Intranasal Administration of Hyaluronan as a Further Resource in Olfactory Performance in Multiple Chemical Sensitivity Syndrome

Abstract

Multiple chemical sensitivity (MCS) is a relatively common clinical diagnosis in western populations and its symptoms (i.e. dysosmia) are mainly triggered by chemical compounds, such as common odorants. The aim of this study was to test the effect of intranasal administration of hyaluronic acid (HA) on odour threshold and related quality of life in MCS syndrome. Two randomized groups of MCS patients received 30 days’ administration of either a nasal spray (Ialumar®) containing HA [HA group (HAG); n=29] or only physiological solution[PS group (PG); n=30]. Both groups were investigated using the Sniffin’ Sticks test (SST) battery, Questionnaire of Olfactory Disorder (QOD) and Zung Anxiety Scale (SAS) before randomization and after treatment. Paired t-test analysis found a statistically significant reduction in odour threshold (OT) and an improvement in QOD and SAS between pre- and post-treatment results only in the HAG. Furthermore, positive correlations were found between the OT reduction, SAS and QOD improvement. Thus, intranasal administration of HA could be suggested as a further well-tolerated resource in alleviating MCS olfactory discomfort.

Cortico-subcortical metabolic correlates of olfactory processing in healthy resting subjects

“…Before undergoing to olfactory stimulation all subjects completed the following VQ:Questionnaire of Olfactory Disorders (QOD) - completed only before NC phase - to assess daily life problems due to olfactory impairment, we used a short modified version of an olfactory-specific QOD developed by Frasnelli and Hummel40 which has recently been used by many researchers41. The modified short version of the QOD consists of 25 statements that are divided into three general domains: 17 negative statements (QOD-NS), two positive statements (QOD-PS), and six socially desired statements (QOD-SD);…”

Deranged Dimensionality of Vestibular Re-Weighting in Multiple Chemical Sensitivity

“…Multiple chemical sensitivity (MCS) is a chronic polysymptomatic, multisystem condition characterized by subjective susceptibility to low levels of a wide spectrum of environmental compounds (such as petrol, perfume or pesticides) [1,2]. It constitutes a relatively common clinical diagnosis in western populations [2], considering that the prevalence of self-reported chemical sensitivity symptoms in population-based studies has been found to range from 9% to 33% [2].…”

“…It constitutes a relatively common clinical diagnosis in western populations [2], considering that the prevalence of self-reported chemical sensitivity symptoms in population-based studies has been found to range from 9% to 33% [2]. Relapsing and remitting central nervous system (CNS) manifestations including difficulty concentrating, memory problems, fatigue, depression, daytime sleepiness, "spaciness" (derealisation), tension, irritability and dizziness are commonly referred to by the patients [2,3].…”

“…Major criteria to define the clinical spectrum of MCS were introduced by Cullen [4]; however, the discussion on definition and nomenclature reflects the fact that the aetiology of MCS is still unclear and a matter of debate [2,5]. The most frequently discussed aetiologies include neurogenic inflammation [6], classical conditioning [7] and biochemical disruptions [8].…”

“…Thus, due to (i) the overlapping psychogenic and organic burdens that, below the level of consciousness, are shared not only in MCS development but also in the vestibular disorders [1,[10][11][12][13][15][16][17]20]; (ii) the number of previous studies describing central processing impairment related to inner ear inflow in this syndrome [21,22]; and (iii) the lack of literature on clinical evidence of the presentation of dizziness [2,3], the purpose of the present exploratory study was to highlight the possible MCS hidden clinical/subclinical aspects of vestibular impairment by inferential and principal component (PC) analysis applied on the contribution of recently implemented otoneurological testings. This, with the aim of disclosing possible implementations in diagnosing and monitoring undiscovered aspects underpinning the natural history of MCS, will possibly assist in suggesting future treatment choices in a clinical setting.…”