Nystagmus - involuntary jerky repetitive oscillations of the eyeballs, which by their nature may be pathological and physiological.So, for example, nystagmus, which manifests itself in response to the rotation of the body in space or optokinetic drum serves to maintain an optimal view and is quite normal.Eye movements, performed for fixation on an object called foveiruyuschimi and movement of the object moves away from the fovea - defoveiruyuschimi.In cases of pathological nystagmus, each engine cycle eyeball often begins spontaneous deviation from the house followed by a spasmodic movement refiksatsionnym.According to its direction of nystagmus is nonspecific, torsion, vertical and horizontal, and the amplitude of the vibrations - small-bore and large-caliber srednekaliberny
Nystagmus - causes of
Most often the development of nystagmus caused by exposure to local and central factors.Typically, this condition occurs when acquired in early childhood or congenital decreased visi
Nystagmus - types
→ pendulum nystagmus .As defoveiruyuschie and foveiruyuschie movement slowed enough (in both directions, the same rate of nystagmus)
• Acquired pendular nystagmus is torsional, vertical and horizontal components.Congenital pendular nystagmus is horizontal, when viewed sideways can move in tolchkoobrazny
• If a vertical and horizontal components of the pendulum nystagmus occur simultaneously (in phase), the perceived direction looks oblique
• If a vertical and horizontal components are out of phaseperceived direction looks rotatory or elliptical
→ jerky nystagmus .Determined quickly correcting jerky motion refoveiruyuschim slow "drift" defoveiruyuschim movement.Typically, the direction indicated by the direction of the nystagmus fast component, whereby tolchkoobrazny nystagmus is rotatory, bottom, top, left and right side.Besides tolchkoobrazny nystagmus divided into nystagmus paresis eye (usually a sign of lesions of the brain stem) and vestibular (installation)
→ Mixed nystagmus includes tolchkoobrazny nystagmus in a side view and a primary pendulum nystagmus
→ vestibular nystagmus - it tolchkoobrazny nystagmus, which is caused by the change in input from the vestibular nuclei to the imaginary center of the horizontal movements of the eyeballs.Fast phase is initiated by frontomezentsefaliticheskim and brain stem, and the slow phase - the vestibular nuclei.Most often rotatory nystagmus is associated with abnormalities of the vestibular system.This type of nystagmus can be called caloric stimulation:
• If you pour in the right ear with cold water, appears tolchkoobrazny left-hand nystagmus
• If you pour in the left ear with warm water, will jog right-nystagmus
• If the warm water at the same time pour in both ears,will nystagmus with fast phase-down;cold water, pour in both ears, will result in a jerky nystagmus with fast phase up
→ optokinetic nystagmus - is caused by repetitive movements of the observed object in sight tolchkoobrazny nystagmus.Trailing behind the object is slow eye movement phase and sakkalicheskoe movement in the opposite direction in which the eyes are fixed next object - fast phase.In the case of optokinetic drum movement from right to left, the left occipital-parietal region of the tracking control (slow) phase of the left and the left frontal lobe controls sakkalicheskuyu (fast) phase right.Use optokinetic nystagmus to determine in young children visual acuity and identify malingerers simulating blindness
→ installation nystagmus - a small frequency tolchkoobrazny small nystagmus at the extreme abduction sight.His rapid phase in the direction of gaze
→ Nystagmus motor imbalance seen as a consequence of primary defects efferent mechanisms
It does not combine with the vertical deviation and associated with infantile esotropia.Latent nystagmus is characterized by the following features: nystagmus absent when both eyes are open;priotkryvanii when one eye appears horizontal nystagmus;in the direction of the uncovered eye fixing comes fast phase;in the case of covering one eye amplitude nystagmus increases
type of inheritance of autosomal dominant or X-linked recessive.Congenital nystagmus manifests itself throughout life, and appears on the second - third month after birth.
Symptoms of congenital nystagmus: there may be an abnormal position of the head in the case of setting the zero point in the eye (gaze direction in which the symptoms are minimal nystagmus);Congenital nystagmus often jerky type were observed in the phase of sleep may be weakened convergence
very rare condition that can occur between three and eighteen months.Its causes include: porentsefalicheskuyu cyst syndrome empty sella and glioma of the anterior visual pathway.Symptoms sternocleidomastoid spasm: two-sided high frequency horizontal nystagmus melkoamplitudny with nodding head;there may be a torsion and vertical components;nystagmus often asymmetrical, with increased amplitude in the abduction
periodic alternating nystagmus
The causes of this condition: ataxia teleangiekstaziya, demyelination diseases of the cerebellum, the impact of certain drugs (phenytoin and so forth.)
Symptoms periodically takes the opposite directiontolchkoobrazny horizontal nystagmus;Each cycle is divided into a phase of immobility and an active phase;during the active phase of the speed, frequency and amplitude of the slow phase progressively increases initially and then gradually decreases;then goes quiet short interlude lasting from five to twenty seconds, eyeballs during which perform low-amplitude pendulum motion;after that should continue from one to three minutes, the cycle of successive movements in the opposite direction
Nystagmus - symptoms
Some types of this disease remains high visual acuity, which says that the cause of nystagmus is different regulatory violations oculomotor apparatus.
Depending on which direction oscillate, distinguish the horizontal (most common), vertical, diagonal, and rotational nystagmus.Division by the nature of the movements: tolchkoobrazny mixed and pendulum.
jerky nystagmus, building on the direction of its quick phase, called the right- or left-handed.In this type of pathology observed a forced rotation of the head to the side of the fast phase.So people turn compensates for the weakness of the eye muscles, which results in a decrease in nystagmus.
When small-caliber vibrational amplitude nystagmus eye movements less than 5%, while the amplitude of the oscillation srednekalibernom from 5 to 15%, with large-oscillation deviations exceed 15%.
to determine the nature, frequency and amplitude of vibrational motion nistagmoidnyh used this method of research as nistagmografiya.In the absence of nistagmografa amplitude is determined by the degree of displacement of the ophthalmoscope to the light reflex on the cornea.In a study of patients with the disorder necessarily shown electrophysiological studies that allow us to determine the presence of amblyopia, the degree of organic lesions and to determine the future tactics of treatment
Nystagmus - treatment
Treatment of nystagmus is very time-consuming, difficult and often completely unsuccessful.All the efforts of many professionals address the root causes that led to the development of this condition.To decrease nystagmus, restore muscle tone and improve visual acuity could lead therapeutic measures such as reflexology, keratoplasty, cataract extraction, correction with glasses, treatment of amblyopia.
Medication nystagmus is to improve the nutrition of all the tissues of the retina and the eye (vitamin complexes, vasodilators).
Surgical treatment of nystagmus is carried out to reduce the vibrational movements of the eyeballs.The greatest effect is achieved only when the horizontal nystagmus
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