Neurocognitive Function of Emergency Department Patients With Mild Traumatic Brain Injury
Received 18 February 2008; received in revised form 17 June 2008; accepted 15 October 2008. published online 27 January 2009.
Study objective
We characterize the neurocognitive function of patients presenting to the emergency department (ED) with mild traumatic brain injury.
Methods
This prospective study took place at an urban, academic ED and Level I trauma center. Case patients consisted of a convenience sample of ED patients aged 18 to 59 years, presenting to the ED with mild traumatic brain injury and having a head computed tomography scan without traumatic abnormalities. Controls consisted of patients aged 18 to 59 years, presenting to the ED with an isolated, nondominant hand extremity injury. We excluded patients with multiple injuries and recent alcohol consumption. Subjects completed a computerized neurocognitive test battery (Immediate Post-concussion Assessment and Cognitive Testing). The primary measures were verbal memory, visual memory, and visual motor and reaction speed. We compared raw and age-normalized neurocognitive performance between case patients and controls by using nonparametric statistics.
Results
We included a total of 23 head-injured case patients and 31 non–head-injured controls. Case patients and controls exhibited similar raw (median 80.1 versus 85.0 points; difference in medians –4.9; P=.26) and age-normalized (31.9 versus 57.4 percentile; difference in medians –25.5; P=.12) verbal memory. Case patients and controls exhibited similar raw (64.6 versus 63.5; difference 1.1; P=.79) and age-normalized (20.8 versus 25.8 percentile; difference –5.0; P=.44) visual memory. Compared with controls, mild traumatic brain injury case patients demonstrated slower raw (31.6 versus 37.0 points; difference –5.4; P=.002) and age-normalized (17.1 versus 57.6 percentile; difference –40.5; P=.001) visual motor speed. Mild traumatic brain injury case patients exhibited slower raw (median 0.66 versus 0.60 seconds; difference 0.06; P=.01) and age-normalized (29.3 versus 42.8 percentile; difference –13.5; P=.009) reaction times.
Conclusion
In conclusion, compared with the non–head-injured patients, ED mild traumatic brain injury patients demonstrated subtle but discernible neurocognitive deficits.
aDepartment of Emergency Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA
bDepartment of Orthopedic Surgery, Sports Concussion Program, University of Pittsburgh Medical Center, Center for Sports Medicine, Pittsburgh, PA
Address for correspondence: Henry E. Wang, MD, MS, Department of Emergency Medicine, University of Alabama at Birmingham, 619 19th Street South, JTN266, Birmingham, AL 35249
Author contributions: MWC and HEW conceived and designed the study. SEP, MJS, and HEW obtained funding. SEP and MJS carried out data collection. SEP, MJS, and HEW analyzed the data. All authors contributed to drafting and editing the article. HEW takes responsibility for the paper as a whole.
Funding and support: By Annals policy, all authors are required to disclose any and all commercial, financial, and other relationships in any way related to the subject of this article, that might create any potential conflict of interest. See the Manuscript Submission Agreement in this issue for examples of specific conflicts covered by this statement. Grant support for this study was provided by the Pittsburgh Emergency Medicine Foundation and the University of Pittsburgh School of Medicine Dean's Summer Research Program. Dr. Wang is supported by Clinical Scientist Development Award K08-HS013628 from the Agency for Healthcare Research and Quality. Dr. Collins is co-developer and co-owner of IMPACT Applications, the company that distributes the IMPACT Concussion Management Software used in this study.
Dr. Wang is now affiliated with the Department of Emergency Medicine, University of Alabama at Birmingham, Birmingham, AL.
Publication date: Available online January 24, 2009.
ABSTRACT