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jws-mds.21414.mpg13728KSegment 1. Ocular motor testing revealed broken-up smooth pursuit, bilateral gaze-evoked horizontal nystagmus and hypermetric saccades in both horizontal and vertical directions.Segment 2. While the patient is counting aloud, irregular myoclonus of particularly the left arm and shoulder and a dystonic tremor of the left thumb are noted.Segment 3. Bilateral positive and negative action myoclonus are present, more pronounced on the left side. Dystonic posturing of the left arm and hand is most noticeable during finger tapping and diadochokinesis.Segment 4. On finger-nose testing and finger chase tests, cerebellar ataxia is evident from dysmetria, decomposition of movement and terminal tremor, although the myoclonus in the left arm interfered significantly with task performance.Segment 5. Gait is broad-based and ataxic, with locking of the knees. Myoclonic jerks in the upper arms are noticeable during walking.

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