Clinical Reaction Time Performance in a Concussed Pediatric Population

Abstract

PURPOSE: The puck-drop (PD) test has been used to assess clinical reaction time (CRT) and has been proposed as a tool to aid in the diagnosis and management of sports concussion. The simplicity of the test and low cost make it an attractive tool in the management of these injuries; however, it is not known whether the test discriminates between concussed and non-concussed patients. The purpose of this study is to determine the discriminatory utility of the PD test to differentiate acutely concussed pediatric athletes relative to an uninjured cohort. METHODS: Patients (ages 8-18) who remained symptomatic on presentation to a sports medicine clinic and diagnosed with a concussion were eligible for study inclusion. Patients with concomitant injuries that precluded completion of the PD test were excluded. Testing was conducted in accordance with protocols established in the literature. Two practice trials were conducted. The distance of stick transversal was recorded as well as the number of drops and failed attempts. Eight successful trials were completed for each hand. Children with hands too small to circumvent the puck diameter were accommodated by starting at 10 cm above the puck base. RESULTS: 196 concussed (m-103, f-93) and 463 healthy (m-178, f-285) subjects were included in this study. The average CRT for right/left hands for healthy and injured subjects were 229.7+21.6ms/229.6+21.8ms, and 243.4+29.4ms/242.3+29.8ms, respectively. Injured patients were categorized by age and compared to healthy controls. Although significant associations were noted between age and CRT among healthy and concussed subjects overall (both hands), no statistical difference was found between control and concussed groups by age. CONCLUSION: This study demonstrated the association of age on CRT in both concussed and healthy subjects; however, the CRT of injured subjects did not differ from age matched healthy controls for either hand. Thus, CRT measured at the time of clinic presentation did not appear to have a discriminatory effect for diagnostic purposes. Future studies will need to examine the time point of CRT measurement, larger sample size, and longitudinal follow up to evaluate associations with recovery.