Vestibular Agnosia: Toward a Better Understanding of Its Mechanisms

Audiology Research, Journal Year: 2025, Volume and Issue: 15(1), P. 15 - 15

Published: Feb. 11, 2025

Background/Objectives: Vestibular agnosia is characterized by a reduced or absent self-motion perception while demonstrating the presence of normal peripheral vestibular function following stimulation. This condition has previously been reported previous authors in different populations and more recently traumatic brain injury patients. However, underlying mechanisms responsible for remain matter debate. The objective this manuscript to review compare behavioral neuroanatomical findings where demonstrated better understand mechanism. Methods: A literature was conducted using four databases: Medline, Embase, Google Scholar, PubMed. vestibulo-ocular reflex with an impaired stimulation represented inclusion criteria used. Results: Behavioral data reviewed studies revealed clear association postural instability. no consensus can be drawn from due variability impairments those even though parietal cortex are often reported. Conclusions: In general, regarding have poorly documented throughout literature. observed present concomitant control deficits, important predictor falls. Finally, associated agnosia, future required adequately identify Indeed, could part larger network mediating agnosia. proposes various methods that should use overcome limitations.

Language: Английский

Analysis, Design, and Implementation of a User-Friendly Differential Privacy Application

Sensors, Journal Year: 2025, Volume and Issue: 25(5), P. 1358 - 1358

Published: Feb. 23, 2025

In the era of artificial intelligence, ensuring privacy in publicly released data is critical to prevent linkage attacks that can reveal sensitive information about individuals. Differential (DP) has emerged as a robust approach for safeguarding privacy, but its mathematical complexity often limits accessibility non-experts. This paper introduces novel, user-friendly web application bridges gap between theoretical DP concepts and their practical application. The includes two main features: query version, which demonstrates mechanisms statistical queries; privatize applies techniques entire datasets. A key contribution this work identification discrepancies implementation maximum minimum queries within OpenDP library, revealing gaps theory practice. Additionally, foundational framework dataset privatization using OpenDP’s built-in methods. By providing an interactive platform, advances public understanding highlights areas improvement existing libraries. serves both educational tool step toward addressing challenges DP.

Language: Английский

The utility of artificial vestibular stimulation in decoding the pathophysiology of mal de débarquement syndrome

Frontiers in Neurology, Journal Year: 2025, Volume and Issue: 16

Published: March 24, 2025

Mal de débarquement syndrome (MdDS) is an under-recognized and poorly understood illness.Typically triggered by prolonged exposure to passive motion during a voyage on cruise ship or airplane, MdDS primarily characterized continuous phantom perception of oscillatory self-motion such as rocking, swaying, bobbing, sensation gravitational pull (collectively identified non-spinning vertigo) associated sensations imbalance (1)(2)(3).The symptoms are generally accompanied somatic complaints (e.g., headaches visually induced dizziness), reduced cognitive functions decreased attention short-term memory), affective problems depression anxiety). These can be severe enough often lead long-term disability (4)(5)(6) for some patients develop suicidal thoughts (7,8).Transient mal (commonly known "sea legs"), representing the common after-sensation that mimics exposed physical postural instability, has been recognized centuries (9,10). Although MdDS, chronic manifestation débarquement, gained increasing recognition following 1987 publication six-patient case series (1), illness yet permeate awareness clinicians misdiagnosed mental disorder, vestibular migraine, dizziness caused peripheral dysfunction. Patients said typically make 2-5 visits healthcare professionals before their diagnosis, but those who undergo 20 more not uncommon (2,4,5,11). As such, actual prevalence cannot determined presently, at least small percentage seen large clinical centers specializing in balance having (12,13) approximately 80% reported cases women (4,6,14,15).The pathogenesis understood, experience suggests form motion-induced entrainment central pathways (16)(17)(18)(19).MdDS with injury overt structural change nervous system, rather thought disorder generated from synaptic changes reversed (14,(19)(20)(21)(22). Most people spontaneously recover transient within hours several days (16,21). Why condition persists into people, how accompanying clear.The likelihood spontaneous remission decrease time (2,23). Further, once diagnosed face limited treatment options. believed hinge processing, conventional therapy offers little benefit (6,19,24). Some partial symptom relief benzodiazepines, class GABA-A agonists (6,19,21), site pharmaceutical pharmacological action harmful effects including dependence must considered (25,26). Other may improved quality life migraine medications, improvement appears domain-specific, patients' sensitivity medications require greater degree dose management than typical (27,28).It was against this backdrop possible link discovered between velocity storage mechanism system (20,29). This discovery opened opportunities positive outcomes through approaches target neural malleability storage, thereby addressing root cause (14,20,(30)(31)(32).Velocity closely vestibulo-ocular reflex (VOR) it first examined stored eye movement drive prolongs optokinetic responses beyond input activity slow charging discharging (33)(34)(35)(36), also activated proprioceptive cues rotation (37)(38)(39). Indeed, center multimodal sensory integration. In addition ocular reflexes, contribute control (31,40) (34,35,37,41,42). Ocular, postural, perceptual conceptualized sum outputs non-velocity pathways, latter directly relaying (Figure 1) (31,(33)(34)(35)42,43). Sectioning commissural fibers caudal abducens nucleus selectively abolishes sluggish VOR components attributed while sparing fast direct responses, supporting presence separate (44,45).

Velocity does merely prolong signals received sensors, actively reconstructs dynamically reshapes information about self-motion, embodying dynamic working-memory like memory (46). For example, offvertical axis (OVAR) darkness induces compensatory nystagmus activating otolith organs, which sensors normal sense (47). Similarly, stepping place circular treadmill compensates apparent circling (38,39). per-rotatory response off-center facing away direction develops out-of-plane, vertical component centripetal acceleration tilts gravito-inertial field sideways (48). Critically, order interpret incoming perform coordinate transformations these manners, needs maintain its own referential representation three-dimensional space.Studies reflexes have revealed sensorimotor transformation brain facilitated use frame consistent orthogonal arrangement semicircular canals (49)(50)(51)(52)(53). Such aided external related constant gravity terrestrial environment (47,(54)(55)(56)(57). However, organization established exposure-dependent neuroplasticity unusual (29,53,56,58,59). Damage cerebellar vermis (nodulus uvula) compromises ability generate OVAR reorient (60)(61)(62)(63). Therefore, indirect (velocity storage) pathway shaped brainstem-cerebellar interactions subject flexibility internal reference frame. contrast, operate fixed whose outcome gain calibration vector summation channels (64-66) 1).MdDS result failure readapt after adapting (29,59). A approach designed correct presumably maladapted spatial properties combination visual stimuli significantly overall success rate ≈80% ≈50% short long terms, respectively (14,15,20,(30)(31)(32)(67)(68)(69)(70)(71). Still, substantially many do treatment, basis far clear.Physical signs direction-changing present all nor unique they indicate subjective severity (3,20). Instead, diagnosis based solely history reports (3,72). The greatly overlap another persistent (PPPD) (73), represent spectrum vertigo (3,6). worsens PPPD temporarily alleviates (2,3,72). Thus, effect critical difference (3).The reveals inner-ear-driven modulate MdDS. phenomenon known. experimental animals, neurons vestibulo-olivo-cerebellar were found minutes cyclic tilting period motion, vermis, transiently reset by, superimpose with, consisting other frequencies, only resume when stimulus stopped (74). relevance finding clear, vermal adaptation moving well cessation new seem significant given area's close storage.Galvanic stimulation (GVS) affords primary afferents without head, instead passing low electrical current skin over mastoids. GVS becoming widely applied both testing health neurological conditions (75,76), used head virtual/simulated environments (77)(78)(79).Cathodal anodal activates silences afferent fibers, lower threshold irregular regular (75,76,(80)(81)(82). By summation, directionally different elicited. bilateral bipolar anode right side rightward sway (or illusory leftward rotational immobilized subjects), monopolar distant electrode backward (75,78,79). Under certain conditions, blindfolded human subjects steered remotely-controlled walking (83). Bilateral injection noise increases stochastic manner (76) induce non-specific (70,78), 'weird' unpleasantgenerally comfortable less irritating nauseating square-wave pulses equivalent amplitude (84).Bone conducted vibration (BCV) skull 100 Hz means stimulate itself, 1 mm intensity body massager (85)(86)(87). BCV reportedly highly (88)(89)(90), otherwise global because stimulates nerves ears.Normally, bilaterally will negated centrally push-pull system; h. unilateral dysfunction creates asymmetry, forming vibration-induced (SVIN) test (85,87). safety SVIN (85,86). individuals loss disappears abruptly onset BCV, respectively, progressive buildup slow-decaying after-nystagmus (91,92). characteristic behavior seconds even (93,94). interference nystagmic cold caloric intact ear similarly abrupt accordance duration SVIN, indicating separately sustained (92). "tilt dump" (95) concurrent otolithic ruled out explanation lack SVIN.From characteristics underlying hypothesized bypass (96,97). afferents' contribution supported existing knowledge.Vestibular type I II hair cells contact calyceal bouton endings roughly firing patterns (97,98).Vestibular phylogenetically new, anamniotes (fishes amphibians) cells, species demonstrate well-functioning (99)(100)(101)(102). sinusoidal genetically manipulated mice deficient cell development suggest impaired (98). note significance, however, selectivity afferents, modest observed accompany GVS-induced (103,104). GVS, thus level recruitment required higher inducing (75,81,82,105).Although etiology factors mechanisms postulated, maladaptation (20,29), cerebral networks (106), (27,28), hormonal dysregulation (107,108). Since damage, glance inform pathophysiology illness. if temporary alleviation low-intensity GVS. preferentially activate negative would specific role modulating indirectly support storagebasis pathogenesis. pathogenic necessitate revision understanding potential utility still accessed high-intensity find utility.Lastly, premorbid asymmetry activation naturally interacting environment, possibly making individual susceptible (59). useful probing possibility.MdDS debilitating presently understood.An animal-based model (29,59,109).BCV well-studied artificial safely tested patients.Since may, perhaps degree, mechanism, studying fill piece puzzle pathophysiology.

Language: Английский

Citations

0

---

Galvanic vestibular stimulation for Mal de Debarquement syndrome: a pilot study on therapeutic potential

Catho Schoenmaekers,

Dario De Smet,

Stefaan Peeters

et al.

Experimental Brain Research, Journal Year: 2025, Volume and Issue: 243(6)

Published: May 14, 2025

Language: Английский

Citations

0

---

Virtual reality application matches the most established treatment for Mal de Debarquement Syndrome: A non-inferiority, randomized, open clinical trial

Catho Schoenmaekers,

Dario De Smet,

Choi Deblieck

et al.

Neurotherapeutics, Journal Year: 2024, Volume and Issue: 21(5), P. e00390 - e00390

Published: June 27, 2024

Mal de Debarquement Syndrome (MdDS) is a debilitating neuro-otological disorder where individuals consistently feel self-motion, often triggered by motion like being on boat (MT-MdDS). Due to the unknown pathophysiological mechanism, available treatment options for managing symptoms are limited. Our objective was develop virtual reality application (VRA) simulate full field optokinetic stimulation (OKS) booth and evaluate its efficacy compared standard treatment. In our randomized, open, non-inferiority clinical trial with 30 ​MT-MdDS patients, 15 received OKS new VRA over four consecutive days. Two 4-min blocks were scheduled in morning afternoon, total of blocks. Treatment effectiveness evaluated through questionnaires posturography. findings suggest that choice modality does not significantly differ achieving an overall improvement symptoms. We advocate can be used as accessible alternative method worldwide, effectively mitigating MdDS enhancing QoL numerous patients.

Language: Английский

Citations

2

---

On labyrinthine function loss, motion sickness immunity, and velocity storage

Jun Maruta

Frontiers in Neurology, Journal Year: 2024, Volume and Issue: 15

Published: June 28, 2024

Keywords: cerebellar nodulus, mal de débarquement, nystagmus, semicircular canals, space flight, spatial orientation, vestibular habituation, vestibulo-ocular reflex (VOR)

Language: Английский

Citations

2

---