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Patients with acute vestibulopathy are among the most uneasy (in terms of severity of symptoms) and challenging (in terms of determining the level of damage). At the same time, the methods of traditional otoneurological examination often do not allow to reveal the cause of unexpected balance disorders. In order to determine the degree of vestibular function decompensation and develop the tactic for the urgent treatment, Saint Petersburg Research Institute of Ear, Throat, Nose and Speech uses both screening methods included in the Vestibular Passport and computerized vestibulometry techniques. Methods of oculomotor and postural reactions assessment are described in details using the example of case history. The high diagnostic significance of the results of instrumental vestibulometry using the Frenzel glasses, foam pad, computer electrooculography, video oculography and computer dynamic posturography is demonstrated. The therapeutic tactics of managing a patient with acute mixed vestibulopathy is shown.

Background: Establishing an association between gait variability and direction specific balance indices may help in identifying the risk of falls in patients with spinocerebellar ataxia (SCA) which may help in developing an appropriate intervention. This study is intended to identify the association between balance and gait parameters especially gait variability in these patients. Methods: Patients with genetically confirmed SCA (n = 24) as well as controls (n = 24) who met the study criteria were recruited. Gait was assessed using the GAITRite system and balance was assessed using dynamic posturography (Biodex) to record direction-specific dynamic balance indices. Disease severity was assessed using international cooperative ataxia rating scale (ICARS). Results: The mean age of the SCA group (38.83 ± 13.03 years) and the control group (36.38 ± 9.09 years) were comparable. The age of onset of illness was 32 ± 10.62 years and duration of 5.67 ± 3.62 years. The mean ICARS was 45.10 ± 16.75. There was a significant difference in the overall balance index (OBI), anterior–posterior index (API), medial/lateral index (MLI) between SCA patients (4.56 ± 2.09, 3.49 ± 1.88, 2.94 ± 1.32) and the controls (2.72 ± 1.25, 2.08 ± 0.85, 1.85 ± 0.97). However, correlation was observed only between gait stability and balance parameters in API direction. Conclusions: There was an increased anteroposterior oriented balance deficit in patients with SCA, which was significantly correlating with the gait parameters. The balance training intervention may focus on improving anteroposterior direction to prevent falls and improving walking efficiency.

Posture of human body corresponds to a certain stable relationship between head, torso and limbs, where a minimal amount of energy is needed for its support. Although clinicians in the field have studied the connection between the muscle chains, maintaining balance of the body, and the musculature in the maxillofacial area (cervical, masticatory), more can be studied and proven in the area. If there is a change of the center of gravity of the body, it is certain that a negative change of posture has been diagnosed. Postural disorders are increasingly common nowadays. The prevalence of musculoskeletal disorders is increasing as well, along with temporomandibular disorders (TMD), vertigo, dizziness, tinnitus, memory loss and others. The present study aims to demonstrate the need for complex examination of patients with symptoms from the audiovestibular system, stomatognathic and other anatomical systems in the head and neck area. In the present study, 40 (20 male and 20 female) patients who have passed through the Audio-vestibular and Sleep laboratory of the University Medical and Dental Center at the Faculty of Dental Medicine of Medical University – Varna in the period February – June 2022 were included. All of them were invited to fill out an informed consent form. They were also given questionnaires to describe the symptoms, concerning audio-vestibular and stomatognathic systems. Thorough examinations were performed by an ENT-specialist and a physician in dental medicine. All patients were examined on a dynamic stabilometric platform, under different modalities – with eyes open/closed, teeth clenched/relaxed, head tilted left and right, for fixed amount of time – 20 sec. Posturographic platform is not a source of ionizing radiation. Patients who reported pain and noise from the temporomandibular joints, when examined with the posturography platform, shifted the center of gravity of the body more often backwards and to the right side (especially if the TMD was bilateral). In patients who also had vestibular symptoms (dizziness, vertigo), with or without a disorder in the mandibular joints, the center of gravity of the body was more often shifted back and to the right as well. Most of the patients with the described displacement also had an orthodontic deformity. Based on intraoral dental examination, cephalograms, and analysis, patients with Angle class 2 (distal bite), crossbite in the lateral area, laterognathia were diagnozed, the first being the most common in patients with a shift in the center of gravity. In all studied patients, an increase in the length of the stabilogram curve above the reference values of 150 mm was found. A change in the feet - flat feet - was found in half of the patients, included in the study. Postural problems can worsen existing symptoms from other systems with a disorder. Establishing the direction of the displacement helps to establish the genesis of the disorder and directs the appropriate therapy, according to the specific clinical case. [ABSTRACT FROM AUTHOR]

Background: Establishing an association between gait variability and direction specific balance indices may help in identifying the risk of falls in patients with spinocerebellar ataxia (SCA) which may help in developing an appropriate intervention. This study is intended to identify the association between balance and gait parameters especially gait variability in these patients. Methods: Patients with genetically confirmed SCA (n = 24) as well as controls (n = 24) who met the study criteria were recruited. Gait was assessed using the GAITRite system and balance was assessed using dynamic posturography (Biodex) to record direction-specific dynamic balance indices. Disease severity was assessed using international cooperative ataxia rating scale (ICARS). Results: The mean age of the SCA group (38.83 ± 13.03 years) and the control group (36.38 ± 9.09 years) were comparable. The age of onset of illness was 32 ± 10.62 years and duration of 5.67 ± 3.62 years. The mean ICARS was 45.10 ± 16.75. There was a significant difference in the overall balance index (OBI), anterior--posterior index (API), medial/lateral index (MLI) between SCA patients (4.56 ± 2.09, 3.49 ± 1.88, 2.94 ± 1.32) and the controls (2.72 ± 1.25, 2.08 ± 0.85, 1.85 ± 0.97). However, correlation was observed only between gait stability and balance parameters in API direction. Conclusions: There was an increased anteroposterior oriented balance deficit in patients with SCA, which was significantly correlating with the gait parameters. The balance training intervention may focus on improving anteroposterior direction to prevent falls and improving walking efficiency. [ABSTRACT FROM AUTHOR]

Purpose: To measure body balance using computerised dynamic posturography in young adults wearing multifocal contact lenses (MFCL) with high addition powers designed for myopia control. Methods: Twenty‐four young adults (mean age: 24 years) wearing distance‐centred soft MFCL (SwissLens Orbis Relax) with two different central zones (3 and 4.5 mm), two addition powers (+2 D, +4 D) and single vision control lenses. Body balance was measured on a moving platform under three viewing conditions: (1) eyes open when fixating on letters at 3 m or (2) at 40 cm, as well as (3) with the eyes closed. Parameters of body stabilisation were analysed: the rate of body stabilisation (τrelax), the stabilisation time (Tmax) and the number of oscillations (Nosc). Results: The MFCLs did not produce a significant difference in the mean values of the analysed parameters (p > 0.05 for τrelax, Tmax, Nosc). However, a positive correlation was found between pupil size and Nosc and Tmax (p < 0.01), suggesting an effect of the +4 D add with the 3 mm central zone on the posturographic parameters. As was expected, dynamic body stabilisation was better with eyes open versus eyes closed (p < 0.005). Conclusions: Distance‐centred MFCLs with a medium addition (+2 D) do not disturb body stabilisation in young adults. However, high additions (+4 D) with a small central zone may affect body balance control in subjects with large pupil size. [ABSTRACT FROM AUTHOR]

Postural stability is commonly decreased in individuals with chronic post-stroke hemiparesis due to multisystemic deficits. Transcranial direct current stimulation (tDCS) is a non-invasive method to modulate cortical excitability, inducing neuroplastic changes to the targeted cortical areas and has been suggested to potentially improve motor functions in individuals with neurological impairments. The purpose of this double-blinded, sham-controlled study was to examine the acute effects of anodal tDCS over the lesioned motor cortex leg area with concurrent limits of stability training on postural control in individuals with chronic post-stroke hemiparesis. Ten individuals with chronic post-stroke hemiparesis received either anodal or sham tDCS stimulation over the lesioned leg region of the motor cortex while undergoing 20 min of postural training. The type of stimulation to receive during the first session was pseudorandomized, and the two sessions were separated by 14 days. Before and immediately after 20 min of tDCS, the 10 m walk test, the Berg Balance Scale, and dynamic posturography assessments were performed. After a single session of anodal tDCS with concurrent postural training, we observed no changes in clinical measures of balance and walking, assessed using the Berg Balance Scale and 10 m walk test. For dynamic posturography assessments, participants demonstrated improvements in adaptation responses to toes-up and toes-down perturbations, regardless of the type of tDCS received. Additionally, improved performance in the shifting center of gravity was observed during anodal tDCS. Taken together, these preliminary findings suggest that tDCS can potentially be used as a feasible approach be incorporated into the rehabilitation of chronic post-stroke individuals with issues related to postural control and fear of falling, and that multiple sessions of tDCS stimulation may be needed to improve functional measures of postural control and walking.

Background According to embryological and anatomical connection between the cochlea and vestibular end-organs, children with sensorineural hearing loss (SNHL) may exhibit abnormalities of vestibular and balance function. Documentation of vestibular dysfunction in children with SNHL has a long and rich history indicating that 20–70% of children with SNHL demonstrate an element of vestibular end-organ dysfunction. Vestibular dysfunction was proved to correlate with severity of cochlear loss in many research works. Aim of the work To assess normative data of sensory organization test (SOT) and head shaking (HS) test according to age, weight, and height of children in control group and to detect any deviation from normal values of SOT and head shacking test in children with SNHL. Patients and methods This study was carried out in Audiology and Vestibular Units of Hearing and Speech Institute, Giza, Egypt, and included 50 children (29 males and 21 females). Their age range was from 6 to 12 years. They were divided into two groups: control group, which consisted of 20 children (12 males and eight females) with normal hearing, and case group, which consisted of 30 children (17 males and 13 females) with SNHL. All children underwent full basic audiological evaluation, Fukuda stepping test, videonystagmography, SOT of posturography, and HS–SOT. Results There were differences in balance skills between children with normal hearing and children with SNHL in Fukuda stepping test, caloric test, and HS–SOT; otherwise, there were no statistical significant differences between the two groups in smooth pursuit test, Dix–Hallpike test, and SOT. Conclusion HS–SOT showed significant difference between the two groups in horizontal, vertical, and roll axes of HS test, especially in horizontal CD5, vertical CD5, roll CD2, and roll CD5. This means that these axes could diagnose vestibular peripheral dysfunction accurately in children with SNHL.

• A robotic device with applications in balance assessment was designed and fabricated. • It provides controlled mechanical perturbations with appropriate dynamics for balance assessment. • The functionality of the device was evaluated. • The sensitivity of the CoP indices increases when the mechanical perturbations are present. Balance impairment is critical for many patient groups such as those with neural and musculoskeletal disorders and also the elderly. Accurate and objective assessment of balance performance has led to the development of several indices based on the measurement of the center of pressure. In this study, a robotic device was designed and fabricated to provide controlled and repeatable mechanical perturbations to the standing platform of the user. The device uses servo-controlled actuators and two parallel mechanisms to provide independent rotations in mediolateral and anterior-posterior directions. The device also provides visual feedback of the center of pressure position to the user. Functional tests were run and showed that the device is able to provide an appropriate dynamics (time constant of 0.19 s and bandwidth of 0.85 Hz) for the two motions. The efficacy of the device on the balance assessment was then evaluated experimentally. Ten healthy subjects performed a balance task with and without perturbations and seven center of pressure indices were measured. It was shown that the sensitivity of the indices to the user's performance was statistically increased in all indices particularly in anterior/posterior direction when the mechanical perturbations were present. [ABSTRACT FROM AUTHOR]

Postural stability is commonly decreased in individuals with chronic post-stroke hemiparesis due to multisystemic deficits. Transcranial direct current stimulation (tDCS) is a non-invasive method to modulate cortical excitability, inducing neuroplastic changes to the targeted cortical areas and has been suggested to potentially improve motor functions in individuals with neurological impairments. The purpose of this double-blinded, sham-controlled study was to examine the acute effects of anodal tDCS over the lesioned motor cortex leg area with concurrent limits of stability training on postural control in individuals with chronic post-stroke hemiparesis. Ten individuals with chronic post-stroke hemiparesis received either anodal or sham tDCS stimulation over the lesioned leg region of the motor cortex while undergoing 20 min of postural training. The type of stimulation to receive during the first session was pseudorandomized, and the two sessions were separated by 14 days. Before and immediately after 20 min of tDCS, the 10 m walk test, the Berg Balance Scale, and dynamic posturography assessments were performed. After a single session of anodal tDCS with concurrent postural training, we observed no changes in clinical measures of balance and walking, assessed using the Berg Balance Scale and 10 m walk test. For dynamic posturography assessments, participants demonstrated improvements in adaptation responses to toes-up and toes-down perturbations, regardless of the type of tDCS received. Additionally, improved performance in the shifting center of gravity was observed during anodal tDCS. Taken together, these preliminary findings suggest that tDCS can potentially be used as a feasible approach be incorporated into the rehabilitation of chronic post-stroke individuals with issues related to postural control and fear of falling, and that multiple sessions of tDCS stimulation may be needed to improve functional measures of postural control and walking. [ABSTRACT FROM AUTHOR]

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BACKGROUND: The vestibulo-sympathetic reflex operates during orthostatically challenging movements to initiate cardiovascular responses in advance of a baroreceptor-mediated response. The objective of this study was to determine whether there was an association between changes in vestibular function and cardiovascular responses during a prone-to-stand movement in astronauts after return from long-duration spaceflight. METHODS: Thirteen crewmembers who participated in International Space Station missions were tested before spaceflight and 1 d after landing. Vestibular function was evaluated by computerized dynamic posturography while their head was erect and while they performed dynamic head tilts. Heart rate and mean arterial blood pressure were measured while the subjects were in prone and standing positions. RESULTS: The 21.4% increase in the astronauts’ heart rate during the prone to stand maneuver after spaceflight correlated significantly with their spaceflight-induced 48.7% decrease in postural stability during dynamic head tilts. The larger mean arterial pressure in the prone position after spaceflight compared to preflight (+7%) also correlated with the postflight decrease in postural stability during dynamic head tilts. CONCLUSION: These results indicate that an appropriate vestibular function is important to evoke optimum vestibulo-sympathetic response during orthostatically challenging voluntary movements performed after spaceflight. They also suggest that there may be a greater need to generate an anticipatory cardiovascular response after spaceflight. [ABSTRACT FROM AUTHOR]

Background and Objective: Patients with profound Sensorineural Hearing Loss (SNHL) are susceptible to vestibular disturbances following Cochlear Implant (CI) surgery. This study aimed to evaluate vestibular dysfunctions following unilateral CI in the congenitally deaf children. Methods: This was a cross-sectional study conducted on 24 children (mean age: 10.56 ± 5.49 years old) who underwent unilateral CI and 24 age-matched controls (mean age: 11.13 ± 6.21 years old). Vestibular functions were assessed by Vestibular Evoked Myogenic Potential (VEMP) and Computerized Dynamic Posturography (CDP). The VEMP test was performed for otolith's function (especially saccule) evaluation. Sensory Organization Test (SOT) protocol of CDP was also utilized to differentiate the role of various sensory systems contributing to postural stability. In addition, total equilibrium score was calculated. The variables were comparatively assessed between the two groups. Results: The mean p13-n23 amplitude in the CI users was significantly lower than the controls (p<0.05). However, the two groups showed no significant difference in cVEMP latency values (p>0.05). The SOT analysis revealed that 45.83% (11/24) of the CI subjects had some kind of sensory abnormalities: 7 cases (29.17%) vestibular, 2 cases (8.33%) visual, 2 cases (8.33%) vestibular and somatosensory involvements. Furthermore, total equilibrium score was significantly reduced in implanted group than the controls (p<0.001). At least, 70.59% (12/24) CI patients showed abnormal values in the CDP or cVEMP examinations. Conclusion: This study shows functional vestibular impairments in children who underwent CI. These patients showed significantly increased postural instability which was more evident in dynamic conditions. These findings provide the basis for better pre-operative counseling and postoperative vestibular rehabilitation to CI recipients. [ABSTRACT FROM AUTHOR]

Introduction: people with Down Syndrome (DS) present sensorial and motor control deficits that generate difficulties in their functional performance. Case presentation and aim: the aim of the present study was to analyze the short-term effects of two intervention sessions with Whole Body Vibration (WBV) in terms of balance, graphomotor skills and strength in a participant with DS, and determine which frequency is more effective. The Functional Reach Test and Computerized Dynamic Posturography were used as a result to evaluate changes in balance, and a graphomotor test and manual dynamometry to determine variations in writing and muscle strength, respectively. Results: clinically relevant results were obtained, as well as differences between the frequency of intervention used, highlighting positive changes in muscle strength and balance after the intervention at 6 Hz and an improvement in the stroke after the intervention at 3 Hz. Conclusions: immediate and clinically relevant effects cuan were found after a single session of WBV, as well as differences in the results according to the frequency of intervention used. The most relevant results were achieved after the intervention session at 6 Hz. [ABSTRACT FROM AUTHOR]

Background. Organic solvents cause diseases of the vestibular system. However, little is known regarding the correlation between vestibular damage and exposure to organic solvents below threshold limit values. The best measure by which to evaluate vestibular disorders is static and dynamic posturography. Objective. The aim of this study was to evaluate equilibrium disorders via static and dynamic posturography in workers without clear symptoms and exposed to low doses of mixed solvents. Methods. 200 subjects were selected. Using an Otometrics device (Madsen, Denmark), all subjects endured static and dynamic posturography testing with both eyes-open and eyes-closed conditions. Results were compared with a control group of unexposed individuals. Result. Based on the obtained data, the following results can be drawn: (a) subjects exposed to mixtures of solvents show highly significant differences regarding all static and dynamic posturography parameters in comparison to the control group; (b) posturography testing has proven to be a valid means by which to detect subliminal equilibrium disorders in subjects exposed to solvents. Conclusion. We can confirm that refinery workers exposed to mixtures of solvents can present subliminal equilibrium disorders. Early diagnosis of the latter is made possible by static and dynamic posturography. [ABSTRACT FROM AUTHOR]

• Oscillation of sway was increased in PD ≤ 65 years. • The pathway and velocity of posturographies were elevated in PD > 65 years. • Dyskinesia was significantly increased by dynamic posturography. • The postural instability is part of the early PD. • The cerebellum takes part in the formation of early symptoms. The early stage of Parkinson's disease (PD) (Hoehn-Yahr (HY) I-II stages) is characterized by a negative pull test, which clinically excludes postural instability. Previous studies with dynamic posturography detected balance disturbances even at the onset of the disease but the age dependency or prediction of dyskinesia with dynamic posturography are not known. We hypothesized that the postural instability evoked by dynamic posturography was part of the early stage of PD. Furthermore, we studied how we can provoke dyskinesia. Postural instability with static and dynamic posturography (passing balls with different weights around the body) was studied in 45 patients with PD in their HY I, II stages. They were compared with 35 age-matched healthy controls. Eighteen patients with dyskinesia were involved in the study. Fourteen patients were followed for two years. The pathway and velocity of the movement assessed by static and the dynamic posturography were significantly higher in the group >65 years than that of age-matched healthy controls, while the group ≤65 years showed a significant increment only in the antero-posterior sway during dynamic posturography. The imbalance of patients with dyskinesia was significantly (p < 0.05) provoked by dynamic posturography compared to patients with PD without dyskinesia. The results were independent of age. Postural instability is part of the early symptoms of PD. Non-dopaminergic pathways may be involved in the early stage of PD. [ABSTRACT FROM AUTHOR]

Highlights • Moving platform-embedded force plate signals contain inertial components. • Removal of inertial components requires knowledge of the system's inertial properties. • We proposed a method to estimate inertial properties and components for any platform. • The method was used to estimate the inertial properties for one specific platform. • We found excellent agreement between measured and computed force plate signals. Abstract Kinetic data acquired from force plates embedded in moving platforms naturally contain artifacts due to platform acceleration, called force plate inertial components. While they can be estimated and removed from the measured signals, the system's inertial properties need to be known. Our objective was to: (1) develop a method for estimating the inertial properties and force plate inertial components for any instrumented platform; (2) estimate the inertial properties specifically for the Computer-Assisted Rehabilitation Environment (CAREN); and (3) validate the estimates with new experimental data. Unloaded ramp-and-hold perturbations (for estimation) and unloaded random perturbations (for validation) were executed to obtain the force, moment, and motion of the CAREN platform. Inertial properties were estimated by minimizing the error between the measured and computed inertial forces and moments. Obtained estimates were validated by calculating the coefficient of determination (R2) between the measured and computed forces or moments when keeping the inertial properties fixed. The estimates of the CAREN's inertial properties exhibited low variability across trials, and R2 for the validation trials was 0.90 ± 0.08 (mean ± standard deviation). The developed method can be used for removing inertial components from force plate signals, yielding reliable estimates of ground reactions in dynamic biomechanical research and clinical assessments. [ABSTRACT FROM AUTHOR]

Background: Decreased endogenous melatonin concentrations in people with multiple sclerosis (PwMS) are associated with fatigue and pain that impair postural balance and muscle strength. Melatonin ingestion had analgesic and anti-fatigue effects. However, the acute effect of exogenous melatonin on dynamic postural stability and muscle strength has not been studied yet in PwMS. This study aimed to investigate the safety and the efficacy of a nighttime melatonin intake on dynamic postural balance and lower-extremity muscle strength the following morning in PwMS., Methods: Fourteen PwMS (28.36 ± 6.81 years) were assessed (8 a.m.) pre- and post-acute intake of melatonin or placebo (6mg, 30 minutes before nocturnal bedtime). Evaluated parameters included dynamic postural balance (force platform), lower-extremity muscle strength [Five-Repetition Sit-To-Stand Test (5-STST)], hand dexterity (Nine-Hole Peg Test), nociceptive pain [Visual Analogue Scale (VAS)], neuropathic pain [Neuropathic Pain 4 Questions (DN4)], sleep quality and fatigue perception [Hooper Index (HI)]., Results: In the frontal plane, melatonin reduced the center of pressure (CoP) path length (CoPL), CoPL in the anteroposterior axis (CoPLY) and CoP sway area (CoPAr) compared with placebo by 7.56% (p=0.02, Cohens'd (d)=1.24), 19.27% (p<0.001, d=2.60) and 13.82% (p<0.001, d=2.02), respectively. Melatonin induced a higher decrease in these posturographic parameters compared with placebo in the sagittal plane [CoPL: 9.10% (p=0.005, d=1.02), CoPLY: 4.29% (p=0.025, d=1.07) and CoPAr: 7.45% (p=0.038, d=0.74)]. Melatonin decreased 5-STST duration as well as VAS, DN4, HI-fatigue and HI-sleep scores compared with placebo by 8.19% (p=0.008, d=1.19), 5.74% (p=0.04, d=0.82), 27.30% (p=0.023, d=0.98), 40.15% (p=0.044, d=0.85) and 30.16% (p=0.012, d=1.10), respectively., Conclusion: This preliminary study, among PwMS, showed that acute melatonin ingestion was safe and efficient for improving dynamic postural stability and lower-extremity muscle strength probably through its analgesic and anti-fatigue effects., Competing Interests: Declaration of Competing Interest None to declare., (Copyright © 2024 Elsevier B.V. All rights reserved.)

The aim of this study was to investigate changes in balance control for stance and gait tasks in patients 2 years before and after vestibular neurectomy (VN) performed to alleviate intractable Meniere's disease. Amplitudes of trunk sway in roll and pitch directions were measured for stance and gait tasks in 19 patients using gyroscopes mounted at the lower-back. Measurements before VN and 2 years later were compared to those of healthy age-matched controls (HC). We also examined if changes in trunk sway amplitudes were correlated with patients' subjective assessment of disability using the AAO-HNS scale. For patients with low AAO-HNS scores 0-2 (n = 14), trunk roll and pitch sway velocities, standing eyes closed on foam, increased 2 years post VN compared to HC values (p < 0.01). Trunk sway amplitudes remained at levels of HC for simple gait tasks, but task durations were longer and therefore gait slower. For complex gait tasks (stairs), balance control remained impaired at 2 years. In patients with AAO-HNS high scores level 6 (n = 5), balance control remained abnormal, compared to HC, 2 years postoperatively for all stance, several simple and all complex gait tasks. Trunk sway in the pitch and roll directions for stance tasks was correlated with clinical (AAO-HNS) scores (p ≤ 0.05). These results indicate that VN leads to chronic balance problems for stance and complex gait tasks. The problems are greater for patients with high compared to low AAO-HNS scores, thereby explaining the different symptoms reported by these patients. The lack of balance recovery in VN patients to levels of HCs after 2 years contrasts with the 3 months average recovery period for acute vestibular neuritis patients and is indicative of the effects of neurectomy on central compensation processes. [ABSTRACT FROM AUTHOR]

Objectives: To evaluate the prevalence and management of residual symptoms in recovered BPPV patients.Methods: We performed a retrospective study on BPPV patients of any of the three semicircular canals. Exclusion criteria were multiple-canal BPPV, refractory BPPV, central nervous system pathologies or other vestibular diseases. Patients were treated with repositioning maneuvers until the vertigo disappeared and evaluated for symptoms of instability at 1 month after resolution. A dynamic computerized posturography was then performed on every patient complaining of residual instability. We analyzed demographic data, the affected semicircular canal, number of repositioning maneuvers, presence of anxiety disorders, and we correlated these variables with the presence of residual disequilibrium 1 month after vertigo resolution.Results: We included 361 patients. Residual disequilibrium was found in 107 patients (29.6%) with no significant difference between the rates associated with the three semicircular canals (p = 0.73). The group who needed more than one repositioning maneuver (1 maneuver-229 patients, ≥ 2maneuvers-132 patients) showed a significantly higher prevalence of instability (17.9 vs. 50%; p < 0.0001). 47.2% of the patients with anxiety disorders presented with instability symptoms (p = 0,01). Patients older than 65 showed a significantly higher percentage of residual symptoms (23.3 vs. 34.8%; p = 0.03).Conclusions: Persistence of residual symptoms 1 month after the acute BPPV can be associated with certain risk factors that should be taken into consideration (age, number of repositioning maneuvers needed, anxiety and/or depressive disorders). These patients could benefit of treatment with vestibular rehabilitation. [ABSTRACT FROM AUTHOR]

Background The spectrum of symptoms exhibited by patients with essential tremor (ET) extends far beyond the classical tremor. This study aims to explore and establish the presence of subtle balance abnormalities in ET using dynamic posturography (DP). Methods DP was performed on 18 patients with ET and 26 controls. Diagnosis of ET was based on the Consensus Statement of the Movement Disorder Society on Tremor. Dynamic stability which included the overall balance index, anterior-posterior index and mediolateral index, and limits of stability were measured. Results Patients with ET had significantly impaired balance indices. Impairment of dynamic stability revealed poor static balance control in all directions. Lower limits of stability scores indicated a smaller range of motion prior to which patients have to shift foot balance. No correlations were observed between age at evaluation, age at onset, duration of illness and the balance indices. Conclusions Dynamic posturography reveals significant balance impairment in patients with ET which is unrelated to the age at onset, age at evaluation or duration of illness. This finding concurs with pre-existing reports and adds to the growing body evidence of cerebellar involvement in ET. [ABSTRACT FROM AUTHOR]

Gymnastics by nature is a balance sport requiring both static and dynamic stability. To our knowledge, the center of pressure (COP) movement of collegiate gymnasts has not been compared to other collegiate athletes and healthy controls during static and dynamic postural stability tasks. Our purpose was to investigate static and dynamic stability in collegiate gymnasts, non-gymnast athletes and non-athlete controls. Data were collected on female university gymnasts (n=10), university athletes in other sports (n=10), and active non-athlete controls (n=10). Static balance was measured using a commercially available six-condition static test and dynamic plantar/dorsiflexion perturbation test. Static stability variables included: mediolateral and anteroposterior COP sway, total COP displacement, average COP velocity, and standard deviation of vertical force. Dynamic perturbation variables included: initial COP sway, total COP sway, and sway velocity. A two factor ANOVA was performed (group x condition) on each variable (a=0.05) in each assessment. Significant differences were found between the groups for mediolateral COP sway (gymnasts

Introduction: Several studies have indicated better balance control in dancers than in control participants, but some controversy remains. The aim of our study is to evaluate the postural stability in a cohort of dancers, non-dancers, compensated, and non-compensated unilateral vestibular neuritis (VN). Methods: This is a prospective study of control subjects, dancers, and VN patients between June 2009 and December 2015. Dancers from the Dance Conservatory of Madrid and VN patients were referred to our department for analysis. After the clinical history, neuro-otological examination, audiogram, and caloric tests, the diagnosis was done. Results from clinical examination were used for the categorization of compensation situation. A computerized dynamic posturography was performed to every subject. Results: Forty dancers and 38 women formed both 'dancer' and 'normal' cohorts. Forty-two compensated and 39 uncompensated patients formed both 'compensated' and 'uncompensated' cohorts. Dancers had significantly greater antero-posterior (AP) body sway than controls during condition 5 and 6 in the Sensory Organization Test (SOT) (p<.05). When we compared the uncompensated cohort with both control and dancers groups, we found significant greater body sway in every SOT studied condition (p<.05). While mean AP body say in SOT 5 and 6, showed greater values in compensated patients than the control group, the mean analysis did not show any statistical difference between the compensated and dancer groups, in such SOT conditions. Conclusions: Dancers demonstrated greater sways than non-dancers when they relied their postural control on vestibular input alone. Compensated patients had a similar posturographic pattern that the dancers cohort, suggesting a similar shift from visual to somatosensory information. [ABSTRACT FROM AUTHOR]

BACKGROUND. Computerized dynamic posturography is the most important battery test designed to assess the ability to use visual, vestibular and proprioceptive cues in the maintenance of posture. Foam posturography reduces the availability of proprioceptive inputs, which makes more difficult the balance control. OBJECTIVE. The objective of the study was to assess the clinical use of foam posturography in evaluating peripheral vestibular dysfunction. MATERIAL AND METHODS. We evaluated 41 patients with vestibular disorders and 41 normal patients by using the sensory organization test in eyes opened, eyes closed and mislead vision conditions with and without the foam. We measured several parameters: the position of the center of pressure, the displacement in the center of pressure in anteroposterior and mediolateral planes and Romberg's ratio on static and foam rubber. RESULTS. The values of all parameters were significantly higher in patients with peripheral vestibular disorders than in the control group (p<0.05). Also. comparing the Romberg test results, the foam surface used by the patient was larger than the static one. CONCLUSION. Foam posturography can be a reliable test in assessing patients with peripheral vestibulopathy, being also able to identify the visual and proprioceptive dependence levels. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to assess if 65 dB and 4000 Hz stimuli affect postural stability of young normally hearing people. Methods: Posturography examinations belong to clinical tests which evaluate the motor skills. Posturography can be divided into static posturography and dynamic posturography. In both static and dynamic posturography patient stays on the platform with opened and closed eyes, but in the case of dynamic one, platform is unstable. In this study the Multitest Equilibre platform produced by FRAMIRAL was used. Patients took part in tests with opened and closed eyes, on stable and unstable platform. Additionally, patients were exposed to 65 dB and 4000 Hz acoustic stimuli. The sound pressure level, and frequency was belonging to the best audibly frequency range. Results: Parameters such as velocity and surface were examined. The difference between velocity measured with acoustic stimuli and without acoustic stimuli was observed. On the other hand there was no difference in surface results. Conclusions: The statistically significant difference between velocity of patients center of gravity movements, measured on unstable platform, in the presence of 4000 Hz, 65 dB acoustic stimulus and without additional disturbances was observed. [ABSTRACT FROM AUTHOR]

ObjectivesFalls are a major problem in the elderly. Age-related degeneration of the human balance system increases the risk of falls. Kyphosis is a common condition of curvature of the upper spine in the elderly and its development occurs through degenerative change. However, relatively little is known about the effect of kyphotic changes on balance in the elderly. The aim of this study is to investigate the influence of kyphosis on the balance strategy through use of the motor control test (MCT) in computerized dynamic posturography.MethodsFifty healthy subjects who were not affected by other medical disorders that could affect gait or balance were enrolled in the study. By simulation of kyphotic condition through change of the angles of the line connecting the shoulder to the hip and the ankle axis by approximately 30°, the latency and amplitude of the MCT were measured in upright and kyphotic condition.ResultsIn the kyphotic condition, latency was shortened in backward movement. In forward movement, latency was shortened only in large stimulation. The amplitude in forward movement was decreased in kyphotic condition. However, the change of amplitude was not significant in large intensity backward movement in the same condition.ConclusionKyphotic condition decreases the latency of MCT, especially in backward movement. These findings imply that kyphotic condition may serve as a protective factor against falls.

AbstractTo investigate cortical roles in standing balance, cortical hemodynamic activity was recorded from the right hemisphere using near-infrared spectroscopy (NIRS) while subjects underwent the Sensory Organization Test (SOT) protocol that systematically disrupts sensory integration processes (i.e., somatosensory or visual inputs or both). Eleven healthy men underwent the SOT during NIRS recording. Group statistical analyses were performed based on changes in oxygenated hemoglobin concentration in 10 different cortical regions of interest and on a general linear analysis with NIRS statistical parametric mapping. The statistical analyses indicated significant activation in the right frontal operculum (f-Op), right parietal operculum (p-Op), and right superior temporal gyrus (STG), right posterior parietal cortex (PPC), right dorsal and ventral premotor cortex (PMC) and the supplementary motor area (SMA) under various conditions. The activation patterns in response to specific combinations of SOT conditions suggested that 1) f-Op, p-Op, and STG are essential for sensory integration when standing balance is perturbed; 2) the SMA is involved in the execution of volitional action and establishment of new motor programs to maintain postural balance; and 3) the PPC and PMC are involved in the updating and computation of spatial reference frames during instances of sensory conflict between vestibular and visual information.

Objective:To determine whether demographic characteristics or balance examination findings can predict the adherence of older people with instability to a vestibular rehabilitation programme.Methods:A prospective case–control study was conducted of 120 patients aged 65 years or more (mean age, 77.3 ± 6.33 years). Two groups were classified according to patients’ adherence with the follow-up post-rehabilitation protocol. Analysed variables included: age, sex, body mass index, Timed Up and Go test findings, computerised dynamic posturography, Dizziness Handicap Inventory scores and Short Falls Efficacy Scale – International questionnaire results, number of falls, and type of vestibular rehabilitation.Results:Two groups were established: adherents (99 individuals) and non-adherents (21 individuals). There were differences between the groups regarding: sex (female-to-male ratio of 4.8:1 in adherents and 1.63:1 in non-adherents), age (higher in non-adherents) and voluntary movement posturographic test results (non-adherents had poorer scores).Conclusion:The patients most likely to abandon a vestibular rehabilitation programme are very elderly males with low scores for centre of gravity balancing and limits of stability. [ABSTRACT FROM AUTHOR]

Background: Multiple Sclerosis (MS) is a widespread progressive neurologic disease with consequent impairments in daily activities. Disorders of balance are frequent and equilibrium tests are potentially useful to quantify disability and to verify treatment effectiveness. The fair sensitivity of the widely used not-perturbed tests to detect balance disturbances in MS patients have prompted the development of mechatronic systems capable to impose known equilibrium perturbations, in order to challenge the balance control and, consequently, to better assess the level of impairment. We sought to clarify whether the proposed perturbed-test is capable to discriminate healthy subjects from patients with MS, even in mild or in the absence of clinically evident balance disturbances.Methods: We assessed balance performances of 17 adults with MS and 13 age-matched healthy controls (HC) using both perturbed (PT) and not-perturbed (NPT) postural tests by means of a 3 Degree Of Freedom (DOF) rotational mechatronic platform. Participants stood barefoot on the platform in standing position and their center of pressure (CoP) was gathered by using a pressure matrix. Each trial lasted 30 s and was carried out with and without visual stimuli. Several postural indices were computed for each trial. Correlations between postural indices and clinical scales were analyzed.Results: No significant differences were found between groups for all indices when subjects performed NPTs. Conversely, significant differences in postural indices between MS and HC emerged during PTs. Additionally, PTs revealed significant differences between patients without any cerebellar impairment (cerebellar EDSS subscore equal to 0) and HC. The discrimination capability of PTs was confirmed by the ROC analysis. No significant change of the selected metrics occurred in HC when NPTs were performed with eyes closed, while indices presented a significant worsening in MS subjects.Conclusions: Not-perturbed tests showed lower sensitivity than perturbed ones in the identification of equilibrium impairments in minimally disabled MS patients. However, not-perturbed tests allow to better evaluate the influence of visual flow disturbances on balance control in MS. In conclusion, our findings proved that the use of the novel tests based on a 3DOF mechatronic device represents an effective tool to investigate early balance disturbances in MS. [ABSTRACT FROM AUTHOR]

Conclusions:There was a difference in average score of thesensory organization test(SOT) of the case group (elderly instability) compared to the control group (healthy subjects). Cases had worse scores on thelimits of stability(LOS) than controls, but were only able to confirm statistically significant differences in the movement velocity. Objective:To study the LOS of elderly patients with instability vs healthy subjects of the same age to try to explain the increased risk of falls in elderly patients with instability. Methods:Fifty individuals ≥65 years, 30 cases (at least one of the next inclusion criteria: ≥1 fall in the last 12 months, >15 s or some support in thetimed up and go test, composite <68 in SOT, ≥1 fall during production of the SOT) compared to 20 controls. Postural study: SOT and LOS, Smart Equitest Neurocom®platform. Statistical analysis:t-Student test (p < 0.05). Result:Mean value of overall balance: patients with instability =56% vs controls =77.1% (p< 0.001). Movement velocity: cases =2243°/s vs controls =2860°/s (p = 0.029). The reaction time (cases =1217 s vs controls =1.077 s), excursion (56.95% vs 59.35%) and directional control (56.95% vs 59.35%) differences were not statistically significant. [ABSTRACT FROM PUBLISHER]

This study compares postural and trunk responses to translating platform perturbations of varied velocities and directions. A group of 18 young and physically active subjects were exposed to a set of postural perturbations at varied velocities (5, 10, 15, and 20 cm/s) and directions of platform movement (forward, backward, left-lateral, and right-lateral). The center of pressure (CoP) displacement measurement, in addition to the trunk motion (representing the center of mass (CoM) displacement), were both monitored. Results identified that the CoP displacement increased from slow to faster velocities of platform motion more widely in both anterior and posterior directions (50.4% and 48.4%) as compared to the CoM displacement (17.8% and 14.9%). However a greater increase in the peak CoM velocity (70.3% and 69.6%) and the peak CoM acceleration (60.5% and 53.1%) was observed. The values in the anterior and posterior direction only differed significantly at the highest velocity of platform motion (i.e. 20 cm/s). A similar tendency was observed in the medio-lateral direction, but there were no significant differences in any parameter in the left-lateral and right-lateral direction. The velocity of the platform motion highly correlated with peak velocity (r=0.92-0.97, P<0.01) and moderately with amplitude of trunk displacement (r=0.56-0.63, P<0.05). These findings indicate that the velocity of perturbation alters peak CoM velocity rather than the magnitude of CoM displacement. The effect of the direction of perturbations on the trunk response emerges only at a high velocity of platform motion, such that the peak CoM velocity and peak CoM acceleration are significantly greater in anterior than posterior direction. [ABSTRACT FROM AUTHOR]

Objectives: To compare the clinical, balance, and radiological profile of progressive supranuclear palsy (PSP) of Richardson type (PSP-R) and Parkinsonian type (PSP-P).Materials and Methods: Twenty-nine patients with PSP (PSP-R: 17, PSP-P: 12) satisfying the probable/possible National Institute of Neurological Disorders and Stroke-PSP criteria were recruited and assessed with Unified Parkinson's Disease Rating Scale-III, PSP rating scale (PSPRS), Berg balance scale (BBS), Tinetti performance-oriented mobility assessment gait and total (TPG and TPT) score, dynamic posturography (DP), and magnetic resonance imaging. Data were compared with 30 age- and gender-matched healthy controls.Results: The mean ages of PSP-R, PSP-P, and controls were comparable (62.5 ± 6.6, 59 ± 8.9, and 59.8 ± 7.6 years). The PSP group had significantly poor DP scores and more radiological abnormalities than controls. The PSPRS, TPG, and TPT scores were significantly more impaired in PSP-R compared to PSP-P (P = 0.045, P = 0.031, and P = 0.037, respectively). In DP, the limits of overall stability were most significant (P < 0.001) and PSP-R had lower scores. PSP-R compared to PSP-P had more often "Humming Bird" sign (P < 0.001), "Morning Glory" sign (P < 0.008), and generalized cortical atrophy (P < 0.001). The area of midbrain (P < 0.002) and midbrain/pons ratio (P < 0.013) was significantly lower in PSP-R. In PSP-P, the overall balance index significantly correlated with BBS, TPG, and TPT (r = -0.79, P = 0.002; r = -0.772, P = 0.003; and r = -0.688, P = 0.013) and the midbrain axial anterior-posterior diameter significantly correlated with the TPG and TPT (r = 0.74, P = 0.01; r = 0.66, P = 0.018).Conclusions: While balance and radiological abnormalities were more severe in PSP-R, the qualitative and quantitative measurements of severity of balance in PSP-P rather than PSP-R was a better reflection of the pathology of the midbrain. [ABSTRACT FROM AUTHOR]

Summary Objective Falls are a serious health problem for older adults. Several studies have identified the decline of postural balance as one of the main risk factors for falls. Contrary to what may be believed, the capability of force platform measurements to predict falls remains uncertain. The focus of this narrative review is the identification of postural characteristics of older adults at risk of falling using both static and dynamic postural balance assessments. Methods The literature analysis was conducted on Medline/PubMed. The search ended in May 2015. Results Centre of pressure (CoP) path length, CoP velocity and sway in medial lateral and anterior-posterior are the variables that distinguish older adult fallers from non-fallers. Discussion Recommendations to medical personnel on how to provide efficient balance training for older adults are offered, discussing the relevance and limitations of postural stability on static and dynamic board in falling risk prevention. [ABSTRACT FROM AUTHOR]

To investigate cortical roles in standing balance, cortical hemodynamic activity was recorded from the right hemisphere using near-infrared spectroscopy (NIRS) while subjects underwent the sensory organization test (SOT) protocol that systematically disrupts sensory integration processes (i.e., somatosensory or visual inputs or both). Eleven healthy men underwent the SOT during NIRS recording. Group statistical analyses were performed based on changes in oxygenated hemoglobin concentration in 10 different cortical regions of interest and on a general linear analysis with NIRS statistical parametric mapping. The statistical analyses indicated significant activation in the right frontal operculum (f-Op), right parietal operculum (p-Op), and right superior temporal gyrus (STG), right posterior parietal cortex (PPC), right dorsal and ventral premotor cortex (PMC), and the supplementary motor area (SMA) under various conditions. The activation patterns in response to specific combinations of SOT conditions suggested that (1) f-Op, p-Op, and STG are essential for sensory integration when standing balance is perturbed; (2) the SMA is involved in the execution of volitional action and establishment of new motor programs to maintain postural balance; and (3) the PPC and PMC are involved in the updating and computation of spatial reference frames during instances of sensory conflict between vestibular and visual information. [ABSTRACT FROM AUTHOR]

Objectives Impaired postural control in individuals with multiple sclerosis (MS) is associated with falls. The objective was to evaluate the direction-specific limits of stability in people with MS. Methods Balance control of 18 individuals with relapsing-remitting MS and 18 healthy controls was assessed using instrumented (Limits of Stability (LOS) test) and clinical (Berg Balance Scale (BBS) and Activities-specific Balance Confidence (ABC) scale) tests. Results There were significant differences in reaction time, movement velocity, endpoint excursion, maximum excursion, and directional control measures of the LOS test between individuals with MS and healthy controls. The BBS and ABC clinical balance measures were significantly lower in individuals with MS compared to control subjects. The directional control impairment was seen in the right side and backward diagonals (backward-right and backward-left) directions. A significant difference between the fallers and non-fallers was found on all the components of the LOS test. There was a significant correlation between the BBS and ABC scores and different components of the LOS test. Conclusions Direction-specific impairment of limits of stability components was observed in individuals with MS. This information could be used in balance rehabilitation of people with MS. [ABSTRACT FROM AUTHOR]

We explored how changes in vision and perturbation frequency impacted upright postural control in healthy adults exposed to continuous multiaxial support-surface perturbation. Ten subjects were asked to maintain equilibrium in standing stance with eyes open (EO) and eyes closed (EC) during sinusoidal 3D rotations at 0.25 (L) and 0.50 Hz (H). We measured upper-body kinematics – head, trunk, and pelvis – and analyzed differences in horizontal displacements and roll, pitch, and yaw sways. The presence of vision significantly decreased upper-body displacements in the horizontal plane, especially at the head level, while in EC the head was the most unstable segment. H trials produced a greater segment stabilization compared to L ones in EO and EC. Analysis of sways showed that in EO participants stabilized their posture by reducing the variability of trunk angles; in H trials a sway decrease for the examined segments was observed in the yaw plane and, for the pelvis only, in the pitch plane. Our results suggest that, during continuous multiaxial perturbations, visual information induced: (i) in L condition, a continuous reconfiguration of multi-body-segments orientation to follow the perturbation; (ii) in H condition, a compensation for the ongoing perturbation. These findings were not confirmed in EC where the same strategy – that is, the use of the pelvis as a reference frame for the body balance was adopted both in L and H. [ABSTRACT FROM AUTHOR]

Background: Ménière's disease has been remained as a difficult therapeutic challenge. The present study aimed to determine the effects of one-shot low-dosage intratympanic gentamicin on vertigo control, auditory outcomes and findings of computerized dynamic posturography and vestibular evoked myogenic potentials in patients with unilateral Ménière's disease. Methods: In a prospective clinical study, 30 patients with unilateral Ménière's disease were treated with one-shot intratympanic injection of 20 milligrams gentamicin. Main outcome measures included clinical, audiometric, postural and vestibular outcomes evaluated 1 and 9 months after the treatment. Results: Mean vertigo attacks frequency, pure tone average threshold and functional level scale significantly decreased after the treatment (P < 0.05). Effective vertigo control (class A and B) obtained in 95.8% of the patients. In total, 75% of patients reported decrease in both aural fullness and tinnitus. Vestibular evoked myogenic potentials became absent in all the patients but four of them. Posturographic scores were improved after the treatment. Conclusion: One-shot low-dosage gentamicin was effective in controlling vertigo attacks in Ménière's disease and has useful effects on aural fullness and tinnitus of patients as well. Postural and vestibular tests only have adjunctive role for monitoring therapeutic responses in intratympanic gentamicin-therapy. [ABSTRACT FROM AUTHOR]

Objective. The aim of this study was to investigate balance control in asthmatic patients. Methods. Thirty subjects with controlled persistent asthma were compared with 30 non-asthmatic subjects who were matched by age and sex. Individuals who had received psychiatric treatment, demonstrated chronic musculoskeletal pain, had limited joint movements, or showed vestibular or other equilibrium disorders were excluded from both the groups to avoid biomechanical bias in the dynamic posturography. Balance control was evaluated with the subject standing still on a force platform under four different sensory test conditions. These conditions combined the subject's eyes being opened or closed with a fixed or mobile force platform. A mobile platform provides a somatosensory perturbation, and when associated with the eyes closed condition, only vestibular information is available to moderate balance control. Sensory manipulation provides a more sensitive condition to differentiate postural control between populations or pathologies. Data were sampled at 100 Hz in three 20-second trials and four postural conditions were assessed. The center of pressure (CoP) displacement values were used to calculate area and velocity in the medial-lateral and forward-backward directions. A two-factor analysis of variance with repeated measurements was applied to the data. Results. In comparison to the control group, the asthma group demonstrated a greater area of CoP displacement in conditions using the mobile force platform (with eyes opened or closed) and a higher velocity in forward-backward direction on the mobile platform with the eyes closed. Conclusion. Asthmatic individuals presented a greater area for the CoP displacement under somatosensory perturbations and a higher velocity in the forward-backward direction when vestibular information only was made available. Our data suggest that balance needs to be evaluated in asthmatic patients. [ABSTRACT FROM AUTHOR]

Objectives: Vertigo associated with rhinosinusitis has seldom been reported, and the pathophysiologic mechanism is still vague. Our aim was to evaluate sinugenic vertigo with computerized dynamic posturography (CDP) and suggest a possible pathophysiologic mechanism. Methods: We conducted a prospective study of 16 patients with a clinical and radiologic diagnosis of rhinosinusitis made between January 2007 and December 2008. All patients underwent CDP on the first 2 days after diagnosis. Patients with abnormal CDP results and/or complaints of vertigo underwent follow-up CDP when healthy. Results: Five patients complained of a new onset of vertigo. The CDP demonstrated a combined disorder in 3 of them, even though the vestibular signs were intact. On follow-up examination, all 3 patients were asymptomatic, and the follow-up CDP values were normal. Conclusions: We report a surprising 20% prevalence of sinugenic vertigo associated with abnormal results on CDP. Our results might possibly indicate that the somatosensory system of the paranasal sinuses plays a major role in the pathophysiologic mechanism of sinugenic vertigo. [ABSTRACT FROM AUTHOR]

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Copyright of Lettre de Medecine Physique et de Readaptation is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract: Objectives: To quantitatively detect the nature of balance impairment in patients with progressive supranuclear palsy (PSP) using dynamic posturography. Methods: Twenty clinically diagnosed PSP patients (8 women, 12 men; age: 62.1±7.7 years; duration: 2.6±1.3 years) and 20 healthy controls were studied. All subjects were right side dominant. They were evaluated by dynamic posturography (Biodex, USA). The measurements included (i) balance indices: ability to control balance in all directions (overall balance index, OBI), front to back (anterior–posterior index, API) and side-to-side (medio-lateral index, MLI), and (ii) the limits of stability (LOS) in 8 directions: forward (FW), backward (BW), right (RT), left (LT), forward-right (FW-RT), forward-left (FW-LT), backward-right (BW-RT) and backward-left (BW-LT). Results: Compared to controls, patients showed significantly higher OBI (p <0.001), API (p =0.003) and MLI (p <0.001), implying impaired balance. The total LOS score was significantly lower (implying poor stability) in PSP than in controls (18.3±7.3 vs. 28.4±8.5, p <0.001). Patients took significantly longer time to complete LOS test (262.7±33.0s vs. 135.4±20.6s, p <0.001). Direction-wise analysis showed that PSP patients had significantly lower LOS scores in FW, BW, RT, FW-RT, BW-RT and BW-LT directions compared to controls. However the scores in LT and FW-LT did not differ significantly. Conclusions: PSP patients showed impaired balance indices and decreased overall LOS compared to controls. Though LOS is affected in PSP, the scores in the left (non-dominant side) and forward-left (non-dominant forward diagonal) directions were preserved. [Copyright &y& Elsevier]

Postural control is achieved through the integration at the central nervous system level of information obtained by the visual, somatosensory and vestibular systems. Computerized dynamic posturography and the Sway Star system are both used to carry out sensory analysis. The purpose of this study was to determine the influence of sex and age on sensory analysis, measured with these two systems, and to compare their results. A prospective trial was conducted with 70 healthy individuals (average age: 44.9 years) uniformly distributed in seven age groups, who underwent postural study with both systems. We used SPSS 16.0 for statistical study: comparison of means test for influence of gender and age and Pearson's correlation test ( p < 0.05). Gender variable had no influence. The influence of age in vestibular input was found to be significant with both posturography systems, while visual input was only found to be significant with the Sway Star. The results with the two systems were not comparable. Sensory contribution does not remain stable throughout life. Visual information decreases with age, reaching a minimum at 40-49 years, and may correspond to the deterioration of eyesight with age. Propioceptive information showed no statistically significant changes, and several forms of treatment might correct the deterioration of this system. Vestibular information reaches a maximum in the 40-49 years age group in an attempt to compensate for visual deterioration, and decreases again in subsequent decades. This may be due to aging of the vestibular system and the difficulty in its correction. [ABSTRACT FROM AUTHOR]

The article discusses a study which evaluated and associated the postural control of young adults through Foam-laser dynamic posturography (FLP) and the force platform. Study subjects were 19 men and 11 women who were submitted to the evaluation of the postural control through FLP and force platform simultaneously. Based on the findings, researchers concluded that FLP is a very useful approach for balance evaluation.

In this paper a novel electrically actuated parallel robot with three degrees-of-freedom (3 DOF) for dynamic postural studies is presented. The design has been described, the solution to the inverse kinematics has been found, and a numerical solution for the direct kinematics has been proposed. The workspace of the implemented robot is characterized by an angular range of motion of about \pm10^\circ for roll and pitch when yaw is in the range \pm15^\circ. The robot was constructed and the orientation accuracy was tested by means of an optoelectronic system and by imposing a sinusoidal input, with a frequency of 1 Hz and amplitude of 10^\circ, along the three axes, in sequence. The collected data indicated a phase delay of 1^\circ and an amplitude error of 0.5%–1.5%; similar values were observed for cross-axis sensitivity errors. We also conducted a clinical application on a group of normal subjects, who were standing in equilibrium on the robot base with eyes open (EO) and eyes closed (EC), which was rotated with a tri-axial sinusoidal trajectory with a frequency of 0.5 Hz and amplitude 5^\circ for roll and pitch and 10^\circ for the yaw. The postural configuration of the subjects was recorded with an optoelectronic system. However, due to the mainly technical nature of this paper, only initial validation outcomes are reported here. The clinical application showed that only the tilt and displacement on the sagittal pane of head, trunk, and pelvis in the trials conducted with eyes closed were affected by drift and that the reduction of the yaw rotation and of the mediolateral translation was not a controlled parameter, as happened, instead, for the other anatomical directions. [ABSTRACT FROM PUBLISHER]

Abstract: Objectives: To assess subclinical balance impairment in patients of Parkinson’s disease (PD) with normal “pull test”, using dynamic posturography. Methods: Twenty PD patients (H&Y stage 2) and 20 matched healthy controls were studied. The patients were evaluated in best ‘ON’ state using UPDRS and Dynamic Posturography. The latter measured dynamic balance indices and limits of stability (LOS) in 8 directions: forward (FW), backward (BW), right (RT), left (LT), forward-right (FW-RT), forward-left (FW-LT), backward-right (BW-RT) and backward-left (BW-LT). Results: The dynamic balance indices and total LOS scores did not differ significantly between PD and controls. Direction-wise analysis of LOS showed significantly lower scores (suggesting impaired balance) in PD compared to controls only in FW-RT (21.2±13.8 vs 34.5±17.5, p =0.005) and BW-LT (20.8±9.8 vs 31.8±15.1, p =0.018) directions. In LOS test, controls had better stability in FW than BW (p =0.002) and on RT than LT directions (p =0.0005). Analysis in diagonal directions showed greater stability in FW-RT than FW-LT, in BW-LT than BW-RT, in FW-RT than BW-RT, and BW-LT than FW-LT directions. Though PD patients maintained greater stability in FW direction like controls, they lost the advantage in other directions. Conclusions: Despite normal “pull test”, PD patients had subclinical direction-specific balance impairment, more apparent in forward-right and backward-left directions. This information may be useful in modifying the standard “pull test” with addition of pull in diagonal directions for detection of early balance impairment. [ABSTRACT FROM AUTHOR]

This paper characterizes the moment measurement accuracy for a novel parallel spherical robot (SR) for dynamic posturography, controllable by position or impedance. The SR consists of three linearmotors placed on a support base, amoving base, and three passive arms equipped with uniaxial load cells permitting impedance controlled perturbations. To evaluate the accuracy, a subject stood still on the SR, set in position control mode, while selected sinusoidal trajectories were applied. The moments computed by the load cells were compared to the value measured by a six-component force platform, placed on top of the rotating base. For the intended application of the SR, the errors were negligible with the worse case of only 4 Nm in a total of 15 trials (five conditions, three repetitions). The observed moment error was related mainly to the intrinsic accuracy of the sensors, equal to about 7 N. To demonstrate clinical applicability, the platform was set to impedance control mode and a protocol was tested with a 12-yearold girl with brain injury and a group of four healthy subjects. In total, 24 trials (eight conditions, three repetitions) were recorded for each subject. The results of this pilot study identified distinctive postural behaviors and therefore showed that the SR can be considered as an effective tool for dynamic posturography. [ABSTRACT FROM AUTHOR]

Abstract: Muscle weakness is consistently associated with falls in the elderly people, typically when present along with other risk factors. However, it remains unknown whether and how muscle weakness alone affects balance. This hampers development of more effective fall prevention strategies. Clinical observations suggest that the amount and distribution of muscle weakness influences balance control. We therefore investigated balance corrections in patients with either predominantly proximal (limb girdle muscular dystrophy (LGMD); n=8) or distal (distal spinal muscular atrophy; n=5) leg weakness, and 27 matched healthy controls. Balance was perturbed using surface tilt rotations that were delivered randomly in eight directions. Balance measures were full body kinematics and surface electromyographic activity (EMG) of leg, arm, and trunk muscles. Both patient groups were more unstable than controls, as reflected by greater excursions of the centre of mass (COM), especially in the pitch (anterior–posterior (AP)) plane. COM displacements were greater in distal weakness patients. Patients with distal weakness had excessive and unstable trunk, knee and ankle movements, and this was present following both forward and backward directed balance perturbations, possibly reflecting the greater use of distal leg muscles in these directions. In contrast, the less weak proximal weakness patients demonstrated unstable trunk and ankle movements only for backward directed balance perturbations. Both patient groups used arm movements to compensate for their instability. We conclude that primarily distal but also proximal muscle weakness leads to significant postural instability. This observation, together with the retained ability of patients to use compensatory arm movements, provides targets that may be amenable to improvement with therapeutic intervention. [Copyright &y& Elsevier]

Conclusions. Elderly subjects without vestibular dysfunction had an overall worse performance as compared with the group of normal adults, confirming that age has a negative impact on balance. The group of elderly subjects with vestibular dysfunction had more important balance alterations than those without, confirming that vestibular dysfunction has a major impact on balance control in the elderly. The visual and vestibular systems presented more important functional changes with ageing than the somatosensory system. Objective. The main sensory input comes from the visual, vestibular and somatosensory systems; all of them may present changes due to ageing. This study aimed to investigate the performance of vestibular, visual and somatosensory systems in aged subjects with or without vestibular dysfunction, as compared to normal adults. Subjects and methods. Dynamic posturography was used in 60 elderly subjects without vestibular dysfunction (Gaa), 60 with vestibular dysfunction (Gas) and 58 normal adults (Gn). Results. For condition 1 and 2 Gn performed significantly better than Gaa and Gas, with no difference between the latter. In conditions 4, 5 and 6 the performance of Gn was statistically superior to that of Gaa, which in turn, was better than that of Gas. The somatosensory responses showed no significant differences between the three groups. The performance of visual and vestibular systems showed progressive dysfunction: Gn did better than than Gaa, and Gaa did better than Gas. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine whether the greater medial-lateral (ML) instability observed in patients with compensated unilateral vestibular loss (UVL), tested on a seesaw platform with eyes closed, is task-dependent. UVL patients, categorized into three groups according to time since lesion (1 week, 1 month and 1 year), bilateral vestibular loss patients and age-matched healthy control subjects were tested in three dynamic postural tasks. These tasks involved different supports – a seesaw platform (Satel), a platform generating horizontal linear translations (Synapsys) and foam rubber placed on a static platform – each requiring different somatosensory cues to maintain equilibrium. Displacements of the subjects’ center of pressure in both the anterior-posterior (AP) and ML directions were recorded by strain gauges within the platforms. Only tests performed with eyes closed were analyzed. Bilateral vestibular loss patients fell during foam and seesaw trials but not on the platform generating translations. We previously reported that UVL patients had greater postural oscillations on the seesaw platform in the ML compared to AP direction. In this study, we show similar ML/AP differences in patient performance on foam when standing with ‘feet close together’. In contrast, these differences were not found when patients were tested on linear translation or on foam standing with feet apart. In conclusion, the postural performance of patients with vestibular loss depends on the exact task used to measure postural stability. UVL patients are less stable when subjected to movement in the ML direction because of the biomechanical constraints of the tasks and/or the availability of proprioceptive information. Copyright © 2008 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]