Nystagmoscopy

Nystagmoscopy is a method for studying the function of the vestibular apparatus by recording eye movements (nystagmus) during irritation of the vestibular analyzer.

When performing nystagmoscopy, spontaneous and evoked nystagmus is examined. Spontaneous nystagmus occurs with lesions of the vestibular apparatus. Induced nystagmus is provoked using rotational or caloric tests.

Rotation tests involve rotating the patient in a special chair or his head relative to the body. In this case, the semicircular canals of the vestibular apparatus are irritated.

Caloric tests are based on thermal stimulation of the horizontal semicircular canals when the external auditory canal is irrigated with cold or warm water.

Registration of nystagmus during nystagmoscopy can be carried out using electronystagmography, videonystagmography, and frenzelography.

Nystagmoscopy allows you to identify disturbances in the functioning of the vestibular apparatus and localize the lesion.

Nystagmography (nystagmography) or nystagmology is one of the methods of ophthalmological examination of the visual system. Described by F. G. Girshberg in 1927, it is used to diagnose disorders of the functions of the vestibular and visual apparatus, conditions that led to this, mental disorders and mental disorders in general.

The study includes determining the speed and pattern of movements of the eyeballs or eyelids. One of the classic studies: determining the direction of eye movement of a patient with his eyes closed when submitting optotypes; determining the dynamics of oculomotor reactions.

The patient fixes his gaze at a given point in the distance, and the experimenter suddenly darkens the patient’s field of vision, applying shadows from his fingers to the back of his eyelids, which turns off the light. In this case, a nystagmic reaction occurs - intense spontaneous flutter of the pupil (the eyes make circular movements with a frequency of 5-25 per second). The duration of these movements for various studies ranges from 20 to 180 seconds. The observation duration is 4 minutes.

These actions are repeated up to ten times with pauses of 1 minute. The patient is in a state of rest and relaxation on a chair with his back to the light source or in a supine position with his eyes closed. The patient’s perception becomes impossible in the first two seconds after a sudden darkening, then the correctness of eye movements and ocular coordinate functions, the symmetry of eye movements, the latent period of the reaction, etc. are clarified.