This has small (less than 0.5 degree) high frequency (15-30Hz) oscillations that cause intermittent oscillopsia. There is a rare description of microsaccadic flutter(1553). Of note is a report that paraneoplastic flutter can spontaneously subside, sometimes before the discovery of the tumor (1542). The prognosis of ocular flutter varies with the underlying condition. Older reports suggest that flutter can also occur with Friedreich’s ataxia, poliomyelitis, and hydrocephalus (1551). Rare cases of flutter, double saccadic pulses and flutter dysmetria have been described with cerebellar tumors (1551,1552). Flutter may occur in multiple sclerosis (47,1546) and as a toxic effect of vidarabine (1547), cyclosporine A (1548), probably phenytoin (1549), and a combination of imipramine and phenelzine (1550), where it is accompanied by mydriasis rather than cerebellar signs. Specific infectious agents include enterovirus (1544) and malaria (1545). CSF shows a small lymphocytic pleocytosis in these cases. This has not only cerebellar signs but also the ‘shuddering’ tremor or myoclonus described with opsoclonus. Parainfectious ocular flutter is more common (1495,1538,1543).
Paraneoplastic ocular flutter occurs with breast adenocarcinoma and oat cell carcinoma of the lung (1542). The minimal expression of flutter is the ‘double saccadic pulse’ in which an abnormal intruding horizontal saccade is followed by another that returns the eye to the target (47,1541).Īs with opsoclonus, ocular flutter is usually associated with cerebellar signs such as titubation, limb dysmetria, and truncal and gait ataxia (1542). Ocular flutter occurs in frequent, discrete bursts, often provoked by saccades, sometimes released by blinks (46). Sometimes a saccade terminates in a burst of flutter, called ‘ flutter dysmetria’(47). Sometimes this is in the form of ‘ dynamic overshoots’, in which a large initial saccade is followed by a return saccade without an interval. Ocular flutter is frequently accompanied by saccadic dysmetria (1538,1541), particularly hypermetric horizontal saccades. Nevertheless, ocular flutter and opsoclonus likely exist as a spectrum, as both can occur in the same patient (1538), sometimes one evolving into the other (1534,1539,1540). Ocular flutter also consists of conjugate back-to-back saccades, but only in the horizontal plane (Figure “ocular flutter”, Video “ocular flutter”).
Among those with such an interval are square wave jerks, macro square wave jerks, and macro-saccadic oscillations. Among the intrusions that lack an intersaccadic interval (‘back-to-back saccades’) are opsoclonus, ocular flutter, and so-called voluntary nystagmus. They are classified according to whether or not the intrusive saccades are separated by a brief interval in which the eyes are stationary.
OCULAR FLUTTER SERIES
Saccadic intrusions are irregular episodic occurrences of a series of two or more fast eye movements. Saccadic Intrusionsįixation or slow eye movements such as pursuit can be interrupted by a variety of saccadic intrusions in both normal subjects and patients. Superior oblique myokymia, or microtremor
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