Olfactory assessment using the NIH Toolbox

Abstract

The human olfactory system provides us with information about our environment that is critical to our physical and psychological well-being. Individuals can vary widely in their ability to detect, recognize, and identify odors, but still be within the range of normal function. Although several standardized tests of odor identification are available, few specifically address the issues in testing very young children, most of whom are likely to be unfamiliar with many of the odor stimuli used in adult tests and have limited ability to read and identify labels to select among choices. Based on the format of the San Diego Odor Identification Test and the delivery system of the University of Pennsylvania Smell Identification Test, we developed 2 versions of an odor identification test using standardized odor stimuli in a scratch-and-sniff format in which participants match 5 (children) or 9 (adults) odors to pictures representing the odor source. Results from normative testing and validation showed that for most participants, the test could be completed in 5 minutes or less and that the poorer performance among the youngest children and the elderly was consistent with data from tests with larger numbers of items. Expanding on the pediatric version of the test with adult-specific and public health-relevant odors increased the ecological validity of the test and facilitated comparisons of intraindividual performance across developmental stages. The human olfactory system allows us to detect odors, to recognize and discriminate odor qualities, and to identify the sources of odors in our world. Humans are capable of detecting and discriminating thousands of different odorant molecules, many at extremely low concentrations (i.e., parts per billion or trillion). Our sense of smell provides us with information about our air, water, and food that is critical to our health and safety, nutrition, and psychological well-being.The process of olfaction is initiated when volatile chemicals stimulate olfactory receptor neurons located on a relatively small patch of specialized epithelial tissue high in the nasal cavity. 1 These sensory neurons have axons that travel as the olfactory nerve (cranial nerve I) to terminate in the olfactory bulb. In turn, the olfactory bulb projects more centrally and contributes inputs for higher cortical processing, which results in olfactory perception. 2 Odorants reach the olfactory receptors in 2 ways: they can enter the nostrils during normal inhalation (orthonasal route) or travel from the back of the oral cavity to the olfactory receptors via the nasal pharynx (retronasal route). The perception of food flavor involves a combination of olfactory activation caused by odorous compounds released into the nasopharynx retronasally through chewing, drinking, and deglutition, and the blending of taste (salty, sour, bitter, sweet, umami) and oral somatosensory sensations (texture, heat, cold). 3 Nasal blockage and swelling can prevent odors from entering the retronasal stream, resulting in a shi...

Olfactory function evaluation in a 1102 community-dwelling 20-90-year old Japanese population in relation with age, sex and mental decline

“…All participants reported the self-awareness of their olfactory function in daily-living activity as normosmia or hyposmia, then received the mPST, a 4-item (soap, grape, onion, rose), four-choice, scratch-and-sniff, forced choice olfactory identification test, to measure their olfactory identification function with slight modifications to the NHANES 2011-2014 Chemosensory protocol [12,13]. The perfect score for the test is set to 4.…”

Diagnóstico en la patología del olfato: Revisión de la literatura

“…El sistema olfatorio humano detecta olores, sus fuentes y reconoce las cualidades de éstos. Nuestro sentido del olfato nos provee información acerca del aire, el agua y los alimentos, lo que juega un papel crítico en nuestra salud, seguridad, nutrición y bienestar psicológico 10 . Durante la inspiración las moléculas odoríferas penetran en la cavidad nasal.…”

“…Las substancias odoríferas llegan a los receptores olfatorios de dos maneras: a través de la inhalación (ruta ortonasal) o por vía posterior (ruta retronasal) 3,10 . Existe una estrecha relación entre el olfato y el gusto.…”

“…Por lo general la pérdida del gusto se debe a la pérdida de la función olfatoria retronasal, más que a una disminución del gusto per se 10 . Las sensaciones somatosensoriales de la mucosa nasal como calor, frío e irritación son mediadas por el sistema del nervio trigémino.…”

Input on NIH Toolbox inclusion criteria

“…Subdomain selection for each of these areas is discussed in the domain-specific articles found later in this supplement. [3][4][5][6][7][8][9][10][11][12][13][14] Request for information #2. This sample of experts was asked how much cost there should be for the equipment needed to administer the NIH Toolbox, as well as persubject costs to gather data.…”