Abstract
Abnormalities in olfactory function have been identified in a number of neurological and psychiatric disorders, including Parkinson’s disease and schizophrenia. However, little is known about olfactory function in autism spectrum disorder (ASD). The present study aims to assess the olfactory profiles of children with ASD, compared to an age- and sex-matched comparison group of typically developing children and a second clinical control group consisting of non-ASD children with sensory processing dysfunction (SPD). Participants completed a battery of sensory and behavioral assessments including olfactory tasks (Sniffin’ Sticks Threshold Test and self-reported valence ratings for two target odorants (phenylethyl alcohol and vanillin) and the University of Pennsylvania Smell Identification Test), and an autism evaluation (Autism Diagnostic Observation Schedule-2). Children with ASD showed intact odor detection with reduced odor identification ability. Poor odor identification was significantly correlated with autism symptom severity. Children with SPD demonstrated reduced odor detection and identification ability. These findings provide evidence for differential patterns of smell processing among ASD and non-ASD neurodevelopmental disorders. Future studies are needed to determine whether the association of impaired olfaction and increased autism symptoms is due to shared etiology.
Highlights
Autism spectrum disorder (ASD) is defined by a combination of social communication deficits and the presence of restricted, repetitive behaviors [1]
Efforts to characterize the olfactory profile of autism spectrum disorder (ASD) remain inconclusive and prior studies are inconsistent with regard to the type of olfactory alteration found in ASD, variably identifying dysfunction in peripheral odor detection, secondary odor identification, or both [7,8,9,10,11,12,13,14,15]
The present study aims to better characterize olfactory function in ASD, namely, odor detection threshold and odor identification, and to discover how these processes relate to ASD symptomology in a sample of children with ASD relative to two age- and sex-matched control groups: typically developing children with no history of developmental or psychiatric disorders and children with sensory processing dysfunction (SPD) but do not meet criteria for ASD
Summary
Autism spectrum disorder (ASD) is defined by a combination of social communication deficits and the presence of restricted, repetitive behaviors [1]. Sensory dysfunction is recognized as part of the restricted, repetitive behaviors domain and is highly prevalent, with multiple sensory modalities affected in both children and adults with ASD [2]. The most commonly affected sensory modalities include auditory processing, tactile hypersensitivity, and increased sensory-seeking behaviors [3,4]. Brain Sci. 2020, 10, 362; doi:10.3390/brainsci10060362 www.mdpi.com/journal/brainsci. Symptoms of sensory dysfunction may further impair social functioning and may contribute to increased restrictive and repetitive behaviors [5]. Less is known about the olfactory domain in ASD than other sensory modalities. Efforts to characterize the olfactory profile of ASD remain inconclusive and prior studies are inconsistent with regard to the type of olfactory alteration found in ASD, variably identifying dysfunction in peripheral odor detection, secondary odor identification, or both [7,8,9,10,11,12,13,14,15]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
