MULES is a novel measure of speeded object naming relying on initiation and sequencing of saccadic eye movements, as well as rapid object recognition and naming. Symptoms from multiple domains including visual symptoms are commonly reported following concussion. Few studies have investigated the relationship between MULES score and symptom domain severity.

We analyzed results from 109 college students presenting to a university-based concussion clinic (60% women - mean age of 21.1 years (SD=2.1 years, range 18-27 years), median days since concussion (DSC) 1 day (IQR=2 days, range 0-25 days). Iverson et al. (2015) criteria was modified to group self-reported concussion symptoms into physical/cognitive, visual, sleep, and emotion domains measured by the Sport Concussion Assessment Tool – Third Edition Symptom Evaluation (S3SE). Multivariate analysis of variance (MANOVA) examined the association of the MULES time score on symptom domains.

These findings suggest that in the acute recovery period, slower performance on the MULES is associated with increased physical/cognitive, emotional, and sleep symptoms. MULES score was not significantly associated with vision symptoms.  This may demonstrate that MULES is an assessment of predominantly complex visual processing, and is unlikely to assess the integrity of the direct visual pathways in the acute setting. It suggests that concussive injuries are prominently associated with physical/cognitive, emotional and sleep domains acutely, with decreased association with complex visual processing.