Yes / PURPOSE: There is little research evidence to explain why older adults have more problems adapting to new spectacles incorporating astigmatic changes than younger adults. We tested the hypothesis that astigmatic lenses oriented obliquely would lead to errors in verticality perception that are greater for older than younger adults. METHODS: Participants included 12 young (mean ± SD age 25.1 ± 5.0 years) and 12 older (70.2 ± 6.3 years) adults with normal vision. Verticality perception was assessed using a computer-based subjective visual vertical (SVV) task, under static and dynamic (in the presence of a moving peripheral distractor) conditions and when viewing targets through the near refractive correction (control condition), and two forms of astigmatic lenses oriented in the vertical, horizontal, and oblique meridians. RESULTS: The older group demonstrated much greater dynamic SVV errors (e.g., 3.4° for the control condition) than the younger group (1.2°, P = 0.002), larger errors with vertical and horizontal astigmatic lenses (older group 4.1°and 5.2° for toric and magnifier lenses vs. younger group 1.2° and 1.4°, respectively, P < 0.001), and a larger influence of the oblique astigmatic lenses (older group 5.6° vs. younger group 2.1°, P<0.001). CONCLUSIONS: Astigmatic lenses produced little or no errors in SVV in young adults, but large static and dynamic SVV errors in older adults. This indicates a greater reliance on visual input with increased age for SVV, and helps explain why oblique astigmatic refractive corrections can cause dizziness in older patients and why they report greater difficulties adapting to new spectacles with astigmatic changes.

The vestibular system senses changes in head position and is responsible for the brain’s perception of verticality. Vestibular dysfunction is caused by deficits in the semicircular canals and/or otolith end-organs with resulting symptoms including dizziness, vertigo, and unsteadiness. Current vestibular rehabilitation focuses on compensation of the semicircular canal-mediated vestibulo-ocular reflex through gaze and balance exercises. Little is known about rehabilitation of otolith organ function, yet research findings suggest that fall risk may be related to otolith dysfunction. A recent case study demonstrated improvement of vertical perception and balance following off-axis rotation in a rotary chair, showing that such stimulation may be useful for compensation of otolith organ dysfunction. The purpose of our research was to further investigate off-axis rotation as a possible treatment method by evaluating subjective visual vertical (SVV) in healthy controls. Two distance parameters (3.5 cm off-axis and 7.0 cm off-axis) were applied to the rotary chair, with results measured through the SVV test, visual analog scales (VAS), and the balance tilt test (BTT). The magnitude of SVV shift following off-axis rotation was measured in both the 3.5 cm and 7.0 cm off-axis experiments. The greater distance parameter (7.0 cm) did not increase SVV shift magnitude more than the 3.5 cm parameter; yet, resulted in greater symptom intensity as measured through the VAS. These findings led to the conclusion that a distance parameter of 3.5 cm off-axis is optimal for stimulating the otolith organs. This discovery may be helpful in future research utilizing off-axis rotation as a possible treatment method for vestibular patients suffering from otolith dysfunction.

Cerebro-vascular accident often affects parts of brain responsible for spatial orientation. Optimal integration of afference from visual, somatosensory and vestibular system is necessary for maintaining balance and often in the end for the functional indepencence of the patient. Examination of subjective vertical is a sensitive signifier for spatial orientation and the ability to discern graviception. By using clinical examination of subjective visual vertical it is possible to objectify and quantify graviception disorder excluding visual context. Current level of understanding in this field is briefly summarized in theoretical part of this study. In practical part subjective visual vertical examination by bucket-method was for statistically comparison of 29 patients after a cerebro- vascular accident with 34 healthy seniors. Hypotheses about the influence of a side of a lesion and a time elapsed since the lesions were also tested. The study concludes that the perception of verticality in patients after cerebro- vascular accident can be severely affected. Additionally, the study highlights the reliability of examination of patients after cerebro-vascular accident using clinically practical bucket-method.

INTRODUCTION - The ability to maintain stability while standing given by function of multisenzory system consists of vision, somatosensory and vestibular system and integration of the CNS. Due to aging there is a decrease of functional capacity of the organism, including these systems, resulting in a deterioration of the balance. Examination of subjective visual and haptic vertical is sensitive diagnostic criterion for functionality of these systems. OBJECTIVE - To compare the ability of verticality perception in young and elderly. METHODS - We examined 64 probands in visual and haptic subjective vertical. The first group consisted of 30 subjects aged 20 to 30 years. In the second group there were 34 people aged over 60. RESULTS - The values of the subjective visual vertical not differ between groups (0.1 ± 0.75 ř for the young and 0.1 ± 1.91 ř for seniors). Results of subjective haptic vertical differed on the significance level of p = 0.004 (0.8 ± 3.67 in the young and 3.7 ± 4.15 for seniors). CONCLUSION - Because subjective haptic vertical is diagnostic criterion mainly for the somatosensory system, we can assume that this particular system is responsible for a decrease in functional capacity and deterioration of stability in the elderly.

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The thesis deals with the evaluation of the impact of preoperative application of gentamicin on vestibular compensations of patient after vestibular schwannoma surgery. The trial involved 32 patients with diagnosed vestibular schwannoma and hospitalized with the indicated for neurosurgical resection at the University Hospital Motol. Ototoxic gentamicin was transtympanically applied to ten of these patients two months before their surgery. After the surgery the patients underwent a rehabilitation program based on the visual biofeedback using the Homebalance system. To evaluate the vestibular compensation the subjective visual vertical measurement and the Dynamic Gait Index standardized walking test were used. In total, each patient performed three examinations: before the surgery, after the surgery and before the end of hospitalization. Statistical analysis of the measured data showed the statistically significant increase tilt of subjective visual vertical and the decrease in the overall score of Dynamic Gait Index after surgery. Reduction in the subjective visual vertical tilt and the overall score of Dynamic Gait Index after rehabilitation has not been proven to be statistically significant. Any statistically significant difference was found between the group of patients treated by gentamicin and...

The otoliths are vestibular organs that act as gravito-inertial force sensors and contribute to the perception of spatial orientation (earth verticality). The subjective visual vertical (SVV) is a psychophysical measure of the angle between perceptual vertical and true (gravitational) vertical. The otoliths contribute to the estimation of the physical vertical orientation, and individuals with normal vestibular function align the SVV within 2 degrees of true vertical (0 degrees). Impaired SVV has been documented in patients with unilateral vestibular disorders. Most research has focused on measuring the static SVV (head upright and stationary); however, more recently, methods have been developed to measure the SVV during stimulation of the otolith organs using on-axis yaw rotation (bilateral centrifugation), off-axis eccentric rotation (unilateral centrifugation), or head tilt for tests of bilateral or unilateral otolith function. The SVV test may be a useful method to assess utricular function in patients complaining of dizziness and/or imbalance and identify stages of recovery for otolith involvement.

Bibliographic identification Author's first name and surname: Bc. Radim Žídek Title of the master thesis: Perception of verticality in patiens with developmental coordination disorder Department: Department of Rehabilitation and Sports Medicine, 2nd faculty of medicine, Charles University and FN Motol Supervisor: PhDr. Ondřej Čakrt, Ph.D. The year of presentation: 2017 Annotation: Developmental coordination disorder is typical for poor motor learning and motor coordination that cannot be related to any neurological or mental disease. The exact reason of it stays still unknown. There are theories that say that dysfunctional collaboration of afferent systems causes developmental coordination disorder. Thanks to afferent systems a human organism is able to perceive different modalities. One of the modalities is a perception of verticality. In theoretical part of this thesis we summarized information about developmental coordination disorder and postural and balance control. In experimental part we tested 35 pupils of primary school (age 13-15). Using MABC-2 we classified the pupils into children with and without predispositions for developmental coordination disorder. Then we tested their ability of perceiving subjective visual and subjective haptic verticality. According to statistical evaluation there is no...