to smell and taste. It further raises the question whether chemical senses in general decrease mutually after acquired damage.

"Taste Strips" - a rapid, lateralized, gustatory bedside identification test based on impregnated filter papers.

OBJECTIVE: To elaborate normative values for a clinical psychophysical taste test ("Taste Strips"). BACKGROUND: The "Taste Strips" are a psychophysical chemical taste test. So far, no definitive normative data had been published and only a fairly small sample size has been investigated. In light of this shortcoming for this easy, reliable and quick taste testing device, we attempted to provide normative values suitable for the clinical use. SETTING: Normative value acquisition study, multicenter study. METHODS: The investigation involved 537 participants reporting a normal sense of smell and taste (318 female, 219 male, mean age 44 years, age range 18-87 years). The taste test was based on spoon-shaped filter paper strips ("Taste Strips") impregnated with the four (sweet, sour, salty, and bitter) taste qualities in four different concentrations. The strips were placed on the left or right side of the anterior third of the extended tongue, resulting in a total of 32 trials. With their tongue still extended, patients had to identify the taste from a list of four descriptors, i. e., sweet, sour, salty, and bitter (multiple forced-choice). To obtain an impression of overall gustatory function, the number of correctly identified tastes was summed up for a "taste score". RESULTS: Taste function decreased significantly with age. Women exhibited significantly higher taste scores than men which was true for all age groups. The taste score at the 10(th) percentile was selected as a cut-off value to distinguish normogeusia from hypogeusia. Results from a small series of patients with ageusia confirmed the clinical usefulness of the proposed normative values. CONCLUSION: The present data provide normative values for the "Taste Strips" based on over 500 subjects tested.

Event-related potentials in patients with olfactory loss.

CONCLUSION: The olfactory event-related potential (OERP) method provides a means of objectively assessing olfactory function. However, further validation is needed before OERPs can be routinely applied in clinical assessment of olfactory dysfunction. OBJECTIVE: To assess OERPs in patients with olfactory impairment and in healthy controls to investigate possible dose-response effects of odor concentration on OERP parameters in these groups, thereby exploring possibilities and limitations regarding the clinical utility of the OERP method. SUBJECTS AND METHODS: Twenty-three patients with a history of impaired olfactory function and 24 controls participated in the study. Olfactory function was assessed with psychophysical tests, i.e. assessment of the odor threshold, and odor identification. OERPs were obtained in response to the olfactory stimulant butanol at two different concentrations, presented via an olfactometer. RESULTS: The OERP amplitudes increased and the latencies shortened with increasing stimulus concentration. Furthermore, a difference between the groups was found, with higher OERP amplitudes and shorter latencies in healthy subjects compared with patients.

Complaints of olfactory disorders: epidemiology, assessment and clinical implications.

PURPOSE OF REVIEW: Recent studies illuminate the difficulties that patients with olfactory disorder face in daily life, which underlines the need to understand its prevalence, and to diagnose and treat these patients. The purpose of the present review is to characterize olfactory disorders and describe associated complaints, present recent insights into epidemiology, suggest procedures to assess these disorders, and discuss clinical implications. RECENT FINDINGS: A compilation of previous and new studies of olfactory disorders suggests associated complaints of poor quality of life, depression, and various specific consequences. Epidemiological studies show that loss in odor sensitivity is common in both general and clinical populations, whereas dysosmia is less common in general populations but frequent in clinical populations. The most common etiologies are post-upper respiratory infection, nasal/sinus disease and head trauma. SUMMARY: Procedures to diagnose olfactory disorders and to identify etiologies are available. Depending on etiology, certain types of treatment are often successful, such as endoscopic sinus surgery and corticosteroid administration in nasal/sinus disease. In post-upper respiratory infection and head trauma, spontaneous recovery is fairly high. In any case, it is advisable to counsel the patient with regards to strategies to cope with olfactory disorders.

Prevalence of parosmia: the Skövde population-based studies.

AIM: Parosmia can be defined as a qualitative odor distortion. Despite the consequences of this condition for quality of life, the scientific literature lacks information about the prevalence of parosmia in the general population, which was the objective of the present study. METHODS: Random samples of 1,900 adult and 401 teenage inhabitants, stratified for age and gender, were drawn from the municipal population register of Skövde, Sweden. In total, 1,713 individuals (74% of the samples) agreed to participate, of which 1,387 (73%) were adults and 326 (81%) were teenagers. They responded to a question about parosmia by means of either a structured interview (adults) or a questionnaire (teenagers). RESULTS: The overall prevalence of parosmia was 3.9% (4.0% in adults and 3.4% in teenagers), which was stable across gender, but differed somewhat between age groups, with highest prevalence in the age group 20-29 years. CONCLUSIONS: The rather high overall prevalence, 3.9%, does indeed suggest that parosmia deserves attention when attempting to better understand olfactory dysfunction in clinical settings and in the general population of both adults and teenagers.

Clinical experience with patients with olfactory complaints, and their quality of life.

CONCLUSION: A special consulting team for patients with olfactory disorders would be able to verify, describe, and explain the characteristics of the disorders, also in cases where a patient experiences a disorder, but has a normal sense of smell. OBJECTIVES: The general purpose of this paper was to present our experience with patients seeking medical attention for olfactory disorders, and to describe how quantitative and qualitative olfactory disorders are diagnosed, what the etiologies are, and how quality of life is compromised in patients with olfactory disorders. SUBJECTS AND METHODS: This investigation was performed prospectively over a 10-year period by one physician responsible for the consulting team for patients with olfactory disorders. Based on a standardized clinical examination, a structured interview, and assessment of olfactory function, its aim was to diagnose quantitative and qualitative disorders in 303 consecutive patients. Health-related quality of life was assessed with the Nottingham Health Profile (NHP) in about one-third of patients. RESULTS: In the majority of patients, a reduced sense of smell was found after testing. Often, but not always, this was combined with qualitative disorders. Dominating etiologies were infections, nasal polyposis, head trauma, and aging. Patients complaining of olfactory disorders experience a significantly reduced quality of life regarding the impact of their health problem on paid employment, household work, and social and family life.

Substance and tongue-region specific loss in basic taste-quality identification in elderly adults.

Physiological anorexia, decreased dietary variation, and weight loss associated with poor health are common conditions in the elderly population, with changes in chemosensory perception as important contributing causes. The present study of age-related taste loss aimed to investigate the question whether this loss is generalised and unspecific, or whether it exhibits differences in relation to certain tastants and/or differences in the topographical distribution of age-related loss. Impregnated "taste strips" with four concentrations of each of the tastants sucrose, NaCl, quinine-hydrochloride, and citric acid were applied on the tip, midlateral and posteromedial tongue regions to be identified as either sweet, salty, bitter, or sour by 30 young and 26 elderly adults. The results showed more pronounced age-related loss in identification for citric acid and quinine-hydrochloride than for sucrose and NaCl at both the tip and midlateral regions, but not at the posteromedial region where both age groups performed close to chance level. These findings may have implications for food preferences, and thus, the diets of elderly people.

Prevalence of olfactory dysfunction: the skövde population-based study.

OBJECTIVES/HYPOTHESIS: Patients with olfactory dysfunction appear repeatedly in ear, nose, and throat practices, but the prevalence of such problems in the general adult population is not known. Therefore, the objectives were to investigate the prevalence of olfactory dysfunction in an adult Swedish population and to relate dysfunction to age, gender, diabetes mellitus, nasal polyps, and smoking habits. STUDY DESIGN: Cross-sectional, population-based epidemiological study. METHODS: A random sample of 1900 adult inhabitants, who were stratified for age and gender, was drawn from the municipal population register of Skövde, Sweden. Subjects were called to clinical visits that included questions about olfaction, diabetes, and smoking habits. Examination was performed with a smell identification test and nasal endoscopy. RESULTS: In all, 1387 volunteers (73% of the sample) were investigated. The overall prevalence of olfactory dysfunction was 19.1%, composed of 13.3% with hyposmia and 5.8% with anosmia. A logistic regression analysis showed a significant relationship between impaired olfaction and aging, male gender, and nasal polyps, but not diabetes or smoking. In an analysis of a group composed entirely of individuals with anosmia, diabetes mellitus and nasal polyps were found to be risk factors, and gender and smoking were not. CONCLUSION: The sample size of the population-based study was adequate, with a good fit to the entire population, which suggests that it was representative for the Swedish population. Prevalence data for various types of olfactory dysfunction could be given with reasonable precision, and suggested risk factors analyzed. The lack of a statistically significant relationship between olfactory dysfunction and smoking may be controversial.

Prevalence of self-reported poor odor detection sensitivity: the Skövde population-based study.

OBJECTIVE: To enable adequate planning of ENT healthcare it is important to know the prevalence of olfactory dysfunction in the general population. Whether an individual will actually seek medical attention for olfactory dysfunction is likely to depend predominantly on his/her self-evaluation of the sense of smell. This motivated an investigation of the prevalences of self-reported poorer- and better-than-normal odor detection sensitivity in the general population. MATERIAL AND METHODS: A random sample of 1900 adult inhabitants, stratified for age and gender, was drawn from the municipal population register of Skövde, Sweden. Subjects were asked to attend a structured interview concerning their self-evaluation of their odor detection sensitivity. RESULTS: In total, 1387 volunteers (73% of the sample) were investigated. The overall prevalences of self-reported poorer- and better-than normal odor detection sensitivity were 15.3% and 17.4%, respectively. The prevalence of poorer sensitivity was found to increase with age, and the prevalence of better sensitivity was lower in men than women. CONCLUSIONS: Considering the fairly high participation rate in this study and the fact that the population of Skövde is representative of the general Swedish population, the obtained prevalences can be considered representative of the general Swedish adult population.

Consequences of olfactory loss and adopted coping strategies.

UNLABELLED: The aims of this study were to investigate the effects of loss of smell as regards the quality of life and the coping strategies used. METHODS: Seventy-two patients with anosmia (46%) or hyposmia (54%) filled in the validated Multi-Clinic Smell and Taste Questionnaire, the validated General Well-being Schedule (GWBS), and answered other questions shown to be of good validity. RESULTS: Several kinds of negative effects, risks associated with the loss, interference with daily routines and deteriorations in well-being were common. Physical health, financial security, profession, partnership, friendship, emotional stability and leisure were also deemed to be negatively affected and GWBS scores show compromised psychological well-being. The importance of olfaction seemed to be more noticeable after the loss of smell, and several kinds of problem- and emotion-focused coping strategies were adopted by these patients. CONCLUSIONS: We found that the loss of smell had substantial adverse effects on the quality of life and that high priority should be given to its diagnosis and treatment and to further research in this field. Furthermore, a combination of problem- and emotion-focused coping strategies may be suggested to patients who have recently lost the sense of smell.