Prediction of winning amateur boxers using pretournament reaction times.

AIM: Boxing requires agility and manual dexterity, which is associated with fast reflexes and reaction time. This study evaluated the relation between reaction times on cognitive tasks and competition outcomes in boxers. METHODS: The design was a prospective cohort study. Participants were collegiate amateur boxers who won at least one bout in a single elimination tournament. Optimal pre-participation performance using a computerized cognitive assessment tool (CCAT, Axon Sports) and no significant deterioration in cognitive performance within 24 hours post-bout was required to compete in future bouts. Winners were assumed to be motivated to perform optimally on testing. Performance on speed and accuracy measures were compared in winning and non-winning boxers. Pre-competition minutes of sparring and tournament seedings were recorded. RESULTS: There were 96 eligible boxers who won at least one of 160 bouts. The mean age was 21.3 (SD 1.9) years (range 18.5-29.7). A significant improvement in mean reaction times as a function of advancement in the boxing tournament was observed. The 18 winning boxers who advanced to the finals had significantly faster mean reaction times at the baseline assessment before the competition began (speed composite z-score F(1,94)=4.14, P<0.05, effect size 0.54). Winners also had more sparring experience (Mann-Whitney U=302.5, P<0.001) and higher pre-competition rankings (Mann-Whitney U=288.5, P<0.001). CONCLUSION: In highly motivated amateur boxers, finalists performed significantly faster than those who failed to reach the finals on measures of pre-competition reaction time. These findings suggest that winners of boxing tournaments might be predicted using pre-competition measures of processing speed.

A prospective controlled study of cognitive function during an amateur boxing tournament.

BACKGROUND: Few studies have reported acute postbout cognitive function in amateur boxers, and none have documented the effects of repeated boxing bouts within a short time frame. OBJECTIVE: To determine whether participation in a 7-day amateur boxing tournament is associated with acute deterioration in cognitive test performance. METHODS: A prospective study was done of 82 collegiate amateur boxers participating in a 7-day single elimination tournament and a group of 30 matched nonboxing control participants. No participants had a history of recent concussion or past history of brain injury. For boxers, cognitive assessment using a computerized test battery was performed before the tournament and within 2 hours of completing each bout. Tests of simple and choice reaction time, working memory, and learning were administered. Analysis of variance was conducted to compare the serial performance of control participants with that of boxers participating in one, two, and three bouts. RESULTS: The 82 boxers fought 159 times. Cognitive testing was performed after 142 of these bouts. On simple reaction time, choice reaction time, and working memory tasks, the serial performance of boxers participating in three bouts (n = 22) was equivalent to that of boxers participating in two bouts (n = 22) and one bout (n = 32) and to nonboxing control participants (n = 30). An improvement in performance was observed on the learning task in boxers participating in three bouts. Boxers whose bout was stopped by the referee (n = 7) displayed significant slowing in simple and choice reaction time. CONCLUSIONS: With the exception of boxers whose contest is stopped by the referee, amateur boxers participating in multiple bouts during a 7-day tournament display no evidence of cognitive dysfunction in the immediate postbout period.

Human "memories" can be evoked by stimulation of the lateral temporal cortex after ipsilateral medial temporal lobe resection.

A patient with medically intractable seizures and mesial temporal sclerosis underwent a left anterior temporal lobectomy and amygdalohippocampectomy. After 4 months, his seizures recurred and a left temporal, subdural grid of electrodes was placed to localise his seizure focus. Stimulation through the grid evoked four distinct "memories", or experiential phenomena, despite absence of the ipsilateral medial temporal lobe. To our knowledge, this is the first documented case of experiential phenomena evoked by cortical stimulation in the absence of the ipsilateral medial temporal lobe.

Reversible posterior leukoencephalopathy occurring during resection of a posterior fossa tumor: case report and review of the literature.

OBJECTIVE AND IMPORTANCE: Our goal was to present a clinically and radiographically documented case of reversible posterior leukoencephalopathy (RPL) that occurred during resection of a posterior fossa tumor. Although RPL has been previously described in multiple nonsurgical settings, we hope that this case description makes RPL more clinically and radiographically recognizable to neurosurgeons. CLINICAL PRESENTATION: RPL is the clinical syndrome of headaches, altered mental status, seizures, and visual loss, with radiographic findings of reversible parieto-occipital changes on cerebral computed tomographic and magnetic resonance imaging scans. It has been previously reported in the settings of malignant hypertension, renal disease, eclampsia, and immunosuppression. To our knowledge, the patient presented represents the first clinically and radiographically documented case of RPL occurring during resection of a posterior fossa tumor. The patient intraoperatively exhibited wide fluctuations in blood pressure and awoke with clinical and radiographic findings consistent with RPL. INTERVENTION: Aggressive intraoperative and postoperative management of the patient's blood pressure, supportive intensive care, rehabilitation, and close radiographic follow-up were performed. CONCLUSION: RPL can occur as a result of intraoperative variations in blood pressure, even among young, previously healthy individuals. With the aforementioned interventions, the patient experienced significant clinical and radiographic recovery.

Dynamic nature of cavernous malformations: a prospective magnetic resonance imaging study with volumetric analysis.

OBJECT: Although cavernous malformations (CMs) are not detected in angiographic studies, they have a characteristic appearance on magnetic resonance (MR) images. A number of reports published in the last decade have focused on the behavior of these lesions within the clinical environment. However, little has been published about the evolution of CMs over time, as observed in imaging studies. To understand imaging-documented changes in CMs over time, we analyzed MR images of 114 cavernous malformations in 68 patients who were followed prospectively. METHODS: For each CM the location, volume, and MR imaging signal characteristics were recorded. Volume data were available for 107 lesions from initial images. The mean volume of these 107 CMs was 2779 mm3. The lesions ranged in size from 0.5 to 46,533 mm3 (46.5 cm3). Volume data from a second set of images were available for 76 CMs (mean interval from first imaging session 26 months), and from a third set of images for 24 lesions (mean interval from second imaging session 18 months). Over the first follow-up interval, the mean volume change was -991 mm3 (a decrease of approximately 1 cm3) and over the second interval the mean volume change was -642 mm3. Although these mean volume changes appear modest, volume changes in single lesions during follow-up intervals were more dramatic, with decreases as large as 45,629 mm3 (45.6 cm3) and increases as large as 6,074 mm3 (6 cm3). Serial examinations of the MR imaging signal characteristics of these CMs demonstrate a trend for maturation of blood products from a subacute, to a mixed, and finally to a chronic appearance. Three lesions appeared de novo during the follow-up period. CONCLUSIONS: On the basis of their analysis, the authors conclude that CMs exhibit a range of dynamic behaviors including enlargement, regression, and de novo formation, as well as progression through a series of characteristic MR imaging appearances.

Serum uric acid and risk of coronary heart disease: Atherosclerosis Risk in Communities (ARIC) Study.

PURPOSE: Approximately half of previous studies on serum uric acid have reported it to be an independent risk factor for coronary heart disease (CHD). We tested this hypothesis in the Atherosclerosis Risk in Communities (ARIC) Study. METHODS: A total of 13,504 healthy middle-aged men and women were followed prospectively for up to eight years. We identified 128 fatal and nonfatal CHD events in women and 264 in men. RESULTS: The age-, race-, and ARIC field center-adjusted relative risk of CHD for sex-specific quartiles of serum uric acid were 1.0, 1.39, 1.08, and 2.35 in women (p for trend = 0.009) and 1.0, 1.03, 0.89, and 1.21 in men (p for trend = 0.44), respectively. However, serum uric acid was correlated positively with many risk factors, and after multivariable adjustment, there was little evidence of an association of uric acid with CHD in either sex. CONCLUSIONS: Our results are not consistent with serum uric acid being an independent risk factor for CHD.

Dopamine genes and ADHD.

Family, twin, and adoption studies have documented a strong genetic basis for ADHD/HKD, but these studies do not identify specific genes linked to the disorder. Molecular genetic studies can identify allelic variations of specific genes that are functionally associated with ADHD/HKD, and dopamine genes have been the initial candidates based on the site of action of the stimulants drugs, which for a half century have provided the primary pharmacological treatment for ADHD/HKD. Two candidate dopamine genes have been investigated and reported to be associated with ADHD/HKD: the dopamine transporter (DAT1) gene [Cook et al., American Journal of Human Genetics 1995;56:993-998, Gill et al., Molecular Psychiatry 1997;2:311-313] and the dopamine receptor D4 (DRD4) gene [LaHoste et al., Molecular Psychiatry 1996;1:121-124: Smalley et al., 1998;3:427-430; Swanson et al., Molecular Psychiatry 1998;3:38-41]. Speculative hypotheses [Swanson and Castellanos, NIH Consensus Development Conference: Diagnosis and Treatment of Attention Deficit Hyperactivity Disorder, November 1998. p. 37-42] have suggested that specific alleles of these dopamine genes may alter dopamine transmission in the neural networks implicated in ADHD/HKD (e.g. that the 10-repeat allele of the DAT1 gene may be associated with hyperactive re-uptake of dopamine or that the 7-repeat allele of the DRD4 gene may be associated with a subsensitive postsynaptic receptor). These and other variants of the dopamine hypothesis of ADHD will be discussed.

The natural history of cavernous malformations.

This article reviews general information about cavernous malformations, including histology, radiology, epidemiology, and symptomatology. Rates of hemorrhage as reported in the literature are presented. Familial cavernous malformations and their genetic basis are discussed. Finally, the variations in the biological behavior of cavernous malformations in different regions of the central nervous system are discussed and outcomes are assessed.

Distant entry pneumothorax in a competitive fencer.

An elite level fencer sustained a penetrating wound to the upper arm after his opponent's blade broke. Standard care for a deep puncture wound was given but it was some time before the athlete presented symptoms of a pneumothorax, which was confirmed by radiograph. Although resolution of this case was unremarkable, the possibility of penetrating thoracic injury, even when the point of entry is well outside the thorax and the athlete is not immediately symptomatic, should be born in mind by medical personnel working with fencers.

Portal venous thrombosis in a backpacker: the role of exercise.

Effort thrombosis usually afflicts an extremity and is caused by compression. This case report, in contrast, involves superior mesenteric and left portal vein septic thrombosis in a backpacker following prolonged hiking and abdominal straining. The condition may have been caused by localized splanchnic venous ischemia, erosion of the bowel-blood barrier, and release of bacterial endotoxin in this dehydrated and detrained athlete. Diagnosis of this disorder is aided by noting characteristic abdominal pain, fever, nausea, and vomiting, as well as by imaging with MRI, CT, or duplex ultrasonography. Antibiotics and anticoagulants are key to treatment.

Surgical obliteration for vein of Galen malformation: a case report.

BACKGROUND: Vein of Galen aneurysm is a relatively rare vascular malformation, often resulting in high morbidity or mortality. Outcome is particularly poor in the neonatal population. METHODS: We report staged surgical treatment of a vein of Galen aneurysm in a neonate who presented in congestive heart failure. RESULTS: Cerebral angiography 6 months following staged surgical treatment revealed complete obliteration of the aneurysm. The patient tolerated surgery well, and at 6 years of age is free of neurologic or cardiovascular impairment. CONCLUSIONS: While the endovascular approach is the procedure of first choice, aggressive medical management followed by staged surgical clipping of aneurysm feeders produced excellent results in this case of neonatal vein of Galen aneurysm. Staged surgical obliteration of arterial feeders should be considered as a therapy when endovascular methods are unsuccessful in safely curing these difficult vascular lesions.