Children with epilepsy can experience significant cognitive dysfunction that can lead to academic underachievement. Traditionally believed to be primarily due to the effects of factors such as the chronicity of epilepsy, medication effects, or the location of the primary epileptogenic lesion;, recent evidence has indicated that disruption of cognition-specific distributed neural networks may play a significant role as well. Specifically, over the last decade, researchers have begun to characterize the mechanisms underlying disrupted cognitive substrates by evaluating neural network abnormalities observed during specific cognitive tasks, using task-based functional magnetic resonance imaging (fMRI). This targeted review assesses the current literature investigating the relationship between neural network abnormalities and cognitive deficits in pediatric epilepsy. The findings indicate that there are indeed neural network abnormalities associated with deficits in executive function, language, processing speed, and memory. Overall, cognitive dysfunction in pediatric epilepsy is associated with a decrease in neural network activation/deactivation as well as increased recruitment of brain regions not typically related to the specific cognitive task under investigation. The research to date has focused primarily on children with focal epilepsy syndromes with small sample sizes and differing research protocols. More extensive research in children with a wider representation of epilepsy syndromes (including generalized epilepsy syndromes) is necessary to fully understand these relationships and begin to identify underlying cognitive phenotypes that may account for the variability observed across children with epilepsy. Furthermore, more uniformity in fMRI protocols and neuropsychological tasks would be ideal to advance this literature.

This article focuses on irregular sleep-wake rhythm disorder (ISWRD) and its associations with several other comorbidities. Irregular sleep-wake rhythm disorder is a circadian disorder characterized by a lack of a clear sleep-wake pattern. The disorder has yet to be fully understood from pathophysiologic perspective. Treatments are available, but there is a need for development of novel interventions. The goal of this article is to focus on multiple aspects of ISWRD.

We investigated the existence of the "winner effect" (winning an aggressive encounter following previous victories) and an associated rise in testosterone (T) in the white-footed mouse (Peromyscus leucopus) which generally display low levels of aggression and territoriality. We compared the effect of previously winning three, two, one, or zero resident-intruder encounters on the likelihood of winning a subsequent aggressive encounter. Although 50% of males were removed during training because of peaceful encounters, the winner effect was weak and not significant. We hypothesize that territoriality/aggression may be associated with the strength of the winner effect and discuss whether the slight winner effect exhibited by P. leucopus may become significant when population densities increase and males become more territorial. There was also no associated change in T with winning; however, corticosterone (Cort) changed with experience as winners had low Cort levels compared to losers and controls. Furthermore, low Cort levels in winners were associated with quicker attack latencies. These results contrast with findings of a significant winner effect and increase in T in males of the highly territorial and aggressive California mouse (Peromyscus californicus) using an identical methodology. California mice also attacked their opponents at more caudal regions of the body compared to white-footed mice that attacked their opponents at more rostral regions of the body, possibly related to different levels/types of aggression expressed by the two species.

The 'winner effect' has been studied in a variety of species, but only rarely in mammals. We compared effects of winning three, two, one, or zero resident-intruder encounters on the likelihood of winning a subsequent aggressive encounter in the California mouse (Peromyscus californicus). During the training phase, we ensured that resident males won all encounters by staging contests with mildly sedated, smaller intruders. During the test phase, the resident male encountered an unfamiliar, more evenly matched intruder that had experience winning an encounter and was larger than the resident. Testosterone (T) plasma levels significantly increased after the final test when they had experienced two prior winning encounters, and the probability of winning a future encounter increased significantly after three prior wins independent of intrinsic fighting ability. We hypothesize a 'winner-challenge' effect in which increased T levels serve to reinforce the winner effect in male California mice.

The objective was to characterize cognitive deficits and postconcussive symptoms in a pediatric population with no concussion, a single concussion, and ≥2 concussions, using a cross-sectional design. Cognitive function and postconcussive symptoms were assessed in participants (age 10-20) with no concussion (n = 1118), single concussion (n = 368), and repeated (≥2) concussions (n = 252). Analyses were adjusted for age and gender. Individuals with ≥2 concussions exhibited more total postconcussive symptoms; more loss of consciousness, amnesia and confusion; more headaches; and poorer cognitive function compared to no concussion and single concussion. Postconcussive symptoms may play a modulatory role in cognitive dysfunction after repeated concussions as those with loss of consciousness, amnesia, confusion, or headaches exhibited worse verbal memory, visual memory, visual-motor processing, and poorer impulse control compared to those without these symptoms. This analysis demonstrates that repeated concussions is associated with poorer cognitive function and postconcussive symptoms compared to a single concussion.

There are notable gender differences in concussion as well as sleep. Sleep disturbance is a major symptom of post-concussive syndrome. The interplay between sleep disturbance, concussion, and gender has yet to be examined. The objective of this study was to determine whether sleep disturbance plays a role in the known gender differences associated with concussion.Males and females (ages 10-35 years) completed a pre-concussion and post-concussion evaluation. Levels of sleep disturbance were assessed at baseline (N = 1284), after first concussion (N = 432) and after repeated concussions (one or more concussions, N = 296). Sleep disturbance levels were also compared among males and females with headaches, mood changes, and cognitive dysfunction. Analyses included group comparisons and correlations of post-concussive symptoms and cognitive dysfunction, respectively. Data was adjusted for age.Compared to males, females reported higher levels of sleep disturbance after a single concussion; however, levels of sleep disturbance equalized after repeated concussions. Females with higher levels of sleep disturbance had more headaches and more mood changes requiring medical treatment, compared to males. In addition, sleep disturbance was more strongly correlated with cognitive dysfunction in females compared to males.Gender differences in concussion recovery after repeat concussions may be primarily due to a difference in sleep disturbance between the genders. This difference in sleep appears to moderate the levels of other post-concussive symptoms. This indicates that sleep disturbance should be closely monitored and treated in females after a concussion. Further studies are required to determine the underlying reasons for these gender differences.

The processes through which salient social experiences influence future behavior are not well understood. Winning fights, for example, can increase the odds of future victory, yet little is known about the internal mechanisms that underlie such winner effects. Here, we use the territorial California mouse (Peromyscus californicus) to investigate how the effects of postvictory testosterone (T) release and winning experience individually mediate positive changes in future winning ability and antagonistic behavior. Male mice were castrated and implanted with T capsules to maintain basal levels of this hormone. We found that males form a robust winner effect if they win three separate territorial disputes and experience a single T surge roughly 45 min after each encounter. Meanwhile, males exhibit only an intermediate winner effect if they either 1) acquire three previous wins but do not experience a change in postvictory T or 2) acquire no previous wins but experience three separate T pulses. The results indicate that the effect of postvictory T must be coupled with that of winning experience to trigger the maximum positive shift in winning ability, which highlights the importance of social context in the development of the winner effect. At the same time, however, postvictory T and winning experience are each capable of increasing future winning ability independently, and this finding suggests that these two factors drive plasticity in antagonistic behavior via distinct mechanistic channels. More broadly, our data offer insight into the possible ways in which various species might be able to adjust their behavioral repertoire in response to social interactions through mechanisms that are unlinked from the effects of gonadal steroid action.

Background

Studies have documented gender differences associated with concussion. The purpose of this study was to determine if these gender differences are also noted within a pediatric population.

Methods

This prospective study analyzed 1971 patients who had completed preconcussion and postconcussion neuropsychological testing within the Washington, DC, area.

Results

Our results showed that children and adolescents with concussion exhibit gender differences with respect to risk factors, recovery, and symptomatology. Females are more likely to present with a concussion (P < 0.001), experience more discomfort from a concussion (P < 0.001), and seek treatment for postconcussive headaches (P < 0.001). On the other hand, males are more likely to sustain a concussion from a contact sport (P < 0.001) and experience loss of consciousness, confusion, and amnesia with a concussion more frequently than females (P < 0.001). Postconcussive cognitive function also differs by gender. Both males and females exhibit a decline in cognitive testing compared with baseline (P < 0.001); however, visual memory (P = 0.02) is more affected in females than in males. These findings remain unchanged among pediatric patients aged ≥14 years; however, no gender differences were noted in individuals aged ≤13 years.

Conclusion

It is important for health care providers, schools, athletic trainers, and coaches to be aware of these gender differences associated with concussion in order to provide adequate surveillance and appropriate monitoring and support during the recovery period.

BACKGROUND: This study compared the efficacy of three different masks, nasal pillows, nasal masks and full face (oronasal) masks, during a single night of titration with continuous positive airway pressure (CPAP). METHODS: Fifty five subjects that included men (n=33) and women (n=22) were randomly assigned to one of three masks and underwent a routine titration with incremental CPAP applied through the different masks. RESULTS: CPAP applied through the nasal pillows and nasal mask was equally effective in treating mild, moderate, and severe sleep apnea. However, CPAP applied through the oronasal mask required a significantly higher pressure compared to nasal masks to treat moderately severe (2.8 cm of H(2)O ± 2.1 SD) and severe (6.0 cm of H(2)O ± 3.2 SD) obstructive sleep apnea. CONCLUSION: CPAP applied with either nasal mask was effective in treating mild, moderate, and severe sleep apnea. The oronasal mask required significantly higher pressures in subjects with moderate to severe disease. Therefore, when changing from a nasal to an oronasal mask, a repeat titration is required to ensure effective treatment of sleep apnea, especially in patients with moderate to severe disease.

Objectives: The relationship between repeated concussions and sleep disturbance is yet to be fully understood. The objective of this study was to examine the relationship between sleep disturbance, concussion duration, and repeated concussions by assessing postconcussive symptoms and cognition. Methods: Subjects (ages 13-33 years) underwent postconcussion cognitive function evaluation and reported postconcussion symptoms including severity of disturbed sleep (drowsiness, trouble falling asleep, sleeping more than usual, and sleeping less than usual), mood disturbance (sadness, irritability, nervousness, and emotional lability), and headache. Data on cognitive function and concussive symptoms were collected for 430 subjects after first concussion, 192 subjects after second concussion, and 118 subjects after three or more concussions. A subset of subjects (119) were monitored longitudinally to assess concussion duration. Analyses included group comparisons, regression, and correlation; data were adjusted for age and gender. Results: Sleep disturbance differed significantly by group (mean[SEM]: 1st concussion = 2.56[0.2]; 2nd concussion = 3.65[0.34]; 3+ concussions = 4.32[0.43]). Concussion history predicts concussion duration (R² = 0.20, F[1,116] = 27.33, p < 0.001). Furthermore, trouble falling asleep (β = 0.15) and sleeping less than usual (β = 0.15) predicted concussion duration (R² = 0.062, F[1,116] = 3.15, p = 0.047). Reported sleep disturbance after repeated concussions was higher in patients with higher headache (F[2,732] = 3.15, p = 0.043) and mood disturbance (F[2,733] = 3.35, p = 0.036) severity. In addition, after repeated concussions, the positive correlation between sleep disturbance and cognitive dysfunction strengthened. Conclusions: History of repeated concussion is associated with longer concussion duration and higher reported sleep disturbance. Furthermore, those with sleep disturbance after repeated concussion exhibit more severe headaches, mood disturbance, and cognitive dysfunction.Abbreviations: ImPACT: Immediate Postconcussion Assessment and Cognitive Assessment (ImPACT); this is a computer-based test that assesses an individual's cognitive function and cumulatively documents current concussion symptoms. PCSS: Post Concussion Symptom Scale; this scale assesses the severity of concussion symptoms. SPSS: Statistical Package for Social Sciences. This is a statistical software package.