NEUROCOGNITIVE ASSESSMENT OF SPORTS-RELATED CONCUSSION PROGRAM SYLLABUS All rights reserved. No part of this work can be reproduced, distributed, or otherwise used without the express permission from the American Academy of Neurology Institute. 2014 American Academy of Neurology Institute Printed in the USA
NEUROCOGNITIVE ASSESSMENT OF SPORTS-RELATED CONCUSSION AAN Concussion June 20, 2014 Ruben J. Echemendía, Ph.D. Disclosure: Dr. Echemendia receives compensation as a consultant to: NHL, MLS, USSoccer Neuropsychology: Historical Perspectives Neuropsychology has been used in the evaluation of brain disorders since the early 1900 s. Significant impact in the assessment of Traumatic Brain Injury following WWII. Early 1970 s applied to the assessment of MTBI. Late 1980 s, early 1990 s incorporated into sports concussion management Early work in Europe using NP tests with professional soccer players. Early work in US and Europe in boxing. Gronwall & Wrightson (1974) in NZ looked at concussed pts PTA<24 hrs using PASAT. Found deficits resolved in < 35 days. Dikmen et al., 1986; Gentilini et al., 1985; Levin et al., 1987 examined MTBI and generally found deficit resolution in 3 days to 3 months. Some studies did not find such rapid recovery among MTBI patients (Barth et al., 1983; Rimel, et al., 1981) Wrightson & Gronwall (1981) found nearly 20% of patients had neurocognitive deficits 90+ days past injury. Dacey & Dikmen (1987) noted possible premorbid confounds may account for disparate findings: premorbid intellectual, neurocognitive, psychiatric/psychological, trauma, substance abuse differences. Sports Neuropsychology: Historical Perspectives Pivotal pioneering work by Jeff Barth at UVA using SLAM model (1989). Using college football players from 10 institutions Barth employed a pre-injury baseline testing paradigm followed by serial testing post-injury. 2,300 were tested at baseline. Concussed athletes evaluated at 24 hrs, 5 days, 10 days post injury. Found deficits resolved within 5-10 days. within 5-10 days. Pathophysiology Neurometabolic Changes The primary elements of the pathophysiologic cascade following concussive brain injury include abrupt neuronal depolarization, release of excitatory neurotransmitters, ionic shifts, changes in glucose metabolism, altered cerebral blood flow, and impaired axonal function. Giza & Hovda, JAT, 2001 Assessment Assessment Neuroimaging Conventional neuroimaging is not very helpful in understanding the microstructure of the human brain and in the past had only limited utility in assessing the neural effects of concussion [The] structural and physiological imprint of the concussion is below the threshold of detection using conventional neuroimaging methods. Erin Bigler, 2012. Neurocognitive Assessment The brain is the most complex organ in the body, controlling all of its functions. Fully assessing the functioning of the brain is equally complex. It cannot be done quickly, with one measure, or by people inadequately trained to do so.
Neuropsychological Testing Concussions are largely functional rather than structural. Neuropsychological testing examines what the brain does: Learning, Memory, Information Processing Speed, Problem Solving Skills, Cognitive Flexibility Emphasis on functional rather than structural assessment Can be repeated serially during recovery Provides quantitative indices of neurocognitive functioning. Does Neuropsychological Testing work in the sports domain? YES Acute and post-injury cognitive recovery patterns. Meta analytic data - effect sizes Limitations to the use of neuropsychological assessment in the sports domain? Important to Remember: ImPACT does NOT equal neuropsychological assessment. It is only one of many different instruments than can be used. Neuropsychological tests should NEVER be used in isolation to make RTP decisions. Differentiating Between Brief Cognitive Screening and Neuropsychological Assessment is important. Brief measures of cognitive functioning (e.g. SAC, SCAT) are designed as screening measures. They only assess isolated domains of functioning in very rudimentary ways. Typically have marked ceiling effects. Generally lose sensitivity within a short period of time (e.g. 72 hours). Good for identifying acute, significant neurocognitive dysfunction. Not good for RTP. Differentiating Between Brief Cognitive Screening and Neuropsychological Assessment Sports Concussion Batteries are far less comprehensive than traditional NP batteries. But, much more comprehensive than screening batteries. Not practical in the acute phase of injury for most settings. More useful for management, determining severity of cognitive dysfunction, and assisting in RTP decisions. Paper & Pencil Tests Paper & Pencil Tests Selected from tests already in use and validated for assessing MTBI Test Requirements: Short Easily administered by non-nps Easily scored Sensitive to changes in specified domain Acceptable psychometrics Alternate forms. Assess several cognitive domains. Typical Tests: HVLT. BVMT. Trails, Digit Span, SDMT, Verbal Fluency, LNS, Cancellation tests. Paper & Pencil Tests Cont. Advantages: Direct observation of player behavior Direct monitoring of effort/motivation & task performance Superior assessment of memory Broad normative db with multiple samples. Disadvantages: Labor intensive (Expensive) Variability in standardized admin Less reliable assessment of info proc speed. Tests must be hand scored
Computerized Batteries Two approaches: Adapt existing P&P measures into computer platform Measure multiple cognitive functions (memory, proc speed, reaction time, etc.) Develop tests de novo for computers Limited assessment of domains (largely RT, Info Proc Speed) New Instruments are being developed rapidly Existing Instruments: ImPACT, ANAM/Vista, CNS Vital Signs, C3 Logix, CogSport. Advantages: Can be used in groups (Less costly) Could be problematic Standardized administration (Maybe) Immediate scoring/data capture Finer assessment of RT/Proc Speed (altho other problems) Multiple languages Theoretically infinite alternate forms Disadvantages: Less complete assessment of memory Loss of observational data Less control of effort/motivation Diminished ability to assess understanding/track task performance Computer-specific measurement issues Data loss Hybrid Approaches Combine strengths of both P&P and Computerized tests Once adequate normative data have been established. Computer for baseline testing Computer plus P&P post-injury Test administration/interpretation Test administration is relatively routine and does not require extensive specialized knowledge. The administration of selected NP tests may be delegated to paraprofessionals who have been trained by the NP and are supervised by the NP. Interpretation of test data is complex and requires comprehensive knowledge of test theory, psychometric principles, statistics, individual test properties, the pathology being examined, etc. Clinical NPs are uniquely trained and qualified to interpret NP tests. Failure to consult with NPs may lead to inaccurate interpretation of data and present a medico-legal quandary. Baseline Testing: The Theory Pretest Posttest models are very strong methodological designs. Designed to limit confounding variability due to individual differences at baseline. First introduced into Sports by Barth, et al. Very strong intuitive appeal. Establishing the Premorbid Baseline There is tremendous variability in cognitive functioning PRIOR to a head injury Premorbid Learning Disabilities Premorbid Head Injuries Drug/Alcohol Use Surgeries/General Anesthetics Complications with pregnancy or delivery Pre-existing psychological/psychiatric dx. Amount and Quality of Education
Cultural and Linguistic Differences Establishing the Premorbid Baseline Neuropsychological Approaches Historical/Demographic Variable Approach Education Socioeconomic Status Functional Levels Psychometric Approach Hold vs. No Hold Tests Tests of Reading (e.g. WTAR, NAART, WRAT) Combined test/demographic approach Baseline Testing Broadly Adopted Sports laboratory model Unique opportunity to examine cognitive and other domains of functioning prior to injury Endorsed by Consensus Groups CISG, NATA, Team Physicians Statement, NAN, NCAA Adopted by professional sports worldwide. Attempts have been made in the U.S. to legislate the use of baseline testing. Baseline testing has taken on a life of its own. Mass marketing of tests. Baseline testing = concussion program. Provides simple interpretation of post-injury test data. Baselines can be taken at home, unsupervised. Results are printed and taken to PCP in case of concussion. Mobile Baselines? Assumptions in Baseline Testing Baseline assessment is equivalent to post-injury testing. Without intervening injury, baseline and post-injury test scores should be equivalent. Are they? Several authors have begun to question the widespread use of baseline testing models: Randolph & Kirkwood, 2009; Randolph, McCrea, & Barr, 2005; Echemendia, 2010. Challenges to Baseline Testing Logistical Expensive, Large Numbers, equipment Psychometric Test-retest reliability Motivation Differential motivation at baseline vs. post-injury Sandbagging Administration Group vs. Individual Supervised vs. Unsupervised Instrumentation Variable timing across computers, mice, keyboards, etc. Test Error Test-Retest Data Utility of Baseline Data Baseline vs. Normative Echemendia et al., 2012 266 concussed multi sport college athletes with Pre and Post-injury ImPACT tests. 223 after removal of invalid baselines. 19 yo football player, 13 years ed., tested 3.4 days after injury. Reliable change (RC) from baseline was computed using two different RC methods. classified as showing a clinically significant change.
Baseline vs. Normative Echemendia et al., 2012 Compared RC methods to clinical normative approach Normative: Athletes scoring 1.0 and 1.5 standard deviation units below group means JT vs. GLN Methods Echemendia et al., 2012 Moderate to Substantial agreement between RC methods. Verbal Memory: Kappa =.76 Visual Motor Speed: Kappa =.70 Reaction Time: Kappa =.60 PCS: Kappa =.83 GLN method consistently identified more participants as having experienced a decline than the JT method. Agreement between Normative Method (1.5 SD) and GLN Method Agreement between Normative Method (1.5 SD) and GLN Method ImPACT Composites Verbal Memory: Kappa =.71 Sensitivity - 86%; Specificity 95%; Positive Predictive Value - 66%. Negative Predictive Value.98%. Visual Motor Speed: Kappa =.76 Sensitivity.78%. Specificity.98%. Positive Predictive Value.78%. Negative Predictive Value.98%. Reaction Time: Kappa =.75 Sensitivity.80%. Specificity.96%. Positive Predictive Value.77%.Negative Predictive Value.97%. Baseline vs. Normative Schmidt, et al., 2012 258 concussed college students tested with the Automated Neuropsychological Assessment Metrics (ANAM) Battery at baseline and following injury. Gender specific normative values were generated from a sample of 673 athletes. Two interpretive methods: Individualized baseline post injury comparison (Post Injury Baseline) Normative data baseline comparison (Post Injury Norm). Baseline vs. Normative Schmidt, et al., 2012 cont. Individual baseline method identified 2.6 times more athletes with impairment than the normative method on the Simple Reaction Time subtest. Normative method identified athletes with impairment 7.6 times more often than the individual baseline method on the Mathematic Processing subtest. No differences occurred among the other ANAM measures, measures of postural control on the Sensory Organization Test (SOT), or a graded symptom checklist. Summary/Questions These data are preliminary and limited to college samples. They do raise questions about the necessity for widespread baseline testing, particularly in situations of limited resources. Other important questions: Which groups of individuals are not identified using normative comparisons? LD? ADHD? Multiple Prior Concussions? Cognitively Gifted/Limited? Culturally/Linguistically Different? Educational differences? Thank you!