Joseph Maroon - Academia.edu (original) (raw)
Papers by Joseph Maroon
Recovery from mild concussion in high school athletes
Annals of Emergency Medicine, 2004
Object. A computerized neuropsychological test battery was conducted to evaluate memory dysfuncti... more Object. A computerized neuropsychological test battery was conducted to evaluate memory dysfunction and self-reporting of symptoms in a group of high school athletes who had suffered concussion. Methods. Neuropsychological performance prior to and following concussion was compared with the test performance of an age-matched control group. Potentially important diagnostic markers of concussion severity are discussed and linked to recovery within the 1st week of injury. Conclusions. High school athletes who had suffered mild concussion demonstrated significant declines in memory processes relative to a noninjured control group. Statistically significant differences between preseason and postinjury memory test results were still evident in the concussion group at 4 and 7 days postinjury. Self-reported neurological symptoms such as headache, dizziness, and nausea resolved by Day 4. Duration of on-field mental status changes such as retrograde amnesia and posttraumatic confusion was related to the presence of ...
Chronic Traumatic Encephalopathy in the National Football League
Neurosurgery, 2007
... Cantu, Robert CMD. ... However, as the list of NFL players retired as a result of postconcuss... more ... Cantu, Robert CMD. ... However, as the list of NFL players retired as a result of postconcussion symptoms (eg, Harry Carson, Al Toon, Merrill Hodge, Troy Aikman, Steve Young, Ted Johnson, Wayne Chrebet) grows and as the number of documented CTE cases increases, I ...
Neurosurgery, 2002
OBJECTIVE A common assumption in sports medicine is that a history of concussion is predictive of... more OBJECTIVE A common assumption in sports medicine is that a history of concussion is predictive of a lower threshold for, as well as a worse outcome after, subsequent concussive injury. The current study was conducted to investigate the relationship between concussion history in high school athletes and the on-field presentation of symptoms after subsequent concussion. METHODS One hundred seventy-three athletes who experienced sports-related concussion composed the initial study group. Binary groups were subsequently created on the basis of concussion history. Sixty athletes with no concussion history were compared with 28 athletes with a history of three or more concussions. The groups were compared in terms of the on-field presentation of symptoms after an in-study concussion. Dependent variables included the postinjury presence of loss of consciousness, anterograde amnesia, retrograde amnesia, and confusion. RESULTS Athletes with three or more prior concussions were more likely to...
Treatment of failed Adult Chiari Malformation decompression with CSF drainage: observations in six patients
Acta Neurochirurgica, 2003
We report the use of CSF drainage for the management of failed Adult Chiari Malformation (ACM) de... more We report the use of CSF drainage for the management of failed Adult Chiari Malformation (ACM) decompression. All patients with more than one year follow-up after treatment of their failed ACM were included in this study. They underwent initial decompression between September 1998 and April 2000. Clinical and radiological data were collected initially and at recurrence. Lumbar punctures (LP) were done at recurrence for diagnostic and therapeutic purposes. Opening pressures and symptomatic relief were recorded. Therapeutic options included intermittent LP and ventriculo-peritoneal shunting (VPS). There were 6 patients (5 females and one male). Their age ranged from 19 to 43 years. Tonsillar descent ranged from 5 to 21 mm. The symptoms recurred 1.5 to 9 months postoperatively (average 5.6 months). Postoperative imaging revealed the presence of CSF flow behind the tonsils and the formation of a retrotonsillar neocistern in all patients. On LP, the opening pressure ranged from 17 to 31 cm of water (average 23 cm). All patients improved after CSF drainage, and four patients underwent VPS. The other patients were treated with repeat LP+/-Acetazolamide. There was significant improvement in all patients, with 18 months follow-up after CSF drainage (range 16-21 months). Our results suggest a role for CSF drainage in the treatment of some patients with failed ACM surgery. Possible explanations for the failure of ACM surgery in this subgroup include: surgical complications leading to neural hydrodynamic alteration, inadequate initial surgery, and coexistence with another pathology, possibly a mild form of intracranial hypertension. More prospective and hydrodynamic studies are needed to further clarify these issues.
Journal of neurotrauma, 2017
Blast-related traumatic brain injury (TBI) is a signature injury of recent military conflicts, le... more Blast-related traumatic brain injury (TBI) is a signature injury of recent military conflicts, leading to increased Department of Defense (DoD) interest in its potential long-term effects, such as chronic traumatic encephalopathy (CTE). The DoD Blast Injury Research Program Coordinating Office convened the 2015 International State-of-the-Science Meeting to discuss the existing evidence regarding a causal relationship between TBI and CTE. Over the course of the meeting, experts across government, academia, and the sports community presented cutting edge research on the unique pathological characteristics of blast-related TBI, blast-related neurodegenerative mechanisms, risk factors for CTE, potential biomarkers for CTE, and treatment strategies for chronic neurodegeneration. The current paper summarizes these presentations. Although many advances have been made to address these topics, more research is needed to establish the existence of links between the long-term effects of single...
Does age playa role in recovery from sports-related concussion? A comparison of high school and collegiate athletes
The Journal of Pediatrics, 2003
Comment on: Orbitozygomatic approach for excisions of orbital tumors with 1 piece of craniotomy bone flap : 2 case reports by Chi-Wen Chang et al. Surg Neurol 2007; 68 (S1):56-58. Authors' reply
Surgical Neurology, 2008
Concussion in professional football: players returning to the same game--part 7
Neurosurgery, 2005
A 6-year study was conducted to determine the signs, symptoms, and outcome of players who were co... more A 6-year study was conducted to determine the signs, symptoms, and outcome of players who were concussed and either returned immediately or were rested and returned to the same game in the National Football League (NFL). From 1996 to 2001, concussions were recorded by NFL teams by use of a special standardized reporting form filled out by team physicians. Signs and symptoms were grouped by general symptoms, somatic complaints, cranial nerve effects, cognition problems, memory problems, and unconsciousness. Action taken after concussion was recorded for 887 patients. There were 135 players (15.2%) who returned immediately and 304 (34.3%) who rested and returned to the same game after concussion. There were few differences by player position or team activity about the injury or action taken. However, the mean number of signs and symptoms progressively increased from those who returned immediately (1.52), rested and returned to play (2.07), were removed from play (3.51), or were hospit...
Is there a future for percutaneous intradiscal therapy?
Clinical neurosurgery, 1996
The Management of Optic Nerve Sheath and Sphenoid Wing Meningiomas
Present Status and Future Challenges, 2005
Surgical Neurology International, 2011
Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concuss... more Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concussions, are thought to develop a slowly progressive encephalopathy characterized by a number of the neuropathological elements shared with various neurodegenerative diseases. A central pathological mechanism explaining the development of progressive neurodegeneration in this subset of individuals has not been elucidated. Yet, a large number of studies indicate that a process called immunoexcitotoxicity may be playing a central role in many neurodegenerative diseases including chronic traumatic encephalopathy (CTE). The term immunoexcitotoxicity was first coined by the lead author to explain the evolving pathological and neurodevelopmental changes in autism and the Gulf War Syndrome, but it can be applied to a number of neurodegenerative disorders. The interaction between immune receptors within the central nervous system (CNS) and excitatory glutamate receptors trigger a series of events, such as extensive reactive oxygen species/reactive nitrogen species generation, accumulation of lipid peroxidation products, and prostaglandin activation, which then leads to dendritic retraction, synaptic injury, damage to microtubules, and mitochondrial suppression. In this paper, we discuss the mechanism of immunoexcitotoxicity and its link to each of the pathophysiological and neurochemical events previously described with CTE, with special emphasis on the observed accumulation of hyperphosphorylated tau.
From Icarus to Aequanimitas
Neurosurgery, 1987
Journal of Neurosurgery, 1985
✓ Mucoceles arising from accessory paranasal sinuses about the orbit are quite rare. A case is re... more ✓ Mucoceles arising from accessory paranasal sinuses about the orbit are quite rare. A case is reported of a retro-orbital mucocele arising from the pterygoid recess of the sphenoid sinus. The clinical and anatomical presentations, computerized tomographic and magnetic resonance imaging characteristics, and laser surgical management of such lesions are described.
Journal of Neurosurgery, 1990
✓ Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are... more ✓ Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are increasingly recognized as a cause of spinal nerve root compression syndromes at the upper lumbar levels. Failure to diagnose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the incorrect interspace. If these herniations are diagnosed, they often cannot be adequately exposed through the typical midline hemilaminectomy approach. Many authors have advocated a partial or complete unilateral facetectomy to expose these herniations, which can lead to vertebral instability or contribute to continued postoperative back pain. The authors present a series of 25 patients who were diagnosed as having far lateral lumbar disc herniations and underwent paramedian microsurgical lumbar-disc excision. Twelve of these were at the L4–5 level, six at the L5–S1 level, and seven at the L3–4 level. In these cases, myelography is uniformly normal and hig...
Sensitivity of the concussion assessment battery
Neurosurgery, 2007
OBJECTIVE: Sports medicine clinicians commonly use multiple tests when evaluating patients with c... more OBJECTIVE: Sports medicine clinicians commonly use multiple tests when evaluating patients with concussion. The specific tests vary but often include symptom inventories, posturography, and neurocognitive examinations. The sensitivity of these tests to ...
Surgical Neurology, 2004
BACKGROUND The purpose of the study is to describe anatomic topographic landmarks for transethmoi... more BACKGROUND The purpose of the study is to describe anatomic topographic landmarks for transethmoidal approach to optic canal for optic nerve decompression. The study focuses on microsurgical/radiologic anatomies and their relationships in the region of the optic canal and orbit. METHODS Human optic canal and related anatomic structures were studied in orbits of 6 formalin preserved adult human cadavers. In addition, anatomic measurements were made with digital vernier caliper on the orbits of 25 adult human skulls. The relation between ethmoidal and sinus was assessed with computed tomography (CT) scan in 25 living human heads needing cranial CT scan for any reason. RESULTS The suture on the conjunction of frontal, maxilla, and lacrimal bones with a location in medial side of the orbit was accepted as a landmark. When the measurements were taken from this landmark, the distances to supraorbital margin were:
The aims of this study were to quantify the sensitivity of various biomechanical measures (linear... more The aims of this study were to quantify the sensitivity of various biomechanical measures (linear acceleration, rotational acceleration, impact duration, and impact location) of head impact to the clinical diagnosis of concussion in United States football players and to develop a novel measure of head impact severity combining these measures into a single score that better predicts the incidence of concussion. METHODS: On-field head impact data were collected from 449 football players at 13 organizations (n ϭ 289,916) using in-helmet systems of six single-axis accelerometers. Concussions were diagnosed by medical staff and later associated with impact data. Principal component analysis and a weighting coefficient based on impact location were used to transform correlated head impact measures into a new composite variable, weighted principal component score (wPCS). The predictive power of linear acceleration, rotational acceleration, head injury criterion, and wPCS was quantified using receiver operating characteristic curves. The null hypothesis, that a measure was no more predictive than guessing, was tested (α ϭ 0.05). In addition, receiver operating characteristic curves for wPCS and classical measures were directly compared to test the hypothesis that wPCS was more predictive of concussion than were classic measures (α ϭ 0.05). RESULTS: When all of the impacts were considered, every biomechanical measure evaluated was statistically more predictive of concussion than guessing (P Ͻ 0.005). However, for the top 1 and 2% of impacts based on linear acceleration, a subset that consisted of 82% of all diagnosed concussions, only wPCS was significantly more predictive of concussion than guessing (P Ͻ 0.03); when compared with each other, wPCS was more predictive of concussion than were classical measures for the top 1 and 2% of all of the data (P Ͻ 0.04). CONCLUSION: A weighted combination of several biomechanical inputs, including impact location, is more predictive of concussion than a single biomechanical measure. This study is the first to the authors' knowledge to quantify improvements in the sensitivity of a biomechanical measure to incidence of concussion when impact location is considered.
Long-term outcome of optic nerve encasement and optic nerve decompression in patients with fibrous dysplasia: risk factors for blindness and safety of observation
On-field predictors of neuropsychological and symptom deficit following sports-related concussion
Clinical Journal of …, 2003
Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > July ...
Asanguineous whole body perfusion with a new intracellular acellular solution and ultraprofound hypothermia provides cellular protection during 3.5 hours of cardiac arrest in a canine model
Temporary cessation of blood flow is a necessary aid for certain complex neurosurgical and cardio... more Temporary cessation of blood flow is a necessary aid for certain complex neurosurgical and cardiovascular procedures, and hypothermia is often used to help protect against the deleterious effects of ischemia and anoxia. In an attempt to protect cellular integrity during ultraprofound hypothermia (< 10 degrees C) and complete blood substitution, two new crystalloid-colloid blood substitutes (Hypothermosol-maintenance [HTS-M] and Hypothermosol-purge [HTS-P]) have been evaluated. Using extracorporeal bypass, 14 dogs were totally exsanguinated during cooling using the HTS-P solution, then perfused (40-85 ml/kg/min; mean arterial blood pressure = 25-40 mmHg) with either TS-M (Group I, n = 11), or with HTS-P as controls (Group II, n = 3) for 3 hr at 7 degrees C. During warming, the dogs were autotransfused and observed neurologically and biochemically during recovery. All dogs in Group I recovered and eight have survived long term (12-80 weeks) without apparent neurologic deficits. In contrast, dogs in Group II were more difficult to revive (cardiac resuscitation); two survived long term with delayed neurologic recovery. Evaluation of biochemical parameters showed only a transient and inconsequential elevation in enzymes (e.g., brain, liver, and heart) in Group I compared with the markedly greater elevations in Group II. The faster neurologic recovery of dogs treated with the "intracellular" maintenance solution supports the biochemical data showing the benefits of this type of blood substitute for extending the safe limits of hypothermic cardiac arrest to beyond 3 hr.
Recovery from mild concussion in high school athletes
Annals of Emergency Medicine, 2004
Object. A computerized neuropsychological test battery was conducted to evaluate memory dysfuncti... more Object. A computerized neuropsychological test battery was conducted to evaluate memory dysfunction and self-reporting of symptoms in a group of high school athletes who had suffered concussion. Methods. Neuropsychological performance prior to and following concussion was compared with the test performance of an age-matched control group. Potentially important diagnostic markers of concussion severity are discussed and linked to recovery within the 1st week of injury. Conclusions. High school athletes who had suffered mild concussion demonstrated significant declines in memory processes relative to a noninjured control group. Statistically significant differences between preseason and postinjury memory test results were still evident in the concussion group at 4 and 7 days postinjury. Self-reported neurological symptoms such as headache, dizziness, and nausea resolved by Day 4. Duration of on-field mental status changes such as retrograde amnesia and posttraumatic confusion was related to the presence of ...
Chronic Traumatic Encephalopathy in the National Football League
Neurosurgery, 2007
... Cantu, Robert CMD. ... However, as the list of NFL players retired as a result of postconcuss... more ... Cantu, Robert CMD. ... However, as the list of NFL players retired as a result of postconcussion symptoms (eg, Harry Carson, Al Toon, Merrill Hodge, Troy Aikman, Steve Young, Ted Johnson, Wayne Chrebet) grows and as the number of documented CTE cases increases, I ...
Neurosurgery, 2002
OBJECTIVE A common assumption in sports medicine is that a history of concussion is predictive of... more OBJECTIVE A common assumption in sports medicine is that a history of concussion is predictive of a lower threshold for, as well as a worse outcome after, subsequent concussive injury. The current study was conducted to investigate the relationship between concussion history in high school athletes and the on-field presentation of symptoms after subsequent concussion. METHODS One hundred seventy-three athletes who experienced sports-related concussion composed the initial study group. Binary groups were subsequently created on the basis of concussion history. Sixty athletes with no concussion history were compared with 28 athletes with a history of three or more concussions. The groups were compared in terms of the on-field presentation of symptoms after an in-study concussion. Dependent variables included the postinjury presence of loss of consciousness, anterograde amnesia, retrograde amnesia, and confusion. RESULTS Athletes with three or more prior concussions were more likely to...
Treatment of failed Adult Chiari Malformation decompression with CSF drainage: observations in six patients
Acta Neurochirurgica, 2003
We report the use of CSF drainage for the management of failed Adult Chiari Malformation (ACM) de... more We report the use of CSF drainage for the management of failed Adult Chiari Malformation (ACM) decompression. All patients with more than one year follow-up after treatment of their failed ACM were included in this study. They underwent initial decompression between September 1998 and April 2000. Clinical and radiological data were collected initially and at recurrence. Lumbar punctures (LP) were done at recurrence for diagnostic and therapeutic purposes. Opening pressures and symptomatic relief were recorded. Therapeutic options included intermittent LP and ventriculo-peritoneal shunting (VPS). There were 6 patients (5 females and one male). Their age ranged from 19 to 43 years. Tonsillar descent ranged from 5 to 21 mm. The symptoms recurred 1.5 to 9 months postoperatively (average 5.6 months). Postoperative imaging revealed the presence of CSF flow behind the tonsils and the formation of a retrotonsillar neocistern in all patients. On LP, the opening pressure ranged from 17 to 31 cm of water (average 23 cm). All patients improved after CSF drainage, and four patients underwent VPS. The other patients were treated with repeat LP+/-Acetazolamide. There was significant improvement in all patients, with 18 months follow-up after CSF drainage (range 16-21 months). Our results suggest a role for CSF drainage in the treatment of some patients with failed ACM surgery. Possible explanations for the failure of ACM surgery in this subgroup include: surgical complications leading to neural hydrodynamic alteration, inadequate initial surgery, and coexistence with another pathology, possibly a mild form of intracranial hypertension. More prospective and hydrodynamic studies are needed to further clarify these issues.
Journal of neurotrauma, 2017
Blast-related traumatic brain injury (TBI) is a signature injury of recent military conflicts, le... more Blast-related traumatic brain injury (TBI) is a signature injury of recent military conflicts, leading to increased Department of Defense (DoD) interest in its potential long-term effects, such as chronic traumatic encephalopathy (CTE). The DoD Blast Injury Research Program Coordinating Office convened the 2015 International State-of-the-Science Meeting to discuss the existing evidence regarding a causal relationship between TBI and CTE. Over the course of the meeting, experts across government, academia, and the sports community presented cutting edge research on the unique pathological characteristics of blast-related TBI, blast-related neurodegenerative mechanisms, risk factors for CTE, potential biomarkers for CTE, and treatment strategies for chronic neurodegeneration. The current paper summarizes these presentations. Although many advances have been made to address these topics, more research is needed to establish the existence of links between the long-term effects of single...
Does age playa role in recovery from sports-related concussion? A comparison of high school and collegiate athletes
The Journal of Pediatrics, 2003
Comment on: Orbitozygomatic approach for excisions of orbital tumors with 1 piece of craniotomy bone flap : 2 case reports by Chi-Wen Chang et al. Surg Neurol 2007; 68 (S1):56-58. Authors' reply
Surgical Neurology, 2008
Concussion in professional football: players returning to the same game--part 7
Neurosurgery, 2005
A 6-year study was conducted to determine the signs, symptoms, and outcome of players who were co... more A 6-year study was conducted to determine the signs, symptoms, and outcome of players who were concussed and either returned immediately or were rested and returned to the same game in the National Football League (NFL). From 1996 to 2001, concussions were recorded by NFL teams by use of a special standardized reporting form filled out by team physicians. Signs and symptoms were grouped by general symptoms, somatic complaints, cranial nerve effects, cognition problems, memory problems, and unconsciousness. Action taken after concussion was recorded for 887 patients. There were 135 players (15.2%) who returned immediately and 304 (34.3%) who rested and returned to the same game after concussion. There were few differences by player position or team activity about the injury or action taken. However, the mean number of signs and symptoms progressively increased from those who returned immediately (1.52), rested and returned to play (2.07), were removed from play (3.51), or were hospit...
Is there a future for percutaneous intradiscal therapy?
Clinical neurosurgery, 1996
The Management of Optic Nerve Sheath and Sphenoid Wing Meningiomas
Present Status and Future Challenges, 2005
Surgical Neurology International, 2011
Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concuss... more Some individuals suffering from mild traumatic brain injuries, especially repetitive mild concussions, are thought to develop a slowly progressive encephalopathy characterized by a number of the neuropathological elements shared with various neurodegenerative diseases. A central pathological mechanism explaining the development of progressive neurodegeneration in this subset of individuals has not been elucidated. Yet, a large number of studies indicate that a process called immunoexcitotoxicity may be playing a central role in many neurodegenerative diseases including chronic traumatic encephalopathy (CTE). The term immunoexcitotoxicity was first coined by the lead author to explain the evolving pathological and neurodevelopmental changes in autism and the Gulf War Syndrome, but it can be applied to a number of neurodegenerative disorders. The interaction between immune receptors within the central nervous system (CNS) and excitatory glutamate receptors trigger a series of events, such as extensive reactive oxygen species/reactive nitrogen species generation, accumulation of lipid peroxidation products, and prostaglandin activation, which then leads to dendritic retraction, synaptic injury, damage to microtubules, and mitochondrial suppression. In this paper, we discuss the mechanism of immunoexcitotoxicity and its link to each of the pathophysiological and neurochemical events previously described with CTE, with special emphasis on the observed accumulation of hyperphosphorylated tau.
From Icarus to Aequanimitas
Neurosurgery, 1987
Journal of Neurosurgery, 1985
✓ Mucoceles arising from accessory paranasal sinuses about the orbit are quite rare. A case is re... more ✓ Mucoceles arising from accessory paranasal sinuses about the orbit are quite rare. A case is reported of a retro-orbital mucocele arising from the pterygoid recess of the sphenoid sinus. The clinical and anatomical presentations, computerized tomographic and magnetic resonance imaging characteristics, and laser surgical management of such lesions are described.
Journal of Neurosurgery, 1990
✓ Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are... more ✓ Lumbar-disc herniations that occur beneath or far lateral to the intervertebral facet joint are increasingly recognized as a cause of spinal nerve root compression syndromes at the upper lumbar levels. Failure to diagnose and precisely localize these herniations can lead to unsuccessful surgical exploration or exploration of the incorrect interspace. If these herniations are diagnosed, they often cannot be adequately exposed through the typical midline hemilaminectomy approach. Many authors have advocated a partial or complete unilateral facetectomy to expose these herniations, which can lead to vertebral instability or contribute to continued postoperative back pain. The authors present a series of 25 patients who were diagnosed as having far lateral lumbar disc herniations and underwent paramedian microsurgical lumbar-disc excision. Twelve of these were at the L4–5 level, six at the L5–S1 level, and seven at the L3–4 level. In these cases, myelography is uniformly normal and hig...
Sensitivity of the concussion assessment battery
Neurosurgery, 2007
OBJECTIVE: Sports medicine clinicians commonly use multiple tests when evaluating patients with c... more OBJECTIVE: Sports medicine clinicians commonly use multiple tests when evaluating patients with concussion. The specific tests vary but often include symptom inventories, posturography, and neurocognitive examinations. The sensitivity of these tests to ...
Surgical Neurology, 2004
BACKGROUND The purpose of the study is to describe anatomic topographic landmarks for transethmoi... more BACKGROUND The purpose of the study is to describe anatomic topographic landmarks for transethmoidal approach to optic canal for optic nerve decompression. The study focuses on microsurgical/radiologic anatomies and their relationships in the region of the optic canal and orbit. METHODS Human optic canal and related anatomic structures were studied in orbits of 6 formalin preserved adult human cadavers. In addition, anatomic measurements were made with digital vernier caliper on the orbits of 25 adult human skulls. The relation between ethmoidal and sinus was assessed with computed tomography (CT) scan in 25 living human heads needing cranial CT scan for any reason. RESULTS The suture on the conjunction of frontal, maxilla, and lacrimal bones with a location in medial side of the orbit was accepted as a landmark. When the measurements were taken from this landmark, the distances to supraorbital margin were:
The aims of this study were to quantify the sensitivity of various biomechanical measures (linear... more The aims of this study were to quantify the sensitivity of various biomechanical measures (linear acceleration, rotational acceleration, impact duration, and impact location) of head impact to the clinical diagnosis of concussion in United States football players and to develop a novel measure of head impact severity combining these measures into a single score that better predicts the incidence of concussion. METHODS: On-field head impact data were collected from 449 football players at 13 organizations (n ϭ 289,916) using in-helmet systems of six single-axis accelerometers. Concussions were diagnosed by medical staff and later associated with impact data. Principal component analysis and a weighting coefficient based on impact location were used to transform correlated head impact measures into a new composite variable, weighted principal component score (wPCS). The predictive power of linear acceleration, rotational acceleration, head injury criterion, and wPCS was quantified using receiver operating characteristic curves. The null hypothesis, that a measure was no more predictive than guessing, was tested (α ϭ 0.05). In addition, receiver operating characteristic curves for wPCS and classical measures were directly compared to test the hypothesis that wPCS was more predictive of concussion than were classic measures (α ϭ 0.05). RESULTS: When all of the impacts were considered, every biomechanical measure evaluated was statistically more predictive of concussion than guessing (P Ͻ 0.005). However, for the top 1 and 2% of impacts based on linear acceleration, a subset that consisted of 82% of all diagnosed concussions, only wPCS was significantly more predictive of concussion than guessing (P Ͻ 0.03); when compared with each other, wPCS was more predictive of concussion than were classical measures for the top 1 and 2% of all of the data (P Ͻ 0.04). CONCLUSION: A weighted combination of several biomechanical inputs, including impact location, is more predictive of concussion than a single biomechanical measure. This study is the first to the authors' knowledge to quantify improvements in the sensitivity of a biomechanical measure to incidence of concussion when impact location is considered.
Long-term outcome of optic nerve encasement and optic nerve decompression in patients with fibrous dysplasia: risk factors for blindness and safety of observation
On-field predictors of neuropsychological and symptom deficit following sports-related concussion
Clinical Journal of …, 2003
Wolters Kluwer Health may email you for journal alerts and information, but is committed to maint... more Wolters Kluwer Health may email you for journal alerts and information, but is committed to maintaining your privacy and will not share your personal information without your express consent. For more information, please refer to our Privacy Policy. ... Skip Navigation Links Home > July ...
Asanguineous whole body perfusion with a new intracellular acellular solution and ultraprofound hypothermia provides cellular protection during 3.5 hours of cardiac arrest in a canine model
Temporary cessation of blood flow is a necessary aid for certain complex neurosurgical and cardio... more Temporary cessation of blood flow is a necessary aid for certain complex neurosurgical and cardiovascular procedures, and hypothermia is often used to help protect against the deleterious effects of ischemia and anoxia. In an attempt to protect cellular integrity during ultraprofound hypothermia (< 10 degrees C) and complete blood substitution, two new crystalloid-colloid blood substitutes (Hypothermosol-maintenance [HTS-M] and Hypothermosol-purge [HTS-P]) have been evaluated. Using extracorporeal bypass, 14 dogs were totally exsanguinated during cooling using the HTS-P solution, then perfused (40-85 ml/kg/min; mean arterial blood pressure = 25-40 mmHg) with either TS-M (Group I, n = 11), or with HTS-P as controls (Group II, n = 3) for 3 hr at 7 degrees C. During warming, the dogs were autotransfused and observed neurologically and biochemically during recovery. All dogs in Group I recovered and eight have survived long term (12-80 weeks) without apparent neurologic deficits. In contrast, dogs in Group II were more difficult to revive (cardiac resuscitation); two survived long term with delayed neurologic recovery. Evaluation of biochemical parameters showed only a transient and inconsequential elevation in enzymes (e.g., brain, liver, and heart) in Group I compared with the markedly greater elevations in Group II. The faster neurologic recovery of dogs treated with the "intracellular" maintenance solution supports the biochemical data showing the benefits of this type of blood substitute for extending the safe limits of hypothermic cardiac arrest to beyond 3 hr.