Normal olfactory functioning is related to quality of life, emotions, cognition and memory. Abnormal olfactory functioning occurs in neurodegenerative diseases (e.g. Alzheimer’s and Parkinson’s disease) and in many neurodevelopmental/psychiatric disorders (e.g. Attention deficit hyperactivity disorder, Autism Spectrum Disorder). Olfactory functioning is processed predominantly by frontal regions, but also by temporal regions and therefore, indicates conclusions regarding information processing at different points of the olfactory pathway. So far, olfactory functioning has not been examined in patients with incontinence. As central nervous system functions are also involved in incontinence, the aim of the study was to examine olfactory functions as a potential neurobiological correlate for incontinence.
This study included children with daytime urinary incontinence (DUI), nocturnal enuresis (NE) or fecal incontinence (FI) between 6-18 years of age that were treated at the specialized outpatient clinic for incontinence as well as typically developed children (healthy controls-HC). Olfactory functioning was assessed at baseline (t1), after 3 months (t2) and after 6 months (t3) by the Sniffin’ Sticks standardized olfactory test battery, including 3 different subtests for olfactory performance.
So far, 40 patients (26 male, mean age=8.8 years) of whom 26 had NE, 12 had DUI and 6 had FI as well as 27 HC (8 male, mean age=11.5 years) completed the olfactory testing at t1. When comparing patients and HC there was a significant lower olfactory threshold (p=.010) and discrimination performance (p=.004) in patients. Children with only NE showed a significant lower discrimination performance (p=.004) and a marginal lower olfactory threshold (p=.056) compared to HC.
Investigation of olfactory functioning is a feasible and non-invasive method to assess frontal neurobiological correlates in children with incontinence. Children with incontinence showed a worse olfactory threshold and discrimination performance compared to HC, indicating potential differences in frontal processing or neuronal networks specific to incontinence.