Neck Vibration Research Articles

Investigating the influence of neck muscle vibration on illusory self-motion in virtual reality

The illusory experience of self-motion known as vection, is a multisensory phenomenon relevant to self-motion processes. While some studies have shown that neck muscle vibrations can improve self-motion parameter estimation, the influence on vection remains unknown. Further, few studies measured cybersickness (CS), presence, and vection concurrently and have shown conflicting results. It was hypothesized that 1) neck vibrations would enhance vection and presence, and 2) CS to negatively relate to presence and vection, whereas presence and vection to positively relate to one another. Thirty-two participants were visually and audibly immersed in a virtual reality flight simulator and occasional neck muscle vibrations were presented. Vection onset and duration were reported through button presses. Turning angle estimations and ratings of vection quality, presence, and CS were obtained after completion of the flights. Results showed no influence of vibrations on turning angle estimation errors, but a medium positive effect of vibrations on vection quality was found. Presence and vection quality were positively related, and no strong association between CS and presence or vection was found. It is concluded that neck vibrations may enhance vection and presence, however, from the current study it is unclear whether this is due to proprioceptive or tactile stimulation.

Vocal Dose and Vocal Demands in Contemporary Musical Theatre.

To document and quantify vocal dose and student-singers' self-assessment during rehearsals for a contemporary musical theater production. Six student singers fastened the sensor from the KayPentax APM 3200 dosimeter to the lower neck to capture neck vibration data during their preparation for the musical Wonderland by Frank Wildhorn. Data were collected during 8-hour periods, at four different stages throughout the rehearsal process: beginning (music and choreography learning phase), middle (staging phase), and end (running the entire show/dress rehearsal phase), plus a post-production day once the production had concluded to establish a baseline vocal load. Students concurrently completed the EASE questionnaire1 after each data collection day. The EASE score (Appendix1) and demographics/perceptual questionnaire (Appendix2) revealed that all subjects (three males and three females) found the singing role vocally and physically demanding but only two found the roles to be emotionally challenging. The musical score demanded a higher usage of chest register (judged perceptually) than mixed register from lead singers. All subjects' maximum fundamental frequency range exceeded the pitch range required by the score. The mean daily vibration dose (distance dose, as computed with Kay Pentax Software) of the three individual female singers' during rehearsals, 5,203 meters, was higher than the mean daily dose of the three male singers, 3,766 meters. The subjects' self-ratings on the EASE were not correlated with the distance dose. A review of Wonderland's score and perceptual judgment of the singers' performances revealed extensive use of chest register, with belting and mix vocal strategies being the predominant stylistic choices. Students described the singing roles' vocal and physical requirements as more challenging than the character's emotional components. This pilot study provides information on the vocal dose for lead and ensemble singers in rehearsal for a Contemporary Musical Theatre production. Singers and voice professionals may find dosimetry a valuable tool for monitoring the vocal dose during rehearsals and performances.

Vocal Demands of Musical Theatre Rehearsals: A Dosimetry Study

To investigate singers' vocal load by documenting three types of vocal doses (time, cycle, and distance doses) and sound pressure levels during the four phases of rehearsal and how the vocal doses vary between singers across rehearsals in the musical Nine, written by Maury Yeston. Five student-singers participating in the musical Nine gave informed consent to participate in the study. All five participants were assigned female at birth and female-identifying individuals. They attached a KayPENTAX APM 3300 dosimeter sensor to their lower neck and wore the accelerometer during four three-hour rehearsals throughout the rehearsal process (the music learning phase, the choreography learning phase, the blocking learning phase, and the dress rehearsal) of the musical. The dosimeter records neck vibrations at a rate of 20 samples per second. but it does not record linguistic content. A dosimetric analysis of five student singers identified variability in voice production throughout the rehearsal process. According to the dosimetry findings, singers employed extensive low-frequency voicing below the first passaggio, with belting and mixed vocal strategies as the predominant stylistic choices when performing in Nine. Additionally, the singers used an occasional head voice effect at specific moments. The roles of Carla, Saraghina, La Fleur, and Ensemble One and Two required specific vocal ranges due to the musical score. Researchers have yet to establish a safe baseline vocal dose for singers. The vocal dose is affected by many factors, such as duration of phonation, frequency range, SPL, and styles of vocalism required by the score. Louder and heavier vocalization produces larger distance doses, representing the cumulative load placed on vibrating tissue. The cycle dose, distance dose, and SPL reported in this study varied within and between singers. The phonation density graphs show this variability and the low tessitura required by the score. Time doses ranged from 4% to 7% of rehearsal time; this short dose suggests that the rehearsals provided healthy conditions for the successful rehearsal process with efficient attention to the vocalization of a score that requires heavy vocal styles, including belting. While the rehearsal pace was not alarming, the demands of the score alone may prove to be much greater than the vocal dose reported through the rehearsal. Further studies are needed to establish the overall dose of each Broadway role to serve as parameters for vocal pacing and voice care.

Neck Muscle Vibration Alters Cerebellar Processing Associated with Motor Skill Acquisition of a Proprioceptive-Based Task.

Experimentally induced neck fatigue and neck pain have been shown to impact cortico-cerebellar processing and sensorimotor integration, assessed using a motor learning paradigm. Vibration specifically impacts muscle spindle feedback, yet it is unknown whether transient alterations in neck sensory input from vibration impact these neural processing changes following the acquisition of a proprioceptive-based task. Twenty-five right-handed participants had electrical stimulation over the right median nerve to elicit short- and middle-latency somatosensory evoked potentials (SEPs) pre- and post-acquisition of a force matching tracking task. Following the pre-acquisition phase, controls (CONT, n = 13, 6 F) received 10 min of rest and the vibration group (VIB, n = 12, 6 F) received 10 min of 60 Hz vibration on the right sternocleidomastoid and left cervical extensors. Task performance was measured 24 h later to assess retention. Significant time by group interactions occurred for the N18 SEP peak, 21.77% decrease in VIB compared to 58.74% increase in CONT (F(1,23) = 6.475, p = 0.018, np2 = 0.220), and the N24 SEP peak, 16.31% increase in VIB compared to 14.05% decrease in CONT (F(1,23) = 5.787, p = 0.025, np2 = 0.201). Both groups demonstrated improvements in motor performance post-acquisition (F(1,23) = 52.812, p < 0.001, np2 = 0.697) and at retention (F(1,23) = 35.546, p < 0.001, np2 = 0.607). Group-dependent changes in the SEP peaks associated with cerebellar input (N18) and cerebellar processing (N24) suggests that an altered proprioceptive input from neck vibration impacts cerebellar pathways.

Using Neck Muscle Afferentation to Control an Ongoing Limb Movement? Individual Differences in the Influence of Brief Neck Vibration.

When preparing and executing goal-directed actions, neck proprioceptive information is critical to determining the relative positions of the body and target in space. While the contribution of neck proprioception for upper-limb movements has been previously investigated, we could not find evidence discerning its impact on the planning vs. online control of upper-limb trajectories. To investigate these distinct sensorimotor processes, participants performed discrete reaches towards a virtual target. On some trials, neck vibration was randomly applied before and/or during the movement, or not at all. The main dependent variable was the medio-lateral/directional bias of the reaching finger. The neck vibration conditions induced early leftward trajectory biases in some participants and late rightward trajectory biases in others. These different patterns of trajectory biases were explained by individual differences in the use of body-centered and head-centered frames of reference. Importantly, the current study provides direct evidence that sensory cues from the neck muscles contribute to the online control of goal-directed arm movements, likely accompanied by significant individual differences.

Proprioceptive Modulation of Pallidal Physiology in Cervical Dystonia.

There is a growing body of evidence suggesting that botulinum toxin can alter proprioceptive feedback and modulate the muscle-spindle output for the treatment of dystonia. However, the mechanism for this modulation remains unclear. We conducted a study involving 17 patients with cervical dystonia (CD), seven of whom had prominent CD and 10 with generalized dystonia (GD) along with CD. We investigated the effects of neck vibration, a form of proprioceptive modulation, on spontaneous single-neuron responses and local field potentials (LFPs) recorded from the globus pallidum externus (GPe) and internus (GPi). Our findings demonstrated that neck vibration notably increased the regularity of neck-sensitive GPi neurons in focal CD patients. Additionally, in patients with GD and CD, the vibration enhanced the firing regularity of non-neck-sensitive neurons. These effects on single-unit activity were also mirrored in ensemble responses measured through LFPs. Notably, the LFP modulation was particularly pronounced in areas populated with burst neurons compared to pause or tonic cells. The results from our study emphasize the significance of burst neurons in the pathogenesis of dystonia and in the efficacy of proprioceptive modulation for its treatment. Moreover, we observed that the effects of vibration on focal CD were prominent in the α band LFP, indicating modulation of pallido-cerebellar connectivity. Moreover, the pallidal effects of vibration in GD with CD involved modulation of cerebro-pallidal θ band connectivity. Our analysis provides insight into how vibration-induced changes in pallidal activity are integrated into the downstream motor circuit. © 2023 International Parkinson and Movement Disorder Society.

Does vibration frequency and location influence the effect of neck muscle vibration on postural sway? A cross-sectional study in asymptomatic participants.

Postural control is of utmost importance for human functioning. Cervical proprioception is crucial for balance control. Therefore, any change to it can lead to balance problems. Previous studies used neck vibration to change cervical proprioception and showed changes in postural control, but it remains unknown which vibration frequency or location causes the most significant effect. Therefore, this study aimed to investigate the effect of different vibration frequencies and locations on postural sway and to serve as future research protocol guidance. Seventeen healthy young participants were included in the study. We compared postural sway without vibration to postural sway with six different combinations of vibration frequency (80, 100, and 150Hz) and location (dorsal neck muscles and sternocleidomastoid). Postural sway was evaluated using a force platform. The mean center of pressure (CoP) displacement, the root mean square (RMS), and the mean velocity in the anteroposterior and mediolateral direction were calculated, as well as the sway area. The aligned rank transform tool and a three-way repeated measures ANOVA were used to identify significant differences in postural sway variables. Neck vibration caused a significant increase in all postural sway variables (p < 0.001). Neither the vibration frequency (p > 0.34) nor location (p > 0.29) nor the interaction of both (p > 0.30) influenced the magnitude of the change in postural sway measured during vibration. Neck muscle vibration significantly changes CoP displacement, mean velocity, RMS, and area. However, we investigated and found that there were no significant differences between the different combinations of vibration frequency and location.

Effects of neck proprioceptive modulation on pallidal network connectivity in dystonia.

Cervical dystonia (CD) is the third most common movement disorder affecting 1 million people worldwide. Proprioceptive modulation is the hallmark of contemporary therapies for dystonia, but the mechanism for this intervention is unclear. We studied proprioceptive influence on CD by measuring the spontaneous single-neuron responses and local field potentials (LFP) from the globus pallidus interna (GPi) in 17 CD patients (9 isolated CD and 8 with CD as a feature of generalized dystonia). The goal was to examine how high-frequency neck vibration, a putative modulator of neck proprioception changes pallidal physiology. We found that the neck vibration instantaneously alters the pallidal single neuron activity. We also found that neck vibration modulates pallido-cerebellar connectivity by changing alpha band in LFP recordings. The effects were more robust in those with isolated CD. The vibration also affects pallido-hippocampal connectivity by modulating theta-band power. These effects were more robust in CD with generalized dystonia. Vibration changed LFP only in select pallidal regions. Regions where LFP power was substantially modulated had a prominent proportion of burst subtypes of neurons, compared to pause or tonic subtypes. Such disparity in subtype was absent in regions where the LFP power was not modulated or subtly reduced with neck vibration. When changes in the theta, alpha and beta bands of the LFP recordings were compared against each other in response to vibration, high correlation was observed.

P14: Vibration-Mediated Endothelial Cell-Platelet Interaction: A Thrombotic Risk Factor in Obstructive Sleep Apnea and Beyond

Background: Obstructive sleep apnea (OSA) is an independent risk factor for thrombotic stroke. OSA stroke is felt to be driven by hypoxia and post apneacatecholamine surge, leading to platelet activation and thrombosis. OSA is also associated with significant snoring and related neck vibration. In our work related to thrombogenicity of mechanical circulatory support (MCS) devices we demonstrated that device vibration and related shear are biomechanical activators of platelets. Recently we showed that snore-associated vibration is platelet activating. As OSA snore, vibration is imparted to major neck blood vessels, i.e. carotid and jugular, and activated platelets interact with vessel endothelial cells, the effect of vibration on endothelial thrombogenicity warrants further definition. Methods: OSA snore recordings were obtained from the human sleep lab. A speaker-platform device, validated to generate snore neck vibrations, was fabricated (snore emulator). Human umbilical vein endothelial cells (HUVECs) grown on petri dishes, placed on the emulator and exposed to snore vibrations for 4,8,12, 24,or 36 hours at 37oC., non-vibration cultures serving as controls. HUVEC viability (LDH assay) and platelet adhesion (inactivated platelets bound, measured via scanning EM) were serially assessed. Results: HUVEC exposed to snore vibration remained viable, though with a progressive decline in viability vs control, i.e. a 28.9% and 46.5% reduction at 24h and 36h, respectively (p<0.05). Interestingly, vibration led to a disproportionally greater increase in thrombogenicity, with net platelet adhesion increasing by 64% and 86% at 24h and 36h respectively (p<0.05) Conclusion: Vibration, as a general biomechanical stimulus, previously demonstrated to increase platelet activation, also leads to endothelial dysfunction, including loss of viability, with an even greater increase in endothelial thrombogenicity. Further definition of vibration-mediated endothelial dysfunction has implication for developing translational therapeutics for OSA, as well as providing insight for endothelial-contacting therapeutic device design.

Assessing the cervico-ocular reflex system via modifying the ocular vestibular-evoked myogenic potential test

Purpose The aim of this study was to devise a novel test for assessing the cervico-ocular reflex (COR) system via head vibration (termed h-COR) or neck vibration (termed n-COR) method. Materials and methods Thirteen patients with complete loss of bilateral vestibulo-ocular reflex (VOR) showing oscillopsia were assigned to Group A, while 13 patients with bilateral VOR loss but no oscillopsia were Group B. Another 13 healthy elderly served as a control. The COR test was performed via modifying the ocular vestibular-evoked myogenic potential (oVEMP) test by tapping at the forehead with head rotation (h-COR) or at mid-dorsal neck with head straight (n-COR). Results Both h-COR and n-COR tests displayed similar cI–cII waveforms. None of the Group A or healthy elderly showed present h-COR, while 8% of Group A and 31% of the healthy elderly revealed present n-COR. In contrast, present h-COR and n-COR were elicited in 85 and 77% of Group B, respectively. Restated, significantly higher response rate of COR in Group B (without oscillopsia) than Group A (with oscillopsia) indicates that present COR is related to the alleviation of oscillopsia. Conclusions Head vibration method (h-COR test) is superior to neck vibration method (n-COR test) for assessing the COR system.

Nonlinearly Frequency-Adaptive, Self-Powered, Proton-Driven Somatosensor Inspired by a Human Mechanoreceptor.

In the human skin, it has been well known that several mechanoreceptors uniquely sense external stimuli with specific frequencies and magnitudes. With regard to sensitivity, the output response shows nonlinearity depending on the frequency magnitude of the stimulus. We demonstrate a self-powered proton-driven solid-state somatosensor, which mimics a unique nonlinear response and intensity behavior of human mechanoreceptors. For this, a solid-state sensor is fabricated by combining a piezoelectric film and a proton generation device. The proton injection electrode and the Nafion layer conjugated with sulfonated graphene oxide are used for proton generation and transport. Two types of nonlinear signals from the sensor are similar to the Merkel/Ruffini (low deviation of threshold intensity), and in contrast, the behavior of Pacinian/Meissner (high deviation of threshold intensity) is simultaneously shown. The region of the most responsive frequency is also discriminated according to proton conduction. Moreover, it is asserted that unique signal patterns are obtained from the stimuli of various frequencies, such as respiration, radial artery pulse, and neck vibration, which naturally occur in the human body.

Difference between neck muscle vibration and gluteus muscle vibration on standing balance in healthy subjects

Introduction Muscle vibrations can be used to induce a body tilt. Even though several muscle sites have been tested for various diseases their respective mode of action were not highlighted. The objective was to compare the effects of neck muscle vibrations (NMV) and gluteus medius vibrations (GMV) on posture in healthy subjects. Material and methods Thirty-one healthy subjects (23yr ± 2) were tested, closed eyes, in standing position on force platform with Optitrack 3D capture system. They received successively a 5 min-session of NMV and 5 min-session of GMV in a randomized order. They were evaluated during the vibration, immediately at the end of the vibration and 5 minutes after. Results GMV induced a Center of Pressure tilt to the opposite side of the vibration (−7.6 ± 2 mm P Discussion These results are in favor of a different mode of action between neck and gluteus medius vibrations.

Sensory trick efficacy in cervical dystonia is linked to processing of neck proprioception

BackgroundMuscle vibration activates muscle spindles and when applied over posterior neck muscles during stance modulates global body orientation. This is characterised by a tonic forward sway response that is reportedly diminished or absent in patients with idiopathic cervical dystonia. ObjectiveTo investigating the impact of the sensory trick on vibration-induced postural responses. Methods20 patients with idiopathic cervical dystonia and a sensory trick, 15 patients without a trick, and 16 healthy controls were recruited. Neck muscle vibration was applied bilaterally over the upper trapezius under three different conditions: 1) Quiet standing; 2) standing while performing the trick (or trick-like movement in non-responders); 3) standing while elevating the flexed arm without touching any part of the body. Centre of pressure position and whole-body orientation in the sagittal plane were analysed. ResultsPatients with a sensory trick responded similarly to healthy controls: neck muscle vibration led to an initial forward sway of the body that slowly increased during the prolonged vibration for all three conditions. This response was mainly mediated by ankle flexion. In patients without a trick, the initial sagittal sway was significantly reduced in all three conditions and the later slow increase was absent. Performance of the trick did not have an effect on any aspect of the response in either cervical dystonia group. ConclusionsThe whole-body response to neck vibration in cervical dystonia differs depending on the effectiveness of the sensory trick to alleviate the dystonic neck posture. Variable pathophysiology of proprioceptive processing may be the common factor.

Effects of repetitive neck muscle vibrations on postural disturbances in standing position in chronic patients

Asymmetrical postural behaviors are frequent and related to poor equilibrium after a stroke. Proprioceptive neck vibration corrects in the short term the postural asymmetry probably through a sensory recalibration, but the effects of repetitive has yet to be tested. The objective was to test the effects of repetitive neck muscle vibration (rNMV) on postural disturbances and on spatial frame reference in right (RBD) and left (LBD) brain damage patients. Thirty-two chronic stroke patients (mean age 60.9 ± 10 y and mean delay after stroke 4.9 ± 4 years), 16 RBD and 16 LBD, underwent a program of 10 sessions of vibrations (10 min) during a period of two weeks. Postural asymmetry on force platform (Weight Body Asymmetry WBA), spatial frames (Subjective Straight Ahead SSA, Longitudinal Body Axis LBA, Subjective Visual Vertical SVV) and clinical assessment (Motricity Index, Sensibility, Spasticity, Berg Balance Scale, Time Up and Go) were ascertained at the end of the vibrations (D + 15) and at D + 22, D + 45. In the post-test, the results were depending of the side of the lesion with a significant reduction in WBA in the RBD ( P = 0.0001), whereas no effect was observed in the LBD. No significant modification was found on the spatial frame in both groups. A significant improvement was found for the Motricity, TUG and BBS in the both groups at the end and at distance. rNMV causes a reduction of postural asymmetry only in the RBD patients. These results suggest that rNMV could be effective on sustainable disorders of balance of spatial cognition disorders. Further, this result was not maintained at distance.

Exploring head and neck vibration exposure from quad bike use in agriculture

ObjectivesAlthough musculoskeletal disorders of the low back have been linked to excessive whole body vibration during vehicle use, there is a need to explore head/neck vibration in occupational environments. Resonant frequencies may amplify vibration transmitted to the head/neck and increase risk of musculoskeletal disorders. MethodsAn observational fieldwork study directly measuring vibration exposure at the seat and head of 10 rural workers operating quad bikes over farm terrain for ∼30 min. ResultsVertical axis root-mean-squared acceleration was higher at the head/neck compared to the seat. Mean spectral coherence was strong (>0.8) in the vertical axis from 1.3 to 4.9 Hz, indicating a strong relationship between vertical vibrations measured at the seat and the head. Power spectral densities demonstrated system amplification, with mean and peak seat-to-head transfer functions of 1.44 (95% CI ± 0.08) and 1.66 (±0.14), respectively, from 1.3 to 4.9 Hz. There was also a peak phase lag of −66.5° (±13.9°) at 4.9 Hz for head relative to seat measured vertical vibration, which may increase compressive loads of the cervical spine. ConclusionsWhile it is unknown whether these amplified and out-of-phase vibrations measured at the head/neck increase the risk of musculoskeletal disorder, the current biodynamic response to vibration exposure may help explain previously reported high prevalence of neck pain in farmers that use quad bikes. Our future laboratory based studies will aim to validate these fieldwork seat and head data and explore the effect of such vibration transmission on spinal biomechanical models as well as on proprioceptive and perceptual pathways that may also relate to injury.

Neck Vibration Proprioceptive Postural Response Intact in Progressive Supranuclear Palsy unlike Idiopathic Parkinson's Disease.

Progressive supranuclear palsy (PSP) and late-stage idiopathic Parkinson’s disease (IPD) are neurodegenerative movement disorders resulting in different postural instability and falling symptoms. IPD falls occur usually forward in late stage, whereas PSP falls happen in early stages, mostly backward, unprovoked, and with high morbidity. Postural responses to sensory anteroposterior tilt illusion by bilateral dorsal neck vibration were probed in both groups versus healthy controls on a static recording posture platform. Three distinct anteroposterior body mass excursion peaks (P1–P3) were observed. 18 IPD subjects exhibited well-known excessive response amplitudes, whereas 21 PSP subjects’ responses remained unaltered to 22 control subjects. Neither IPD nor PSP showed response latency deficits, despite brainstem degeneration especially in PSP. The observed response patterns suggest that PSP brainstem pathology might spare the involved proprioceptive pathways and implies viability of neck vibration for possible biofeedback and augmentation therapy in PSP postural instability.

The long-lasting effects of repetitive neck muscle vibration on postural disturbances in standing position in chronic patients

Introduction Asymmetrical postural behaviours are frequent and related to poor equilibrium after a stroke. Proprioceptive neck vibration could correct the postural asymmetry through a sensory recalibration but the long lasting effect has not yet tested. Objective To test the long-lasting effects of repetitive neck muscle vibration (rNMV) on postural disturbances and on spatial frame reference in chronic patients. Methods Twenty chronic stroke patients (mean age: 61.4 y11, mean delay since stroke: 5.5y3), 10 right (RDB) and 10 left (LDB) brain damage, underwent a program of 10 vibrations of 10 min sessions during two weeks–the evaluation of postural asymmetry on force platform (weight body asymmetry WBA), spatial frames (subjective straight ahead SSA, longitudinal body axis LBA, subjective visual vertical SVV) and clinical assessment (Motricity Index, Sensibility, Spasticity, Berg Balance Scale, time up and go) were ascertained before (D−15, D0) and at the end of the vibrations (D + 15, D + 22, D + 45). Results In the post-test, a significant reduction in WBA was established in the RBD (P = 0.009) and was maintained at D + 15 (P = 0.01) and D + 22 (P = 0.05), no effect was observed in the LBD. In addition, no significant modification was found on the spatial frame in both group. A significant improvement was found for the motricity and time up and go in the RBD. Discussion rNMV causes a reduction of postural asymmetry in the RBD group independently of the space representation improvement. Likewise, rNMV can modify the postural asymmetry in chronic patients but this result was not maintained at D + 45.

Ocular vestibular evoked myogenic potentials (o-VEMPs) testing in cervicogenic vertigo and its relation to radiological findings: a correlation study

Background: The term cervicogenic vertigo is reserved for cases where the suspected mechanism is proprioceptive. For a diagnosis of cervicogenic vertigo, it is essential to exclude other causes of vertigo. Generally, the patient has no hearing complaints and characteristically the symptoms are elicited by neck massage or neck vibration. The ocular vestibular evoked myogenic potential (o-VEMP) is a test for utricular function that has been introduced and validated.Objectives: To assesses o-VEMPs in patients with cervicogenic vertigo using 500 Hz tone bust stimuli at 95 dB nHL. Consequently, correlate the relation between o-VEMPs test results and radiological imaging, in the form of MRI cervical spine and CT angiography of the vertebral artery.Subjects: Fifty two subjects participated in the study; the group comprised 32 patients with diagnosed cervicogenic vertigo and also included 20 healthy matched adults.Methods: A random sample of consenting case and control subjects were obtained. MRI cervical spine with CT angiography of vertebral artery was done with o-VEMPs recordings.Results: Abnormal MRI cervical spines were found in all study group participants. The results for the CT angiography were variable with abnormal o-VEMPs latencies.Conclusion: A link co-exists between utricle and superior vestibular nerve in patients with cervicogenic vertigo. This may play a role in the pathogenesis of vertigo in these affected patients.

Combining left neck muscle vibration to voluntary arm movements: To new perspectives in the therapeutic care in neglect

Among “Bottom-Up” treatments of unilateral spatial neglect (USN), left neck muscle vibration may reduce clinical symptoms in patients with right-sided brain damage. Shifting whole egocentric coordinate system, one of interests of this stimulation is that the patient is unaware of the perceptual and behavioral changes induced. Moreover, several studies have shown superior effects of combination treatments when their own effects were convergent. However, their practical applications are often conflicting with the constraints of patient care. This study aimed to assess the effects of a protocol of left neck muscle vibration during arm movements in the peri-personal space on the egocentric and allocentric perceptions of patients with left-sided spatial neglect (USNleft). Five USNleft patients (54.5 ± 5.5 years) were asked to perform the Marguerite test and a haptic straight-ahead test (20 ballistic pointings) without vision before protocol (Pre), immediately after (Post0), one hour later (Post1 h). During a therapeutic protocol of 15 minutes left trapezius muscle vibration (100 Hz–300 μm), they were asked to point to one of 5 lit targets [0° (straight ahead), 10° and 20° on the right and on the left], from the base of the chin rest with their right index finger, as quickly as possible. The results suggested a reduction of neglect symptoms for at least 1 hour after the protocol. The Marguerite test (Pre = 20.01 ± 8.21) showed an evolution by step of the laterality index with a dramatic decreasing at Post0 (−13.29), followed by a small reduction of this effect at Post1 h (−5.82). The errors during straight-ahead test (Pre = 12.66° ± 10) indicated a left lasting deviation after the protocol (stimulation effect at Post0 = −3.49°; Post1 h = −4.80°). Combining left neck vibration to arm movements has shown allocentric and egocentric improvements lasting for at least 1 hour, and our data in progress even suggest during 24 hours. Non-invasive and simple to use, these promising findings for the rehabilitation of spatial cognition disorders argue in favor of the ecological use of the vibratory tool during the rehabilitation sessions.

Vibration over the larynx increases swallowing and cortical activation for swallowing

Sensory input can alter swallowing control in both the cortex and brainstem. Electrical stimulation of superior laryngeal nerve afferents increases reflexive swallowing in animals, with different frequencies optimally effective across species. Here we determined 1) if neck vibration overlying the larynx affected the fundamental frequency of the voice demonstrating penetration of vibration into the laryngeal tissues, and 2) if vibration, in comparison with sham, increased spontaneous swallowing and enhanced cortical hemodynamic responses to swallows in the swallowing network. A device with two motors, one over each thyroid lamina, delivered intermittent 10-s epochs of vibration. We recorded swallows and event-related changes in blood oxygenation level to swallows over the motor and sensory swallowing cortexes bilaterally using functional near infrared spectroscopy. Ten healthy participants completed eight 20-min conditions in counterbalanced order with either epochs of continuous vibration at 30, 70, 110, 150, and 70 + 110 Hz combined, 4-Hz pulsed vibration at 70 + 110 Hz, or two sham conditions without stimulation. Stimulation epochs were separated by interstimulus intervals varying between 30 and 45 s in duration. Vibration significantly reduced the fundamental frequency of the voice compared with no stimulation demonstrating that vibration penetrated laryngeal tissues. Vibration at 70 and at 150 Hz increased spontaneous swallowing compared with sham. Hemodynamic responses to swallows in the motor cortex were enhanced during conditions containing stimulation compared with sham. As vibratory stimulation on the neck increased spontaneous swallowing and enhanced cortical activation for swallows in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.NEW & NOTEWORTHY Vibratory stimulation at 70 and 150 Hz on the neck overlying the larynx increased the frequency of spontaneous swallowing. Simultaneously vibration also enhanced hemodynamic responses in the motor cortex to swallows when recorded with functional near-infrared spectroscopy (fNIRS). As vibrotactile stimulation on the neck enhanced cortical activation for swallowing in healthy participants, it may be useful for enhancing swallowing in patients with dysphagia.