Faculty Bibliography

OBJECTIVE:To evaluate the performance of the EyeTribe compared to the EyeLink for eye movement recordings during a rapid number naming test in healthy control participants. BACKGROUND:With the increasing accessibility of portable, economical, video-based eye trackers such as the EyeTribe, there is growing interest in these devices for eye movement recordings, particularly in the domain of sports-related concussion. However, prior to implementation there is a primary need to establish the validity of these devices. One current limitation of portable eye trackers is their sampling rate (30-60 samples per second, or Hz), which is typically well below the benchmarks achieved by their research-grade counterparts (e.g., the EyeLink, which samples at 500-2000 Hz). METHODS:We compared video-oculographic measurements made using the EyeTribe with those of the EyeLink during a digitized rapid number naming task (the King-Devick test) in a convenience sample of 30 controls. RESULTS:EyeTribe had loss of signal during recording, and failed to reproduce the typical shape of saccadic main sequence relationships. In addition, EyeTribe data yielded significantly fewer detectable saccades and displayed greater variance of inter-saccadic intervals than the EyeLink system. CONCLUSION/CONCLUSIONS:Caution is advised prior to implementation of low-resolution eye trackers for objective saccade assessment and sideline concussion screening.

BACKGROUND: Given that post-traumatic headache is one of the most prevalent and long-lasting post-concussion sequelae, causes significant morbidity, and might be associated with slower neurocognitive recovery, we sought to evaluate the use of concussion screening scores in a concussion clinic population to assess for post-traumatic headache. METHODS: This is a retrospective cross-sectional study of 254 concussion patients from the New York University (NYU) Concussion Registry. Data on the headache characteristics, concussion mechanism, concussion screening scores were collected and analyzed. RESULTS: 72% of the patients had post-traumatic headache. About half (56.3%) were women. The mean age was 35 (SD 16.2). 90 (35%) patients suffered from sport-related concussions (SRC). Daily post-traumatic headache patients had higher Sport Concussion Assessment Tool (SCAT)-3 symptom severity scores than the non-daily post-traumatic headache and the headache-free patients (50.2 [SD 28.2] vs. 33.1 [SD 27.5] vs. 21.6 SD23], p < 0.001). Patients with SRC had lower headache intensity (4.47 [SD 2.5] vs. 6.24 [SD 2.28], p < 0.001) and SCAT symptom severity scores (33.9 [SD 27.4] vs. 51.4 [SD 27.7], p < 0.001) than the other patients, but there were no differences in post-traumatic headache prevalence, frequency, and Standardized Assessment of Concussion (SAC) scores. CONCLUSION: The presence and frequency of post-traumatic headache are associated with the SCAT-3 symptom severity score, which is the most important predictor for post-concussion recovery. The SCAT-3 symptom severity score might be a useful tool to help characterize patients' post-traumatic headache.

Background/UNASSIGNED:Sports concussion has an annual incidence of approximately 3.8 million. Over half go unreported and a substantial number may be asymptomatic. A rapid, cost-effective, and reliable tool that facilitates diagnosis of concussion is needed. The King-Devick (K-D) test is a vision-based tool of rapid number naming for assessment of concussion. In this study, we evaluated the utility of the K-D test in real time for identification of symptomatic concussion in youth athletes and to determine if similar impairment (subclinical concussion) exists in youth athletes without an obvious head injury or symptoms. Methods/UNASSIGNED:Youth hockey players underwent K-D testing preseason, postseason, and immediately after suspected concussion. Additional testing was performed in a subgroup of nonconcussed athletes immediately before and after a game to determine effects of fatigue on K-D scores. Results/UNASSIGNED:< 0.05) and 51 nonconcussed players assessed before and after a game revealed no significant time change as a result of fatigue. Conclusions/UNASSIGNED:Rapid number naming using the K-D test accurately identifies real-time, symptomatic concussion in youth athletes. Scores in concussed players may remain abnormal over time. Athletes should undergo preseason and postseason K-D testing, with additional evaluation real time to inform the assessment of suspected concussion. Classification of Evidence/UNASSIGNED:This study provides Class III evidence that the K-D test accurately identifies real-time concussions in youth athletes.

Introduction: The optic nerve and visual pathway are frequent sites for involvement in multiple sclerosis (MS). Optical coherence tomography (OCT) detects retinal nerve fiber layer (RNFL) thinning in eyes of patients with MS or in the case of clinically-or radiologically-isolated syndromes. Current diagnostic criteria do not include the optic nerve as an imaging lesion site despite a high prevalence of acute optic neuritis (ON) among early MS and clinically isolated syndrome (CIS) patients. We sought to determine optimal thresholds for inter-eye difference in RNFL thickness that are most predictive of an optic nerve lesion. Methods: Spectral-domain (SD-)OCT data from an ongoing collaborative study of visual outcomes in MS were analyzed for a single site. Median values for inter-eye difference in RNFL thickness were also calculated from the RENEW trial cohort at the 6-month endpoint. RENEW was a randomized, placebo-controlled trial of opicinumab in subjects with a first episode of acute unilateral ON, and represents the most well-characterized cohort of CIS patients with ON incorporating modern tests of visual structure and function. RENEW utilized SD-OCT with a centralized reading center. Results: Among healthy volunteer control participants in the collaborative investigation (convenience sample, n=31), the 95th percentile value for inter-eye difference (upper boundary of expected for normals) was 6.0 microns. This value, as well as median intereye differences from the RENEW cohort (8.5 microns for placebo, n=41; 13.0 microns for opicinumab, n=41), were applied to convenience sample group of MS patients (n=136) as a validation cohort. Positive predictive value, sensitivity and specificity for identifying MS patients with a history of unilateral ON were greatest for the 6-micron value compared to the RENEW medians in a 2x2 table analysis (p< 0.0001, chi-square). The 6-micron threshold was also predictive of worse binocular low-contrast acuity at 2.5% (p=0.02) and 1.25% (p=0.002, linear regression). ROC curve analysis demonstrated an optimal inter-eye difference threshold of 5 microns for identifying unilateral ON in the MS cohort. Conclusion: Inter-eye differences of 5-6 microns in RNFL thickness are thus far optimal for predicting a unilateral optic nerve lesion in MS. Larger international collaborative investigations involving 20 or more MS validation cohort sites are underway to maximize precision and generalizability for these OCT-based thresholds

This article consists of a Letter to the Editor regarding Post-traumatic headache: the use of the sport concussion assessment tool (SCAT-3) as a predictor of post-concussion recovery, recently published in The Journal of Headache and Pain, along with a response from the original authors.

OBJECTIVE: This study investigated the utility of sideline concussion tests, including components of the Sports Concussion Assessment Tool, 3rd Edition (SCAT3) and the King-Devick (K-D), a vision-based test of rapid number naming, in an outpatient, multidisciplinary concussion center treating patients with both sports-related and non-sports related concussions. The ability of these tests to predict clinical outcomes based on the scores at the initial visit was evaluated. METHODS: Scores for components of the SCAT3 and the K-D were fit into regression models accounting for age, gender, and sport/non-sport etiology in order to predict clinical outcome measures including total number of visits to the concussion center, whether the patient reached a SCAT3 symptom severity score