Validation of Korean Olfactory Questionnaire for Perioperative Olfactory Assessment in Endoscopic Endonasal Skull Base Surgery

Objective: To analyze changes in olfactory function after endoscopic endonasal skull base surgery and compare performance of the olfactory questionnaire with those of conventional psychophysical tests. Methods: Patients were classified into 5 categories for olfactory function evaluation (normal, mild hyposmia, moderate hyposmia, severe hyposmia, and anosmia) based on a self-assessment. Patients also underwent the butanol threshold test (BTT), Cross-Cultural Smell Identification Test (CCSIT), and 11-item olfactory questionnaire. Subjects with normosmia preoperatively and who were followed up at least 6 months after surgery were analyzed. Receiver operating characteristic curves and confusion matrix analysis were performed for BTT, CCSIT, and olfactory questionnaire to compare their diagnostic abilities. The effects of age, preoperative olfaction, septal flap, tumor pathology, and tumor size on postoperative olfaction were evaluated using multivariate linear regression analysis. Results: Data from 108 patients were analyzed. Postoperative changes in the olfactory questionnaire were significantly associated with changes in the BTT and CCSIT. The area under the curve for postoperative self-olfactory function classification was highest for olfactory questionnaire (0.894), followed by BTT (0.767) and CCSIT (0.688). Patient age at the time of surgery and preoperative BTT score were significantly related to postoperative olfactory outcomes. Conclusion: The olfactory questionnaire correlated well with conventional psychosomatic olfactory function tests. In combination with clinical parameters and preoperative psychosomatic olfactory function tests, the olfactory questionnaire is suitable for assessing subjective olfactory function after endoscopic endonasal skull base surgery.

Post-traumatic olfactory dysfunction: a scoping review of assessment and rehabilitation approaches

Post-traumatic Olfactory Dysfunction (PTOD) consists of a complete or partial loss of olfactory function that may occur after a traumatic brain injury (TBI). PTOD may be linked to some neuropsychiatric features, such as social, cognitive and executive dysfunction, as well as behavioral symptoms, especially when TBI involves the orbito-frontal cortex. The diagnosis of PTOD is based on medical history and clinical data and it is supported by psychometric tests (i.e., subjective tools) as well as electrophysiological and neuroimaging measures (i.e., objective methods). The assessment methods allow monitoring the changes in olfactory function over time and help to establish the right therapeutic and rehabilitative approach. In this context, the use of the olfactory training (OT), which is a non-pharmacological and non-invasive treatment option, could promote olfactory function through top-down (central) and bottom-up (peripheral) processes. To better manage patients with TBI, PTOD should be detected early and properly treated using the various therapeutic rehabilitative possibilities, both conventional and advanced, also taking into consideration the emerging neuromodulation approach.

Function of Trunk-Mediated "Greeting" Behaviours between Male African Elephants: Insights from Choice of Partners

A common behavioural interaction between male African elephants is for an actor to direct his trunk to contact a same sex conspecific's mouth, temporal gland, or genital region. Such behaviours are often referred to as "greetings". Along with its inherent tactile element, these behaviours also likely provide olfactory information to actors concerning aspects of the target's phenotype, including sexual status, feeding history, individual identity, and emotional state. Here, we explore whether the age and novelty of potential interactors affect the choice of individuals targeted by male African elephants for these trunks to scent emitting organ (SEO) behaviours at social hotspots in a male-dominated area. Male elephants of all ages, except older adolescents aged 16-20 years, preferentially targeted elephants of the same age class for trunk-to-SEO behaviours. Elephants younger than 26 years did not direct trunk-to-SEO behaviours to mature bulls (26+ years) more than expected by chance, suggesting these behaviours are not primarily used for younger males to establish contact with, or obtain information from or about older, more experienced individuals. We also found no evidence that males directed these behaviours preferentially to new individuals they encountered at male aggregations (compared to those they arrived in groups with), suggesting these behaviours are not primarily employed by males as a reunion display to establish relationships between new individuals or update relationships between familiar individuals separated over time. Age-mates may be preferentially targeted with these behaviours as a means to facilitate further interaction with partners (e.g., for sparring activity), or as a safe way to assess relative dominance rank in similarly aged and hence, size and strength, matched dyads. Our results suggest male African elephants use close contact trunk-to-SEO behaviours continuously over time, to facilitate positive relationships, test willingness to interact, and assess aspects of phenotype, between males occupying the same ecological space.

A Method for Computerized Olfactory Assessment and Training Outside of Laboratory or Clinical Settings

There are currently few ways to reliably and objectively assess olfaction outside of the research laboratory or clinic. The COVID-19 pandemic has highlighted the need for remote olfactory assessment; in particular, smell training at home is a promising method for olfactory rehabilitation, but further methodological advances might enhance its effectiveness and range of use. Here, we present Exerscent, a portable, low-cost olfactory display designed primarily for uses outside of the laboratory and that can be operated with a personal computer. Exerscent includes Radio Frequency Identification (RFID) tags that are attached to odor stimuli and read with a MFRC522 module RFID reader/antenna that encodes the odor in order to provide adaptive challenges for the user (e.g., an odor identification task). Hardware parts are commercially available or 3D printed. Instructions and code for building the Exerscent are freely available online (https://osf.io/kwftm/). As a proof of concept, we present a case study in which a participant trained daily to identify 54 odors, improving from 81% to 96% accuracy over 16 consecutive days. In addition, results from a laboratory experiment with 11 volunteers indicated a very high level of perceived usability and engagement. Exerscent may be used for olfactory skills development (e.g., perfumery, enology), and rehabilitation purposes (e.g., postviral olfactory loss), but it also allows for other forms of technological interactions such as olfactory-based recreational interactions.

Changes of Olfactory Performance during the Process of Aging - Psychophysical Testing and Its Relevance in the Fight against Malnutrition

OBJECTIVES

Olfactory performance plays a vital role in several aspects of everyday life. A decrease in olfactory function leading to reduced appetite and inadequate food intake could contribute to higher risk of malnutrition and has a significant impact on quality of life. Early detection of olfactory impairment may help to maintain normal, or - through early training - to improve olfactory function and could thus contribute to the prevention of malnutrition. This review summarizes recent findings on the association between decreased olfactory performance in older adults, its implication for overall health and discusses issues regarding the assessment of olfactory performance in older people.

METHODS

A non-systematic literature search using databases (PubMed, ScienceDirect, Google Scholar) was conducted up to March 2016 to review recent findings on the topics of olfactory impairment, age, malnutrition and issues in psychophysical testing.

RESULTS

Although the association of olfactory impairment and malnutrition is widely accepted strong evidence is scarce. This could be because existing psychophysiological olfactory performance tests are not suitable and inefficient for older adults or people with cognitive impairment due to their required time and concentration. Since prevalence of olfactory impairment remains poorly documented in European regions and varies from 13.9% to >60% depending on age and due to considerable methodological diversity in studies there is need to develop rapid and efficient screening tools which are suitable for this target group.

CONCLUSION

Due to numerous causes and health consequences of olfactory impairment in older people, early detection of olfactory malfunction by rapid, inexpensive but valid tests, which could be used by geriatricians and other healthcare professionals, might be useful in patient counselling by identifying individuals at nutritional risk.

Olfaction - Quantification and management

Patients with olfactory disorders are often referred to the otolaryngologist for assessment and treatment. Karely, however, is the otolaryngologist prepared to provide such services. In a previous paper in this journal, we described the basic anatomy and physiology of the olfactory system. Additionally, we listed a standardized nomenclature for classifying olfactory disturbances, and reviewed means for clinically assessing such disorders. In this paper, we provide a more detailed protocol for evaluating patients with loss of smell, incorporating sensory, imaging, and medical approaches employed at the Smell and laste Center of the University of Pennsylvania, USA. Examples of common syndromes encountered in everyday practice are deicribed.