Head trauma in sports - clinical characteristics, epidemiology and biomarkers.

Traumatic brain injury (TBI) is clinically divided into a spectrum of severities, with mild TBI being the least severe form and a frequent occurrence in contact sports, such as ice hockey, American football, rugby, horse riding and boxing. Mild TBI is caused by blunt nonpenetrating head trauma that causes movement of the brain and stretching and tearing of axons, with diffuse axonal injury being a central pathogenic mechanism. Mild TBI is in principle synonymous with concussion; both have similar criteria in which the most important elements are acute alteration or loss of consciousness and/or post-traumatic amnesia following head trauma and no apparent brain changes on standard neuroimaging. Symptoms in mild TBI are highly variable and there are no validated imaging or fluid biomarkers to determine whether or not a patient with a normal computerized tomography scan of the brain has neuronal damage. Mild TBI typically resolves within a few weeks but 10-15% of concussion patients develop postconcussive syndrome. Repetitive mild TBI, which is frequent in contact sports, is a risk factor for a complicated recovery process. This overview paper discusses the relationships between repetitive head impacts in contact sports, mild TBI and chronic neurological symptoms. What are these conditions, how common are they, how are they linked and can they be objectified using imaging or fluid-based biomarkers? It gives an update on the current state of research on these questions with a specific focus on clinical characteristics, epidemiology and biomarkers.

Prevalence of Traumatic Findings on Routine MRI in a Large Cohort of Professional Fighters.

BACKGROUND AND PURPOSE: Previous studies investigating MR imaging abnormalities among fighters have had small sample sizes. This investigation assessed a large number of fighters using the same conventional sequences on the same scanner. MATERIALS AND METHODS: Conventional 3T MR imaging was used to assess 499 fighters (boxers, mixed martial artists, and martial artists) and 62 controls for nonspecific WM changes, cerebral microhemorrhage, cavum septum pellucidum, and cavum vergae. The lengths of the cavum septum pellucidum and cavum vergae and the ratio of cavum septum pellucidum to the septum pellucidum lengths were assessed. RESULTS: The prevalence of nonspecific WM changes was similar between groups. Fighters had a prevalence of cerebral microhemorrhage (4.2% versus 0% for controls, P = .152). Fighters had a higher prevalence of cavum septum pellucidum versus controls (53.1% versus 17.7%, P < .001) and cavum vergae versus controls (14.4% versus 0%, P < .001). The lengths of the cavum septum pellucidum plus the cavum vergae (P < .001), cavum septum pellucidum (P = .025), and cavum septum pellucidum to the septum pellucidum length ratio (P = .009) were higher in fighters than in controls. The number of fights slightly correlated with cavum septum pellucidum plus cavum vergae length (R = 0.306, P < .001) and cavum septum pellucidum length (R = 0.278, P < .001). When fighters were subdivided into boxers, mixed martial artists, and martial artists, results were similar to those in the whole-group analysis. CONCLUSIONS: This study assessed MR imaging findings in a large cohort demonstrating a significantly increased prevalence of cavum septum pellucidum among fighters. Although cerebral microhemorrhages were higher in fighters than in controls, this finding was not statistically significant, possibly partially due to underpowering of the study.

Diffusion measures indicate fight exposure-related damage to cerebral white matter in boxers and mixed martial arts fighters.

BACKGROUND AND PURPOSE: Traumatic brain injury is common in fighting athletes such as boxers, given the frequency of blows to the head. Because DTI is sensitive to microstructural changes in white matter, this technique is often used to investigate white matter integrity in patients with traumatic brain injury. We hypothesized that previous fight exposure would predict DTI abnormalities in fighting athletes after controlling for individual variation. MATERIALS AND METHODS: A total of 74 boxers and 81 mixed martial arts fighters were included in the analysis and scanned by use of DTI. Individual information and data on fight exposures, including number of fights and knockouts, were collected. A multiple hierarchical linear regression model was used in region-of-interest analysis to test the hypothesis that fight-related exposure could predict DTI values separately in boxers and mixed martial arts fighters. Age, weight, and years of education were controlled to ensure that these factors would not account for the hypothesized effects. RESULTS: We found that the number of knockouts among boxers predicted increased longitudinal diffusivity and transversal diffusivity in white matter and subcortical gray matter regions, including corpus callosum, isthmus cingulate, pericalcarine, precuneus, and amygdala, leading to increased mean diffusivity and decreased fractional anisotropy in the corresponding regions. The mixed martial arts fighters had increased transversal diffusivity in the posterior cingulate. The number of fights did not predict any DTI measures in either group. CONCLUSIONS: These findings suggest that the history of fight exposure in a fighter population can be used to predict microstructural brain damage.

Statins and cognitive function in the elderly: the Cardiovascular Health Study.

OBJECTIVE: To examine the association of statin drug use on cognitive and MRI change in older adults. METHODS: Participants in the Cardiovascular Health Study, a longitudinal study of people age 65 or older, were classified into three groups determined by whether they were taking statin drugs on a continuous basis, intermittently, or not at all. The untreated group was further divided into categories based on National Cholesterol Education Program recommendations for lipid-lowering treatment. Participants with prevalent or incident clinical TIA or stroke or with baseline Modified Mini-Mental State Examination (3MS) scores at or below 80 were excluded. Outcomes examined included rate of change on the 3MS over an average observational period of 7 years, along with changes in MRI white matter grade and measures of atrophy. RESULTS: Three thousand three hundred thirty-four participants had adequate data for analysis. At baseline, the untreated group in which lipid-lowering drug treatment was recommended were slightly older, less likely to be on estrogen replacement, and had higher serum cholesterol and lower 3MS scores than the statin-treated group. The rate of decline on the 3MS was 0.48 point/year less in those taking statins compared with the untreated group for which treatment was recommended (p = 0.069) and 0.49 point/year less in statin users compared with the group in which lipid-lowering treatment was not recommended (p = 0.009). This effect remained after controlling for serum cholesterol levels. One thousand seven hundred thirty participants with baseline 3MS scores of > 80 underwent cranial MRI scans on two occasions separated by 5 years. There was no significant difference in white matter grade change or atrophy measures between groups. CONCLUSION: Statin drug use was associated with a slight reduction in cognitive decline in an elderly population. This relationship could not be completely explained by the effect of statins on lowering of serum cholesterol.

Silent MRI infarcts and the risk of future stroke: the cardiovascular health study.

BACKGROUND: Silent infarcts are commonly discovered on cranial MRI in the elderly. OBJECTIVE: To examine the association between risk of stroke and presence of silent infarcts, alone and in combination with other stroke risk factors. METHODS: Participants (3,324) in the Cardiovascular Health Study (CHS) without a history of stroke underwent cranial MRI scans between 1992 and 1994. Silent infarcts were defined as focal lesions greater than 3 mm that were hyperintense on T2 images and, if subcortical, hypointense on T1 images. Incident strokes were identified and classified over an average follow-up of 4 years. The authors evaluated the risk of subsequent symptomatic stroke and how it was modified by other potential stroke risk factors among those with silent infarcts. RESULTS: Approximately 28% of CHS participants had evidence of silent infarcts (n = 923). The incidence of stroke was 18.7 per 1,000 person-years in those with silent infarcts (n = 67) compared with 9.5 per 1,000 person-years in the absence of silent infarcts. The adjusted relative risk of incident stroke increased with multiple (more than one) silent infarcts (hazard ratio 1.9 [1.2 to 2.8]). Higher values of diastolic and systolic blood pressure, common and internal carotid wall thickness, and the presence of atrial fibrillation were associated with an increased risk of strokes in those with silent infarcts (n = 53 strokes). CONCLUSION: The presence of silent cerebral infarcts on MRI is an independent predictor of the risk of symptomatic stroke over a 4-year follow- up in older individuals without a clinical history of stroke.

When your culture needs a makeover.

In 1994, the consumer products company Alberto-Culver North America faced flattened sales and the most difficult competitive environment of its history. President Carol Bernick knew that overcoming theses challenges would require a certain kind of corporate culture-but it wasn't the culture the company had. She changed that by focusing on four areas. First, Bernick made culture visible and elevated it to priority status, often by highlighting desired values and behaviors that already existed in pockets of the company. Her annual "state of the company" address stresses that people must be attuned to business realities and the drivers of success. Employees now develop statements of individual economic value describing their contributions to the company's profitability. The company's ten cultural imperatives are required knowledge for all. Second, Bernick and her executive team created the role of growth development leader (GDL). Each mentors about a dozen people. Her frequent meetings with GDLs make them effective agents of change upward and downward. The role is coveted because GDLs have real power to make change: every year they vote on the issues, large and small, that must be addressed by the business as a whole. Third, the company uses an employee survey to identify areas for improvement and to provide 360-degree feedback to GDLs and top management. And fourth, successes are celebrated constantly--through stock awards for the best GDLs, Business Builders Awards for great innovators, and many other, less formal means. Since 1994, the company has cut employee turnover in half, seen sales grow 83%, and watched pretax profits rise 336%--indicators of how cultural change is driving business results.

Frequency and predictors of stroke death in 5,888 participants in the Cardiovascular Health Study.

BACKGROUND: Few population-based studies have examined in detail issues of stroke-related deaths in elderly people. METHODS: Participants in the Cardiovascular Health Study (CHS) are 65 years of age or older, have had extensive baseline evaluations, and have been followed-up for fatal and nonfatal cardiovascular and cerebrovascular disease outcomes. Investigators adjudicated these outcomes and classified strokes by types and subtypes. RESULTS: Over 7 years, 1,310 (22.2%) of 5,888 participants died, and 455 (7.7%) experienced incident stroke. For the 5,888, stroke mortality was 3.2 per 1,000 person-years. For the 455, it was 36.1 per 1,000 person-years, with the most lethal type being hemorrhagic and the ischemic subtype being cardioembolic. After controlling for age and stroke type, the only other independent predictor of death after any stroke was poor performance on a timed walk measured before the incident stroke. Considering only ischemic stroke, the independent predictors of death were African American race and poor performance on timed walk. CONCLUSION: In CHS, death attributable to stroke is common. As in other studies, the most lethal stroke type was hemorrhagic, and ischemic stroke subtype, cardioembolic. Slow walking, possibly a measure of frailty, was associated with an increased risk of death of stroke. Finally, African Americans faced a greater risk of death than others after an ischemic stroke.

Lacunar infarcts defined by magnetic resonance imaging of 3660 elderly people: the Cardiovascular Health Study.

OBJECTIVE: To identify risk factors for and functional consequences of lacunar infarct in elderly people. METHODS: The Cardiovascular Health Study (CHS) is a longitudinal study of people 65 years or older, in which 3660 participants underwent cranial magnetic resonance imaging (MRI). Neuroradiologists read scans in a standard fashion without any clinical information. Lacunes were defined as subcortical areas consistent with infarcts measuring 3 to 20 mm. In cross-sectional analyses, clinical correlates were contrasted among groups defined by MRI findings. RESULTS: Of the 3660 subjects who underwent MRI, 2529 (69%) were free of infarcts of any kind and 841 (23%) had 1 or more lacunes without other types present, totaling 1270 lacunes. For most of these 841 subjects, their lacunes were single (66%) and silent (89%), namely without a history of transient ischemic attack or stroke. In multivariate analyses, factors independently associated with lacunes were increased age, diastolic blood pressure, creatinine, and pack-years of smoking (listed in descending order of strength of association; for all, P < .005), as well as maximum internal carotid artery stenosis of more than 50% (odds ratio [OR], 1.81; P < .005), male sex (OR, 0.74; P < .005), and history of diabetes at entrance into the study (OR, 1.33; P < .05). Models for subgroups of single, multiple, silent, and symptomatic lacunes differed only minimally. Those with silent lacunes had more cognitive, upper extremity, and lower extremity dysfunction not recognized as stroke than those whose MRIs were free of infarcts. CONCLUSIONS: In this group of older adults, lacunes defined by MRI are common and associated with factors that likely promote or reflect small-vessel disease. Silent lacunes are also associated with neurologic dysfunction.

The association of antihypertensive agents with MRI white matter findings and with Modified Mini-Mental State Examination in older adults.

OBJECTIVES: To examine the association of antihypertensive regimen with magnetic resonance imaging (MRI) white matter hyperintensity and with cognitive impairment in older adults. DESIGN: Cross-sectional study. SETTING: The Cardiovascular Health study, an observational prospective cohort study of risk factors for coronary heart disease and stroke in men and women 65 years of age and older. PARTICIPANTS: 1268 men and women with pharmacologically treated hypertension. MEASUREMENTS: Information on medication use, medical history, and health habits was collected at clinic examinations. Participants completed the Modified Mini-Mental State Examination (3MS) and underwent MRI examination. Without clinical information, study neuroradiologists assigned an overall grade of white matter signal intensity on MRI on a scale from 0 (no findings) to 9 (extensive findings). RESULTS: Adjusted mean white matter grade was higher for users of calcium channel blockers (2.59, P = .007) and users of loop diuretics (2.60, P = .015) than for users of beta blockers (2.12). The association was present for both dihydropyridine and non-dihydropyridine calcium channel blockers. Adjusted mean 3MS scores were lower for users of calcium channel blockers (89.6, P < .002), especially dihydropyridines, and users of loop diuretics (89.7, P < .006) than for users of beta blockers (92.3). No statistically significant association could be shown for users of other drug regimens, including thiazides and ACE inhibitors. CONCLUSION: In this study, users of antihypertensive regimens which included calcium channel blockers or loop diuretics had more severe white matter hyperintensity on MRI and worse performance on 3MS than users of beta blockers.

Dietary preference for sweet foods in patients with dementia.

Using a telephone survey, patients with probable Alzheimer's disease (n = 31) and vascular dementia (n = 14) were compared with elderly normal controls (n = 43) in preferences for different foods. Patients with Alzheimer's disease had a greater preference than normal controls for relatively high-fat, sweet foods and for high-sugar, low-fat foods, but did not significantly differ in preference for other foods, including those high in complex carbohydrates and protein. Vascular dementia patients showed a similar pattern, not significantly different from that for Alzheimer's patients. Results did not consistently support a hypothesis that increased sweet preference is a nonspecific form of disinhibited behavior related to declining mental status, nor was a hypothesis relating sweet preference to serotonin activity within the brain consistently supported. Results provide preliminary evidence that craving for sweet food may be a significant part of the clinical syndrome of dementia, but further research is needed to delineate the psychological and biological mechanisms accounting for it.

Propranolol for the control of disruptive behavior in senile dementia.

Six patients with senile dementia, exhibiting severe, disruptive behavior were effectively treated with propranolol in doses ranging from 80 mg per day to 560 mg per day. All six patients were given a trial of propranolol after conventional therapy had failed, and in all patients, the agitated behavior significantly improved. There were no adverse side effects requiring the discontinuation of the propranolol, and in all cases, the agitated behavior was controlled without inducing general sedation. Both the nursing home staff and the families were pleased with the therapeutic effects. Propranolol represents a possible alternative way of addressing the severe problem of agitated behavior in senile dementia patients.

L-dopa in uremic patients with the restless legs syndrome.

Restless legs syndrome (RLS) is a poorly understood, often distressing condition that is particularly prevalent among patients with chronic renal failure. A wide variety of medications have been used to treat RLS with variable results. In order to evaluate the efficacy of carbidopa/levodopa therapy, eight consecutive uremic patients with RLS on maintenance hemodialysis were treated with doses ranging from 25/100 to 25/250 twice daily. Six of eight patients obtained satisfactory relief which has continued for 3 months follow-up. Carbidopa-levodopa appears to be an effective opinion in management of RLS in patients with chronic rental failure.

Progressive multifocal leukoencephalopathy in a patient with acquired immune deficiency syndrome.

Progressive multifocal leukoencephalopathy (PML) occurred in a heterosexual Haitian man with acquired immune deficiency syndrome (AIDS). The patient initially had focal neurologic signs and nonenhancing lesions on a computed tomographic scan. Although PML is rare, it should be included in the differential diagnosis of opportunistic infections associated with AIDS. Brain biopsy is suggested in patients suspected of having PML who might benefit from antiviral therapy.