[Coefficients of vertical vestibuloocular reflexes reactivity and vertical component of horizontal vestibular reflexes in the norm].
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Adolescent↗
Biomedical subjects
M I Tarasevich
Publications and source records attributed to M I Tarasevich.
[Vertical vestibuloocular reflexes in unilateral labyrinthine lesions (communication I)].
Vertical vestibuloocular reflexes (VVOR) were studied in 25 patients with unilateral labyrinthine lesions and in 22 healthy subjects. The technique of VVOR is based on stimulation of the internal semicircular canals of the labyrinth by active sagittal head subduction. Dysfunction of the vertical semicircular canals manifested with: VVOR asymmetry with stronger reflexes on the side of the labyrinth affection; predominance of upward VVOR; vertical components of the horizontal vestibuloocular reflexes were not so intensive as VVOR but had the same specific features.
Acute Disease↗
[Vertical vestibulo-ocular interaction in unilateral labyrinth lesion (communication II)].
Vertical vestibuloocular reflex (VVOR) suppression was studied in 25 patients with unilateral labyrinthine disorders and 22 healthy individuals. The method of the suppression investigation was based on stimulation of the internal semicircular channels of the labyrinth by active sagittal nodding with glance fixation of the object moving with the head. VVOR suppression by glance reflex in patients with unilateral labyrinthine lesion is characterized by reduced reflex suppression effectiveness, especially on the side of the affected labyrinth, via a significant VVOR phase shift down.
Adolescent↗
[Vertical vestibuloocular reflexes in affection of central parts of vestibular system (communication III)].
Vertical vestibuloocular reflexes (VVOR) were examined in 45 patients with multiple sclerosis. It is proposed to study VVOR basing on stimulation of the vertical semicircular labirynthine canals with active sagittal nodding of the head. Central lesion of the vestibular system is characterized by VVOR hyperreactivity, total failure of VVOR suppression by glance, two types of VVOR domination (typical--up and atypical--down), interocular asymmetry (dissociated nystagmus).
Acoustic Stimulation↗
[Technique of registering active sagittal head movements in the process of studying vertical vestibuloocular reflexes].
Described is a technique of registration of active head movements in the sagittal plane with a special device secured to the head with rubber bandage. The device includes a potentiometer; signals from the potentiometer wiper are applied to the monitor. The circuit diagram is presented.
Adolescent↗
[The study of vertical vestibulo-ocular reflexes].
Methodical approaches for studying the vertical vestibuloocular reflexes (VVOR) have been proposed. Eye movements were recorded by the electronystagmography: vertical movements of each ball of the eye was separately recorded and horizontal movements--in combination. Stimulation of the semicircular canals was performed by active movements of the head in the saggital plane with a frequency of 0.04 Hz (stimulus 1), 0.12 Hz (stimulus 2) and 0.24 Hz (stimulus 3). The VVORs have been recorded with the eyes closed (Program I) and with fixing the visual object on the eyes (Program II). Then, there has been recorded a vertical component of the horizontal vestibulovertical reflexes which evoked by active turn of the head around vertical axis of the body with the eyes closed (Program III) and fixation with the eyes of visual object (Program IV). The elaborated methods enable one to record steadily the VVOR in the all categories of test-subjects. As the VVOR indices there accepted the coefficient of reactivity, phase displacement; coefficients of asymmetry allowing one to compare the intensity of eye movements directed upwards and downwards; to reveal intraocular asymmetry.
Head↗
[Normal vertical vestibulo-ocular reflexes in man].
The vertical vestibular-ocular reflexes (VVOR) were evaluated in 22 human test subjects aged 18-47 years. The VVOR were evoked by active head movements in the sagittal plane with the frequencies of 0.04 Hz (stimulus 1), 0.12 Hz (stimulus 2), and 0.24 Hz (stimulus 3). Records were made either with eyes closed (Program I) or fixed at an object (Program II). In the norm, the interocular asymmetry was absent and there was an insignificant prevalence of upward VVOR. As was noted, VVOR were largely subdued in the condition of gaze fixation; this was particularly true with the downward vertical vestibular-ocular reflexes.
Adolescent↗