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ABSTRACT: Our understanding of the pathophysiological and biochemical basis of a number of neurological disorders has increased enormously over the last three decades. Parallel with this growth of knowledge has been a clearer understanding of the mechanism by which a number of naturally occurring plant extracts, as well as whole plants, can affect these mechanisms so as to offer protection against injury and promote healing of neurological tissues. Curcumin, quercetin, green tea catechins, balcalein, and luteolin have been extensively studied, and they demonstrate important effects on cell signaling that go far beyond their antioxidant effects. Of particular interest is the effect of these compounds on immunoexcitotoxicity, which, the authors suggest, is a common mechanism in a number of neurological disorders. By suppressing or affecting microglial activation states as well as the excitotoxic cascade and inflammatory mediators, these compounds dramatically affect the pathophysiology of central nervous system disorders and promote the release and generation of neurotrophic factors essential for central nervous system healing. We discuss the various aspects of these processes and suggest future directions for study.
Surgical neurology international. 01/2012; 3:19.
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ABSTRACT: 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.
Surgical neurology international. 01/2011; 2:107.
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Joseph Maroon
Surgical Neurology 08/2008; 70 Suppl 1:S1:92; discussion S1:92. · 1.67 Impact Factor
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ABSTRACT: The purpose of this study was to compare concussion rates and recovery times for athletes wearing newer helmet technology compared to traditional helmet design.
This was a three-year, prospective, naturalistic, cohort study. Participants were 2,141 high school athletes from Western Pennsylvania. Approximately half of the sample wore the Revolution helmet manufactured by Riddell, Inc. (n = 1,173) and the remainder of the sample used standard helmets (n = 968). Athletes underwent computerized neurocognitive testing through the use of ImPACT at the beginning of the study. Following a concussion, players were reevaluated at various time intervals until recovery was complete.
In the total sample, the concussion rate in athletes wearing the Revolution was 5.3% and in athletes wearing standard helmets was 7.6% [chi (1, 2, 141) = 4.96, P < 0.027]. The relative risk estimate was 0.69 (95% confidence interval = 0.499- 0.958). Wearing the Revolution helmet was associated with approximately a 31% decreased relative risk and 2.3% decreased absolute risk for sustaining a concussion in this cohort study. The athletes wearing the Revolution did not differ from athletes wearing standard helmets on the mechanism of injury (e.g., head-to-head strike), on-field concussion markers (e.g., amnesia or loss of consciousness), or on-field presentation of symptoms (e.g., headaches, dizziness, or balance problems).
Recent sophisticated laboratory research has better elucidated injury biomechanics associated with concussion in professional football players. This data has led to changes in helmet design and new helmet technology, which appears to have beneficial effects in reducing the incidence of cerebral concussion in high school football players.
Neurosurgery 02/2006; 58(2):275-86; discussion 275-86. · 2.79 Impact Factor
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ABSTRACT: Positron emission tomography (PET) has become a critical diagnostic tool in the discovery and staging of malignancies in the head and neck. Although PET is accurate for detecting cancer, increased 18 F-fluorodeoxyglucose (FDG) uptake can be seen in healthy tissues such as muscle, fat, and glands and uptake can be seen in tissues affected by inflammation or granulomatous disease. Combined PET and CT (PET/CT) can often overcome these difficulties by fusing anatomic and physiological data, but radiographic findings of some disease processes can be confusing even with fused imaging techniques. We present two cases of FDG uptake in the posterior pharynx, localized by combined PET/CT, which was initially interpreted as squamous cell carcinoma. The increased activity was ultimately attributed to Teflon-induced granulomas. It is important for radiologists to recognize potential causes of false-positive PET/CT findings to improve our diagnostic accuracy and to avoid unnecessary biopsies and surgeries.
American Journal of Neuroradiology 03/2005; 26(2):417-20. · 2.93 Impact Factor
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ABSTRACT: Investigate the relationship between on-field markers of concussion severity and postinjury neuropsychological and symptom presentation in an athlete-specific population.
Case control study.
Multicenter analysis of high school and college athletes.
A total of 78 athletes sustaining sports-related concussion were selected from a larger sample of 139 concussed athletes. ASSESSMENT OF PREDICTOR VARIABLES: On-field presence of disorientation, posttraumatic amnesia, retrograde amnesia, and loss of consciousness.
ImPACT, a computerized neuropsychological test battery, was administered pre-season and, on average, 2 days postinjury. Good postinjury presentation (n = 44) was defined as no measurable change, relative to baseline, in terms of both ImPACT memory and symptom composite scores. Poor presentation (n = 34) was defined as a 10-point increase in symptom reporting and 10-point decrease in memory functioning (exceeding the 80% confidence interval for measurement error on ImPACT). Athletes failing to meet good or poor selection criteria (n = 61) were not included in the analysis.
Odds ratios revealed that athletes demonstrating poor presentation at 2 days postinjury were over 10 times more likely (P < 0.001) to have exhibited retrograde amnesia following concussive injury when compared with athletes exhibiting good presentation. Similarly, athletes with poor presentation were over 4 times more likely (P < 0.013) to have exhibited posttraumatic amnesia and at least 5 minutes of mental status change. There were no differences between good and poor presentation groups in terms of on-field loss of consciousness.
The presence of amnesia, not loss of consciousness, appears predictive of symptom and neurocognitive deficits following concussion in athletes. Athletes presenting with on-field amnesia should undergo comprehensive and individualized assessment prior to returning to sport participation. Continued refinement of sports concussion grading scales is warranted in lieu of consistent findings that brief loss of consciousness is not predictive of concussion injury severity.
Clinical Journal of Sport Medicine 08/2003; 13(4):222-9. · 2.12 Impact Factor
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ABSTRACT: To evaluate symptoms and neurocognitive recovery patterns after sports-related concussion in high school and college athletes.
College athletes (n = 371) and high school athletes (n = 183) underwent baseline neuropsychological evaluation between 1997 and 2000. Individuals who received a concussion during athletic competition (n = 54) underwent serial neuropsychologic evaluation after injury and were compared with a noninjured within-sample control group (n = 38). Main outcome measures included structured interview, four memory measures, and Concussion Symptom Scale ratings. Baseline to postinjury change scores and multiple analyses of variance were used to compare recovery curves within and between groups.
High school athletes with concussion had prolonged memory dysfunction compared with college athletes with concussion. High school athletes performed significantly worse than age-matched control subjects at 7 days after injury (F = 2.90; P <.005). College athletes, despite having more severe in-season concussions, displayed commensurate performance with matched control subjects by day 3 after concussion. Self-report of postconcussion symptoms by student athletes was not predictive of poor performance on neuropsychologic testing.
Caution and systematic evaluation should be undertaken before returning athletes with concussion to competition. Sole reliance on the self-report of the athlete may be inadequate. Preliminary data may suggest a more protracted recovery from concussion in high school athletes.
Journal of Pediatrics 06/2003; 142(5):546-53. · 4.11 Impact Factor
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ABSTRACT: The relevance of headache to outcome after sports-related concussion is poorly understood.
High school athletes reporting headache approximately 1 week after injury will have significantly more other concussion symptoms and will perform more poorly on neuropsychological tests than athletes not experiencing headache.
Prospective cohort study.
Study participants included 109 high school athletes who had sustained concussion and who were divided into two groups: those reporting headache 7 days after injury and those reporting no headaches. The two groups were compared regarding on-field markers of concussion severity at the time of injury and symptoms and neurocognitive test results collected via ImPACT, a computerized neuropsychological test battery and postconcussion symptom scale, at a mean of 6.8 days after injury.
Athletes reporting posttraumatic headache demonstrated significantly worse performance on reaction time and memory ImPACT neurocognitive composite scores. These athletes also reported significantly more symptoms other than headache and were more likely to have demonstrated on-field anterograde amnesia.
Findings suggest that any degree of postconcussion headache in high school athletes 7 days after injury is likely associated with an incomplete recovery after concussion.
The American Journal of Sports Medicine 31(2):168-73. · 3.79 Impact Factor
