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Vestibular and postural biomarkers in spinocerebellar ataxias and peripheral vestibular lesions
Danková, Michaela ; Jeřábek, Jaroslav (advisor) ; Roth, Jan (referee) ; Sivák, Štefan (referee)
Vestibular and postural biomarkers in spinocerebellar ataxias and peripheral vestibular lesions Abstract Vestibular dysfunction can be a part of clinical impairment in spinocerebellar ataxias. Together with cerebellar symptoms, it can lead to imbalance and also to impairment of dynamic visual acuity (DVA) in these patients. The aim of the work was to objectify the involvement of the vestibulo-ocular reflex in patients with SCA using modern diagnostic methods. At first the innovative method of video head impulse test (vHIT) was introduced in patients after vestibular schwannoma surgery, in whom a clearly defined vestibular impairment is present. We investigated DVA in SCA patients, the degree of the DVA impairment correlated proportionally with the impairment of vestibular function measured by vHIT. The best predictive values for DVA impairment were obtained by using a model that combined impairment of vestibulo-ocular reflex measured by vHIT and degree of cerebellar dysfunction according to SARA (scale for assessment and rating of ataxia). The research also aimed at the verification of postural stability disorders in patients with SCA using posturography. Standard posturographic parameters (area, sway path and mean velocity of Centre of foot Pressure - CoP) did not allow to distinguish between individual...
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The evaluation of adaptation of the vestibulo-ocular reflex in patients after vestibular schwannoma surgery
Hladíková, Veronika ; Čakrt, Ondřej (advisor) ; Jeřábek, Jaroslav (referee)
This thesis deals with the evaluation of the vestibulo-ocular reflex in patients indicated for neurosurgical resection of vestibular schwannoma, executed at the Motol University Hospital. To evaluate the function of the vestibulo-ocular reflex, three types of clinical examinations were used. In periods before the surgery, early after the surgery and before leaving the hospital we monitored the patients' ability to perceive subjective visual vertical, which reflects tonic function of otolith organs. Before the surgery we also tested relative dynamic visual acuity during passive isolated head movements in the transversal plane, whose impairment is related to dysfunction of lateral semicircular canals. Furthermore, we obtained patients' preoperative values achieved in caloric reflex test. In the early postoperative period, bordered by the first day after the vestibular schwannoma surgery and the last day of the hospitalization, patients underwent specialized vestibular rehabilitation. Based on statistical analysis of acquired data, we found out that in some patients there was a lesion of the vestibulo-ocular reflex already before the surgery and moreover, there was a correlation between dysfunction of translational and rotational parts of the vestibulo-ocular reflex. Although variance of subjective...
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Dynamic visual acuity testing in healthy individuals
Rezlerová, Pavlína ; Čakrt, Ondřej (advisor) ; Jeřábek, Jaroslav (referee)
In this study we examined dynamic visual acuity as a functional testing of the vestibulo- ocular reflex. Two groups were examined: 22 healthy seniors and 22 healthy young people as controls. We used two types of situations for testing: while walking on a treadmill at a speed of 2, 4 and 5 kmph, and with a subject's head passively moved in yaw and pitch plane. Visual acuity was measured with optotype charts (for the walking test it was a standard Snellen optotype chart at 6 m distance, for the test of head moves it was a Jaeger chart at 30 cm distance). The values obtained in these ways we related to values of a subject's static visual acuity, measured in the same conditions, just before the dynamic situations were examined. We found significant difference of dynamic visual acuity in senior group within each condition tested. We also found a significant decline as for difference of dynamic visual acuity in the senior group compared to young subjects - in the walking test at 4 and 5 kmph and in both head-moving conditions. These results indicate age-related impairment in function of vestibulo-ocular reflex. Based on our results, the test of passive head moves appears to be more suitable for ordinary clinical examination of dynamic visual acuity.
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