Eye paralysis

from Wikipedia, the free encyclopedia
Classification according to ICD-10
H51.0 Other eye movement disorders - conjugated eye paralysis
ICD-10 online (WHO version 2019)

Eye paralysis or eye paresis is a disorder of the same eye movements . It is caused by lesions in the supranuclear gaze centers in the brain. The restriction of the mobility of the right and left eyes are almost the same in "pure" eye paralysis. There is usually no squint in these cases. However, combinations with forms of paralysis strabismus occur much more frequently, as the gaze centers are in close proximity to the core areas and roots of cranial nerves III , IV and VI . The presence of a squint does not rule out paralysis.

Horizontal, one-sided paralysis

Persistent gaze paralysis to one side is due to disorders of the ipsilateral pontine structures and affects either the abducens core or the paramedians pontine reticular formation ( PPRF ). It is noticeable that if the abducens nucleus is damaged, all eye movements to the side are disturbed, while in the case of lesions of the PPRF, the subsequent movements and the vestibulo-ocular reflex ( doll's head phenomenon ) are preserved. Only the quick gaze target and command movements as well as saccades and fast nystagmus phases are disturbed.

In contrast to pons lesions, hemispherical lesions - often after a stroke - almost exclusively lead to temporary paralysis. Gaze paralysis to the left is also found much more frequently than to the right, which suggests a different organization of the processing of gaze impulses in the right and left hemisphere.

Horizontal paralysis on both sides

Eye paralysis to the right and left (while maintaining vertical eye movements) can be due to either bilateral lesions of the abducens nuclei or bilateral lesions of the upper parts of the PPRF. Isolated horizontal paralysis of the eye with preserved convergence reaction occasionally occurs in a congenital form.

Vertical paralysis

Disturbances that are limited to rapid eye movements in the vertical plane - i.e. when looking up and down - can be reliably localized in the area of ​​the midbrain. All vertical supranuclear eye movement disorders are summarized under the term Parinaud's syndrome . Here, isolated paralysis of the sight is much rarer than disturbance of the sight. Many patients show a convergent nystagmus , the origin of which is not yet understood. This symptom can be intensified by offering an optokinetic stimulus pattern that moves from top to bottom. As a simple clinical test, this is of great diagnostic importance.

Vertical paralysis is also a diagnostic criterion for progressive supranuclear palsy (Steele-Richardson-Olszewski syndrome), a neurodegenerative disease with Parkinson- like symptoms.

The vertical paralysis of the eyes is also an important indicator of a possible illness from Niemann-Pick disease . This is a genetic disease that usually occurs in childhood , can have a fulminant course and is often diagnosed far too late due to ignorance.

Another form of vertical paralysis of the upward gaze occurs in early childhood hydrocephalus with the classic sunset phenomenon .

literature

  • Herbert Kaufmann (Ed.): Strabismus. With the collaboration of Wilfried de Decker et al. Enke, Stuttgart 1986, ISBN 3-432-95391-7 .

See also