The Prevalence of Undiagnosed Concussions in Athletes

William P. Meehan, III, MD; Rebekah C. Mannix, MD, MPH; Michael J. O'Brien, MD; Michael W. Collins, PhD


Clin J Sport Med. 2013;23(5):339-342. 

In This Article


A total of 731 patients met the inclusion criteria and were enrolled between the 2 clinics during the study period. Two hundred twenty-seven patients (31%) did not answer the question. An additional 18 were removed for incomplete or inaccurate data. Thus, 486 patients were included in the final analysis with a mean age of 15.5 years (SD, 3.5 years). Most participants (63%) were male.

A total of 148 patients (30.5%) reported that they had sustained a previous blow to the head that resulted in one or more of the signs and symptoms listed on the PCSS but were not diagnosed with a concussion. There were no significant differences in gender, mean age, or mean number of previously diagnosed concussions between participants with previously undiagnosed concussions and those without (Table 1).

Athletes who reported sustaining a previously undiagnosed concussion were more likely to have lost consciousness and have a higher mean PCSS score with their current injury than athletes without previously undiagnosed concussions (Table 2).