Andrea Viziano

Impaired mental rotation in benign paroxysmal positional vertigo and acute vestibular neuritis

Vestibular processing is fundamental to our sense of orientation in space which is a core aspect of the representation of the self. Vestibular information is processed in a large subcortical–cortical neural network. Tasks requiring mental rotations of human bodies in space are known to activate neural regions within this network suggesting that vestibular processing is involved in the control of mental rotation. We studied whether mental rotation is impaired in patients suffering from two different forms of unilateral vestibular disorders (vestibular neuritis – VN – and Benign Paroxysmal positional Vertigo – BPPV) with respect to healthy matched controls (C). We used two mental rotation tasks in which participants were required to: (i) mentally rotate their own body in space (egocentric rotation) thus using vestibular processing to a large extent and (ii) mentally rotate human figures (allocentric rotation) thus using own body representations to a smaller degree. Reaction times and accuracy of responses showed that VN and BPPV patients were impaired in both tasks with respect to C. Significantly, the pattern of results was similar in the three groups suggesting that patients were actually performing the mental rotation without using a different strategy from the control individuals. These results show that dysfunctional vestibular inflow impairs mental rotation of both own body and human figures suggesting that unilateral acute disorders of the peripheral vestibular input massively affect the cerebral processes underlying mental rotations.

Lack of contralateral suppression in transient-evoked otoacoustic emissions in multiple chemical sensitivity: a clinical correlation study.

Multiple chemical sensitivity (MCS) is a chronic disorder characterized by a variety of symptoms associated with the exposure to chemicals at a concentration below the toxic level. Previous studies have demonstrated peculiar responses in brain activity in these patients with respect to sensory stimuli while the association between chemical sensitivity and other environmental intolerances such as noise sensitivity has been questioned by researchers. In this study, a cohort of 18 MCS patients underwent transient-evoked otoacoustic emission (TEOAE) testing with and without contralateral suppression to evaluate the functionality of the medial olivocochlear (MOC) reflex involved in speech-in-noise sensitivity. Results were compared with an age- and gender-matched control group (n = 20) and correlation analysis with disease onset and quick environmental exposure sensitivity inventory (qEESI) symptom severity scale was performed. Subjects affected by MCS showed statistically significant impairment of MOC reflex, and the onset of the disease and several symptom subscales showed to be correlated to such reduction in some of the frequencies tested. These data suggest that alterations of MOC reflex could be part of the complex features of this disease although more studies are needed to further explore auditory perception disorders in environmental intolerances.

Vestibular impairment in Multiple Chemical Sensitivity: Component analysis findings

Multiple chemical sensitivity (MCS) is a common clinical diagnosis in western populations and its symptoms are thought to be mainly related to chemical compounds exposure. Although MCS subjects refer to complain from many central nervous system symptoms, including dizziness, no study to now deepened vestibular detriment nor to what extent such an impairment could worsen MCS. Thus, the purpose of present study was to objectively highlight those clinical/subclinical aspects of vestibular impairment that could be related to MCS symptoms cohorts. A principal component analysis within a wide battery of otoneurological test scores was employed in 18 right-handed MCS patients and 20 sex- and age-matched healthy individuals. A deranged dimensionality in near-optimal re-weighting within otoneurological variables was found in MCS as compared with healthy subjects. These data seem to support the idea that MCS physiopathological underpinnings could lead to a peripheral and higher vestibular decay that could be addressed as a further aspect to better follow MCS patients up along natural history of disease in clinical practice.

Noise sensitivity and hyperacusis in patients affected by multiple chemical sensitivity

PurposeThe aim of this study was to investigate the presence of noise sensitivity and hyperacusis in patients suffering from multiple chemical sensitivity (MCS), a chronic condition characterized by several symptoms following low-level chemical exposure. Moreover, distortion product otoacoustic emissions (DPOAE) were performed to further study cochlear function.MethodsA questionnaire-based survey was performed. Eighteen MCS patients, selected with strict diagnostic criteria, and 20 healthy age- and gender-matched subjects filled Weinstein’s Noise Sensitivity Questionnaire (WNS) and Khalfa’s Hyperacusis Questionnaire (HQ). Results were compared with scores from the quick Environmental Exposure Sensitivity Index (qEESI), a routinarily used questionnaire to screen MCS symptoms, and with DPOAE values. An analysis of variance (ANOVA) was performed between MCS and control subjects scores; moreover, Spearman’s rank correlation test was performed between questionnaire results.ResultsANOVA testing on DPOAE values showed any significant difference between groups, while WNS, HQ and qEESI scores were significantly higher in MCS group compared to controls. Correlation analysis showed strong positive correlation between WNS, HQ and qEESI in MCS subjects.ConclusionsFor the first time, auditory-related perceptual disorders were studied in MCS. A strong association between WNS, HQ results and MCS symptoms severity has been highlighted. These findings suggest that decreased sound tolerance and noise sensitivity could be considered as possible new aspects of this syndrome, contributing to its peculiar phenotype. Furthermore, as DPOAE values did not differ from healthy subjects, present findings might suggest a ‘central’ source for such disorders in this group of patients.

Integrating postural and vestibular dimensions to depict impairment in moderate-to-severe obstructive sleep apnea syndrome patients

Vestibular dysfunction was linked to moderate‐to‐severe obstructive sleep apnea syndrome (OSAS) patients in literature. However, due to a lack of knowledge among valid and recent implementations conceived to study postural control on static posturography (SP) and vestibulo‐ocular reflex (VOR) gain under physiological conditions (video Head Impulse Test; vHIT), the aim of this work was to integrate (i) VOR changes via vHIT implementation, (ii) postural arrangement by studying both classical parameters and frequency spectra (PS) and (iii) correlation between these findings, polygraphic (PG) and subjective scores along Dizziness Handicap Inventory (DHI) and Epworth Sleepiness Scale (ESS). Thus, 32 moderate‐to‐severe OSAS patients and 32 healthy subjects – studied by using PG, DHI and ESS – underwent vHIT and SP posturographic assessment. Analysis of variance was performed to disclose between‐group effects and correlation analysis was implemented between otoneurological, PG, DHI and ESS values. OSAS group demonstrated a significant decay of VOR gain and an increase in both frequency spectra PS values, especially within the low‐frequency interval, and in classical posturographic SP parameters. Further, positive and negative correlations between mean SaO2 and gain and low frequency interval spectra PS were found, respectively. Strengthening previous hypothesis related to brainstem chronic hypoxemia phenomena affecting vestibular network, implementation of these data could generate future attentions (i) for screening under physiological conditions postural and vestibular detriments in OSAS subjects, especially exposed at risk settings, and (ii) among PG parameters, such as mean SaO2, to propose further reliable tools in monitoring postural and vestibular decay in these patients demonstrating PG parameters detriments.

Three-dimensional head-mounted gaming task procedure maximizes effects of vestibular rehabilitation in unilateral vestibular hypofunction: a randomized controlled pilot trial

Considering the emerging advantages related to virtual reality implementation in clinical rehabilitation, the aim of the present study was to discover possible (i) improvements achievable in unilateral vestibular hypofunction patients using a self-assessed head-mounted device (HMD)-based gaming procedure when combined with a classical vestibular rehabilitation protocol (HMD group) as compared with a group undergoing only vestibular rehabilitation and (ii) HMD procedure-related side effects. Therefore, 24 vestibular rehabilitation and 23-matched HMD unilateral vestibular hypofunction individuals simultaneously underwent a 4-week rehabilitation protocol. Both otoneurological measures (vestibulo-ocular reflex gain and postural arrangement by studying both posturography parameters and spectral values of body oscillation) and performance and self-report measures (Italian Dizziness Handicap Inventory; Activities-specific Balance Confidence scale; Zung Instrument for Anxiety Disorders, Dynamic Gait Index; and Simulator Sickness Questionnaire) were analyzed by means of a between-group/within-subject analysis of variance model. A significant post-treatment between-effect was found, and the HMD group demonstrated an overall improvement in vestibulo-ocular reflex gain on the lesional side, in posturography parameters, in low-frequency spectral domain, as well as in Italian Dizziness Handicap Inventory and Activities-specific Balance Confidence scale scores. Meanwhile, Simulator Sickness Questionnaire scores demonstrated a significant reduction in symptoms related to experimental home-based gaming tasks during the HMD procedure. Our findings revealed the possible advantages of HMD implementation in vestibular rehabilitation, suggesting it as an innovative, self-assessed, low-cost, and compliant tool useful in maximizing vestibular rehabilitation outcomes.

Perspectives on multisensory perception disruption in idiopathic environmental intolerance: a systematic review

PurposeMultiple chemical sensitivity (MCS) also known as idiopathic environmental intolerance/illness (IEI) encompasses a cohort of subjective symptoms characterized by susceptibility to a wide spectrum of environmental compounds, causing symptoms involving various organs and a decrease in quality of life. The aim of this systematic review is to summarize evidence about MCS, with focus on indexed studies analyzing sensory pathway-related disorders.MethodsMedical databases were searched for English language articles related to the topic, published between 1965 and 2017 in academic, peer-reviewed journals. Particular focus was concentrated on articles depicting disturbances involving sensory organs. References of the relevant articles were examined to identify additional significant documents.ResultsFifty-eight studies were eligible for full text review. Of these, 34 studies met the selection criteria and were included in this analysis. Many variables, such as different diagnostic criteria, lack of homogeneous symptom questionnaires and the general incidence of personality traits in control subjects, biased studies as confounding factors. However, moderate evidences show that sensory pathways are somewhat altered, especially with respect to information processing in the limbic system and related cortical areas. Recent studies suggested the presence, in MCS cohorts, of attention bias, sensitization and limbic kindling, as well as recently revealed subclinical organic alterations along sensory pathways.ConclusionsEvidences are consistent with MCS/IEI to be the result of a neural altered processing of sensorial ascending pathways, which combined with peculiar personality traits constitutes the underpinning of a multisensory condition needing multidisciplinary clinical approach.

Long-term effects of vestibular rehabilitation and head-mounted gaming task procedure in unilateral vestibular hypofunction: a 12-month follow-up of a randomized controlled trial

Objective: To investigate the long-term effects of adding virtual reality–based home exercises to vestibular rehabilitation in people with unilateral vestibular hypofunction. Design: Follow-up otoneurological examination in two randomized groups following a previous one-month trial. Setting: Tertiary rehabilitation center. Subjects: A total of 47 patients with unilateral vestibular hypofunction, one group (n = 24) undergoing conventional vestibular rehabilitation and the other one (n = 23) implementing, in addition, head-mounted gaming home exercises, 20 minutes per day for one month. Interventions: One year after completing rehabilitation, patients underwent testing with static posturography, video head impulse test, self-report questionnaires, and a performance measure. Main measures: Vestibulo-ocular reflex gain, posturographic parameters such as length, surface, and fast Fourier transform power spectra, self-report, and gait performance measure scores. Results: Vestibulo-ocular reflex gain was significantly better with respect to pretreatment in both groups. The mixed-method group showed significantly higher gain scores: mean (standard deviation (SD)) at 12 months was 0.71 (0.04), versus 0.64 (0.03) for the vestibular rehabilitation–only group (P < 0.001). Accordingly, some classical posturography scores such as surface with eyes open and length with eyes closed and low-frequency power spectra were significantly different between groups, with the virtual reality group showing improvement (P < 0.001). Self-report measures were significantly better in both groups compared to pretreatment, with significant improvement in the mixed-method group as compared to conventional rehabilitation alone: Dizziness Handicap Inventory mean total score was 24.34 (2.8) versus 35.73 (5.88) with a P-value <0.001. Conclusion: Results suggest that head-mounted gaming home exercises are a viable, effective, additional measure to improve long-term vestibular rehabilitation outcomes.

A Comprehensive Insight into the Rehabilitative Treatment of Persistent Benign Paroxysmal Positional Vertigo.

As stated by the above-mentioned authors, persistent benign paroxysmal positional vertigo (PBPPV) can be as an extensive labyrinth disease. Beyond the particular affected canal, it may lead to a chronic, persistent disorder in which the detachment of otoconial deposits from macular receptors, and their movements in endolymphatic fluids can elicit a gravity-related stream that may provoke many clinical features [2].

Early cortical metabolic rearrangement related to clinical data in idiopathic sudden sensorineural hearing loss

Abstract Results in studies concerning cortical changes in idiopathic sudden sensorineural hearing loss (ISSNHL) are not homogeneous, in particular due to the different neuroimaging techniques implemented and the diverse stages of ISSNHL studied. Considering the recent advances in state‐of‐the‐art positron emission tomography (PET) cameras, the aim of this study was to gain more insight into the neuroanatomical differences associated with the earliest stages of unilateral ISSNHL and clinical‐perceptual performance changes. After an audiological examination including the mean auditory threshold (mean AT), mean speech discrimination score (mean SDS) and Tinnitus Handicap Inventory (THI), 14 right‐handed ISSNHL patients underwent brain [18F]fluorodeoxyglucose (FDG)‐PET within 72 h of the onset of symptoms. When compared to an homogeneous group of 35 healthy subjects by means of statistical parametric mapping, a relative increase in FDG uptake was found in the right superior and medial frontal gyrus as well as in the right anterior cingulate cortex in ISSNHL patients. Conversely, the same group showed a significant relative decrease in FDG uptake in the right middle temporal, precentral and postcentral gyrus as well as in the left posterior cingulate cortex, left lingual, superior, middle temporal and middle frontal gyrus and in the left insula. Regression analysis showed a positive correlation between mean THI and glucose consumption in the right anterior cingulate cortex and a positive correlation between mean SDS and glucose consumption in the left precentral gyrus. The relative changes in FDG uptake found in these brain regions and the positive correlation with mean SDS and THI scores in ISSNHL could possibly highlight new aspects of cerebral rearrangement, contributing to further explain changes in those functions that support speech recognition during the sudden impairment of unilateral auditory input. HighlightsBrain changes in idiopathic sudden sensorineural hearing loss are not homogeneous.FDG PET/CT was demonstrated to be a quiet and reliable auditory imaging technique.FDG uptake decrease was found in auditory scene analysis network in ISSNHL.Positive correlation between anterior cingulated cortex and tinnitus score.Positive correlation between insula and speech discrimination score.