## Abstract A patient recovering from an acute encephalopathy demonstrated several ocular motor disturbances reflecting cerebellar and brainstem dysfunction. Two of these, macro squareβwave jerks and macro saccadic oscillations, have never been reported in the same patient. The macro squareβwave je
A hypothetical explanation of saccadic oscillations
β Scribed by Dr. David S. Zee; David A. Robinson
- Publisher
- John Wiley and Sons
- Year
- 1979
- Tongue
- English
- Weight
- 849 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0364-5134
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
Eye movements in a patient with saccadic oscillations (ocular flutter) were recorded and analyzed. Findings were related to recent microelectrode studies in the monkey pontine reticular formation which have identified three types of premotor neurons related to saccadic eye movements: burst, tonic, and pause cells. We incorporated these cell types into a hypothetical circuit that generates saccades by rapidly driving the eye to a designated orbital position rather than preprogramming a distance for movement.
Physiological measurements suggest that this neural network is unstable and that the burst neurons must be tonically inhibited to prevent saccadic oscillations during periods of fixation. Pause cells, which discharge tonically except during saccades, when they pause, appear to inhibit burst cells and prevent such saccadic oscillations. Analysis of our patient's behavior indicates that many types of saccadic oscillations can be explained and classified by assuming an abnormality of pause cell control over saccadic burst neurons.
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