eMULES in concussion: A quantitative ‘Look' at the Eye Movements

MULES (Mobile Universal Lexicon Evaluation System) is a recently developed test of rapid picture naming, which has shown promise in its sensitivity to detect concussion through a post-injury increase in total picture identification times. Our previous work has demonstrated prolonged inter-saccadic-intervals in concussion patients for rapid automatized naming tasks, such as rapid number naming. Here we will compare saccadic biomarkers in patients with concussion and control participants while completing a digital version of the MULES test (eMULES).

Tuesday, March 19th from 9:30 - 9:45 am eMULES in concussion: A quantitative ‘look' at the eye movements Todd Hudson1, John-Ross Rizzo1, John Martone1, Laura Balcer1, Steven Galetta1, Janet Rucker1 New York University School of Medicine, New York, USA 1 Introduction: MULES (Mobile Universal Lexicon Evaluation System) is a recently developed test of rapid picture naming, which has shown promise in its sensitivity to detect concussion through a post-injury increase in total picture identification times. Our previous work has demonstrated prolonged inter-saccadic-intervals in concussion patients for rapid automatized naming tasks, such as rapid number naming. Here we will compare saccadic biomarkers in patients with concussion and control participants while completing a digital version of the MULES test (eMULES). Methods: 61 healthy participants (mean age 25.9 years, range: 18-58) and 31 participants with chronic concussion (more than 3 months) (mean age 37.4 years, range: 15-69) performed the eMULES. Subjects were instructed to identify each picture as quickly as possible and to progress from picture to picture in a left to right and top to bottom quasi-reading strategy. The full test consisted of three screens of pictures, each with 18 pictures arranged in three rows of six. Video-oculographic measures (EyeLink 1000+) were obtained while participants completed the task. Results: Participants with concussion demonstrated prolonged total naming times (32.2s vs. 26.6s, p<0.05) and intersaccadic intervals (195ms vs. 163ms, p<0.05). In addition, participants with concussion made smaller saccades on average (9.2 vs. 10.4 deg, p<0.05), and made a larger proportion of intra-picture saccades (0.59 vs. 0.51, p<0.05) [intra-picture saccades both begin and end spatially within the regional bounds of a single picture]. Saccade peak velocities and durations showed no differences between participant groups. Conclusions: Objective eye movement recording during eMULES performance identifies ocular motor differences between concussed and control participants, thus providing a neurophysiological basis for prolonged test completion times in concussed individuals, augmenting paper and pencil assessment. References: Rizzo JR, Hudson TE, Dai W, Birkemeier J, Pasculli RM, et al., Rapid number naming in chronic concussion: eye movements in the King-Devick test. Ann Clin Transl Neurol. 3(10):801-811, 2016. Keywords: Higher Visual Cortical functions Financial Disclosures: The authors had no disclosures. Grant Support: NYS-DOH ECRIP. 2019 Annual Meeting Syllabus | 269