This study compares HS posturography on inertial sensors (MediPost) with force platform posturography in patients with unilateral vestibular dysfunction. The study group included 38 patients (age ...50.6; SD 11.6) with unilateral vestibular weakness (UV) and 65 healthy volunteers (48.7; SD 11.5). HS tests were performed simultaneously on the force plate and with MediPost sensor attached at L4. Four conditions applied: eyes open/closed, firm/foam. The tests were performed twice, with the head moving at the frequency of 0.3 Hz (HS 0.3) and 0.6 Hz (HS 0.6). Mean sway velocity was significantly lower for MediPost than force plate in 4th condition both in UV and healthy group. For HS 0.3 the differences between devices were marginal; the highest sensitivity (87%) and specificity (95%) were in 4th condition. For HS 0.6 MediPost revealed lower sensitivity than force plate although the surface parameter improved results. MediPost IMU device and force platform posturography revealed a similar ability to differentiate between patients with balance problems in course of vestibular pathology and healthy participants, despite the differences observed between measuring methods. In some tests surface parameter may be more appropriate than sway velocity in improving MediPost sensitivity.
Vestibular impairments affect patients' movements and can result in difficulties with daily life activities. The main aim of this study is to answer the question whether a simple and short test such ...as rotation about a vertical axis can be an objective method of assessing balance dysfunction in patients with unilateral vestibular impairments. A 360˚ rotation test was performed using six MediPost devices. The analysis was performed in three ways: (1) the analytical approach based only on data from one sensor; (2) the analytical approach based on data from six sensors; (3) the artificial neural network (ANN) approach based on data from six sensors. For approaches 1 and 2 best results were obtained using maximum angular velocities (MAV) of rotation and rotation duration (RD), while approach 3 used 11 different features. The following sensitivities and specificities were achieved: for approach 1: MAV-80% and 60%, RD-69% and 74%; for approach 2: 61% and 85% and RD-74% and 56%; for approach 3: 88% and 84%. The ANN-based six-sensor approach revealed the best sensitivity and specificity among parameters studied, however one-sensor approach might be a simple screening test used e.g. for rehabilitation purposes.
This paper presents a fall risk assessment approach based on a fast mobility test, automatically evaluated using a low-cost, scalable system for the recording and analysis of body movement. This ...mobility test has never before been investigated as a sole source of data for fall risk assessment. It can be performed in a very limited space and needs only minimal additional equipment, yet provides large amounts of information, as the presented system can obtain much more data than traditional observation by capturing minute details regarding body movement. The readings are provided wirelessly by one to seven low-cost micro-electro-mechanical inertial measurement units attached to the subject's body segments. Combined with a body model, these allow segment rotations and translations to be computed and for body movements to be recreated in software. The subject can then be automatically classified by an artificial neural network based on selected values in the test, and those with an elevated risk of falls can be identified. Results obtained from a group of 40 subjects of various ages, both healthy volunteers and patients with vestibular system impairment, are presented to demonstrate the combined capabilities of the test and system. Labelling of subjects as fallers and non-fallers was performed using an objective and precise sensory organization test; it is an important novelty as this approach to subject labelling has never before been used in the design and evaluation of fall risk assessment systems. The findings show a true-positive ratio of 85% and true-negative ratio of 63% for classifying subjects as fallers or non-fallers using the introduced fast mobility test, which are noticeably better than those obtained for the long-established Timed Up and Go test.
The
(DHI) was established to assess the impact of dizziness and balance problems on the quality of life. The aim of the study was to validate the Polish version of DHI for patients with vestibular ...disorders.
Two hundred and thirty patients diagnosed with vestibular impairment and/or positional vertigo were included in the study. The mean age of the study group was 56.2 years (SD = 13.6). The factor structure (the principal component analysis - PCA), internal consistency (Cronbach's α), and discrimination ability (the receiver operating characteristic ROC curve) were examined.
satisfactory internal consistency was found (Cronbach's α coefficient = 0.92), while no floor or ceiling effect was revealed. The
demonstrated a good ability to discriminate between patients with and without the handicap (sensitivity and specificity about 80%, the cutoff point = 56). In PCA a 3-factor solution was obtained, with the factors related to restrictions in daily life, positional symptoms and visual-vestibular symptoms, which was not in agreement with the subscales provided in the original version.
The Polish version of DHI demonstrates satisfactory measurement properties and can be used to assess the impact of dizziness on handicap and the quality of life. The functional, emotional, and physical subscales were not confirmed. In particular, the functional subscale revealed no satisfactory internal consistency which provides an indication for further studies. Med Pr. 2019;70(5):529-34.
The posturography test allows assessment of the entire function of balance system and quantitative, device-based verification of the clinical Romberg test. Therefore, the aim of this study is ...assessment of usefulness of posturography as primary test for balance disorders in occupational medicine.
The study is cross-sectional, analyzing anonymous results of 1030 patients reporting dizziness and balance disorders. Based on symptoms, clinical examination and videonystagmography patients were classified into subgroups: benign paroxysmal positional vertigo (BPPV N = 130), non compensated (NS N = 82) and compensated (S N = 174) peripheral vestibular, bilateral vestibular (BV N = 63), Ménière's disease (MD N = 53), central dizziness (central N = 293), migraine (migr. N = 132), psychogenic dizziness (psychog. N = 232), Persistent postural-perceptual dizziness (PPPD N = 150). Besides, 129 healthy people were included in the study.
Ninety nine percent of abnormal static posturography (SP) and 94% of abnormal dynamic posturography (PD) results were found in diseased patients. Normal results were found both in healthy group (59% PS, 67% PD) and in diseased group (24% PS, 31% PD). Static posturography's abnormal results were more frequent in NS, BV and PPPD patients. In PD the differences were visible in the central, psychog. and PPPD subgroups. In NS subgroup the high negative predictive values of static and dynamic tests (82-87%) were calculated in relation to caloric test.
Static tests are the basic test used in examinations of employees for occupational medicine purposes. Posturography is a quantitative record of sways in relation to normative values. Abnormal posturography results most likely indicate the presence of pathologies of the balance system, including psychofunctional disorders. Normal posturography results do not indicate the lack of pathology of balance system what should be included in the work ability assessment. Med Pr. 2022;73(2):143-50.
The aim of our study was to validate the method of head-shake static posturography (HS-posturography) in healthy individuals and to establish the value of this novel method in the diagnostics of ...patients with unilateral vestibular lesion (UV). The study included 202 participants divided into two groups, one consisting of 133 patients with canal paresis CP > 19% and one of 69 healthy subjects. Participant was tested according to the standard protocol of static posturography (SP), and with head movements of 0.3 Hz (HS 40), 0.6 Hz (HS 70) in random order controlled by a metronome. HS-posturography revealed a similar repeatability and internal consistency as the standard posturography. In patients with UV, 4th condition revealed higher sensitivity (74%) and specificity (71%) in HS 40 than in the standard posturography (67%, 65% respectively) and HS 70 (54%, 70% respectively). Static posturography and HS- posturography revealed a high reliability of the testing method. The head movements added to static posturography improve the sensitivity and specificity of the method in group with vestibular impairment. The most important test for that purpose seems to be the one on unstable surface with the eyes closed, with low frequency of head movements.
(1) Objectives: The evaluation of dizzy patients is difficult due to nonspecific symptoms that require a multi-specialist approach. The Dizziness Handicap Inventory (DHI) is widely used in the ...assessment of dizziness-related disability, but its clinical efficacy needs further expansion. The aim of this study was to identify the subscales of DHI that may correlate with some vestibular or nonvestibular dysfunctions. (2) Material and methods: This observational study included 343 dizzy patients with one of the following clinical conditions: Vestibular impairment noncompensated or compensated, central or bilateral, benign paroxysmal positional vertigo (BPPV), migraine and psychogenic dizziness. Principal component analysis was used to examine the factorial structure of the questionnaire. (3) Results: The DHI questionnaire total scoring and its vestibular subscale distinguished between patients with compensated and uncompensated vestibular dysfunction with positive predictive values of 76% and 79%, respectively. The DHI items composing the F3 (positional) subscale revealed the highest scoring in the BPPV group with 75% sensitivity and 92% negative predictive value (NPV) in reference to Dix-Hallpike tests. The DHI total score and the subscales scores correlated with anxiety-depression, and the highest correlation coefficients were calculated for vestibular (F2 0.56) and anxiety (F5 0.51) subscales. (4) Conclusions: Our analysis revealed that the DHI vestibular subscale distinguishes between patients with compensated and uncompensated vestibular dysfunction. The positional subscale showed the highest scoring in the BPPV group with high sensitivity and low specificity of the test. The DHI is highly correlated with patients' psychological status.
Occupational exposure to styrene has been shown to be associated with an increased probability of developing hearing loss. However, the sites of lesions in the auditory system in humans remain ...unknown. The aim of this study was to investigate the possible adverse effects of styrene exposure on the cochlea of human subjects.
The hearing function of 98 styrene-exposed male workers from the glass fibre-reinforced plastics industry (mean concentration of 55 mg/m3) was evaluated bilaterally using pure-tone audiometry (1000-16000 Hz), distortion product otoacoustic emissions (DPOAEs), and auditory brainstem response (ABR). The results were compared to a group of 111 male workers exposed to noise (above 85 dBA) and 70 male white-collar workers exposed to neither noise nor solvents. Age and noise exposure levels were accounted for as confounding variables in all statistical models.
Styrene exposure was significantly associated with poorer pure-tone thresholds (1-8 kHz), lower DPOAE amplitudes (5-6 kHz), and shorter wave V latencies in both ears compared to control-group subjects. Similar results were found among noise-exposed subjects. A further analysis with wave V latency showed that styrene-exposed subjects showed significantly shorter latencies than expected according to normative data. These results suggest that occupational exposure to styrene at moderate concentrations is associated with cochlear dysfunction, at least at high frequencies. DPOAEs may be considered a valuable diagnostic tool in hearing conservation programs in workers exposed to styrene.
The aim of this study was to investigate whether the restriction in neck rotation and increased neck muscle tension could be causally related to vertigo and dizziness.
Seventy-one patients reporting ...vertigo and/or imbalance were divided into 2 groups: 45 subjects with unilateral restriction (R+) and 26 without restriction (R-) of cervical rotation and muscle tension in the clinical flexion-rotation test. The normal caloric test was the inclusion criterion. The control group comprised 36 healthy volunteers with no history of vertigo. The vestibulo-ocular reflex (VOR) and the cervico-occular reflex (COR) were measured through the videonystagmography (VNG) sinusoidal pendular kinetic test in the conditions of not inactivated head and immobilized head, respectively. The VNG-head torsion test (VNG-HTT) nystagmus was recorded.
Among the reported complaints, neck stiffness, headaches and blurred vision were more frequent in the R+ group than in both the R- group and the control group. VNG revealed an increased COR gain and the presence of VNG-HTT nystagmus in the R+ group only. Similarly, only in the R+ group a positive relationship between COR and VOR was observed.
Patients with asymmetric restriction in neck rotation and increased neck muscle tension reveal the tendency to have an increased response of the vestibular system, along with co-existing COR upregulation. Further research is needed to investigate the relationships between the activation of cervical mechanoreceptors and dizziness pathomechanisms. Int J Occup Med Environ Health. 2019;32(5):723-33.
Balance disorders are a growing problem worldwide. Thus, there is an increasing need to provide an inexpensive and feasible alternative to standard posturographic platforms (SP) used for the ...assessment of balance and to provide a possible solution for telemonitoring of patients. A novel mobile posturography (MP) MediPost device was developed to address these issues. This prospective study used a Modified Clinical Test of Sensory Interaction on Balance to evaluate healthy individuals and patients with a unilateral vestibular disorder through SP and MP simultaneously. The control group included 65 healthy volunteers, while the study group included 38 patients diagnosed with a unilateral vestibular deficit. The angular velocity values obtained from both methods were compared by intraclass correlation coefficients (ICC) and Bland−Altman plot analysis. Diagnostic capabilities were measured in terms of sensitivity and specificity. The ICC between the two methods for conditions 2−4 was indicative of excellent reliability, with the ICC > 0.9 (p < 0.001), except for Condition 1 (standing stance, eyes open) ICC = 0.685, p < 0.001, which is indicative of moderate reliability. ROC curve analysis of angular velocity for condition 4 represents the most accurate differentiating factor with AUC values of 0.939 for SP and 0.953 for MP. This condition also reported the highest sensitivity, specificity, PPV, and NPV values with 86.4%, 87.7%, 80%, and 90.5% for SP, and 92.1%, 84.6%, 77.8%, and 94.8% for MP, respectively. The newly developed MediPost device has high sensitivity and specificity in distinguishing between healthy individuals and patients with a unilateral vestibular deficit.
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