Pupillary light reflex measured with quantitative pupillometry has low sensitivity and high specificity for predicting neuroworsening after traumatic brain injury.

BACKGROUND: Triage and neurological assessment of the 1.7 million traumatic brain injuries occurring annually is often done by nurse practitioners and physician assistants in the emergency department. Subjective assessments, such as the neurological examination that includes evaluation of the pupillary light reflex (PLR), can contain bias. Quantitative pupillometry (QP) standardizes and objectifies the PLR examination. Additional data are needed to determine whether QP can predict neurological changes in a traumatic brain injury (TBI) patient. PURPOSE: This study examines the effectiveness of QP in predicting neurological decline within 24 hours of admission following acute TBI. METHODOLOGY: This prospective, observational, clinical trial used pragmatic sampling to assess PLR in TBI patients using QP within 24 hours of ED admission. Chi-square analysis was used to determine change in patient status, through Glasgow Coma Scale (GCS), at baseline and within 24 hours of admission, to the QP. RESULTS: There were 95 participants included in the analysis; of whom 35 experienced neuroworsening, defined by change in GCS of >2 within the first 24 hours of admission. There was a significant association between an abnormal Neurological Pupil index (NPi), defined as NPi of <3, and neuroworsening (p < .0001). The sensitivity (51.43%) and specificity (91.67%) of abnormal NPi in predicting neuroworsening were varied. CONCLUSION: There is a strong association between abnormal NPi and neuroworsening in the sample of TBI patients with high specificity and moderate sensitivity. IMPLICATIONS: NPi may be an early indicator of neurological changes within 24 hours of ED admission in patients with TBI.

Interindividual variation in learning ability in honeybees.

Performance on different cognitive tasks could either be positively correlated in an individual as a measure of general intelligence or costs related to specific aspects of cognition could give rise to specialized cognitive phenotypes. Social living offers the potential for individual specialization in learning and a cooperative group can benefit from a diversity of learning phenotypes. However, there is little empirical data regarding the nature of such interindividual variation in learning abilities in honeybees, a classic model of animal cognition. We tested for the presence of variation in learning abilities in the honeybee, Apis mellifera, and whether any component of learning has an influence on wing damage, a proxy for performance and survival. Our results show considerable interindividual variation in different types of learning abilities. At the individual level, while landmark and olfactory learning abilities are negatively correlated, olfactory learning shows a positive association with maneuverability performance, a measure which in turn shows a positive influence on wing damage, a proxy for survival. We discuss our results in the context of cognitive diversity and specialization in a social group.