FIXATION INSTABILITY (SACCADIC INTRUSIONS)

INDEX

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I ANATOMY                

 

II PHYSIOLOGY OF EYE MOVEMENTS  

III CLINICAL EXAMINATION

V SUPRANUCLEAR to NUCLEAR   

VI VESTIBULAR SYSTEM  

 VII CEREBELLAR EYE   MOVEMENTS 

VIII VISUAL FIELDS, PUPIL & THE EYE

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For steady gaze fixation, pause cells, residing between the rootlets of the abducens nucleus, tonically inhibit burst neurons and thereby prevent the occurrence of unwanted saccadic pulses.

Saccadic intrusions are spontaneously generated in voluntary eye movements which disrupt steady fixation.  Patients typically complain of shimmering-jiggling or wavy vision.  Dizziness and disequilibrium are also described. 

 

There are a variety of intrusions that have been classified:

See also:Physiology of Saccades