Showing papers by "Grant L. Iverson published in 2004"
TL;DR: This study provides preliminary evidence to suggest that athletes with multiple concussions might have cumulative effects of injury, with differences between groups in symptom reporting and memory performance.
Abstract: Primary objective: To examine the possibility that athletes with multiple concussions show cumulative effects of injury. Methods and procedures: Amateur athletes with a history of three or more con...
456 citations
TL;DR: The data suggest that current grade 1 return-to-play recommendations that allow for immediate return to play may be too liberal and a reconsideration of current concussion grading systems appears to be warranted.
Abstract: BackgroundRecent concussion management guidelines have suggested that athletes with mild (grade 1) concussions may be returned to play if asymptomatic for 15 minutes. The purpose of this study was to assess the utility of a current concussion management guideline in classifying and managing mild concussion.HypothesisHigh school athletes diagnosed with a grade 1 concussion will demonstrate measurable decline in neuropsychological functioning that persists during the 1st week of recovery.Study DesignProspective study designed to evaluate neuropsychological functioning both prior to and following concussion.MethodsForty-three high school athletes completed neuropsychological test performance and symptom ratings prior to the season and at two times during the 1st week following mild concussion.ResultsThirty-six hours after injury, mildly concussed high school athletes demonstrated a decline in memory (P < 0.003) and a dramatic increase in self-reported symptoms (P < 0.00001) compared to baseline performance.C...
311 citations
TL;DR: Athletes with any degree of self-reported fogginess at one-week post injury are likely to have adverse effects from their concussions in multiple domains.
Abstract: The purpose of this study was to examine the relation between the subjective report of feeling foggy at one-week post concussion and acute neuropsychological outcome. The outcome variables were derived from a computerized neuropsychological screening battery, Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT). Participants were 110 high school students who sustained a sports-related concussion and were evaluated 5–10 days post injury (M = 6.8 days). Athletes were divided into two groups on the basis of self-reported fogginess. The first group reported no fogginess (n = 91), whereas the second group reported experiencing some degree of fogginess (n = 19) on a 6-point scale. The athletes with persistent fogginess experienced a large number of other post-concussion symptoms, compared to the athletes with no reported fogginess. In addition, the athletes with persistent fogginess had significantly slower reaction times, reduced memory performance, and slower processing speed. Thus, athletes with any degree of self-reported fogginess at one-week post injury are likely to have adverse effects from their concussions in multiple domains. (JINS, 2004, 10, 904–906.)
127 citations
TL;DR: This inventory is a relatively new depression screening test patterned after the DSM–IV criteria for major depression, and adds to a growing literature on the reliability, validity, and clinical usefulness of the test.
Abstract: The purpose of this study was to examine the diagnostic accuracy and clinical usefulness of the British Columbia Major Depression Inventory. Participants were 62 patients with depression referred by their psychiatrist or family physician, 19 general medical outpatients with no psychiatric problems referred by their family physicians, and 49 community control subjects. Mean age for the control subjects was 50.2 yr. (SD= 11.8), and mean education was 14.6 yr. (SD=2.8). Approximately 59% were women. Mean age for the patients with depression was 41.1 yr. (SD= 12.5), and mean education was 14.6 yr. (SD=3.2). Approximately 71% were women. Scores of 9 or less are considered broadly normal. Applying this cut-off, the sensitivity of the test to detect depression was .92, and the specificity was .99. Thus, the test did not identify approximately 8% of the cases of depression, with 1.5% false positives. This inventory is a relatively new depression screening test patterned after the DSM-IV criteria for major depression. This study adds to a growing literature on the reliability, validity, and clinical usefulness of the test.
43 citations
TL;DR: It is concluded that the VIQ-PIQ split has no diagnostic predictive validity in persons with left hemisphere lesions (who are not aphasic) and the VIZ-PIZ split has very limited diagnostic predictivevalid in people with right hemisphere lesions.
Abstract: There is a persistent belief in clinical psychology and neuropsychology that the Verbal IQ-Performance IQ (VIQ-PIQ) split can be used to reliably infer lateralized brain damage. We selected samples of patients with cleanly lateralized right (n = 23) or left (n = 26) hemisphere lesions and used Bayesian analyses to study the predictive validity of the Wechsler Adult Intelligence Scale-Revised VIQ-PIQ difference scores for identifying lateralized brain damage. The patients showed average VIQ-PIQ differences in the expected direction. However, on the basis of sensitivity, specificity, and positive predictive value statistics, we concluded that (a) the VIQ-PIQ split has no diagnostic predictive validity in persons with left hemisphere lesions (who are not aphasic) and (b) the VIQ-PIQ split has very limited diagnostic predictive validity in persons with right hemisphere lesions.
27 citations
TL;DR: In this paper, the relationship between activity level and depression in primary care outpatients was examined, where patients with depression were sorted into two equal groups based on a median split of their Beck Depression Inventory-II scores.
Abstract: The relationship between activity level and depression in primary care outpatients was examined. Forty-eight patients with depression and 25 general medical controls wore a heart and activity level monitor for 24 h. Minute-averaged horizontal movement was collected. Patients with depression were sorted into two equal groups based on a median split of their Beck Depression Inventory-II scores. ANOVAs revealed significant main effects for average movement over the 24-h interval, average movement between 12 and 6 P.M., and a measure of "high activity" level. Patients with more severe depression had lower activity levels than the other two patient groups. The nondepressed and less severely depressed groups were combined and compared to the more severely depressed group using a standard discriminant function analysis. The overall correct classification rate was 74.0%, with 86% of the combined group and 50% of the more severely depressed group correctly classified. Patients with low activity levels were 6.0 times more likely to fall in the severely depressed group than patients with more normal activity levels.
19 citations
01 Jan 2004
TL;DR: Iverson et al. as mentioned in this paper evaluated the validity of ImPACT for measuring attention and processing speed following sports-related concussions and found that it was useful in measuring the performance of a running head.
Abstract: Validity of ImPACT 1 Running Head: VALIDITY OF ImPACT Validity of ImPACT for Measuring Attention & Processing Speed Following Sports-Related Concussion Grant L. Iverson, Ph.D. University of British Columbia & Riverview Hospital Mark R. Lovell, Ph.D. University of Pittsburgh Medical Center Michael W. Collins, Ph.D. University of Pittsburgh Medical Center Author Notes: The authors thank Jennifer Bernardo for assistance with manuscript preparation. Please address correspondence to Grant Iverson, Ph.D., Department of Psychiatry, 2255 Wesbrook Mall, University of British Columbia, Vancouver, B.C. Canada, V6T 2A1.
16 citations
TL;DR: SOM classifications of cardiac time-series data with enhanced ultradian variations and cardiac data recorded around the interval when a person was in bed were useful in differentiating clinically meaningful subgroups with and without depression.
Abstract: Objective: To determine if an unsupervised self-organizing neural network could create a clinically meaningful distinction of ‘depression’ versus ‘no depression’ based on cardiac ti
10 citations