1. Multiple Sclerosis 906-4

2. Eye Movements Transient spontaneous primary position upbeat nystagmus with lid nystagmus Rapid bursts of horizontal square wave oscillations opening her eyes to fix on a target. Horizontal gaze evoked rotary (torsional) nystagmus (Rotation of the globe is best seen by observing conjunctival blood vessels).

3. Eye Movements Gaze evoked unsustained upbeat nystagmus Saccadic pursuit except on downgaze Saccadic Dysmetria Hypermetria left gaze to center.

4. Leigh JR and Zee DS. The Neurology of Eye Movements 4th Edition. Oxford University Press, New York 2006 with permission Clinical Features of Upbeat Nystagmus

5. Localizes to the Caudal Medulla with lesion affecting the Perihypoglossal group of nuclei including nucleus intercalatus nucleus of Roller nucleus of pararaphales Upbeat Nystagmus

6. More rostral brainstem lesions may interrupt the ventral tegmental tract containing projections from the vestibular nuclei that receive inputs from the anterior semicircular canal or Involve the brachuim conjunctivum in the rostral pons and Medulla. Upbeat Nystagmus

7. Leigh JR and Zee DS. The Neurology of Eye Movements 4th Edition. Oxford University Press, New York 2006 with permission Etiology of Upbeat Nystagmus

8. Leigh JR and Zee DS. The Neurology of Eye Movements 4th Edition. Oxford University Press, New York 2006 with permission Clinical Features of Torsional Nystagmus

9. Neuroimaging Figure 1 Series of sagittal and axial FLAIR scans show classical calloseptal and deep periventricular foci of increased signal intensity surrounding cavatating areas in this patient with long standing MS

10. Neuroimaging Note perpendicular orientation Towards the ventricle classic for“Dawson fingers” Note a small foci in the pons Courtesy of Anne Osborn,M.D.

11. Leigh RJ, Zee DS. Diagnosis of Nystagmus and Saccadic Intrusion. Chp 10;475-558. In: The Neurology of Eye Movements, 4 th Edition, Oxford University Press, New York, 2006. Tilikete C, Koene A, Nighoghossian N., Vighetto A, Pélisson. Saccadic lateropulsion in Wallenberg syndrome: a window to access cerebellar control of saccades? Exp Brain Res 2006; 174(3);555-65. References

12. Tilikete C. Hermier M. Pelisson D, Vighetto A. Saccadic lateropulsion and primary position upbeat nystagmus: disorders of caudal medulla. Ann Neurol 2002; 52:658- 662.

13. http://www.library.med.utah.edu/NOVEL