Fralick, M; Thiruchelvam, D; Tien, H C; Redelmeier, D A
Risk of suicide after a concussion Journal Article
In: CMAJ Canadian Medical Association Journal, vol. 188, no. 7, pp. 497–504, 2016.
Abstract | BibTeX | Tags: *Brain Concussion/co [Complications], *Suicide/sn [Statistics & Numerical Data], adult, Canada/ep [Epidemiology], Cohort Studies, Female, Humans, Long-Term Care, Longitudinal studies, Male, ONTARIO, Risk Factors
@article{Fralick2016,
title = {Risk of suicide after a concussion},
author = {Fralick, M and Thiruchelvam, D and Tien, H C and Redelmeier, D A},
year = {2016},
date = {2016-01-01},
journal = {CMAJ Canadian Medical Association Journal},
volume = {188},
number = {7},
pages = {497--504},
abstract = {BACKGROUND: Head injuries have been associated with subsequent suicide among military personnel, but outcomes after a concussion in the community are uncertain. We assessed the long-term risk of suicide after concussions occurring on weekends or weekdays in the community. METHODS: We performed a longitudinal cohort analysis of adults with diagnosis of a concussion in Ontario, Canada, from Apr. 1, 1992, to Mar. 31, 2012 (a 20-yr period), excluding severe cases that resulted in hospital admission. The primary outcome was the long-term risk of suicide after a weekend or weekday concussion. RESULTS: We identified 235,110 patients with a concussion. Their mean age was 41 years, 52% were men, and most (86%) lived in an urban location. A total of 667 subsequent suicides occurred over a median follow-up of 9.3 years, equivalent to 31 deaths per 100,000 patients annually or 3 times the population norm. Weekend concussions were associated with a one-third further increased risk of suicide compared with weekday concussions (relative risk 1.36, 95% confidence interval 1.14-1.64). The increased risk applied regardless of patients' demographic characteristics, was independent of past psychiatric conditions, became accentuated with time and exceeded the risk among military personnel. Half of these patients had visited a physician in the last week of life. INTERPRETATION: Adults with a diagnosis of concussion had an increased long-term risk of suicide, particularly after concussions on weekends. Greater attention to the long-term care of patients after a concussion in the community might save lives because deaths from suicide can be prevented.Copyright © 2016 Canadian Medical Association or its licensors.},
keywords = {*Brain Concussion/co [Complications], *Suicide/sn [Statistics \& Numerical Data], adult, Canada/ep [Epidemiology], Cohort Studies, Female, Humans, Long-Term Care, Longitudinal studies, Male, ONTARIO, Risk Factors},
pubstate = {published},
tppubtype = {article}
}
Little, C E; Emery, C; Black, A; Scott, S H; Meeuwisse, W; Nettel-Aguirre, A; Benson, B; Dukelow, S
Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players Journal Article
In: Journal of Neuroengineering & Rehabilitation, vol. 12, pp. 78, 2015.
Abstract | BibTeX | Tags: *Brain Concussion/di [Diagnosis], *Brain Concussion/px [Psychology], *COGNITION, *Hockey/in [Injuries], *Robotics, *Sensation, Adolescent, Biomechanical Phenomena, Brain Concussion/pp [Physiopathology], Child, Computer simulation, Humans, learning, Longitudinal studies, Male, Neuropsychological Tests, Practice (Psychology), Prognosis, Prospective Studies, Psychomotor Performance/ph [Physiology], Reproducibility of Results, treatment outcome
@article{Little2015,
title = {Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players},
author = {Little, C E and Emery, C and Black, A and Scott, S H and Meeuwisse, W and Nettel-Aguirre, A and Benson, B and Dukelow, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroengineering \& Rehabilitation},
volume = {12},
pages = {78},
abstract = {BACKGROUND: Better diagnostic and prognostic tools are needed to address issues related to early diagnosis and management of concussion across the continuum of aging but particularly in children and adolescents. The purpose of the current study was to evaluate the reliability of robotic technology (KINARM robot) assessments of reaching, position sense, bimanual motor function, visuospatial skills, attention and decision making in youth ice hockey players (ages 10-14). METHODS: Thirty-four male children attended two testing days, one week apart. On day one, each subject completed five tasks on the robot with two examiners (alternating examiner sequence); the 2(nd) examiner followed the same procedure as the 1(st) immediately afterwards. One consistent examiner tested subjects one week later. This is a test-retest reliability study. The robotic tasks characterize sensorimotor and/or cognitive performance; 63 parameters from 5 tasks are reported. Session 1 was the 1(st) time the subject performed the 5 tasks, session 2 the 2(nd) time on day 1, and session 3 one week following. RESULTS: Intra-class correlation coefficients ranged from 0.06 to 0.91 and 0.09 to 0.90 for session 1 to 2 and 2 to 3, respectively. Bland-Altman plots showed agreement in a majority of the parameters and a learning effect in 25 % and 24 % of parameters in session 1 vs 2 and 1 vs 3, respectively but none for session 2 vs 3. Of those that showed a learning effect, only 8 % of parameters in session 1 vs 2 and 10 % in session 1 vs 3 had a clinical relevance measure\>0.8. CONCLUSIONS: The relative homogeneity of the sample and the effect of learning seen in some of the task parameters appears to have negatively impacted the intra-class correlation coefficients from session 1 to 2, with less impact for 2 to 3. The Bland-Altman analysis supports good absolute reliability in healthy male children with no neurological impairment ranging in age from 10 to 14. The clinically relevant learning effect seen, in a small number of parameters could be addressed by creating a learning effect adjustment factor and/or implementing a practice session, which would eliminate the learning effect.},
keywords = {*Brain Concussion/di [Diagnosis], *Brain Concussion/px [Psychology], *COGNITION, *Hockey/in [Injuries], *Robotics, *Sensation, Adolescent, Biomechanical Phenomena, Brain Concussion/pp [Physiopathology], Child, Computer simulation, Humans, learning, Longitudinal studies, Male, Neuropsychological Tests, Practice (Psychology), Prognosis, Prospective Studies, Psychomotor Performance/ph [Physiology], Reproducibility of Results, treatment outcome},
pubstate = {published},
tppubtype = {article}
}
Alexander, D G; Shuttleworth-Edwards, A B; Kidd, M; Malcolm, C M
Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1113–1125, 2015.
Abstract | Links | BibTeX | Tags: academic achievement, Academic performance, ADOLESCENCE, Adolescent, adolescent disease, adult, Article, Athletic Injuries, brain concussion, Brain Injuries, Child, cognition, Concussion, controlled study, Educational Status, football, human, Humans, Injuries, intelligence test, Intelligence Tests, Longitudinal studies, longitudinal study, major clinical study, Male, mild traumatic brain injury, mTBI, neurocognitive, neuropsychological test, Neuropsychological Tests, Pathophysiology, Prospective Studies, prospective study, psychologic test, psychology, rugby, SOUTH Africa, sport injury, TASK performance, traumatic brain injury, treatment outcome
@article{Alexander2015,
title = {Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes},
author = {Alexander, D G and Shuttleworth-Edwards, A B and Kidd, M and Malcolm, C M},
doi = {10.3109/02699052.2015.1031699},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1113--1125},
abstract = {Background: Information is scant concerning enduring brain injury effects of participation in the contact sport of Rugby Union (hereafter rugby) on early adolescents.Objective: The objective was prospectively to investigate differences between young adolescent male rugby players and non-contact sports controls on neurocognitive test performance over 3 years and academic achievement over 6 years.Method: A sample of boys from the same school and grade was divided into three groups: rugby with seasonal concussions (n = 45), rugby no seasonal concussions (n = 21) and non-contact sports controls (n = 30). Baseline neurocognitive testing was conducted pre-season in Grade 7 and post-season in Grades 8 and 9. Year-end academic grades were documented for Grades 6-9 and 12 (pre-high school to year of school leaving). A mixed model repeated measures ANOVA was conducted to investigate comparative neurocognitive and academic outcomes between the three sub-groups.Results: Compared with controls, both rugby groups were significantly lower on the WISC-III Coding Immediate Recall sub-test. There was a significant interaction effect on the academic measure, with improved scores over time for controls, that was not in evidence for either rugby group.Conclusions: Tentatively, the outcome suggests cognitive vulnerability in association with school level participation in rugby. © 2015 Taylor \& Francis Group, LLC.},
keywords = {academic achievement, Academic performance, ADOLESCENCE, Adolescent, adolescent disease, adult, Article, Athletic Injuries, brain concussion, Brain Injuries, Child, cognition, Concussion, controlled study, Educational Status, football, human, Humans, Injuries, intelligence test, Intelligence Tests, Longitudinal studies, longitudinal study, major clinical study, Male, mild traumatic brain injury, mTBI, neurocognitive, neuropsychological test, Neuropsychological Tests, Pathophysiology, Prospective Studies, prospective study, psychologic test, psychology, rugby, SOUTH Africa, sport injury, TASK performance, traumatic brain injury, treatment outcome},
pubstate = {published},
tppubtype = {article}
}
Sikoglu, E M; Liso Navarro, A A; Czerniak, S M; McCafferty, J; Eisenstock, J; Stevenson, J H; King, J A; Moore, C M
Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study Journal Article
In: Cognitive and Behavioral Neurology, vol. 28, no. 4, pp. 181–187, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, athlete, Athletic Injuries, biochemical analysis, bioenergy, brain concussion, clinical article, cognition, college, Concussion, energy consumption, Energy Metabolism, Female, high energy phosphate, human, Humans, Longitudinal studies, longitudinal study, Magnetic Resonance Spectroscopy, Male, metabolism, MR spectroscopy (phosphorus-31), neuroimaging, NTP, NUCLEAR magnetic resonance spectroscopy, nucleoside, nucleoside triphosphate, Nucleosides, Pathophysiology, phosphate, Phosphates, phosphorus, Phosphorus Isotopes, phosphorus nuclear magnetic resonance, PHYSIOLOGY, Prefrontal Cortex, priority journal, procedures, sport injury, Universities, university, Young Adult
@article{Sikoglu2015,
title = {Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study},
author = {Sikoglu, E M and {Liso Navarro}, A A and Czerniak, S M and McCafferty, J and Eisenstock, J and Stevenson, J H and King, J A and Moore, C M},
doi = {10.1097/WNN.0000000000000076},
year = {2015},
date = {2015-01-01},
journal = {Cognitive and Behavioral Neurology},
volume = {28},
number = {4},
pages = {181--187},
abstract = {Background: Although clinical evaluations and neurocognitive assessments are commonly used to evaluate the extent of and recovery from concussion, brain bioenergetics could provide a more quantitative marker. The neurometabolic response to a concussion is thought to increase neuronal energy consumption and thus the demand for nucleoside triphosphate (NTP). Objective: We investigated the possible disruption in high-energy metabolism within the prefrontal cortex of college athletes who had either had a concussion within the past 6 months (n=14) or had never had a concussion (n=13). We hypothesized that concussed athletes would have imbalanced brain bioenergetics resulting from increased NTP consumption, and these biochemical changes would correspond to impaired cognitive abilities. Methods: We used phosphorus-31 magnetic resonance spectroscopy to quantify high-energy phosphates. We performed the neuroimaging in conjunction with neurocognitive assessments targeting prefrontal cortex-mediated tasks. Results: Our results revealed significantly lower $gamma$-NTP levels in the athletes after concussion. Although the concussed and non-concussed participants performed similarly in neurocognitive assessments, lower levels of $gamma$-NTP were associated with worse scores on neurocognitive tasks. Conclusions: Our results support the concept of increased energy demand in the prefrontal cortex of a concussed brain, and we found that while neurocognitive assessments appear normal, brain energetics may be abnormal. A longitudinal study could help establish brain NTP levels as a biomarker to aid in diagnosis and to assess recovery in concussed patients. © 2015 Wolters Kluwer Health, Inc.},
keywords = {Adolescent, adult, Article, athlete, Athletic Injuries, biochemical analysis, bioenergy, brain concussion, clinical article, cognition, college, Concussion, energy consumption, Energy Metabolism, Female, high energy phosphate, human, Humans, Longitudinal studies, longitudinal study, Magnetic Resonance Spectroscopy, Male, metabolism, MR spectroscopy (phosphorus-31), neuroimaging, NTP, NUCLEAR magnetic resonance spectroscopy, nucleoside, nucleoside triphosphate, Nucleosides, Pathophysiology, phosphate, Phosphates, phosphorus, Phosphorus Isotopes, phosphorus nuclear magnetic resonance, PHYSIOLOGY, Prefrontal Cortex, priority journal, procedures, sport injury, Universities, university, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Fralick, M; Thiruchelvam, D; Tien, H C; Redelmeier, D A
Risk of suicide after a concussion Journal Article
In: CMAJ Canadian Medical Association Journal, vol. 188, no. 7, pp. 497–504, 2016.
@article{Fralick2016,
title = {Risk of suicide after a concussion},
author = {Fralick, M and Thiruchelvam, D and Tien, H C and Redelmeier, D A},
year = {2016},
date = {2016-01-01},
journal = {CMAJ Canadian Medical Association Journal},
volume = {188},
number = {7},
pages = {497--504},
abstract = {BACKGROUND: Head injuries have been associated with subsequent suicide among military personnel, but outcomes after a concussion in the community are uncertain. We assessed the long-term risk of suicide after concussions occurring on weekends or weekdays in the community. METHODS: We performed a longitudinal cohort analysis of adults with diagnosis of a concussion in Ontario, Canada, from Apr. 1, 1992, to Mar. 31, 2012 (a 20-yr period), excluding severe cases that resulted in hospital admission. The primary outcome was the long-term risk of suicide after a weekend or weekday concussion. RESULTS: We identified 235,110 patients with a concussion. Their mean age was 41 years, 52% were men, and most (86%) lived in an urban location. A total of 667 subsequent suicides occurred over a median follow-up of 9.3 years, equivalent to 31 deaths per 100,000 patients annually or 3 times the population norm. Weekend concussions were associated with a one-third further increased risk of suicide compared with weekday concussions (relative risk 1.36, 95% confidence interval 1.14-1.64). The increased risk applied regardless of patients' demographic characteristics, was independent of past psychiatric conditions, became accentuated with time and exceeded the risk among military personnel. Half of these patients had visited a physician in the last week of life. INTERPRETATION: Adults with a diagnosis of concussion had an increased long-term risk of suicide, particularly after concussions on weekends. Greater attention to the long-term care of patients after a concussion in the community might save lives because deaths from suicide can be prevented.Copyright © 2016 Canadian Medical Association or its licensors.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Little, C E; Emery, C; Black, A; Scott, S H; Meeuwisse, W; Nettel-Aguirre, A; Benson, B; Dukelow, S
Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players Journal Article
In: Journal of Neuroengineering & Rehabilitation, vol. 12, pp. 78, 2015.
@article{Little2015,
title = {Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players},
author = {Little, C E and Emery, C and Black, A and Scott, S H and Meeuwisse, W and Nettel-Aguirre, A and Benson, B and Dukelow, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroengineering \& Rehabilitation},
volume = {12},
pages = {78},
abstract = {BACKGROUND: Better diagnostic and prognostic tools are needed to address issues related to early diagnosis and management of concussion across the continuum of aging but particularly in children and adolescents. The purpose of the current study was to evaluate the reliability of robotic technology (KINARM robot) assessments of reaching, position sense, bimanual motor function, visuospatial skills, attention and decision making in youth ice hockey players (ages 10-14). METHODS: Thirty-four male children attended two testing days, one week apart. On day one, each subject completed five tasks on the robot with two examiners (alternating examiner sequence); the 2(nd) examiner followed the same procedure as the 1(st) immediately afterwards. One consistent examiner tested subjects one week later. This is a test-retest reliability study. The robotic tasks characterize sensorimotor and/or cognitive performance; 63 parameters from 5 tasks are reported. Session 1 was the 1(st) time the subject performed the 5 tasks, session 2 the 2(nd) time on day 1, and session 3 one week following. RESULTS: Intra-class correlation coefficients ranged from 0.06 to 0.91 and 0.09 to 0.90 for session 1 to 2 and 2 to 3, respectively. Bland-Altman plots showed agreement in a majority of the parameters and a learning effect in 25 % and 24 % of parameters in session 1 vs 2 and 1 vs 3, respectively but none for session 2 vs 3. Of those that showed a learning effect, only 8 % of parameters in session 1 vs 2 and 10 % in session 1 vs 3 had a clinical relevance measure\>0.8. CONCLUSIONS: The relative homogeneity of the sample and the effect of learning seen in some of the task parameters appears to have negatively impacted the intra-class correlation coefficients from session 1 to 2, with less impact for 2 to 3. The Bland-Altman analysis supports good absolute reliability in healthy male children with no neurological impairment ranging in age from 10 to 14. The clinically relevant learning effect seen, in a small number of parameters could be addressed by creating a learning effect adjustment factor and/or implementing a practice session, which would eliminate the learning effect.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Alexander, D G; Shuttleworth-Edwards, A B; Kidd, M; Malcolm, C M
Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1113–1125, 2015.
@article{Alexander2015,
title = {Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes},
author = {Alexander, D G and Shuttleworth-Edwards, A B and Kidd, M and Malcolm, C M},
doi = {10.3109/02699052.2015.1031699},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1113--1125},
abstract = {Background: Information is scant concerning enduring brain injury effects of participation in the contact sport of Rugby Union (hereafter rugby) on early adolescents.Objective: The objective was prospectively to investigate differences between young adolescent male rugby players and non-contact sports controls on neurocognitive test performance over 3 years and academic achievement over 6 years.Method: A sample of boys from the same school and grade was divided into three groups: rugby with seasonal concussions (n = 45), rugby no seasonal concussions (n = 21) and non-contact sports controls (n = 30). Baseline neurocognitive testing was conducted pre-season in Grade 7 and post-season in Grades 8 and 9. Year-end academic grades were documented for Grades 6-9 and 12 (pre-high school to year of school leaving). A mixed model repeated measures ANOVA was conducted to investigate comparative neurocognitive and academic outcomes between the three sub-groups.Results: Compared with controls, both rugby groups were significantly lower on the WISC-III Coding Immediate Recall sub-test. There was a significant interaction effect on the academic measure, with improved scores over time for controls, that was not in evidence for either rugby group.Conclusions: Tentatively, the outcome suggests cognitive vulnerability in association with school level participation in rugby. © 2015 Taylor \& Francis Group, LLC.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Sikoglu, E M; Liso Navarro, A A; Czerniak, S M; McCafferty, J; Eisenstock, J; Stevenson, J H; King, J A; Moore, C M
Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study Journal Article
In: Cognitive and Behavioral Neurology, vol. 28, no. 4, pp. 181–187, 2015.
@article{Sikoglu2015,
title = {Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study},
author = {Sikoglu, E M and {Liso Navarro}, A A and Czerniak, S M and McCafferty, J and Eisenstock, J and Stevenson, J H and King, J A and Moore, C M},
doi = {10.1097/WNN.0000000000000076},
year = {2015},
date = {2015-01-01},
journal = {Cognitive and Behavioral Neurology},
volume = {28},
number = {4},
pages = {181--187},
abstract = {Background: Although clinical evaluations and neurocognitive assessments are commonly used to evaluate the extent of and recovery from concussion, brain bioenergetics could provide a more quantitative marker. The neurometabolic response to a concussion is thought to increase neuronal energy consumption and thus the demand for nucleoside triphosphate (NTP). Objective: We investigated the possible disruption in high-energy metabolism within the prefrontal cortex of college athletes who had either had a concussion within the past 6 months (n=14) or had never had a concussion (n=13). We hypothesized that concussed athletes would have imbalanced brain bioenergetics resulting from increased NTP consumption, and these biochemical changes would correspond to impaired cognitive abilities. Methods: We used phosphorus-31 magnetic resonance spectroscopy to quantify high-energy phosphates. We performed the neuroimaging in conjunction with neurocognitive assessments targeting prefrontal cortex-mediated tasks. Results: Our results revealed significantly lower $gamma$-NTP levels in the athletes after concussion. Although the concussed and non-concussed participants performed similarly in neurocognitive assessments, lower levels of $gamma$-NTP were associated with worse scores on neurocognitive tasks. Conclusions: Our results support the concept of increased energy demand in the prefrontal cortex of a concussed brain, and we found that while neurocognitive assessments appear normal, brain energetics may be abnormal. A longitudinal study could help establish brain NTP levels as a biomarker to aid in diagnosis and to assess recovery in concussed patients. © 2015 Wolters Kluwer Health, Inc.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Fralick, M; Thiruchelvam, D; Tien, H C; Redelmeier, D A
Risk of suicide after a concussion Journal Article
In: CMAJ Canadian Medical Association Journal, vol. 188, no. 7, pp. 497–504, 2016.
Abstract | BibTeX | Tags: *Brain Concussion/co [Complications], *Suicide/sn [Statistics & Numerical Data], adult, Canada/ep [Epidemiology], Cohort Studies, Female, Humans, Long-Term Care, Longitudinal studies, Male, ONTARIO, Risk Factors
@article{Fralick2016,
title = {Risk of suicide after a concussion},
author = {Fralick, M and Thiruchelvam, D and Tien, H C and Redelmeier, D A},
year = {2016},
date = {2016-01-01},
journal = {CMAJ Canadian Medical Association Journal},
volume = {188},
number = {7},
pages = {497--504},
abstract = {BACKGROUND: Head injuries have been associated with subsequent suicide among military personnel, but outcomes after a concussion in the community are uncertain. We assessed the long-term risk of suicide after concussions occurring on weekends or weekdays in the community. METHODS: We performed a longitudinal cohort analysis of adults with diagnosis of a concussion in Ontario, Canada, from Apr. 1, 1992, to Mar. 31, 2012 (a 20-yr period), excluding severe cases that resulted in hospital admission. The primary outcome was the long-term risk of suicide after a weekend or weekday concussion. RESULTS: We identified 235,110 patients with a concussion. Their mean age was 41 years, 52% were men, and most (86%) lived in an urban location. A total of 667 subsequent suicides occurred over a median follow-up of 9.3 years, equivalent to 31 deaths per 100,000 patients annually or 3 times the population norm. Weekend concussions were associated with a one-third further increased risk of suicide compared with weekday concussions (relative risk 1.36, 95% confidence interval 1.14-1.64). The increased risk applied regardless of patients' demographic characteristics, was independent of past psychiatric conditions, became accentuated with time and exceeded the risk among military personnel. Half of these patients had visited a physician in the last week of life. INTERPRETATION: Adults with a diagnosis of concussion had an increased long-term risk of suicide, particularly after concussions on weekends. Greater attention to the long-term care of patients after a concussion in the community might save lives because deaths from suicide can be prevented.Copyright © 2016 Canadian Medical Association or its licensors.},
keywords = {*Brain Concussion/co [Complications], *Suicide/sn [Statistics \& Numerical Data], adult, Canada/ep [Epidemiology], Cohort Studies, Female, Humans, Long-Term Care, Longitudinal studies, Male, ONTARIO, Risk Factors},
pubstate = {published},
tppubtype = {article}
}
Little, C E; Emery, C; Black, A; Scott, S H; Meeuwisse, W; Nettel-Aguirre, A; Benson, B; Dukelow, S
Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players Journal Article
In: Journal of Neuroengineering & Rehabilitation, vol. 12, pp. 78, 2015.
Abstract | BibTeX | Tags: *Brain Concussion/di [Diagnosis], *Brain Concussion/px [Psychology], *COGNITION, *Hockey/in [Injuries], *Robotics, *Sensation, Adolescent, Biomechanical Phenomena, Brain Concussion/pp [Physiopathology], Child, Computer simulation, Humans, learning, Longitudinal studies, Male, Neuropsychological Tests, Practice (Psychology), Prognosis, Prospective Studies, Psychomotor Performance/ph [Physiology], Reproducibility of Results, treatment outcome
@article{Little2015,
title = {Test-retest reliability of KINARM robot sensorimotor and cognitive assessment: in pediatric ice hockey players},
author = {Little, C E and Emery, C and Black, A and Scott, S H and Meeuwisse, W and Nettel-Aguirre, A and Benson, B and Dukelow, S},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neuroengineering \& Rehabilitation},
volume = {12},
pages = {78},
abstract = {BACKGROUND: Better diagnostic and prognostic tools are needed to address issues related to early diagnosis and management of concussion across the continuum of aging but particularly in children and adolescents. The purpose of the current study was to evaluate the reliability of robotic technology (KINARM robot) assessments of reaching, position sense, bimanual motor function, visuospatial skills, attention and decision making in youth ice hockey players (ages 10-14). METHODS: Thirty-four male children attended two testing days, one week apart. On day one, each subject completed five tasks on the robot with two examiners (alternating examiner sequence); the 2(nd) examiner followed the same procedure as the 1(st) immediately afterwards. One consistent examiner tested subjects one week later. This is a test-retest reliability study. The robotic tasks characterize sensorimotor and/or cognitive performance; 63 parameters from 5 tasks are reported. Session 1 was the 1(st) time the subject performed the 5 tasks, session 2 the 2(nd) time on day 1, and session 3 one week following. RESULTS: Intra-class correlation coefficients ranged from 0.06 to 0.91 and 0.09 to 0.90 for session 1 to 2 and 2 to 3, respectively. Bland-Altman plots showed agreement in a majority of the parameters and a learning effect in 25 % and 24 % of parameters in session 1 vs 2 and 1 vs 3, respectively but none for session 2 vs 3. Of those that showed a learning effect, only 8 % of parameters in session 1 vs 2 and 10 % in session 1 vs 3 had a clinical relevance measure\>0.8. CONCLUSIONS: The relative homogeneity of the sample and the effect of learning seen in some of the task parameters appears to have negatively impacted the intra-class correlation coefficients from session 1 to 2, with less impact for 2 to 3. The Bland-Altman analysis supports good absolute reliability in healthy male children with no neurological impairment ranging in age from 10 to 14. The clinically relevant learning effect seen, in a small number of parameters could be addressed by creating a learning effect adjustment factor and/or implementing a practice session, which would eliminate the learning effect.},
keywords = {*Brain Concussion/di [Diagnosis], *Brain Concussion/px [Psychology], *COGNITION, *Hockey/in [Injuries], *Robotics, *Sensation, Adolescent, Biomechanical Phenomena, Brain Concussion/pp [Physiopathology], Child, Computer simulation, Humans, learning, Longitudinal studies, Male, Neuropsychological Tests, Practice (Psychology), Prognosis, Prospective Studies, Psychomotor Performance/ph [Physiology], Reproducibility of Results, treatment outcome},
pubstate = {published},
tppubtype = {article}
}
Alexander, D G; Shuttleworth-Edwards, A B; Kidd, M; Malcolm, C M
Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes Journal Article
In: Brain Injury, vol. 29, no. 9, pp. 1113–1125, 2015.
Abstract | Links | BibTeX | Tags: academic achievement, Academic performance, ADOLESCENCE, Adolescent, adolescent disease, adult, Article, Athletic Injuries, brain concussion, Brain Injuries, Child, cognition, Concussion, controlled study, Educational Status, football, human, Humans, Injuries, intelligence test, Intelligence Tests, Longitudinal studies, longitudinal study, major clinical study, Male, mild traumatic brain injury, mTBI, neurocognitive, neuropsychological test, Neuropsychological Tests, Pathophysiology, Prospective Studies, prospective study, psychologic test, psychology, rugby, SOUTH Africa, sport injury, TASK performance, traumatic brain injury, treatment outcome
@article{Alexander2015,
title = {Mild traumatic brain injuries in early adolescent rugby players: Long-term neurocognitive and academic outcomes},
author = {Alexander, D G and Shuttleworth-Edwards, A B and Kidd, M and Malcolm, C M},
doi = {10.3109/02699052.2015.1031699},
year = {2015},
date = {2015-01-01},
journal = {Brain Injury},
volume = {29},
number = {9},
pages = {1113--1125},
abstract = {Background: Information is scant concerning enduring brain injury effects of participation in the contact sport of Rugby Union (hereafter rugby) on early adolescents.Objective: The objective was prospectively to investigate differences between young adolescent male rugby players and non-contact sports controls on neurocognitive test performance over 3 years and academic achievement over 6 years.Method: A sample of boys from the same school and grade was divided into three groups: rugby with seasonal concussions (n = 45), rugby no seasonal concussions (n = 21) and non-contact sports controls (n = 30). Baseline neurocognitive testing was conducted pre-season in Grade 7 and post-season in Grades 8 and 9. Year-end academic grades were documented for Grades 6-9 and 12 (pre-high school to year of school leaving). A mixed model repeated measures ANOVA was conducted to investigate comparative neurocognitive and academic outcomes between the three sub-groups.Results: Compared with controls, both rugby groups were significantly lower on the WISC-III Coding Immediate Recall sub-test. There was a significant interaction effect on the academic measure, with improved scores over time for controls, that was not in evidence for either rugby group.Conclusions: Tentatively, the outcome suggests cognitive vulnerability in association with school level participation in rugby. © 2015 Taylor \& Francis Group, LLC.},
keywords = {academic achievement, Academic performance, ADOLESCENCE, Adolescent, adolescent disease, adult, Article, Athletic Injuries, brain concussion, Brain Injuries, Child, cognition, Concussion, controlled study, Educational Status, football, human, Humans, Injuries, intelligence test, Intelligence Tests, Longitudinal studies, longitudinal study, major clinical study, Male, mild traumatic brain injury, mTBI, neurocognitive, neuropsychological test, Neuropsychological Tests, Pathophysiology, Prospective Studies, prospective study, psychologic test, psychology, rugby, SOUTH Africa, sport injury, TASK performance, traumatic brain injury, treatment outcome},
pubstate = {published},
tppubtype = {article}
}
Sikoglu, E M; Liso Navarro, A A; Czerniak, S M; McCafferty, J; Eisenstock, J; Stevenson, J H; King, J A; Moore, C M
Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study Journal Article
In: Cognitive and Behavioral Neurology, vol. 28, no. 4, pp. 181–187, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, athlete, Athletic Injuries, biochemical analysis, bioenergy, brain concussion, clinical article, cognition, college, Concussion, energy consumption, Energy Metabolism, Female, high energy phosphate, human, Humans, Longitudinal studies, longitudinal study, Magnetic Resonance Spectroscopy, Male, metabolism, MR spectroscopy (phosphorus-31), neuroimaging, NTP, NUCLEAR magnetic resonance spectroscopy, nucleoside, nucleoside triphosphate, Nucleosides, Pathophysiology, phosphate, Phosphates, phosphorus, Phosphorus Isotopes, phosphorus nuclear magnetic resonance, PHYSIOLOGY, Prefrontal Cortex, priority journal, procedures, sport injury, Universities, university, Young Adult
@article{Sikoglu2015,
title = {Effects of Recent Concussion on Brain Bioenergetics: A Phosphorus-31 Magnetic Resonance Spectroscopy Study},
author = {Sikoglu, E M and {Liso Navarro}, A A and Czerniak, S M and McCafferty, J and Eisenstock, J and Stevenson, J H and King, J A and Moore, C M},
doi = {10.1097/WNN.0000000000000076},
year = {2015},
date = {2015-01-01},
journal = {Cognitive and Behavioral Neurology},
volume = {28},
number = {4},
pages = {181--187},
abstract = {Background: Although clinical evaluations and neurocognitive assessments are commonly used to evaluate the extent of and recovery from concussion, brain bioenergetics could provide a more quantitative marker. The neurometabolic response to a concussion is thought to increase neuronal energy consumption and thus the demand for nucleoside triphosphate (NTP). Objective: We investigated the possible disruption in high-energy metabolism within the prefrontal cortex of college athletes who had either had a concussion within the past 6 months (n=14) or had never had a concussion (n=13). We hypothesized that concussed athletes would have imbalanced brain bioenergetics resulting from increased NTP consumption, and these biochemical changes would correspond to impaired cognitive abilities. Methods: We used phosphorus-31 magnetic resonance spectroscopy to quantify high-energy phosphates. We performed the neuroimaging in conjunction with neurocognitive assessments targeting prefrontal cortex-mediated tasks. Results: Our results revealed significantly lower $gamma$-NTP levels in the athletes after concussion. Although the concussed and non-concussed participants performed similarly in neurocognitive assessments, lower levels of $gamma$-NTP were associated with worse scores on neurocognitive tasks. Conclusions: Our results support the concept of increased energy demand in the prefrontal cortex of a concussed brain, and we found that while neurocognitive assessments appear normal, brain energetics may be abnormal. A longitudinal study could help establish brain NTP levels as a biomarker to aid in diagnosis and to assess recovery in concussed patients. © 2015 Wolters Kluwer Health, Inc.},
keywords = {Adolescent, adult, Article, athlete, Athletic Injuries, biochemical analysis, bioenergy, brain concussion, clinical article, cognition, college, Concussion, energy consumption, Energy Metabolism, Female, high energy phosphate, human, Humans, Longitudinal studies, longitudinal study, Magnetic Resonance Spectroscopy, Male, metabolism, MR spectroscopy (phosphorus-31), neuroimaging, NTP, NUCLEAR magnetic resonance spectroscopy, nucleoside, nucleoside triphosphate, Nucleosides, Pathophysiology, phosphate, Phosphates, phosphorus, Phosphorus Isotopes, phosphorus nuclear magnetic resonance, PHYSIOLOGY, Prefrontal Cortex, priority journal, procedures, sport injury, Universities, university, Young Adult},
pubstate = {published},
tppubtype = {article}
}
Mayer, A R; Ling, J M; Dodd, A B; Gasparovic, C; Klimaj, S D; Meier, T B
A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters Journal Article
In: Journal of Neurotrauma, vol. 32, no. 22, pp. 1759–1767, 2015.
Abstract | Links | BibTeX | Tags: Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult
@article{Mayer2015b,
title = {A Longitudinal Assessment of Structural and Chemical Alterations in Mixed Martial Arts Fighters},
author = {Mayer, A R and Ling, J M and Dodd, A B and Gasparovic, C and Klimaj, S D and Meier, T B},
doi = {10.1089/neu.2014.3833},
year = {2015},
date = {2015-01-01},
journal = {Journal of Neurotrauma},
volume = {32},
number = {22},
pages = {1759--1767},
abstract = {Growing evidence suggests that temporally proximal acute concussions and repetitive subconcussive head injuries may lead to long-term neurological deficits. However, the underlying mechanisms of injury and their relative time-scales are not well documented in human injury models. The current study therefore investigated whether biomarkers of brain chemistry (magnetic resonance [MR] spectroscopy: N-acetylaspartate [NAA], combined glutamate and glutamine [Glx], total creatine [Cre], choline compounds [Cho], and myo-inositol [mI]) and structure (cortical thickness, white matter [WM]/subcortical volume) differed between mixed martial artists (MMA; n = 13) and matched healthy controls (HC) without a history of contact sport participation (HC; n = 14). A subset of participants (MMA = 9; HC = 10) returned for follow-up visits, with MMA (n = 3) with clinician-documented acute concussions also scanned serially. As expected, MMA self-reported a higher incidence of previous concussions and significantly more cognitive symptoms during prior concussion recovery. Fighters also exhibited reduced memory and processing speed relative to controls on neuropsychological testing coupled with cortical thinning in the left posterior cingulate gyrus and right occipital cortex at baseline assessment. Over a 1-year follow-up period, MMA experienced a significant decrease in both WM volume and NAA concentration, as well as relative thinning in the left middle and superior frontal gyri. These longitudinal changes did not correlate with self-reported metrics of injury (i.e., fight diary). In contrast, HC did not exhibit significant longitudinal changes over a 4-month follow-up period (p \> 0.05). Collectively, current results provide preliminary evidence of progressive changes in brain chemistry and structure over a relatively short time period in individuals with high exposure to repetitive head hits. These findings require replication in independent samples. © Mary Ann Liebert, Inc. 2015.},
keywords = {Adolescent, adult, Article, biological marker, Biomarkers, BRAIN chemistry, brain concussion, brain cortex, brain size, Cerebral Cortex, CHOLINE, clinical article, cognition, Concussion, controlled study, cortical thickness (brain), creatine, executive function, Female, follow up, Follow-Up Studies, frontal gyrus, glutamic acid, glutamine, human, Humans, Injuries, inositol, Longitudinal, Longitudinal studies, longitudinal study, Magnetic Resonance Imaging, Male, martial art, Martial Arts, Memory, middle aged, mixed martial art, n acetylaspartic acid, neuropsychological test, Neuropsychological Tests, nuclear magnetic resonance imaging, NUCLEAR magnetic resonance spectroscopy, occipital cortex, pathology, posterior cingulate, psychology, repetitive injury, Spectroscopy, volumetrics, white matter, Young Adult},
pubstate = {published},
tppubtype = {article}
}