Saccadic Intrusions Are Rare In Multiple Sclerosis

Objective: To determine the prevalence and characteristics of saccadic intrusions in patients with multiple sclerosis (MS). Background: Saccadic intrusions (SI) are spontaneous abnormal eye movements that occur due to a number of neurologic conditions, and are indicative of pathology in a wide variety of neuroanatomic sites. Square wave jerks, macro-saccadic oscillations, and ocular flutter have been described in case reports and short series of patients with multiple sclerosis (MS). Design/Methods: All patients with MS seen at an MS center between June 12, 2017 and August 17, 2017 were evaluated for the presence of SI. If the examining provider suspected SI, the patient was evaluated by a neuro-ophthalmologist. Demographic, clinical, and MRI information about affected patients was tabulated. Visual quality of life questionnaires were completed. Results: Three patients were found to have SI out of 614 screened, indicating a prevalence of 0.49%. Two patients had macro-square wave jerks (MSWJ) and one had ocular flutter. Both MSWJ patients had SPMS with significant disability, with MS plaques on MRI scattered throughout the brainstem, the cerebellum, and both cerebral hemispheres. There was a relation to visual quality of life scores. The patient with flutter had relapsing remitting MS, a single MS plaque in the cerebellar peduncle, no other brainstem lesions, and several hemispheric lesions. Conclusions: We estimate the prevalence of SI in the general MS population to be approximately 0.5%, making them rare in this group of patients. The examining providers may not have detected all patients with SI, so this is likely to be an underestimate of true prevalence. Based on the patients we identified, MSWJ may be more likely present in individuals with significant disability, secondary progressive MS, and widespread multi-level plaques. Ocular flutter may occur in individuals with less extensive brainstem and cerebellar burden of disease. Disclosure: Dr. DePledge has nothing to disclose. Dr. Repovic has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Biogen, Genzyme, Teva, Genentech, EMD Serono. Dr. Bowen has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Acorda Therapeutics, Biogen IDEC, EMD Serono, Genzyme, Genentech, Novartis, Teva. Dr. Bowen holds stock and/or stock options in Amgen. Dr. Bowen has received research support from Acorda Therapeutics, Alexion, Alkermes, Allergan, Biogen IDEC, Genzyme, Genentech, Glaxo Smith Kline, Novartis, Roche, Sanofi-Aventis. Dr. Qian has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva, Biogen. Dr. Severson has nothing to disclose. Dr. Hamilton has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva Pharmaceutical. Dr. Keung has nothing to disclose. Dr. May has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Teva, Genzyme. Dr. May holds stock and/or stock options in AstraZeneca, Pfizer, Medtronic, Novartis, Roche, Walgreens.