Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the b... more Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the brain. This study aimed to investigate whether fighter pilots, who are exposed to frequent g-level transitions and high g-levels, show differential functional characteristics compared to matched controls, indicative of neuroplasticity. We acquired resting-state functional magnetic resonance imaging data to assess brain functional connectivity (FC) changes with increasing flight experience in pilots and to assess differences in FC between pilots and controls. We performed whole-brain exploratory and region-of-interest (ROI) analyses, with the right parietal operculum 2 (OP2) and the right angular gyrus (AG) as ROIs. Our results show positive correlations with flight experience in the left inferior and right middle frontal gyri, and in the right temporal pole. Negative correlations were observed in primary sensorimotor regions. We found decreased whole-brain functional connectivity of the left inferior frontal gyrus in fighter pilots compared to controls and this cluster showed decreased functional connectivity with the medial superior frontal gyrus. Functional connectivity increased between the right parietal operculum 2 and the left visual cortex, and between the right and left angular gyrus in pilots compared to controls. These findings suggest altered motor, vestibular, and multisensory processing in the brains of fighter pilots, possibly reflecting coping strategies to altered sensorimotor demands during flight. Altered functional connectivity in frontal areas may reflect adaptive cognitive strategies to cope with challenging conditions during flight. These findings provide novel insights into brain functional characteristics of fighter pilots, which may be of interest to humans traveling to space.
Objectives: Investigate mumps, as a possible cause of sudden deafness, for its relationship with ... more Objectives: Investigate mumps, as a possible cause of sudden deafness, for its relationship with the impairment extent of hearing loss and otolith organs damage. Methods: Twenty-two cases of unilateral hearing impairment in mumps diagnosed in the out-patient department of our hospital have been investigated with audiometry and vestibular evoked myogenic potentials (VEMP) in order to confirm the degree of permanent lesions. Results: Seventeen of twenty-two cases had no response in the test of audiometry, 4 with profound sensorineural hearing loss and 1 with severe sensorineural deafness. In cervical VEMP (cVEMP) test, 14 patients (63.64%) with varied elevated threshold in the affected side, 7 cases (31.82%) with the same threshold binaural sides, 1 case (4.55%) with slightly elevated threshold in the normal side; There were statistical significant differences compared the threshold values of the affected side with that of the normal side, P = 0.000. In ocular VEMP test, 2 of 22 with no response in both sides; Among the other 20 cases, 12 cases (60%) could have at least one ear response with varied elevated threshold in the affected side, 6 cases (30%) with the same threshold binaural sides, 2 cases (10%) with slightly elevated threshold in the normal side; There were statistical significant differences compared the threshold values of the affected side with that of the normal side, P = 0.006. Conclusion: Deafness from mumps is usually profound and permanent. It showed mumps also concerned otolith organs with the functional lesion in vestibular system, yet more slightly than that in auditory system.
Zenodo (CERN European Organization for Nuclear Research), May 22, 2019
Falls, caused by dizziness and balance deficits, and their consequences in terms of the resultant... more Falls, caused by dizziness and balance deficits, and their consequences in terms of the resultant functional limitations and of the associated costs for the involved actors as well as for the healthcare system are a serious problem in modern societies. Vestibular rehabilitation therapy (VRT) is proposed as a personalized intervention both for ameliorating symptoms and for improving balance. The outcomes of the therapy are not the same in all patients and the reasons are explored in this study with data mining methods applied in two retrospective datasets. According to our findings, patients with unstable lesions, concurrent psychological problems and with headaches are poorer candidates for VRT. Patients with stable vestibular deficits, of recent onset and relatively intact psychological, acoustic, visual and proprioceptive systems are better candidates for VRT.
Purpose There is still a clinical-radiologic discrepancy in patients with Menière's disease (MD).... more Purpose There is still a clinical-radiologic discrepancy in patients with Menière's disease (MD). Therefore, the purpose of this study was to investigate the reliability of current MRI endolymphatic hydrops (EH) criteria according to Baráth in a larger study population and the clinical utility of new imaging signs such as a supplementary fourth low-grade vestibular EH and the degree of perilymphatic enhancement (PE) in patients with Menière's disease (MD). Methods This retrospective study included 148 patients with probable or definite MD according to the 2015 American Academy of Otolaryngology, Head and Neck Surgery criteria who underwent a 4-h delayed intravenous Gd-enhanced 3D-FLAIR MRI between January 2015 and December 2016. Vestibular EH, vestibular PE, cochlear EH, and cochlear PE were reviewed twice by three experienced readers. Cohen's Kappa and multivariate logistic regression were used for analysis. The intra-and inter-reader reliability for the grading of vestibular-cochlear EH and PE was excellent (0.7 < kappa < 0.9). The two most distinctive characteristics to identify MD are cochlear PE and vestibular EH which combined gave a sensitivity and specificity of 79.5 and 93.6%. By addition of a lower grade vestibular EH, the sensitivity improved to 84.6% without losing specificity (92.3%). Cochlear EH nor vestibular PE showed added-value. Conclusions MRI using vestibular-cochlear EH and PE grading system is a reliable technique. A four-stage vestibular EH grading system in combination with cochlear PE assessment gives the best diagnostic accuracy to detect MD.
Stria vascularis (SV) as well as other inner ear tissue components are rich in ion and water chan... more Stria vascularis (SV) as well as other inner ear tissue components are rich in ion and water channel/transporter proteins. In the SV they are essential for maintaining endo-cochlear chemical composition and potential (EP) critical for hair cell function and hearing. By using immunohistochemistry combined with confocal and super-resolution microscopy (SIM), we analyzed directly fixed * human cochleae for proteins related to transportation of ions (ion transporters and ion channels) such as Kir4.1 (KCNJ10) and voltage-gated potassium channel proteins Kv7.1 (KCNQ1/KCNE1) in SV. Furthermore, we examined the expression of connexin 30/26 (Cx30/Cx26), ion transporters NKCC1 and Na+-K+-ATPase. Water channel proteins aquaporin2/4/5 and tight junction protein claudin and occluding 11 in human cochlea were also investigated. Human SV was margined apically and basally by tight junctions (TJ) containing occludin and claudin 11. TJs encompass the enclave, assumingly maintaining a high intra-strial K+-concentration and electro-chemical gradient; TJs also constitute an integral part of the blood-labyrinth barrier. The K+ channel KCNJ10 (Kir 4.1), which generates the K+ equilibrium EP, was expressed both in the intermediate and basal cells and partly co-localized with Cx26. NKCC1 encodes the furosemide-sensitive Na+/K+/2Cl co-transporter and was found in the marginal cells. The KCNQ1 gene, which encodes the voltage-gated potassium channel Kv7.1 (KvLQT1) was expressed in the apical cell membrane of the marginal cells. The Cx26 and Cx30 protein expression using super-resolution structured illumination microscopy (SIM) showed closely associated homomeric GJ plaques. The association of Cx26 with the potassium channel KCNJ10 could explain the vulnerability to GJB2 gene disruption.
As space agencies aim to reach and build installations on Mars, the crews will face longer exposu... more As space agencies aim to reach and build installations on Mars, the crews will face longer exposure to extreme environments that may compromise their health and performance. Transcranial magnetic stimulation (TMS) is a painless non-invasive brain stimulation technique that could support space exploration in multiple ways. However, changes in brain morphology previously observed after long-term space missions may impact the efficacy of this intervention. We investigated how to optimize TMS for spaceflightassociated brain changes. Magnetic resonance imaging T1-weighted scans were collected from 15 Roscosmos cosmonauts and 14 non-flyer participants before, after 6 months on the International Space Station, and at a 7-month follow-up. Using biophysical modeling, we show that TMS generates different modeled responses in specific brain regions after spaceflight in cosmonauts compared to the control group. Differences are related to spaceflight-induced structural brain changes, such as those impacting cerebrospinal fluid volume and distribution. We suggest solutions to individualize TMS to enhance its efficacy and precision for potential applications in long-duration space missions.
Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the b... more Exposure to altered g-levels causes unusual sensorimotor demands that must be dealt with by the brain. This study aimed to investigate whether fighter pilots, who are exposed to frequent g-level transitions and high g-levels, show differential functional characteristics compared to matched controls, indicative of neuroplasticity. We acquired resting-state functional magnetic resonance imaging data to assess brain functional connectivity (FC) changes with increasing flight experience in pilots and to assess differences in FC between pilots and controls. We performed whole-brain exploratory and region-of-interest (ROI) analyses, with the right parietal operculum 2 (OP2) and the right angular gyrus (AG) as ROIs. Our results show positive correlations with flight experience in the left inferior and right middle frontal gyri, and in the right temporal pole. Negative correlations were observed in primary sensorimotor regions. We found decreased whole-brain functional connectivity of the l...
Purpose Heavily T2-weighted 3D FLAIR (hT2w-3D-FLAIR) sequence with constant flip angle (CFA) has ... more Purpose Heavily T2-weighted 3D FLAIR (hT2w-3D-FLAIR) sequence with constant flip angle (CFA) has been reported as being more sensitive to low concentrations of gadolinium (Gd) enabling endolymphatic hydrops (EH) visualization. The purpose of this study was to compare signal-to-noise (SNR) ratio, detection rate of EH, and increased perilymphatic enhancement (PE) as well as diagnostic accuracy in diagnosing definite Menière’s disease (MD), using 3D-SPACE FLAIR versus conventional 3D-TSE FLAIR. Methods This retrospective study included 29 definite MD patients who underwent a 4-h delayed intravenous (IV) Gd-enhanced 3D-TSE FLAIR and 3D-SPACE FLAIR MRI between February 2019 and February 2020. MR images were qualitatively and quantitatively analyzed twice by 2 experienced head and neck radiologists. Qualitative assessment included grading of cochlear and vestibular EH and visual comparison of PE. Quantitative assessment of PE was performed by placing a region of interest (ROI) and ratio c...
In this work we present the methodology for the development of the EMBalance diagnostic Decision ... more In this work we present the methodology for the development of the EMBalance diagnostic Decision Support System (DSS) for balance disorders. Medical data from patients with balance disorders have been analysed using data mining techniques for the development of the diagnostic DSS. The proposed methodology uses various data, ranging from demographic characteristics to clinical examination, auditory and vestibular tests, in order to provide an accurate diagnosis. The system aims to provide decision support for general practitioners (GPs) and experts in the diagnosis of balance disorders as well as to provide recommendations for the appropriate information and data to be requested at each step of the diagnostic process. Detailed results are provided for
Journal of musculoskeletal & neuronal interactions, 2015
We tested whether intermittent short-radius centrifugation was effective for mitigating alteratio... more We tested whether intermittent short-radius centrifugation was effective for mitigating alteration in balance and gait following bed rest. Ten male subjects were exposed to 5 days of 6° head-down tilt bed rest with: (a) no countermeasure; (b) daily 1-g centrifugation for a continuous 30-min period; and (c) daily 1-g centrifugation for six periods of 5 min. During and after the bed rest, subjects were asked to scale the severity of neurovestibular symptoms that followed centrifugation or 80° head-up tilt. Following the bed rest, equilibrium scores were derived from anterior-posterior sway while standing on a foam pad with the eyes open or closed while making pitch head movements, and gait was evaluated by grading subjects' performance during various locomotion tasks. At the beginning of bed rest, one single 30-min period of centrifugation induced more severe neurovestibular symptoms than six periods of 5-min centrifugation. After bed rest, although equilibrium scores and gait per...
Objectives: Investigate mumps, as a possible cause of sudden deafness, for its relationship with ... more Objectives: Investigate mumps, as a possible cause of sudden deafness, for its relationship with the impairment extent of hearing loss and otolith organs damage. Methods: Twenty-two cases of unilateral hearing impairment in mumps diagnosed in the out-patient department of our hospital have been investigated with audiometry and vestibular evoked myogenic potentials (VEMP) in order to confirm the degree of permanent lesions. Results: Seventeen of twenty-two cases had no response in the test of audiometry, 4 with profound sensorineural hearing loss and 1 with severe sensorineural deafness. In cervical VEMP (cVEMP) test, 14 patients (63.64%) with varied elevated threshold in the affected side, 7 cases (31.82%) with the same threshold binaural sides, 1 case (4.55%) with slightly elevated threshold in the normal side; There were statistical significant differences compared the threshold values of the affected side with that of the normal side, P = 0.000. In ocular VEMP test, 2 of 22 with no response in both sides; Among the other 20 cases, 12 cases (60%) could have at least one ear response with varied elevated threshold in the affected side, 6 cases (30%) with the same threshold binaural sides, 2 cases (10%) with slightly elevated threshold in the normal side; There were statistical significant differences compared the threshold values of the affected side with that of the normal side, P = 0.006. Conclusion: Deafness from mumps is usually profound and permanent. It showed mumps also concerned otolith organs with the functional lesion in vestibular system, yet more slightly than that in auditory system.
The otoliths of the vestibular system are seen as the primary gravitational sensors and are respo... more The otoliths of the vestibular system are seen as the primary gravitational sensors and are responsible for a compensatory eye torsion called the ocular counter-roll (OCR). The OCR ensures gaze stabilization and is sensitive to a lateral head roll with respect to gravity and the Gravito-Inertial Acceleration (GIA) vector during e.g., centrifugation. This otolith-mediated reflex will make sure you will still be able to maintain gaze stabilization and postural stability when making sharp turns during locomotion. To measure the effect of prolonged spaceflight on the otoliths, we measured the OCR induced by off-axis centrifugation in a group of 27 cosmonauts before and after their 6-month space mission to the International Space Station (ISS). We observed a significant decrease in OCR early post-flight, with first- time flyers being more strongly affected compared to frequent or experienced flyers. Our results strongly suggest that experienced space crew have acquired the ability to ada...
Humans undergo extreme physiological changes when subjected to long periods of weightlessness, an... more Humans undergo extreme physiological changes when subjected to long periods of weightlessness, and as we continue to become a space-faring species, it is imperative that we fully understand the physiological changes that occur in the human body, including the brain. In this study, we present findings of brain structural changes associated with long-duration spaceflight based on diffusion magnetic resonance imaging (dMRI) data. Twelve cosmonauts who spent an average of six months aboard the International Space Station (ISS) were scanned in an MRI scanner pre-flight, ten days after flight, and at a follow-up time point seven months after flight. We performed differential tractography, a technique that confines white matter fiber tracking to voxels showing microstructural changes. We found significant microstructural changes in several large white matter tracts, such as the corpus callosum, arcuate fasciculus, corticospinal, corticostriatal, and cerebellar tracts. This is the first pap...
Objective: The purpose of this retrospective study was to determine the vocal characteristics of ... more Objective: The purpose of this retrospective study was to determine the vocal characteristics of a treatment-seeking population with the primary complaint of vocal fatigue (VF). Methods: Forty-three men (mean age 42 years, range 19-69) and 145 women (mean age 34 years, range 18-68) were included. None of the subjects had received voice therapy or previous laryngeal surgery. A questionnaire, laryngeal and perceptual evaluations, aerodynamic and acoustic parameters, and the Dysphonia Severity Index (DSI) were used to determine vocal characteristics. Results: In 74% of the subjects, flexible laryngeal videostroboscopic evaluation revealed a vocal pathology, with vocal nodules and muscle tension dysphonia as the most frequently diagnosed pathologies. Vocal abuse/misuse was present in 65% of the subjects. A median DSI value of -0.4 and -0.8 was found in female and male patients, respectively. Aerodynamic and acoustic parameters and DSI scores were significantly different from normative d...
Objective: The purpose of this paper was to provide an extensive description of a case of sopite ... more Objective: The purpose of this paper was to provide an extensive description of a case of sopite syndrome, a manifestation of motion sickness scarcely described in the literature. Design: The following questionnaires were used to assess sopite syndrome symptoms pre, during and post parabolic flight; Misery Scale rate, Positive and Negative Affect Scale, the Motion Sickness Assessment Questionnaire and the Epworth Sleepiness Scale. Study sample: Case report of a 35-year old female compared to a control group (n=26). Results: We describe of sopite syndrome during parabolic flight. The subject reported drowsiness and she noted mood changes such as irritation and annoyance. Furthermore, she was not able to perform her assigned task. Her symptoms escalated into extreme fatigue and the inability to stay awake. Nauseogenic symptoms improved, but soporific symptoms persisted for several hours after the motion stimulus (i.e. parabolic flight). Conclusions: This case points towards the need for controlled studies to assess the prevalence of this syndrome among the general population and select groups. Future research should focus on developing tests for personnel screening and explore treatment options.
The reported study investigated the effect of 7 rate control methods (RCM) on running speech inte... more The reported study investigated the effect of 7 rate control methods (RCM) on running speech intelligibility, speaking rate (SR), articulation rate (AR) and pause characteristics in 27 individuals with dysarthria. The data reveal that with the exception of slower on demand, each RCM resulted in lower mean SRs and ARs (p < 0.05). Clinically significant improvements in intelligibility were found in half of the participants with different types of dysarthria. The majority of them had normal or decreased ARs and SRs. The most effective methods were: alphabet board, hand tapping and pacing board. For the majority of speakers, the maximal decrease in speech rate was not associated with the maximal increase in intelligibility.
Purpose: This study investigated the effect of rate control methods (RCMs) on speaking rate (SR),... more Purpose: This study investigated the effect of rate control methods (RCMs) on speaking rate (SR), articulation rate (AR), and intelligibility in dysarthric speakers. Method: Nineteen dysarthric patients (7 unilateral upper motor neuron dysarthria, 6 hypokinetic, 3 flaccid, 3 ataxic) participated. SR, AR and intelligibility ratings were determined on the basis of 1-min recorded reading passages. Seven RCMs were applied: voluntary rate control, hand tapping, alphabet board, pacing board and delayed auditory feedback with a delay of 50, 100 and 150 ms. Results: Almost all methods resulted in lower mean SRs and ARs (p < 0.05). Rate control did not improve overall intelligibility of the dysarthric population. However, a meaningful increase of intelligibility was found in 5 participants. This study indicates that the effect of rate control on intelligibility is independent of habitual speech rate and type of dysarthria. Degree of intelligibility may be an influencing factor. The most e...
Background. Sitting balance and the ability to perform selective truncal movements are important ... more Background. Sitting balance and the ability to perform selective truncal movements are important predictors of functional outcome after stroke. However, few clinical trials have evaluated the effect of truncal exercises. Objective. The authors assessed the effect of additional truncal exercises on truncal function, standing balance, and mobility. Methods. An assessor-blinded randomized controlled trial was carried out at a stroke rehabilitation hospital. A total of 33 participants (mean 35 days post onset) were randomly assigned to an experimental group (n = 18) or a control group (n = 15). In addition to conventional therapy, the experimental group received 16 hours of truncal exercises. The control group received 16 hours of sham treatment. Truncal function was evaluated by the Trunk Impairment Scale (TIS) and standing balance and mobility by the Tinetti Test. The Romberg with eyes open and eyes closed, Four Test Balance Scale (FTBS), Berg Balance Scale (BBS), Rivermead Motor Asse...
The purpose of the present study is to measure the effectiveness of two treatment techniques-voca... more The purpose of the present study is to measure the effectiveness of two treatment techniques-vocalization with abdominal breath support and manual circumlaryngeal therapy (MCT)-in patients with muscle tension dysphonia (MTD). The vocal quality before and after the two treatment techniques was measured by means of the dysphonia severity index (DSI), which is designed to establish an objective and quantitative correlate of the perceived vocal quality. The DSI is based on the weighted combination of the following set of voice measurements: maximum phonation time (MPT), highest frequency, lowest intensity, and jitter. The repeated-measures analysis of variance (ANOVA) revealed a significant difference between the objective overall vocal quality before and after MCT. No significant differences were measured between the objective overall vocal quality before and after vocalization with abdominal breath support. This study showed evidence that MCT is an effective treatment technique for patients with elevated laryngeal position, increased laryngeal muscle tension, and MTD. The precise way in which MCT has an effect on vocal quality has not been addressed in this experiment, but merits study. Further research into this topic could focus on electromyography (EMG) recordings in relation to vocal improvements with larger sample of subjects.
Uploads
Papers by Floris Wuyts