Total Number Of Bouts Research Articles

The aftermath of boxing: Longitudinal changes of cerebral retention patterns of 18F‐florzolotau (18F‐APN‐1607) in the former professional boxers

AbstractBackgroundChronic traumatic encephalopathy (CTE), formerly known as “boxer’s encephalopathy” is a neurodegenerative disease associated with mild‐repetitive TBI. CTE is characterized by the deposition of hyperphosphorylated tau as neurofibrillary tangles around small blood vessels of the cortex, typically at the sulcal depths. Although tau PET studies on American football players reported findings consistent with neuropathological changes identified by postmortem brains, there are no reports of tau PET studies in boxers, and longitudinal changes of tau depositions following boxing remains unknown. The present study was aimed to characterize cerebral retention patterns of 18F‐florzolotau (18F‐APN‐1607) in the former professional boxers.MethodTwenty‐nine former boxers (43.4 ± 10.3 years) and 27 age‐matched healthy control (HC) subjects underwent PET scans with 18F‐florzolotau and 11C‐PiB. Eleven former boxers underwent a second tau PET scan (average interval: 874days). Standard uptake value ratio (SUVR) with the optimized reference tissue was calculated. Regions of interest were defined on brain regions of the gray matter (GM), white matter (WM) and the gray‐white matter boundary (GWB). Association of regional SUVR values with neurocognitive symptoms and various indexes related boxing was investigated.ResultOne boxer was [11C]PiB positive. Former boxers showed higher 18F‐florzolotau retentions than HC subjects in the bilateral frontal GM, right parietal GM, bilateral frontal WM, right parietal WM (P < 0.001). There was a significant correlation between SUVR values in the whole GM and the total number of bouts (p = 0.07,r = 0.40). Subtyping using z‐score heatmap with predetermined criteria revealed heterogeneity in 18F‐florzolotau retention patterns in boxers. Of the 29 boxers, (1) 10 showed increased retention of 18F‐florzolotau in GM (GM dominant), (2) 4 showed increased accumulation mainly in WM (WM dominant), (3) 5 showed increased accumulation in GWB (GWB dominant), and (4) 10 showed no significant increased accumulation in the brain (No tau). These types vary in longitudinal changes of 18F‐florzolotau retention patterns, as well as in clinical features.ConclusionThe present study not only supports pathological heterogeneity of late‐sequalae of professional boxing, but also suggests utility of 18F‐florzolotau PET in detection of late‐life neurodegenerative diseases following mild‐repetitive TBI.

Longitudinal changes in physical activity accumulation patterns during 1-year follow-up in stroke survivors

Purpose Few studies have reported changes in the accumulation patterns of physical activity over a year after stroke. This study characterized the longitudinal changes in physical activity levels and their accumulation patterns for a 1-year follow-up period in stroke survivors. Materials and methods In this single-center, prospective, longitudinal observational study, 47 stroke survivors were assessed at rehabilitation discharge and at 6 and 12 months post-discharge. Physical activity was evaluated, and measures included the number of steps, walking duration, total number of bouts per day, and intensity (light, moderate-to-vigorous) and spread (short, medium, and long bouts). Results There were no significant main or interaction effects of time on any physical activity variables. Light physical activity accounted for 90% of all walking bouts and 70% of walking duration. Regarding moderate-to-vigorous physical activity (MVPA), 85% of walking bouts and 35% of walking duration were accumulated in short and medium bouts. The number of long-bout MVPA was three per day. Conclusions Physical activity levels and accumulation patterns were highly stable throughout the 12-month follow-up period. Accumulating light physical activity and intermittent MVPA is important for maintaining physical activity levels in stroke survivors. These findings will promote a better understanding of disability and rehabilitation practice. IMPLICATIONS FOR REHABILITATION Physical activity levels and accumulation patterns were highly stable throughout the 12-month follow-up period. The accumulation of moderate-to-vigorous physical activity in long bouts might be challenging for stroke survivors. Accumulating light physical activity and intermittent moderate-to-vigorous physical activity may be acceptable for stroke survivors.

Walking activity in community-dwelling stroke survivors within 1 month after discharge from a rehabilitation setting

Objective: To characterize the pattern of activity accumulation in stroke survivors.Method: Nineteen stroke patients and 19 age–sex-matched healthy adults participated. Step counts were measured using a step activity monitor for 3 d. The steps per day, bouts per day, walking time per day, average steps per bout, and average walking time per bout were calculated in each walking-distance category (short, medium, and long-distance bout) and in total.Results: The total steps per day were 8446 and 11,749 steps in stroke survivors and control participants, respectively. The total steps per day and the total bouts per day for the stroke group were both significantly lower compared with the control group. Significant group differences were found in only the medium-distance range. No significant differences were found in average steps per bout.Conclusion: Fewer number of bouts is a characteristic pattern of walking activity in stroke survivors. In particular, a low number of medium-distance bouts in stroke survivors results in a low number of daily steps when compared with healthy adults. To facilitate physical activity in stroke survivors, not only the total number of bouts per day but the number of bouts of varying lengths must be considered. Implications for rehabilitationFewer number of bouts is a characteristic pattern of walking activity in stroke survivors.Low number of bouts, especially medium-distance bouts, in stroke survivors, results in low number of daily steps when compared with healthy adults.The number of long-distance bouts is important for increasing total daily steps after stroke with mild disability.To facilitate physical activity in stroke survivors, not only the total number of bouts per day but the number of bouts of varying lengths must be considered.

Obstructive Sleep Apnea Negatively Impacts Objectively Measured Physical Activity

Obstructive sleep apnea (OSA) is a disorder that results daytime sleepiness and fatigue. Additionally, OSA increases the risk for cardiovascular disease and diabetes, which is exacerbated by sedentary behavior. Obesity and OSA are frequent co-morbid conditions, so the impact of OSA, independent of obesity, on physical activity (PA) is not clear. PURPOSE: To examine the effect of OSA on objectively measured PA via accelerometer. METHODS: Overweight-to-obese individuals were recruited and screened for the presence of OSA via portable diagnostic device and divided into an OSA group [n = 35; Age = 45.2 ± 12.0; body mass index (BMI) = 33.0 ± 5.7 kg/m2] and a Control group (n = 24; Age = 35.0 ± 11.7; BMI = 30.5 ± 4.3 kg/m2). Daytime sleepiness was assessed with the Epworth Sleepiness Scale questionnaire. Body composition was assessed with dual-energy X-ray absorptiometry. Subjects wore an accelerometer for a minimum of 4 and maximum of 7 days, including at least 1 weekend day. RESULTS: The OSA group’s mean OSA severity (Apnea-Hypopnea Index = 20.4 ± 17.6) classifies as “moderate OSA”. There were no group differences in BMI, percent fat, or daytime sleepiness. Waist (106.4 ± 11.7 vs. 98.6 ± 9.1) and neck circumference (41.9 ± 3.3 vs. 38.8 ± 2.7) were higher in the OSA group. The OSA group was significantly older than the control group. Pearson correlation analysis showed that age was not related to any PA variable except for the total number of moderate or greater PA bouts (PA for > 10 consecutive minutes) and the average number of bouts per day. The OSA group had fewer steps (6409.0 ± 2317.6 vs. 7856.8 ± 2942.7, P = 0.04), moderate intensity minutes (29.9 ± 15.1 vs. 44.2 ± 25.4, P < 0.01), moderate-to-vigorous minutes (33.0 ± 3.0 vs. 46.0 ± 5.4, P = 0.03), total number of bouts (3.2 ± 3.4 vs. 5.9 ± 5.0, P = 0.02), and number of bouts per day (0.5 ± 0.5 vs. 1.0 ± 0.8, P = 0.01). When adjusted for age, the PA bout data was no longer significant. CONCLUSION: Individuals screened as likely possessing OSA were less physically active than individuals without OSA when measured through objective means. We found no group differences in daytime sleepiness, BMI or percent fat, suggesting other mechanisms than obesity and sleepiness for this difference.

Sampling frequency impacts measurement of walking activity after stroke

The purpose of this study was to examine the effect of sampling epoch on total time spent walking and number of walking bouts per day in persons with stroke. Ninety-eight persons with average age of 63.8 yr and average time poststroke of 43.6 mo participated. Participants wore a StepWatch Activity Monitor for 3 to 5 consecutive days. The number of strides taken was collected in consecutive 5 s epochs and down sampled into 10, 20, 30, and 60 s epochs. Total time walking and total number of walking bouts were determined for each day. Low activity days were defined as days below the 25th percentile of total steps per day and high activity days as days above the 75th percentile of total steps per day. Total time walking and total number of bouts were different for each sampling epoch (p < 0.001 for all). The 5 s sampling epoch resulted in calculation of ~40% of the walking time and ~6 times as many bouts as a 60 s sampling epoch. Differences were greater for low activity days (p < 0.001 for all). Sampling epoch affects daily step activity variables whose calculation depends on time, especially during low activity days. Sampling epoch must be carefully considered when designing studies aimed at understanding patterns of daily walking activity.

Chronic traumatic brain injury associated with boxing.

Chronic traumatic brain injury (CTBI) associated with boxing occurs in approximately 20% of professional boxers. Risk factors associated with CTBI include increased exposure (i.e., duration of career, age of retirement, total number of bouts), poor performance, increased sparring, and apolipoprotein (APOE) genotype. Clinically, boxers exhibiting CTBI will present with varying degrees of motor, cognitive, and/or behavioral impairments. The severe form of CTBI is referred to as dementia pugilistica. The diagnosis of CTBI is dependent upon documenting a progressive neurological condition that is consistent with the clinical symptomatology of CTBI attributable to brain trauma and unexplainable by an alternative pathophysiological process. Pathologically, CTBI shares many characteristics with Alzheimer's disease (i.e., neurofibrillary triangles, diffuse amyloid plaques, acetylcholine deficiency, and/or tau immunoreactivity). The mainstay of treatment of CTBI is prevention, however medications used in the treatment of Alzheimer's disease and/or parkinsonism may be utilized.

Sparring and Cognitive Function in Professional Boxers

A volunteer group of 42 professional boxers provided information about their careers and training practices and underwent neuropsychological testing. Performance on the neuropsychological tests was not associated with age, boxing record (wins, losses, or total number of bouts), length of career, or history of knockout or technical knockout. However, the amount of sparring the boxers did was inversely associated with their performance on several of the tests. Impairments revealed by the tests were in the areas of attention, concentration, and memory.

Prospective study of central nervous system function in amateur boxers in the United States.

Active amateur boxers from six US cities were studied in 1986-1990 to determine whether changes in central nervous system function over a 2-year interval (as evaluated by tests of perceptual/motor function, attention/concentration, psychomotor speed, memory, visuoconstructional ability, and mental control, measures of ataxia and brain-stem auditory evoked potentials, and electroencephalography) were associated with degree of participation in amateur boxing. A total of 484 participants were examined at baseline; 393 (81.2%) were examined 2 years later. At baseline, 22% of the participants had not yet competed in a bout; 9% had never competed in a bout by the second examination. Exposure was defined by number bouts, sparring-years, and sparring with a professional boxer. Very few statistically significant odds ratios were found between exposure and change in function. Significant tests of trend were found between the total number of bouts incurred before the baseline examination and changes in memory, visuoconstructional ability, and perceptual/motor ability. The significant trends for change in function in the latter two domains were primarily due to performance on the Block Design test, which was common to both test domains. No statistically significant associations were found between more recent bouts (after the baseline visit) and any functional domains, nor between bouts or sparring and any other outcome measures. The significant trends with past bouts, but not more recent bouts, may reflect the need for a long latency period before effects are manifest. Alternatively, given changes in safety practices, the observed association may be related to more severe exposure from bouts that occurred before 1986, when new safety measures were imposed.

The Ocular Complications of Boxing

In cooperation with the New York State Athletic Commission, 74 boxers applying for a new or yearly renewal license were sequentially referred over a 2-year period for a complete dilated ocular examination at the Sports Vision Institute of the Manhattan Eye, Ear and Throat Hospital. At least one ocular injury was found in 66% of boxers. Vision-threatening injuries, defined as significant damage to the angle, lens, macula, or peripheral retina occurred in 58% of boxers. Nineteen percent of boxers had angle abnormalities. Nineteen percent of boxers had pathologic cataracts, over 70% of these were posterior subcapsular. Six boxers had macular lesions. A total of 24% of boxers had retinal tears. Standardized photographs were used to distinguish pathologic cataracts from congenital opacities and pathologic retinal tears from atrophic holes. Attempts were made to identify risk factors in boxing that might be predictive for ocular injury. Variables included age, weight division, left- or right-handedness, total number of losses, and total number of bouts. Significant correlations were found between the total number of bouts and the total number of losses, and the presence of retinal tears. College varsity athletes were selected as controls. Significant differences were found between boxers and controls for the total number of injuries, total vision-threatening injuries, and the number of retinal tears. A series of recommendations are proposed to aide in the early detection and prevention of serious ocular injuries.

Neurological sequelae of boxing.

Blunt trauma to the head results in acceleration of the brain within the skull. This takes 2 forms: linear or translational acceleration which produces focal lesions, and rotational acceleration which results in 'sheering stresses' with stretching of nerves and bridging veins. Deceleration of the brain within the skull occurs when the head strikes a stationary object (e.g. floor, ring post). Cerebrovascular events are not infrequently encountered. The most common vascular sequalae is the subdural haematoma, which is also the most frequent cause of death in boxers. Epidural bleeds rare, and are generally due to deceleration of the brain. Subarachnoid bleeds have been rarely reported, but, like intraparenchymal haemorrhages, they do occur. Sudden flexion/extension of the neck is suggested as the mechanism of the occasional brainstem haemorrhage reported in boxing. Thrombosis of the internal carotid artery can occur secondary to direct blows to the neck or stretching of the contralateral carotid artery. The best known sequalae of boxing is traumatic encephalopathy--the 'punch drunk' syndrome. This is most common in second-rate and slugging type fighters. Severity correlates with the length of a boxer's career and total number of bouts, with an incidence of approximately 18%. Three stages of clinical deterioration are seen, the encephalopathy may be progressive or may remain clinically stable at any level. The first stage consists of affective disturbances with psychiatric symptoms being most marked. During the second stage an accentuation of the psychiatric symptoms occurs and signs/symptoms of Parkinsonism develop. The final stage consists of a decrease in general cognitive function together with pyramidal tract disease. Generally 2 to 3 years elapse between the first and final stages. Neuropathological studies reveal abnormalities of the septum pellucidum, scarring of the cerebellar and cerebral cortices, and loss of pyramidal neurons in the substantia nigra with neurofibrillary tangles in the absence of senile plaques. A 'groggy state' can occur in some fighters with confusion, impaired active attention and alteration of consciousness. During this period the boxer is at greater risk to suffer brain injury as defensive reflexes are frequently lost. Other neurological syndromes have been reported in addition to the 'groggy state'. These include a midbrain syndrome, headaches and cervical spinal injuries. Additionally, boxing appears to be a significant risk factor for the development of meningiomas.(ABSTRACT TRUNCATED AT 400 WORDS)