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Pearce AJ, Hoy K, Rogers MA, Corp DT, Davies CB, Maller JJ, Fitzgerald PB. Acute motor, neurocognitive and neurophysiological change following concussion injury in Australian amateur football. A prospective multimodal investigation. J Sci Med Sport 2014; 18:500-6. [PMID: 25104044 DOI: 10.1016/j.jsams.2014.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 06/27/2014] [Accepted: 07/14/2014] [Indexed: 11/30/2022]
Abstract
OBJECTIVES This multimodal study investigated the motor, neurocognitive and neurophysiological responses following a sports related concussion injury in the acute-phase (up to 10 days) in sub-elite Australian football players. DESIGN Between-group, repeated measures. METHODS Over the course of one season (six months), 43 male players from one football club (25.1 ± 4.5 years) were assessed for fine motor dexterity, visuomotor reaction time, implicit learning and attention. Motor cortex excitability and inhibition were assessed using transcranial magnetic stimulation. RESULTS Of the 43 players, eight suffered concussion injuries, and were compared to 15 non-concussed players (active control) who returned for follow up testing. Post-concussion assessments using the aforementioned tests were carried out at 48 and 96 h, and 10 days. Compared to the non-concussed players, those who suffered concussion showed slowed fine dexterity (P = 0.02), response (P = 0.02) and movement times (P = 0.01) 48 h post-concussion. Similarly, attentional performance was reduced in the concussed group at all time points (48 h: P < 0.01; 96 h: P < 0.01; and 10 days: P = 0.02) post-concussion. TMS revealed significantly increased corticospinal inhibition at 48 (P = 0.04) and 96 h post concussion (P = 0.02) with significant correlations between increased corticospinal inhibition and response (r = 0.48; P < 0.01), movement time (r = 0.42; P = 0.02), and attention performance (r = 0.44; P = 0.01). CONCLUSIONS This study has demonstrated that acutely concussed Australian football players show abnormalities in motor, cognitive and neurophysiological measures with variable rates of recovery. These findings suggest that measuring the recovery of concussed athletes should incorporate a range of testing modalities rather than relying on one area of measurement in determining return to play.
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Affiliation(s)
- Alan J Pearce
- Cognitive Neuroscience Laboratory, School of Psychology, Deakin University, Melbourne, Australia.
| | - Kate Hoy
- Monash Alfred Psychiatric Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Mark A Rogers
- Cognitive Neuroscience Laboratory, School of Psychology, Deakin University, Melbourne, Australia
| | - Daniel T Corp
- Cognitive Neuroscience Laboratory, School of Psychology, Deakin University, Melbourne, Australia
| | - Charlotte B Davies
- Cognitive Neuroscience Laboratory, School of Psychology, Deakin University, Melbourne, Australia
| | - Jerome J Maller
- Monash Alfred Psychiatric Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia
| | - Paul B Fitzgerald
- Monash Alfred Psychiatric Research Centre, The Alfred and Central Clinical School, Monash University, Melbourne, Victoria, Australia
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202
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Tremblay S, Beaulé V, Proulx S, Tremblay S, Marjańska M, Doyon J, Lassonde M, Théoret H. Multimodal assessment of primary motor cortex integrity following sport concussion in asymptomatic athletes. Clin Neurophysiol 2014; 125:1371-9. [PMID: 24462505 PMCID: PMC4381958 DOI: 10.1016/j.clinph.2013.11.040] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 10/22/2013] [Accepted: 11/13/2013] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Recent studies have shown, in asymptomatic concussed athletes, metabolic disruption in the primary motor cortex (M1) and abnormal intracortical inhibition lasting for more than six months. The present study aims to assess if these neurochemical and neurophysiological alterations are persistent and linked to M1 cortical thickness. METHODS Sixteen active football players who sustained their last concussion, on average, three years prior to testing and 14 active football players who never sustained a concussion were recruited for a single session of proton magnetic resonance spectroscopy ((1)H-MRS) and transcranial magnetic stimulation (TMS). Measures of M1 and whole brain cortical thickness were acquired, and (1)H-MRS data were acquired from left M1 using a MEGA-PRESS sequence. Cortical silent period (CSP) and long-interval intracortical inhibition (LICI) were measured with TMS applied over left M1. RESULTS No significant group differences were observed for metabolic concentrations, TMS measures, and cortical thickness. However, whereas GABA and glutamate levels were positively correlated in control athletes, this relationship was absent in concussed athletes. CONCLUSION These data suggest the general absence of neurophysiologic, neurometabolic and neuroanatomical disruptions in M1 three years following the last concussive event. However, correlational analyses suggest the presence of a slight metabolic imbalance between GABA and glutamate concentrations in the primary motor cortex of concussed athletes. SIGNIFICANCE The present study highlights the importance of multimodal assesments of the impacts of sport concussions.
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Affiliation(s)
- Sara Tremblay
- Centre de recherche en neuropsychologie et cognition, Université de Montréal, Canada; Centre de recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte-Justine, Canada
| | - Vincent Beaulé
- Centre de recherche en neuropsychologie et cognition, Université de Montréal, Canada; Centre de recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte-Justine, Canada
| | - Sébastien Proulx
- Unité de Neuroimagerie Fonctionnelle, Centre de recherche de l'institut universitaire de gériatrie de Montréal, Canada; Montreal Neurological Institute, McGill University, Canada
| | - Sébastien Tremblay
- Unité de Neuroimagerie Fonctionnelle, Centre de recherche de l'institut universitaire de gériatrie de Montréal, Canada
| | - Małgorzata Marjańska
- Center for Magnetic Resonance Research and Department of Radiology, University of Minnesota, United States
| | - Julien Doyon
- Unité de Neuroimagerie Fonctionnelle, Centre de recherche de l'institut universitaire de gériatrie de Montréal, Canada
| | - Maryse Lassonde
- Centre de recherche en neuropsychologie et cognition, Université de Montréal, Canada; Centre de recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte-Justine, Canada
| | - Hugo Théoret
- Centre de recherche en neuropsychologie et cognition, Université de Montréal, Canada; Centre de recherche du Centre Hospitalier Universitaire de l'Hôpital Sainte-Justine, Canada.
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203
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Cogan AM. Occupational needs and intervention strategies for military personnel with mild traumatic brain injury and persistent post-concussion symptoms: a review. OTJR-OCCUPATION PARTICIPATION AND HEALTH 2014; 34:150-9. [PMID: 24972412 DOI: 10.3928/15394492-20140617-01] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 06/06/2014] [Indexed: 11/20/2022]
Abstract
Mild traumatic brain injury (mTBI), also known as concussion, has been labeled the "signature injury" of the wars in Iraq and Afghanistan. A subset of military personnel with mTBI experience ongoing symptoms well beyond the normal recovery window. While much research has been dedicated to understanding the etiology and severity of the symptoms, very little has assessed how long-term symptoms impact participation in daily life. A scoping study of the occupational science and occupational therapy literature was conducted to ascertain the current state of research on the impact of mTBI on participation in daily life activities, as well as occupational therapy interventions for mTBI. Although the emphasis in this article is on military personnel with mTBI, studies on civilians with mTBI were included in the review as research with military populations is extremely limited. Based on the literature reviewed, the author suggests a role for occupational science research and occupational therapy practice in meeting the occupational needs of military service members with persistent symptoms after mTBI.
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204
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Petraglia AL, Plog BA, Dayawansa S, Chen M, Dashnaw ML, Czerniecka K, Walker CT, Viterise T, Hyrien O, Iliff JJ, Deane R, Nedergaard M, Huang JH. The spectrum of neurobehavioral sequelae after repetitive mild traumatic brain injury: a novel mouse model of chronic traumatic encephalopathy. J Neurotrauma 2014; 31:1211-24. [PMID: 24766454 DOI: 10.1089/neu.2013.3255] [Citation(s) in RCA: 173] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
There has been an increased focus on the neurological sequelae of repetitive mild traumatic brain injury (TBI), particularly neurodegenerative syndromes, such as chronic traumatic encephalopathy (CTE); however, no animal model exists that captures the behavioral spectrum of this phenomenon. We sought to develop an animal model of CTE. Our novel model is a modification and fusion of two of the most popular models of TBI and allows for controlled closed-head impacts to unanesthetized mice. Two-hundred and eighty 12-week-old mice were divided into control, single mild TBI (mTBI), and repetitive mTBI groups. Repetitive mTBI mice received six concussive impacts daily for 7 days. Behavior was assessed at various time points. Neurological Severity Score (NSS) was computed and vestibulomotor function tested with the wire grip test (WGT). Cognitive function was assessed with the Morris water maze (MWM), anxiety/risk-taking behavior with the elevated plus maze, and depression-like behavior with the forced swim/tail suspension tests. Sleep electroencephalogram/electromyography studies were performed at 1 month. NSS was elevated, compared to controls, in both TBI groups and improved over time. Repetitive mTBI mice demonstrated transient vestibulomotor deficits on WGT. Repetitive mTBI mice also demonstrated deficits in MWM testing. Both mTBI groups demonstrated increased anxiety at 2 weeks, but repetitive mTBI mice developed increased risk-taking behaviors at 1 month that persist at 6 months. Repetitive mTBI mice exhibit depression-like behavior at 1 month. Both groups demonstrate sleep disturbances. We describe the neurological sequelae of repetitive mTBI in a novel mouse model, which resemble several of the neuropsychiatric behaviors observed clinically in patients sustaining repetitive mild head injury.
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Affiliation(s)
- Anthony L Petraglia
- 1 Department of Neurosurgery, University of Rochester Medical Center , Rochester, New York
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205
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Miller NR, Yasen AL, Maynard LF, Chou LS, Howell DR, Christie AD. Acute and longitudinal changes in motor cortex function following mild traumatic brain injury. Brain Inj 2014; 28:1270-6. [PMID: 24841536 DOI: 10.3109/02699052.2014.915987] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PRIMARY OBJECTIVE To evaluate excitability and inhibition of the motor cortex acutely and longitudinally following mild traumatic brain injury (mTBI). RESEARCH DESIGN A longitudinal paired case-control design was used to examine cortical excitability and inhibition in 15 adults who had sustained an mTBI (mean age = 20.8 ± 1.2 years) and 15 matched control participants (mean age = 21.1 ± 1.3 years). METHODS AND PROCEDURES Participants visited the lab within 72 hours of injury and again at 1, 2, 4 and 8 weeks post-injury. During each visit, transcranial magnetic stimulation was used to examine resting motor threshold (RMT), motor evoked potential peak-to-peak amplitude (MEPamp) and cortical silent period (CSP) duration of the first dorsal interosseous muscle. MAIN OUTCOMES AND RESULTS There were no differences between groups in RMT (p = 0.10) or MEPamp (p = 0.22) at 72 hours post-injury or across the 2-month testing period (p ≥ 0.68), indicating similar cortical excitability. However, the CSP duration was higher in individuals with mTBI, indicating greater intra-cortical inhibition compared with the control group at 72 hours post-injury (p = 0.03) and throughout the 2 months of recovery (p = 0.009). CONCLUSIONS mTBI appeared to have little effect on cortical excitability, but an acute and long-lasting effect on intra-cortical inhibition.
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Affiliation(s)
- Nick R Miller
- Department of Human Physiology, University of Oregon , Eugene, OR , USA
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206
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Pearce AJ, Hoy K, Rogers MA, Corp DT, Maller JJ, Drury HGK, Fitzgerald PB. The long-term effects of sports concussion on retired Australian football players: a study using transcranial magnetic stimulation. J Neurotrauma 2014; 31:1139-45. [PMID: 24579780 DOI: 10.1089/neu.2013.3219] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male AF players who played at the elite level (n=20; mean age 49.7±5.7 years) or amateur level (n=20; mean age 48.4±6.9 years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched male controls (mean age 47.56±6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125% of active motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity (p=0.003), reaction (p=0.003), and movement time (p=0.037) than did both AF groups. Differences between AF groups were found in AL (p=0.027) and SWM (p=0.024). TMS measures revealed that both AF groups showed reduced cSP duration at 125% aMT (p>0.001) and differences in SR curves (p>0.001) than did healthy controls. Similarly, SICI (p=0.012) and LICI (p=0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of inhibition differed, however, in terms of which performance measure they had a significant and unique predictive relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two decades previously.
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Affiliation(s)
- Alan J Pearce
- 1 Cognitive Neuroscience Laboratory, School of Psychology, Deakin University , Melbourne, Victoria, Australia
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207
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Pedersen HA, Ferraro FR, Himle M, Schultz C, Poolman M. Neuropsychological factors related to college ice hockey concussions. Am J Alzheimers Dis Other Demen 2014; 29:201-4. [PMID: 24370620 PMCID: PMC10852799 DOI: 10.1177/1533317513517036] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We analyzed data from 74 male collegiate hockey players. Each athlete's season began with a baseline administration of the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) neuropsychology test battery. Fourteen athletes sustained a sport-related head injury and were readministered the test to assess the impact of the injury. A significant decrease in performance (compared to baseline) on immediate and delayed word recall and designs followed the first concussion. Following a second sport-related concussion, the 4 affected athletes showed significant decrease in visual motor speed. Performance improved on 2 response speed measures (Ps < .01). More errors occurred during a visual processing/discrimination task and immediate recall of designs declined (Ps < .05). We discuss the results in light of recent work related to the impact of early-life concussions and head injury on late-life consequences, such as chronic traumatic encephalopathy, and more immediate issues such as return-to-play decisions for athletes.
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Affiliation(s)
| | - F. Richard Ferraro
- Department of Psychology, University of North Dakota, Grand Forks, ND, USA
| | - Michael Himle
- Department of Psychology, University of Utah, Salt Lake City, UT, USA
| | - Caitlin Schultz
- Department of Psychology, Bastyr University, Seattle, WA, USA
| | - Mark Poolman
- Athletic Department, University of North Dakota, Grand Forks, ND, USA
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208
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Powers KC, Cinelli ME, Kalmar JM. Cortical hypoexcitability persists beyond the symptomatic phase of a concussion. Brain Inj 2014; 28:465-71. [PMID: 24702432 DOI: 10.3109/02699052.2014.888759] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PRIMARY OBJECTIVE The purpose of this research was to assess cortical excitability, voluntary activation of muscle and force sensation beyond the initial highly symptomatic period post-concussion (1-4 weeks post-injury). It was hypothesized that reduced excitability of the motor cortex may impair muscle activation and alter perceptions of force and effort. RESEARCH DESIGN Eight concussed varsity football players were age- and position-matched with eight healthy teammates to control for training and body size. Healthy controls had not suffered a concussion in the previous 12 months. METHODS AND PROCEDURES Paired-pulse transcranial magnetic stimulation was used to assess cortical excitability, voluntary activation was calculated using cortical twitch interpolation technique and sense of force was determined using constant-force sensation contractions. MAIN OUTCOMES AND RESULTS The concussed group had lower intra-cortical facilitation (p = 0.036), lower maximal voluntary muscle activation (p = 0.038) and greater perceptions of force (p < 0.05), likely due to compensatory increases in upstream drive, than their healthy matched teammates. CONCLUSIONS Taken together, these findings suggest a state of hypoexcitability that persists beyond the immediate acute phase of a concussion and may result in neuromuscular impairments that would call to question the athlete's readiness to return to sport.
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Affiliation(s)
- Kaley C Powers
- Department of Kinesiology and Physical Education, Wilfrid Laurier University , Waterloo, ON , Canada
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209
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Poltavski DV, Biberdorf D. Screening for lifetime concussion in athletes: importance of oculomotor measures. Brain Inj 2014; 28:475-85. [PMID: 24702485 DOI: 10.3109/02699052.2014.888771] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
HYPOTHESIS/OBJECTIVE The purpose of the present study was to determine the utility of oculomotor-based evaluation protocols in screening for lifetime concussion incidence in elite hockey players. METHODS Forty-two Division I collegiate male and female hockey players were evaluated using the guidelines of an overall oculomotor-based diagnostic clinical test protocol for the mTBI population. The sensitivity of the collected measures to lifetime concussion was then compared with the corresponding sensitivity of measures of neuropsychological functioning (ImPACT) often used with athletes for acute concussion diagnosis. RESULTS This model showed that a hockey player with a Near Point of Fixation Disparity (NPFD) equal to or greater than 15 cm, Visagraph comprehension rate less than 85% and the total score on part A of an ADHD questionnaire equal to or greater than 11 was on average 10.72-times more likely to have previously suffered a concussion than an athlete with lower values on the NPFD and ADHD questionnaire and a higher comprehension rate on the Visagraph. None of the IMPACT baseline assessment measures were significantly predictive of the individual's concussion history. CONCLUSION The study provides a relatively sensitive screening tool to assess the probability of previous concussion(s) in an athlete. This model may allow athletic personnel to address in a timely manner the risks associated with repeat concussions and to develop individualized concussion management protocols.
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Affiliation(s)
- Dmitri V Poltavski
- Department of Psychology, University of North Dakota , Grand Forks, ND , USA and
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210
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Christie A, Kamen G. Cortical inhibition is reduced following short-term training in young and older adults. AGE (DORDRECHT, NETHERLANDS) 2014; 36:749-758. [PMID: 23943112 PMCID: PMC4039252 DOI: 10.1007/s11357-013-9577-0] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2013] [Accepted: 07/31/2013] [Indexed: 05/28/2023]
Abstract
The purpose of this study was to investigate age-related differences in short-term training adaptations in cortical excitability and inhibition. Thirty young (21.9 ± 3.1 years) and 30 older (72.9 ± 4.6 years) individuals participated in the study. Each participant was randomly assigned to a control (n = 30) or a resistance training (n = 30) group, with equal numbers of young and older subjects in each group. Participants completed 2 days of testing, separated by 2 weeks during which time the training group participated in resistance training of the ankle dorsiflexor muscles three times per week. During each testing session, transcranial magnetic stimulation was used to generate motor evoked potentials (MEPs) and silent periods in the tibialis anterior. Hoffmann reflexes (H-reflexes) and compound muscle action potentials (M-waves) were also evoked via electrical stimulation of the peroneal nerve. At baseline, young subjects had higher maximum voluntary contraction (MVC) force (p = 0.002), larger M-wave amplitude (p < 0.001), and longer duration silent periods (p = 0.01) than older individuals, with no differences in the maximal amplitude of the MEP (p = 0.23) or H-reflex (p = 0.57). In the trained group, MVC increased in both young (17.4 %) and older (19.8 %) participants (p < 0.001), and the duration of the silent period decreased by ~15 and 12 ms, respectively (p < 0.001). Training did not significantly impact MEP (p = 0.69) or H-reflex amplitudes (p = 0.38). There were no significant changes in any measures in the control group (p ≥ 0.19) across the two testing sessions. These results indicate that a reduction in cortical inhibition may be an important neural adaptation in response to training in both young and older adults.
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Affiliation(s)
- Anita Christie
- Department of Kinesiology, University of Massachusetts, Amherst, MA, 01003, USA,
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211
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Angoa-Pérez M, Kane MJ, Briggs DI, Herrera-Mundo N, Viano DC, Kuhn DM. Animal models of sports-related head injury: bridging the gap between pre-clinical research and clinical reality. J Neurochem 2014; 129:916-31. [PMID: 24673291 DOI: 10.1111/jnc.12690] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2014] [Revised: 02/10/2014] [Accepted: 02/12/2014] [Indexed: 12/14/2022]
Abstract
Sports-related head impact and injury has become a very highly contentious public health and medico-legal issue. Near-daily news accounts describe the travails of concussed athletes as they struggle with depression, sleep disorders, mood swings, and cognitive problems. Some of these individuals have developed chronic traumatic encephalopathy, a progressive and debilitating neurodegenerative disorder. Animal models have always been an integral part of the study of traumatic brain injury in humans but, historically, they have concentrated on acute, severe brain injuries. This review will describe a small number of new and emerging animal models of sports-related head injury that have the potential to increase our understanding of how multiple mild head impacts, starting in adolescence, can have serious psychiatric, cognitive and histopathological outcomes much later in life. Sports-related head injury (SRHI) has emerged as a significant public health issue as athletes can develop psychiatric and neurodegenerative disorders later in life. Animal models have always been an integral part of the study of human TBI but few existing methods are valid for studying SRHI. In this review, we propose criteria for effective animal models of SRHI. Movement of the head upon impact is judged to be of primary importance in leading to concussion and persistent CNS dysfunction.
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Affiliation(s)
- Mariana Angoa-Pérez
- Research & Development Service, John D. Dingell VA Medical Center, Detroit, MI, USA; Department of Psychiatry and Behavioral Neurosciences, Wayne State University School of Medicine, Detroit, MI, USA
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212
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Broglio SP, Cantu RC, Gioia GA, Guskiewicz KM, Kutcher J, Palm M, Valovich McLeod TC. National Athletic Trainers' Association position statement: management of sport concussion. J Athl Train 2014; 49:245-65. [PMID: 24601910 DOI: 10.4085/1062-6050-49.1.07] [Citation(s) in RCA: 479] [Impact Index Per Article: 47.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To provide athletic trainers, physicians, and other health care professionals with best-practice guidelines for the management of sport-related concussions. BACKGROUND An estimated 3.8 million concussions occur each year in the United States as a result of sport and physical activity. Athletic trainers are commonly the first medical providers available onsite to identify and evaluate these injuries. RECOMMENDATIONS The recommendations for concussion management provided here are based on the most current research and divided into sections on education and prevention, documentation and legal aspects, evaluation and return to play, and other considerations.
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213
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Chamard E, Lassonde M, Henry L, Tremblay J, Boulanger Y, De Beaumont L, Théoret H. Neurometabolic and microstructural alterations following a sports-related concussion in female athletes. Brain Inj 2014; 27:1038-46. [PMID: 23834633 DOI: 10.3109/02699052.2013.794968] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Sports-related concussions are a major public health concern affecting millions of individuals annually. Neurometabolic and microstructural alterations have been reported in the chronic phase following a concussion in male athletes, while no study has investigated these alterations in female athletes. METHODS Neurometabolic and microstructural alterations following a concussion were investigated by comparing 10 female athletes with a concussion and 10 control female athletes, using magnetic resonance spectroscopy (MRS) and diffusion tensor imaging (DTI). Athletes with concussion were scanned at least 7 months post-concussion (mean = 18.9 months). RESULTS MRS revealed a significant lower level of myo-inositol in the hippocampus and the primary motor cortices (M1) bilaterally. DTI analysis using Tract-Based Spatial Statistics (TBSS) showed no difference in fractional anisotropy (FA) while higher level of mean diffusivity (MD) in athletes with concussion was detected in large white matter tracts including the forceps minors, inferior/superior longitudinal fasciculi, inferior fronto-occipital fasciculus, cingulum, uncinate fasciculus, anterior thalamic radiations and corticospinal tract. Moreover, a region of interest approach for the corpus callosum revealed a significant lower level of FA in the segment containing fibres projecting to M1. CONCLUSIONS This study demonstrates persistent neurometabolic and microstructural alterations in female athletes suffering a sports-related concussion.
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Affiliation(s)
- Emilie Chamard
- Centre de Recherche en Neuropsychologie et Cognition, Department of Psychology, University of Montreal, Montréal, Québec, Canada.
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214
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Godbolt AK, Cancelliere C, Hincapié CA, Marras C, Boyle E, Kristman VL, Coronado VG, Cassidy JD. Systematic Review of the Risk of Dementia and Chronic Cognitive Impairment After Mild Traumatic Brain Injury: Results of the International Collaboration on Mild Traumatic Brain Injury Prognosis. Arch Phys Med Rehabil 2014; 95:S245-56. [DOI: 10.1016/j.apmr.2013.06.036] [Citation(s) in RCA: 81] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 04/27/2013] [Accepted: 06/27/2013] [Indexed: 11/16/2022]
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215
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Wilson MJ, Harkrider AW, King KA. The Effects of Visual Distracter Complexity on Auditory Evoked P3b in Contact Sports Athletes. Dev Neuropsychol 2014; 39:113-30. [DOI: 10.1080/87565641.2013.870177] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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216
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Rabinowitz AR, Li X, Levin HS. Sport and Nonsport Etiologies of Mild Traumatic Brain Injury: Similarities and Differences. Annu Rev Psychol 2014; 65:301-31. [DOI: 10.1146/annurev-psych-010213-115103] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Amanda R. Rabinowitz
- Department of Neurosurgery, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104;
| | - Xiaoqi Li
- Physical Medicine and Rehabilitation Alliance, Baylor College of Medicine and the University of Texas-Houston Medical School, Houston, Texas 77030
| | - Harvey S. Levin
- Physical Medicine and Rehabilitation Alliance, Baylor College of Medicine and the University of Texas-Houston Medical School, Houston, Texas 77030
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Abstract
CONTEXT The long-term implications of concussive injuries for brain and cognitive health represent a growing concern in the public consciousness. As such, identifying measures sensitive to the subtle yet persistent effects of concussive injuries is warranted. OBJECTIVE To investigate how concussion sustained early in life influences visual processing in young adults. We predicted that young adults with a history of concussion would show decreased sensory processing, as noted by a reduction in P1 event-related potential component amplitude. DESIGN Cross-sectional study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Thirty-six adults (18 with a history of concussion, 18 controls) between the ages of 20 and 28 years completed a pattern-reversal visual evoked potential task while event-related potentials were recorded. MAIN OUTCOME MEASURE(S) The groups did not differ in any demographic variables (all P values > .05), yet those with a concussive history exhibited reduced P1 amplitude compared with the control participants (P = .05). CONCLUSIONS These results suggest that concussion history has a negative effect on visual processing in young adults. Further, upper-level neurocognitive deficits associated with concussion may, in part, result from less efficient downstream sensory capture.
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Affiliation(s)
- Robert D. Moore
- Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign
| | | | - Charles H. Hillman
- Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign
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Second time around: Corticospinal responses following repeated sports-related concussions within the same season. A transcranial magnetic stimulation study. JOURNAL OF ACUTE DISEASE 2014. [DOI: 10.1016/s2221-6189(14)60042-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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Moore RD, Hillman CH, Broglio SP. The persistent influence of concussive injuries on cognitive control and neuroelectric function. J Athl Train 2013; 49:24-35. [PMID: 24377962 DOI: 10.4085/1062-6050-49.1.01] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
CONTEXT Increasing attention is being paid to the deleterious effects of sport-related concussion on cognitive and brain health. OBJECTIVE To evaluate the influence of concussion incurred during early life on the cognitive control and neuroelectric function of young adults. DESIGN Cross-sectional study. SETTING Research laboratory. PATIENTS OR OTHER PARTICIPANTS Forty young adults were separated into groups according to concussive history (0 or 1+). Participants incurred all injuries during sport and recreation before the age of 18 years and were an average of 7.1 ± 4.0 years from injury at the time of the study. INTERVENTION(S) All participants completed a 3-stimulus oddball task, a numeric switch task, and a modified flanker task during which event-related potentials and behavioral measures were collected. MAIN OUTCOME MEASURE(S) Reaction time, response accuracy, and electroencephalographic activity. RESULTS Compared with control participants, the concussion group exhibited decreased P3 amplitude during target detection within the oddball task and during the heterogeneous condition of the switch task. The concussion group also displayed increased N2 amplitude during the heterogeneous version of the switch task. Concussion history was associated with response accuracy during the flanker task. CONCLUSIONS People with a history of concussion may demonstrate persistent decrements in neurocognitive function, as evidenced by decreased response accuracy, deficits in the allocation of attentional resources, and increased stimulus-response conflict during tasks requiring variable amounts of cognitive control. Neuroelectric measures of cognitive control may be uniquely sensitive to the persistent and selective decrements of concussion.
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Affiliation(s)
- Robert D Moore
- Department of Kinesiology and Community Health, University of Illinois, Urbana-Champaign
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Motor system alterations in retired former athletes: the role of aging and concussion history. BMC Neurol 2013; 13:109. [PMID: 23972282 PMCID: PMC3765614 DOI: 10.1186/1471-2377-13-109] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2012] [Accepted: 08/21/2013] [Indexed: 11/23/2022] Open
Abstract
Background Retired athletes with a history of sports concussions experience cognitive and motor declines with aging, and the risk of severe neurodegenerative conditions is magnified in this population. The present study investigated the effects of aging on motor system metabolism and function in former university-level athletes who sustained their last concussion several decades prior to testing. Methods To test the hypothesis that age and remote concussions induce functional as well as metabolic alterations of the motor system, we used proton magnetic resonance spectroscopy to detect metabolic abnormalities in the primary motor cortex and the serial reaction time task (SRTT) to evaluate motor learning. Results Our results indicate that motor learning is significantly reduced in former concussed athletes relative to controls. In addition, glutamate/H2O ratio in M1 was disproportionately reduced in concussed athletes with advancing age and was found to strongly correlate with motor learning impairments. Conclusion Findings from this study provide evidence that the acquisition of a repeated motor sequence is compromised in the aging concussed brain and that its physiological underpinnings could implicate disproportionate reductions of M1 glutamate concentrations with advancing age.
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222
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Ford JH, Giovanello KS, Guskiewicz KM. Episodic memory in former professional football players with a history of concussion: an event-related functional neuroimaging study. J Neurotrauma 2013; 30:1683-701. [PMID: 23679098 DOI: 10.1089/neu.2012.2535] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Previous research has demonstrated that sport-related concussions can have short-term effects on cognitive processes, but the long-term consequences are less understood and warrant more research. This study was the first to use event-related functional magnetic resonance imaging (fMRI) to examine long-term differences in neural activity during memory tasks in former athletes who have sustained multiple sport-related concussions. In an event-related fMRI study, former football players reporting multiple sport-related concussions (i.e., three or more) were compared with players who reported fewer than three concussions during a memory paradigm examining item memory (i.e., memory for the particular elements of an event) and relational memory (i.e., memory for the relationships between elements). Behaviorally, we observed that concussion history did not significantly affect behavioral performance, because persons in the low and high concussion groups had equivalent performance on both memory tasks, and in addition, that concussion history was not associated with any behavioral memory measures. Despite demonstrating equivalent behavioral performance, the two groups of former players demonstrated different neural recruitment patterns during relational memory retrieval, suggesting that multiple concussions may be associated with functional inefficiencies in the relational memory network. In addition, the number of previous concussions significantly correlated with functional activity in a number of brain regions, including the medial temporal lobe and inferior parietal lobe. Our results provide important insights in understanding the long-term functional consequences of sustaining multiple sports-related concussions.
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Affiliation(s)
- Jaclyn H Ford
- 1 Department of Psychology, University of North Carolina-Chapel Hill , Chapel Hill, North Carolina
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223
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Monti JM, Voss MW, Pence A, McAuley E, Kramer AF, Cohen NJ. History of mild traumatic brain injury is associated with deficits in relational memory, reduced hippocampal volume, and less neural activity later in life. Front Aging Neurosci 2013; 5:41. [PMID: 23986698 PMCID: PMC3749487 DOI: 10.3389/fnagi.2013.00041] [Citation(s) in RCA: 113] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Accepted: 07/29/2013] [Indexed: 12/14/2022] Open
Abstract
Evidence suggests that a history of head trauma is associated with memory deficits later in life. The majority of previous research has focused on moderate-to-severe traumatic brain injury (TBI), but recent evidence suggests that even a mild TBI (mTBI) can interact with the aging process and produce reductions in memory performance. This study examined the association of mTBI with memory and the brain by comparing young and middle-aged adults who have had mTBI in their recent (several years ago) and remote (several decades ago) past, respectively, with control subjects on a face-scene relational memory paradigm while they underwent functional magnetic resonance imaging (fMRI). Hippocampal volumes were also examined from high-resolution structural images. Results indicated middle-aged adults with a head injury in their remote past had impaired memory compared to gender, age, and education matched control participants, consistent with previous results in the study of memory, aging, and TBI. The present findings extended previous results by demonstrating that these individuals also had smaller bilateral hippocampi, and had reduced neural activity during memory performance in cortical regions important for memory retrieval. These results indicate that a history of mTBI may be one of the many factors that negatively influence cognitive and brain health in aging.
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Affiliation(s)
- Jim M Monti
- Department of Psychology, University of Illinois at Urbana Champaign Champaign, IL, USA ; Beckman Institute, University of Illinois at Urbana Champaign Urbana, IL, USA
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Ozen LJ, Itier RJ, Preston FF, Fernandes MA. Long-term working memory deficits after concussion: Electrophysiological evidence. Brain Inj 2013; 27:1244-55. [DOI: 10.3109/02699052.2013.804207] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Lana J. Ozen
- Department of Psychology, University of Waterloo
Waterloo, OntarioCanada
| | - Roxane J. Itier
- Department of Psychology, University of Waterloo
Waterloo, OntarioCanada
| | - Frank F. Preston
- Department of Psychology, University of Waterloo
Waterloo, OntarioCanada
| | - Myra A. Fernandes
- Department of Psychology, University of Waterloo
Waterloo, OntarioCanada
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225
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Seichepine DR, Stamm JM, Daneshvar DH, Riley DO, Baugh CM, Gavett BE, Tripodis Y, Martin B, Chaisson C, McKee AC, Cantu RC, Nowinski CJ, Stern RA. Profile of self-reported problems with executive functioning in college and professional football players. J Neurotrauma 2013; 30:1299-304. [PMID: 23421745 DOI: 10.1089/neu.2012.2690] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Repetitive mild traumatic brain injury (mTBI), such as that experienced by contact-sport athletes, has been associated with the development of chronic traumatic encephalopathy (CTE). Executive dysfunction is believed to be among the earliest symptoms of CTE, with these symptoms presenting in the fourth or fifth decade of life. The present study used a well-validated self-report measure to study executive functioning in football players, compared to healthy adults. Sixty-four college and professional football players were administered the Behavior Rating Inventory of Executive Function, adult version (BRIEF-A) to evaluate nine areas of executive functioning. Scores on the BRIEF-A were compared to published age-corrected normative scores for healthy adults Relative to healthy adults, the football players indicated significantly more problems overall and on seven of the nine clinical scales, including Inhibit, Shift, Emotional Control, Initiate, Working Memory, Plan/Organize, and Task Monitor. These symptoms were greater in athletes 40 and older, relative to younger players. In sum, football players reported more-frequent problems with executive functioning and these symptoms may develop or worsen in the fifth decade of life. The findings are in accord with a growing body of evidence that participation in football is associated with the development of cognitive changes and dementia as observed in CTE.
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Affiliation(s)
- Daniel R Seichepine
- Boston University Alzheimer's Disease Center, Boston University School of Medicine, Boston University, Boston, Massachusetts, USA
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226
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Tallus J, Lioumis P, Hämäläinen H, Kähkönen S, Tenovuo O. Transcranial magnetic stimulation-electroencephalography responses in recovered and symptomatic mild traumatic brain injury. J Neurotrauma 2013; 30:1270-7. [PMID: 23384582 DOI: 10.1089/neu.2012.2760] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Mild traumatic brain injury (mTBI) may cause diffuse damage to the brain, especially to the frontal areas, that may lead to persistent symptoms. We studied participants with past mTBI by means of navigated transcranial magnetic stimulation (nTMS) combined with electroencephalography (EEG). Eleven symptomatic and 8 recovered participants with a history of single mTBI and 9 healthy controls participated. Average time from injury to testing was 5 years. The participants did not have abnormalities or signs of injury on brain magnetic resonance imaging, and they did not use any centrally acting medication. Left primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPFC) were stimulated with nTMS and evoked potentials measured from the corresponding areas of both hemispheres. Delayed ipsilateral P30 and contralateral N45 peak latencies to left DLPFC nTMS were found in the symptomatic group, along with higher DLPFC N100 amplitudes compared with the control or recovered group. The recovered group had shorter P200 latencies in left DLPFC nTMS compared with the other groups. Both mTBI groups had higher motor thresholds compared with the control group. In left M1 nTMS, the mTBI groups showed less P30 amplitude increase, and the symptomatic group showed longer P60 interhemispheric latency difference with higher stimulation intensities. The results suggest altered brain reactivity and connectivity in mTBI. Some of the observed differences may be related to compensatory mechanisms of recovery. nTMS-EEG is a potentially useful tool for studying the effects of mTBI.
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Affiliation(s)
- Jussi Tallus
- Department of Psychology, Centre for Cognitive Neuroscience, University of Turku, Turku, Finland.
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227
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Simma B, Lütschg J, Callahan JM. Mild head injury in pediatrics: algorithms for management in the ED and in young athletes. Am J Emerg Med 2013; 31:1133-8. [DOI: 10.1016/j.ajem.2013.04.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 04/02/2013] [Indexed: 11/15/2022] Open
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Mannix R, Meehan WP, Mandeville J, Grant PE, Gray T, Berglass J, Zhang J, Bryant J, Rezaie S, Chung JY, Peters NV, Lee C, Tien LW, Kaplan DL, Feany M, Whalen M. Clinical correlates in an experimental model of repetitive mild brain injury. Ann Neurol 2013; 74:65-75. [PMID: 23922306 PMCID: PMC6312716 DOI: 10.1002/ana.23858] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2012] [Revised: 12/19/2012] [Accepted: 01/25/2013] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Although there is growing awareness of the long-term cognitive effects of repetitive mild traumatic brain injury (rmTBI; eg, sports concussions), whether repeated concussions cause long-term cognitive deficits remains controversial. Moreover, whether cognitive deficits depend on increased amyloid β deposition and tau phosphorylation or are worsened by the apolipoprotein E4 allele remains unknown. Here, we use an experimental model of rmTBI to address these clinical controversies. METHODS A weight drop rmTBI model was used that results in cognitive deficits without loss of consciousness, seizures, or gross or microscopic evidence of brain damage. Cognitive function was assessed using a Morris water maze (MWM) paradigm. Immunostaining and enzyme-linked immunosorbent assay (ELISA) were used to assess amyloid β deposition and tau hyperphosphorylation. Brain volume and white matter integrity were assessed by magnetic resonance imaging (MRI). RESULTS Mice subjected to rmTBI daily or weekly but not biweekly or monthly had persistent cognitive deficits as long as 1 year after injuries. Long-term cognitive deficits were associated with increased astrocytosis but not tau phosphorylation or amyloid β (by ELISA); plaques or tangles (by immunohistochemistry); or brain volume loss or changes in white matter integrity (by MRI). APOE4 was not associated with worse MWM performance after rmTBI. INTERPRETATION Within the vulnerable time period between injuries, rmTBI produces long-term cognitive deficits independent of increased amyloid β or tau phosphorylation. In this model, cognitive outcome is not influenced by APOE4 status. The data have implications for the long-term mental health of athletes who suffer multiple concussions.
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Affiliation(s)
- Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, MA; Harvard Medical School, Boston, MA
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De Beaumont L, Beauchemin M, Beaulieu C, Jolicoeur P. Long-term attenuated electrophysiological response to errors following multiple sports concussions. J Clin Exp Neuropsychol 2013; 35:596-607. [DOI: 10.1080/13803395.2013.800023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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230
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Snedden TR. Concept analysis of concussion. J SPEC PEDIATR NURS 2013; 18:211-20. [PMID: 23822845 DOI: 10.1111/jspn.12038] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Revised: 12/31/2012] [Accepted: 01/15/2013] [Indexed: 11/29/2022]
Abstract
PURPOSE Concussion has been estimated to occur in 1.6-3.8 million adolescent athletes in the United States each year. However, because of conceptual ambiguity regarding its definition, the true incidence is estimated to be significantly higher. This article seeks to identify and support a single definition for the term concussion. CONCLUSIONS Defining attributes, antecedents, and consequences of concussion allow for a better understanding of this concept. Sample cases from pediatric clinical practice further clarify the concept as it applies to pediatric nursing. PRACTICE IMPLICATIONS A clear definition has the potential to increase knowledge and recognition of concussion injury, leading to strategies that would decrease the risk of long-term effects and devastating outcomes.
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Affiliation(s)
- Traci R Snedden
- College of Nursing, University of Colorado, Aurora, Colorado, USA.
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231
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Gardner A, Iverson GL, McCrory P. Chronic traumatic encephalopathy in sport: a systematic review. Br J Sports Med 2013; 48:84-90. [PMID: 23803602 DOI: 10.1136/bjsports-2013-092646] [Citation(s) in RCA: 127] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
OBJECTIVE To provide a critical review of chronic traumatic encephalopathy (CTE) by considering the range of clinical presentations, neuropathology and the strength of evidence for CTE as a distinct syndrome. DATA SOURCES Seven electronic databases were searched using a combination of MeSH terms and key words to identify relevant articles. REVIEW METHODS Specific inclusion and exclusion criteria were used to select studies for review. Data extracted where present included study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, investigation results and neuropathology results. RESULTS The data from 158 published case studies were reviewed. Critical differences between the older descriptions of CTE (the 'classic' syndrome) and the recent descriptions (the 'modern' syndrome) exist in the age of onset, natural history, clinical features, pathological findings and diagnostic criteria, which suggests that modern CTE is a different syndrome. The methodology of the current studies does not allow determination of aetiology or risk factors. CONCLUSIONS The clinicopathological differences between the 'classic' CTE syndrome and the 'modern' syndrome suggest that the new syndrome needs a different nomenclature. Further research is required to clearly define the clinical phenotype of the modern CTE syndrome and establish the underlying aetiology. Future research needs to address these issues through large-scale, prospective clinicopathological studies.
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Affiliation(s)
- Andrew Gardner
- Centre for Translational Neuroscience and Mental Health, School of Medicine and Public Health, University of Newcastle, , Callaghan, New South Wales, Australia
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232
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Farzan F, Barr MS, Hoppenbrouwers SS, Fitzgerald PB, Chen R, Pascual-Leone A, Daskalakis ZJ. The EEG correlates of the TMS-induced EMG silent period in humans. Neuroimage 2013; 83:120-34. [PMID: 23800790 DOI: 10.1016/j.neuroimage.2013.06.059] [Citation(s) in RCA: 98] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Revised: 06/13/2013] [Accepted: 06/16/2013] [Indexed: 12/14/2022] Open
Abstract
Application of magnetic or electrical stimulation to the motor cortex can result in a period of electromyography (EMG) silence in a tonically active peripheral muscle. This period of EMG silence is referred to as the silent period (SP). The duration of SP shows intersubject variability and reflects the integrity of cortical and corticospinal pathways. A non-invasive technique for assessing the duration of SP is the combination of Transcranial Magnetic Stimulation (TMS) with EMG. Utilizing TMS-EMG, several studies have reported on the shortening or lengthening of SP in neuropsychiatric disorders such as schizophrenia, bipolar disorder, depression, obsessive compulsive disorder, epilepsy, Parkinson's disease, and stroke. However, cortical, corticospinal and peripheral components are difficult to disentangle from EMG alone. Here, we use the multimodal neuroimaging technique of TMS-EMG combined with concurrent electroencephalography (EEG) recording to further examine the cortical origin of SP and the cortical oscillatory activity that underlies SP genesis. We demonstrate that the duration of SP is related to the temporal characteristics of the cortical reactivity and the power of delta to alpha oscillations in both local and remote areas ipsilateral and contralateral to the stimulation site, and beta oscillations locally. We illustrate that, compared to EMG, the EEG indices of the SP provide additional information about the brain dynamics and propose that the EEG measures of SP may be used in future clinical and research investigations to more precisely delineate the mechanisms underlying inhibitory impairments.
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Affiliation(s)
- Faranak Farzan
- Berenson-Allen Center for Non-invasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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Koerte IK, Kaufmann D, Hartl E, Bouix S, Pasternak O, Kubicki M, Rauscher A, Li DKB, Dadachanji SB, Taunton JA, Forwell LA, Johnson AM, Echlin PS, Shenton ME. A prospective study of physician-observed concussion during a varsity university hockey season: white matter integrity in ice hockey players. Part 3 of 4. Neurosurg Focus 2013. [PMID: 23199426 DOI: 10.3171/2012.10.focus12303] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The aim of this study was to investigate the effect of repetitive head impacts on white matter integrity that were sustained during 1 Canadian Interuniversity Sports (CIS) ice hockey season, using advanced diffusion tensor imaging (DTI). METHODS Twenty-five male ice hockey players between 20 and 26 years of age (mean age 22.24 ± 1.59 years) participated in this study. Participants underwent pre- and postseason 3-T MRI, including DTI. Group analyses were performed using paired-group tract-based spatial statistics to test for differences between preseason and postseason changes. RESULTS Tract-based spatial statistics revealed an increase in trace, radial diffusivity (RD), and axial diffusivity (AD) over the course of 1 season. Compared with preseason data, postseason images showed higher trace, AD, and RD values in the right precentral region, the right corona radiata, and the anterior and posterior limb of the internal capsule. These regions involve parts of the corticospinal tract, the corpus callosum, and the superior longitudinal fasciculus. No significant differences were observed between preseason and postseason for fractional anisotropy. CONCLUSIONS Diffusion tensor imaging revealed changes in white matter diffusivity in male ice hockey players over the course of 1 season. The origin of these findings needs to be elucidated.
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Affiliation(s)
- Inga K Koerte
- Psychiatry Neuroimaging Laboratory, Brigham and Women’s Hospital, Harvard University, Boston, Massachusetts, USA
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Chamard E, Théoret H, Skopelja EN, Forwell LA, Johnson AM, Echlin PS. A prospective study of physician-observed concussion during a varsity university hockey season: metabolic changes in ice hockey players. Part 4 of 4. Neurosurg Focus 2013. [PMID: 23199427 DOI: 10.3171/2012.10.focus12305] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Despite negative neuroimaging findings using traditional neuroimaging methods such as MRI and CT, sports-related concussions have been shown to cause neurometabolic changes in both the acute and subacute phases of head injury. However, no prospective clinical study has used an independent physician-observer design in the monitoring of these changes. The objective of this study was to evaluate the effects of repetitive concussive and sub-concussive head impacts on neurometabolic concentrations in a prospective study of two Canadian Interuniversity Sports (CIS) ice hockey teams using MR spectroscopy (MRS). METHODS Forty-five ice hockey players (25 men and 20 women) participated in this study. All participants underwent pre- and postseason MRI, including spectroscopy imaging, using a 3-T MRI machine. The linear combination model was used to quantify the following ratios: glutamate/creatine-phosphocreatine (Cr), myoinositol/Cr, and N-acetylaspartate (NAA)/Cr. Individuals sustaining a medically diagnosed concussion were sent for MRI at 72 hours, 2 weeks, and 2 months after injury. RESULTS No statistically significant differences were observed between athletes who were diagnosed with a concussion and athletes who were not clinically diagnosed as sustaining a concussion. Although no statistically significant longitudinal metabolic changes were observed among athletes who were diagnosed with a concussion, the results demonstrated a predictable pattern of initial impairment, followed by a gradual return to ratios that were similar to, but lower than, baseline ratios. No significant pre- to postseason changes were demonstrated among men who were not observed to sustain a concussion. However, a substantively significant decrease in the NAA/Cr ratio was noted among the female hockey players (t((13)) = 2.58, p = 0.02, η(2) = 0.34). CONCLUSIONS A key finding in this study, from the standpoint of future research design, is the demonstration of substantively significant metabolic changes among the players who were not diagnosed with a concussion. In addition, it may explain why there are few statistically significant differences demonstrated between players who were diagnosed with a concussion and players who were not diagnosed with a concussion (that is, the potency of the independent variable was diminished by the fact that the group of players not diagnosed with a concussion might be better described as a subgroup of the players who may have sustained a concussion but were not observed and diagnosed with a concussion). This result suggests that definitions of concussion may need to be revisited within sports with high levels of repetitive subconcussive head impacts. Future analysis of these data will examine the relationships between the modes of MRI (diffusion tensor imaging, MRS, and susceptibility-weighted MR imaging) used in this study, along with other more sensitive evaluative techniques. This type of intermodal comparison may improve the identification of concussions that were previously dependent on the unreliable self-reporting of recognized concussion symptomatology by the athlete or on poorly validated neuropsychological tests.
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Affiliation(s)
- Emilie Chamard
- Département de Psychologie, Université de Montréal and CHU Sainte-Justine, Montréal, Québec, Canada
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Echlin PS, Skopelja EN, Worsley R, Dadachanji SB, Lloyd-Smith DR, Taunton JA, Forwell LA, Johnson AM. A prospective study of physician-observed concussion during a varsity university ice hockey season: incidence and neuropsychological changes. Part 2 of 4. Neurosurg Focus 2013. [PMID: 23199425 DOI: 10.3171/2012.10.focus12286] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The primary objective of this study was to measure the incidence of concussion according to a relative number of athlete exposures among 25 male and 20 female varsity ice hockey players. The secondary objective was to present neuropsychological test results between preseason and postseason play and at 72 hours, 2 weeks, and 2 months after concussion. METHODS Every player underwent baseline assessments using the Sport Concussion Assessment Tool-2 (SCAT2), Immediate Post-Concussion Assessment and Cognitive Test (ImPACT), and MRI. Each regular season and postseason game was observed by 2 independent observers (a physician and a nonphysician observer). Players with a diagnosed concussion were removed from the game, examined in the team physician's office using the SCAT2 and ImPACT, and sent to undergo MRI. RESULTS Eleven concussions occurred during the 55 physician-observed games (20%). The incidence of concussion, expressed as number of concussions per 1000 athlete exposures, was 10.70 for men and women combined in regular season play, 11.76 for men and women combined across both the regular season and playoff season, 7.50 for men and 14.93 for women in regular season play, and 8.47 for men across both the regular season and playoff season. One male player experienced repeat concussions. No concussions were reported during practice sessions, and 1 concussion was observed and diagnosed in an exhibition game. Neuropsychological testing suggested no statistically significant preseason/postseason differences between athletes who sustained a physician-diagnosed concussion and athletes who did not sustain a physician-diagnosed concussion on either the ImPACT or SCAT2. The athletes who sustained a physician-diagnosed concussion demonstrated few reliable changes postinjury. CONCLUSIONS Although the incidence of game-related concussions per 1000 athlete exposures in this study was half the highest rate reported in the authors' previous research, it was 3 times higher than the incidence reported by other authors within the literature concerning men's collegiate ice hockey and 5 times higher than the highest rate previously reported for woman's collegiate ice hockey. Interestingly, the present results suggest a substantively higher incidence of concussion among women (14.93) than men (7.50). The reproducible and significantly higher incidence of concussion among both men and woman ice hockey players, when compared with nonphysician-observed games, suggests a significant underestimation of sports concussion in the scientific literature.
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Affiliation(s)
- Paul S Echlin
- Elliott Sports Medicine Clinic, Burlington, Ontario, Canada.
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Gosselin N, Bottari C, Chen JK, Huntgeburth SC, De Beaumont L, Petrides M, Cheung B, Ptito A. Evaluating the cognitive consequences of mild traumatic brain injury and concussion by using electrophysiology. Neurosurg Focus 2013. [PMID: 23199430 DOI: 10.3171/2012.10.focus12253] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT Mild traumatic brain injury (MTBI), often referred to as concussion when it occurs in sports, produces persistent cognitive problems in at least 15% of patients. Unfortunately, conventional neuropsychological tests usually yield results within normal limits in this population. The main objective of this event-related potential (ERP) study was to understand brain functioning during the performance of a working memory (WM) task in patients who have sustained an MTBI, mostly due to motor vehicle accident or sports concussion. This study also aimed for a better understanding of the association between brain functioning as measured with ERP, behavioral performance on the WM task, postconcussion symptoms, type of injury (that is, sports concussion vs other types), and time since the injury. METHODS Forty-four patients with MTBI (7.6 ± 8.4 months postinjury) were tested on a visual WM task with simultaneous recording of ERP, and were compared with 40 control volunteers who were their equivalent for age and sex. Amplitude and latency of frontal (N200 and N350) and parietal (P200 and P300) ERP waves were measured and were compared between groups. Correlation analyses were also performed between ERP characteristics, clinical variables, and behavioral performance. RESULTS A significant group difference was found for behavioral performance on the WM task, in which the MTBI group had a lower percentage of correct answers than the control group (p < 0.05). The patients with MTBI also had smaller amplitudes of both frontal N350 and parietal P300 ERP components when compared with control volunteers (p < 0.05). No changes were found for latency of ERP components. Smaller ERP amplitudes were associated with slower reaction times and worse accuracy on the WM task among patients with MTBI (p < 0.05). Types of injury (that is, sports concussion vs other mechanisms) were not associated with different ERP characteristics. CONCLUSIONS Abnormal ERP results are observed in patients after MTBI or sports concussion, even for those in the nonacute stage after their injury. Current standard clinical evaluations most often fail to detect cerebral dysfunction after MTBI, even when patients or athletes report symptoms. Clinicians should be aware that patients with MTBI, including sports concussion, probably have underlying mild but persistent cerebral dysfunctions that require further investigation.
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Affiliation(s)
- Nadia Gosselin
- Research Center, Hôpital du Sacré-Coeur de Montréal, Canada
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237
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Didehbani N, Munro Cullum C, Mansinghani S, Conover H, Hart J. Depressive symptoms and concussions in aging retired NFL players. Arch Clin Neuropsychol 2013; 28:418-24. [PMID: 23644673 DOI: 10.1093/arclin/act028] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We examined the relationship between a remote history of concussions with current symptoms of depression in retired professional athletes. Thirty retired National Football League (NFL) athletes with a history of concussion and 29 age- and IQ-matched controls without a history of concussion were recruited. We found a significant correlation between the number of lifetime concussions and depressive symptom severity using the Beck Depression Inventory II. Upon investigating a three-factor model of depressive symptoms (affective, cognitive, and somatic; Buckley et al., 2001) from the BDI-II, the cognitive factor was the only factor that was significantly related to concussions. In general, NFL players endorsed more symptoms of depression on all three Buckley factors compared with matched controls. Findings suggest that the number of self-reported concussions may be related to later depressive symptomology (particularly cognitive symptoms of depression).
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Affiliation(s)
- Nyaz Didehbani
- Center for BrainHealth®, The University of Texas at Dallas, Dallas, TX, USA.
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238
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Tanriverdi F, Suer C, Yapislar H, Kocyigit I, Selcuklu A, Unluhizarci K, Casanueva FF, Kelestimur F. Growth hormone deficiency due to sports-related head trauma is associated with impaired cognitive performance in amateur boxers and kickboxers as revealed by P300 auditory event-related potentials. Clin Endocrinol (Oxf) 2013; 78:730-7. [PMID: 22994791 DOI: 10.1111/cen.12037] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2012] [Revised: 08/18/2012] [Accepted: 08/31/2012] [Indexed: 11/29/2022]
Abstract
OBJECTIVES It has been recently reported that boxing and kickboxing may cause pituitary dysfunction, GH deficiency in particular. The strong link between poor cognitive performance and GH deficiency due to causes other than head trauma and the improvement of cognitive function after GH replacement therapy have been previously shown. P300 auditory event-related potential (ERP) measure is widely used to evaluate cognitive performance. In this study, we investigated the relation between the GH-IGF-I axis and cognitive performance in boxers and kickboxers. DESIGN AND PATIENTS Forty-one actively competing or retired male boxers (n: 27) and kickboxers (n: 14) with a mean age of 29·04 ± 9·30 year and 14 age- and education-matched healthy male controls were included in the study. For neuropsychological tests, the mini-mental state examination (MMSE) and Quality of Life Assessment of GH Deficiency in Adults (QoL-AGHDA) questionnaires were administered. Moreover, cognitive performance was evaluated according to P300 ERPs. RESULTS Nine of 41 (21·9%) athletes had GH deficiency. P300 amplitudes were lower at all electrode sites in the GH-deficient group than in controls, and the differences were statistically significant at Fz and Oz electrode sites (P < 0·05). When GH-deficient athletes were compared with GH-sufficient athletes, the P300 amplitudes were lower at all electrode sites in the GH-deficient group; these differences were statistically significant at Fz, Pz and Cz electrode sites (P < 0·05). In all athletes, there were significant negative correlations between IGF-I levels vs P300 latencies, and there were significant positive correlations between IGF-I levels vs P300 amplitudes (P < 0·05). CONCLUSION This study provides the first electrophysiological evidence for the close relation between the P300 ERPs and the GH-IGF-I axis in boxers and kickboxers.
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Affiliation(s)
- Fatih Tanriverdi
- Department of Endocrinology, Erciyes University Medical School, Kayseri, Turkey.
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239
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Hart J, Kraut MA, Womack KB, Strain J, Didehbani N, Bartz E, Conover H, Mansinghani S, Lu H, Cullum CM. Neuroimaging of cognitive dysfunction and depression in aging retired National Football League players: a cross-sectional study. JAMA Neurol 2013; 70:326-35. [PMID: 23303193 DOI: 10.1001/2013.jamaneurol.340] [Citation(s) in RCA: 231] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVES To assess cognitive impairment and depression in aging former professional football (National Football League [NFL]) players and to identify neuroimaging correlates of these dysfunctions. DESIGN We compared former NFL players with cognitive impairment and depression, cognitively normal retired players who were not depressed, and matched healthy control subjects. SETTING Research center in the North Texas region of the United States. PATIENTS Cross-sectional sample of former NFL players with and without a history of concussion recruited from the North Texas region and age-, education-, and IQ-matched controls. Thirty-four retired NFL players (mean age, 61.8 years) underwent neurological and neuropsychological assessment. A subset of 26 players also underwent detailed neuroimaging; imaging data in this subset were compared with imaging data acquired in 26 healthy matched controls. MAIN OUTCOME MEASURES Neuropsychological measures, clinical diagnoses of depression, neuroimaging mea-sures of white matter pathology, and a measure of cerebral blood flow. RESULTS Of the 34 former NFL players, 20 were cognitively normal. Four were diagnosed as having a fixed cognitive deficit; 8, mild cognitive impairment; 2, dementia; and 8, depression. Of the subgroup in whom neuroimaging data were acquired, cognitively impaired participants showed the greatest deficits on tests of naming, word finding, and visual/verbal episodic memory. We found significant differences in white matter abnormalities in cognitively impaired and depressed retired players compared with their respective controls. Regional blood flow differences in the cognitively impaired group (left temporal pole, inferior parietal lobule, and superior temporal gyrus) corresponded to regions associated with impaired neurocognitive performance (problems with memory, naming, and word finding). CONCLUSIONS Cognitive deficits and depression appear to be more common in aging former NFL players compared with healthy controls. These deficits are correlated with white matter abnormalities and changes in regional cerebral blood flow.
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Affiliation(s)
- John Hart
- Berman Laboratory for Learning and Memory, Center for Brain Health, School of Behavioral and Brain Sciences, The University of Texas at Dallas, 2200 W Mockingbird Ln, Dallas, TX 75235, USA.
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Abstract
Acute and chronic sports-related traumatic brain injuries (TBIs) are a substantial public health concern. Various types of acute TBI can occur in sport, but detection and management of cerebral concussion is of greatest importance as mismanagement of this syndrome can lead to persistent or chronic postconcussion syndrome (CPCS) or diffuse cerebral swelling. Chronic TBI encompasses a spectrum of disorders that are associated with long-term consequences of brain injury, including chronic traumatic encephalopathy (CTE), dementia pugilistica, post-traumatic parkinsonism, post-traumatic dementia and CPCS. CTE is the prototype of chronic TBI, but can only be definitively diagnosed at autopsy as no reliable biomarkers of this disorder are available. Whether CTE shares neuropathological features with CPCS is unknown. Evidence suggests that participation in contact-collision sports may increase the risk of neurodegenerative disorders such as Alzheimer disease, but the data are conflicting. In this Review, the spectrum of acute and chronic sport-related TBI is discussed, highlighting how examination of athletes involved in high-impact sports has advanced our understanding of pathology of brain injury and enabled improvements in detection and diagnosis of sport-related TBI.
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241
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Moretti L, Cristofori I, Weaver SM, Chau A, Portelli JN, Grafman J. Cognitive decline in older adults with a history of traumatic brain injury. Lancet Neurol 2013; 11:1103-12. [PMID: 23153408 DOI: 10.1016/s1474-4422(12)70226-0] [Citation(s) in RCA: 154] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Traumatic brain injury (TBI) is an important public health problem with potentially serious long-term neurobehavioural sequelae. There is evidence to suggest that a history of TBI can increase a person's risk of developing Alzheimer's disease. However, individuals with dementia do not usually have a history of TBI, and survivors of TBI do not invariably acquire dementia later in life. Instead, a history of traumatic brain injury, combined with brain changes associated with normal ageing, might lead to exacerbated cognitive decline in older adults. Strategies to increase or maintain cognitive reserve might help to prevent exacerbated decline after TBI. Systematic clinical assessment could help to differentiate between exacerbated cognitive decline and mild cognitive impairment, a precursor of Alzheimer's disease, with important implications for patients and their families.
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Affiliation(s)
- Laura Moretti
- Traumatic Brain Injury Research Laboratory, Kessler Foundation, West Orange, NJ, USA
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Abstract
OBJECTIVE To review novel techniques of noninvasive brain stimulation (NBS), which may have value in assessment and treatment of traumatic brain injury (TBI). METHODS Review of the following techniques: transcranial magnetic stimulation, transcranial direct current stimulation, low-level laser therapy, and transcranial Doppler sonography. Furthermore, we provide a brief overview of TMS studies to date. MAIN FINDINGS We describe the rationale for the use of these techniques in TBI, discuss their possible mechanisms of action, and raise a number of considerations relevant to translation of these methods to clinical use. Depending on the stimulation parameters, NBS may enable suppression of the acute glutamatergic hyperexcitability following TBI and/or counter the excessive GABAergic effects in the subacute stage. In the chronic stage, brain stimulation coupled to rehabilitation may enhance behavioral recovery, learning of new skills, and cortical plasticity. Correlative animal models and comprehensive safety trials seem critical to establish the use of these modalities in TBI. CONCLUSIONS Different forms of NBS techniques harbor the promise of diagnostic and therapeutic utility, particularly to guide processes of cortical reorganization and enable functional restoration in TBI. Future lines of safety research and well-designed clinical trials in TBI are warranted to determine the capability of NBS to promote recovery and minimize disability.
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Abstract
In this review the authors discuss persistent and cumulative alterations in both cognitive and motor function after sports concussions detected with some of the newest, most sophisticated brain investigation techniques. Ranging from subclinical neurophysiological alterations in young concussed athletes to quantifiable cognitive and motor function declines in former athletes in late adulthood with concussions sustained decades earlier, this review is also intended to provide new insights into the neuropathophysiology of sports concussion.
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Affiliation(s)
- Louis De Beaumont
- 1Montreal Sacred Heart Hospital Research Centre, Montreal
- 2Department of Psychology, University of Quebec at Trois-Rivières, Quebec, Canada; and
| | - Luke C. Henry
- 3University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
| | - Nadia Gosselin
- 1Montreal Sacred Heart Hospital Research Centre, Montreal
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Abstract
PURPOSE OF REVIEW According to recent Centers for Disease Control (CDC) data, the annual incidence of traumatic brain injury (TBI) in the United States is 1.6-3.2 million, of which the majority is classified as mild. Over half of these injuries occur in the pediatric population, and can often be attributed to a sports-related mechanism. Although postconcussion symptoms are usually short-lived, more lasting deficits can occur, which can be particularly disruptive to the developing brain. Recent literature detailing the pathophysiology of mild TBI (mTBI), with attention to pediatric studies, is presented. RECENT FINDINGS Although concussion generally does not produce any structural damage on conventional computed tomography (CT) or MRI, advanced neuroimaging modalities reveal microstructural and functional neurobiological changes. Diffuse axonal injury, metabolic impairment, alterations in neural activation and cerebral blood flow perturbations can occur and may contribute to acute symptomatology. Although these physiological changes usually recover to baseline in 7-10 days, sustaining recurrent injury before full recovery may increase the potential for persistent deficits. SUMMARY Understanding the pathophysiology of concussion in the pediatric population can potentially open therapeutic avenues to decrease symptom persistence and prevent further injury. Future studies in the pediatric population are necessary given the pathophysiologic differences between the developing and adult brains.
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Normative Data in a Sample of Canadian University Athletes Using ANAM Tests. JOURNAL OF CLINICAL SPORT PSYCHOLOGY 2012. [DOI: 10.1123/jcsp.6.4.336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The baseline / postconcussion neuropsychological (NP) assessment model has been shown to be of clinical value and currently contributes significant information in sport concussion evaluation. Computerized NP batteries are now widely used in elite sport environments and are rapidly becoming more commonly utilized at the community level. With the growth of computerized NP testing, it is important to identify and understand unique characteristics with respect to baseline NP performance. The Automated Neuropsychological Assessment Metrics (ANAM) is a library of computerized NP tests designed to detect speed and accuracy of attention, memory, and thinking ability. This article describes baseline ANAM test scores in a sample of Canadian university athletes and explores the following two factors: (a) performance differences between male and female student-athletes using ANAM tests and (b) the relationship between self-reported history of concussion and baseline NP performance.
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248
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Watelet J. Traumatismes faciaux. Sci Sports 2012. [DOI: 10.1016/j.scispo.2012.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
Concussion has been viewed historically as a transient injury with no evidence supporting the existence of persistent effects. However, our recent work demonstrates electroencephalographic and motor control changes in otherwise healthy individuals with a history of concussion. We therefore hypothesize that concussive and subconcussive head impacts set about a cascade of pathological events that accelerates declines in cognitive function typically associated with the aging process.
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250
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Abstract
BACKGROUND Efforts to produce definitions and diagnostic standards for mild traumatic brain injury (TBI) have a long and complex history. The diagnosis of TBI must be considered in the larger context of neuropsychiatric diagnosis. A major reconceptualization of diagnosis is now underway in which the classical syndrome conceptualization is being discarded. We address the question, what are the implications of this revision of thinking in the specific context of TBI? METHODS A recent literature on logical structures for neuropsychiatric disorders was reviewed. The symptom pattern of TBI was identified, and a literature survey determined the frequency of these symptom patterns in other disorders and in healthy control populations. RESULTS The frequency of symptom endorsement in populations without a history of TBI can be equal to endorsement frequencies in populations with a history of mild TBI. In some studies, the frequency of symptom endorsement in healthy controls having no history of head injury actually exceeded the endorsement rates in a comparison group with a history mild TBI. CONCLUSION The heterogeneity of this clinical population and their clinical presentations, the absence of a unitary etiology of postinjury deficits, and the complex idiosyncratic time course of the appearance of these deficits argue against the valid implementation of the classical model of diagnosis. In addition, the accepted criteria of diagnostic utility are not satisfied. TBI is not a disease; it is an event. More precisely, TBI is an event or a sequence of events that can, in some instances, lead to a diagnosable neurological or psychiatric disorder.
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