Recovery of Sensorimotor Function in Rats Following Acute Rapid Eye Movement Sleep Deprivation and Controlled Cortical Impact

Traumatic brain injury (TBI) resulting from bomb blasts and explosions is common among military personnel. The effects of Rapid Eye Movement (REM) sleep deprivation on the sensorimotor behavior and physiological mechanisms related to TBI are unknown. Thirty-two Long Evans rats were randomly assigned to REM sleep deprivation (RSD) with controlled cortical impact (CCI), social isolation (SI) with CCI, or normal housing (NH) with CCI or Sham. Two behavioral tasks [beam walk and bilateral tactile adhesive removal somatosensory (BTARS)] testing motor and sensory function were used to investigate recovery of function. Brain tissue was analyzed using Cresyl Violet stain (cell bodies), GFAP (astrocytes) and Fluoro Jade-B (dying cells) labeling. Results indicated that 24 hour RSD immediately prior to CCI impaired recovery of sensorimotor function when tested on the adhesive removal task. Recovery of sensorimotor function as a result of 24 hour RSD immediately prior to CCI was not significantly impaired when tested on the balance beam walk task. Results also indicated that sleep deprivation seemed to intensify inflammation, lesion size and neuron loss when compared to non sleep deprived animal

Recovery of Sensorimotor Function in Rats Following Acute Rapid Eye Movement Sleep Deprivation and Controlled Cortical Impact

Traumatic brain injury (TBI) resulting from bomb blasts and explosions is common among military personnel. The effects of Rapid Eye Movement (REM) sleep deprivation on the sensorimotor behavior and physiological mechanisms related to TBI are unknown. Thirty-two Long Evans rats were randomly assigned to REM sleep deprivation (RSD) with controlled cortical impact (CCI), social isolation (SI) with CCI, or normal housing (NH) with CCI or Sham. Two behavioral tasks [beam walk and bilateral tactile adhesive removal somatosensory (BTARS)] testing motor and sensory function were used to investigate recovery of function. Brain tissue was analyzed using Cresyl Violet stain (cell bodies), GFAP (astrocytes) and Fluoro Jade-B (dying cells) labeling. Results indicated that 24 hour RSD immediately prior to CCI impaired recovery of sensorimotor function when tested on the adhesive removal task. Recovery of sensorimotor function as a result of 24 hour RSD immediately prior to CCI was not significantly impaired when tested on the balance beam walk task. Results also indicated that sleep deprivation seemed to intensify inflammation, lesion size and neuron loss when compared to non sleep deprived animal

Microstructural abnormalities in deep and superficial white matter in youths with mild traumatic brain injury

BACKGROUND: Diffusion Tensor Imaging (DTI) studies of traumatic brain injury (TBI) have focused on alterations in microstructural features of deep white matter fibers (DWM), though post-mortem studies have demonstrated that injured axons are often observed at the gray-white matter interface where superficial white matter fibers (SWM) mediate local connectivity. OBJECTIVES: To examine microstructural alterations in SWM and DWM in youths with a history of mild TBI and examine the relationship between white matter alterations and attention. METHODS: Using DTIDWM fractional anisotropy (FA) and SWM FA in youths with mild TBI (TBI, n=63) were compared to typically developing and psychopathology matched control groups (n=63 each). Following tract-based spatial statistics, SWM FA was assessed by applying a probabilistic tractography derived SWM mask, and DWM FA was captured with a white matter fiber tract mask. Voxel-wise z-score calculations were used to derive a count of voxels with abnormally high and low FA for each participant. Analyses examined DWM and SWM FA differences between TBI and control groups, the relationship between attention and DWM and SWM FA and the relative susceptibility of SWM compared to DWM FA to alterations associated with mild TBI. RESULTS: Case-based comparisons revealed more voxels with low FA and fewer voxels with high FA in SWM in youths with mild TBI compared to both control groups. Equivalent comparisons in DWM revealed a similar pattern of results, however, no group differences for low FA in DWM were found between mild TBI and the control group with matched psychopathology. Slower processing speed on the attention task was correlated with the number of voxels with low FA in SWM in youths with mild TBI. CONCLUSIONS: Within a sample of youths with a history of mild TBI, this study identified abnormalities in SWM microstructure associated with processing speed. The majority of DTI studies of TBI have focused on long-range DWM fiber tracts, often overlooking the SWM fiber type

Adolescent athletes with learning disability display atypical maturational trajectories on concussion baseline testing : Implications based on a Finnish sample

Previous research has reported lower cognitive test scores on baseline testing in athletes reporting multiple previous concussions or a history of learning disability (LD). Age also has an important influence on cognitive performance. While these factors have been considered individually in previous studies, the present study is the first to explore the interaction of age, self-reported LD, and history of concussion on baseline Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT (R)) in a nationwide study of adolescent athletes. ImPACT (R) was administered to 1823 Finnish male ice hockey players (aged 12-21 years old) prior to the 2015-2016 or 2016-2017 playing seasons. Linear regressions and simple slopes analyses were used for clarifying the impact of LD and previous concussion history on maturational trajectories. In comparison to typically developing athletes, athletes with LD had lower neurocognitive scores in all composites and differing maturational trajectory in verbal memory and visual motor speed. The number of previous concussions did not impair neurocognitive performance at baseline assessment. Application of standard age-based norms to adolescent athletes with a history of LD has the potential to negatively skew clinical decision-making. Separate reference values for LD athletes are warranted due to their unique developmental cognitive trajectories. The reference values for the Finnish participants in this study are presented.Peer reviewe

Theta-Band Functional Connectivity and Single-Trial Cognitive Control in Sports-Related Concussion: Demonstration of Proof-of-Concept for a Potential Biomarker of Concussion

Objectives: This report examined theta-band neurodynamics for potential biomarkers of brain health in athletes with concussion. Methods: Participants included college-age contact/collision athletes with (N=24) and without a history of concussion (N=16) in Study 1. Study 2 (N=10) examined changes over time in contact/collision athletes. There were two primary dependent variables: (1) theta-band phase-synchronization (e.g., functional connectivity) between medial and right-lateral electrodes; and (2) the within-subject correlation between synchronization strength on error trials and post-error reaction time (i.e., operationalization of cognitive control). Results: Head injury history was inversely related with medial-lateral connectivity. Head injury was also related to declines in a neurobehavioral measure of cognitive control (i.e., the single-trial relationship between connectivity and post-error slowing). Conclusions: Results align with a theory of connectivity-mediated cognitive control. Mild injuries undetectable by behavioral measures may still be apparent on direct measures of neural functioning. This report demonstrates that connectivity and cognitive control measures may be useful for tracking recovery from concussion. Theoretically relevant neuroscientific findings in healthy adults may have applications in patient populations, especially with regard to monitoring brain health. (JINS 2019, 25, 314-323)National Collegiate Athletics Association (NCAA); Graduate and Professional Student Council of the University of ArizonaThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Akuuttia sairaalahoitoa vaatineiden aivovammapotilaiden hoitopolku

Tutkielmassani perehdyn sairaalahoitoa vaatineiden aivovammapotilaiden hoitopolkuun suomalaisessa terveydenhuoltojärjestelmässä. Asiaa käsitellään sekä potilaan subjektiivisten kokemusten että hoitokäytäntöjen toimivuuden pohjalta. Tarkoituksena on tuoda esiin aivovammapotilaiden hoitoon osallistuvien tahojen moninaisuutta sekä pohtia esimerkiksi sitä, olisiko hoitopolkujen yhtenäistämisestä hyötyä hoidon jatkuvuuden sekä potilaiden tyytyväisyyden kannalta. Tutkielma toteutettiin havainnoivana seurantatutkimuksena. Aineisto kerättiin Turun ylipistollisen keskussairaalan päivystyspoliklinikalle aivovamman vuoksi tulleista potilaista. Potilaat rekrytoitiin mukaan tutkimukseen kesäkuun 2015 ja elokuun 2017 välillä, ja tämän jälkeen heidän hoitopolkuaan terveydenhuoltojärjestelmässä seurattiin puolen vuoden ajan. Hoitopolusta kerättiin tietoa potilasasiakirjamerkinnöistä sekä potilaiden oman raportoinnin pohjalta. Subjektiivisia kokemuksia kartoitettiin kyselylomakkeen muodossa. Hoitopolkua käsittelevä tieto on kerätty yhteensä 91 henkilöstä ja hoitotyytyväisyyttä käsittelevä tieto 77 henkilöltä. Tutkielman perusteella voidaan aivovammapotilaiden hoitopolussa huomata paljon yhtäläisyyksiä. Silti osa potilaista on kokenut hoidon jatkuvuuden ongelmalliseksi ja myös objektiivisesti tarkasteltuna tiedon siirtyminen eri hoitopaikkojen välillä on osittain puutteellista. Tämän perusteella hoitokäytäntöjen yhtenäistäminen voisi lisätä sekä hoidon laatua että potilaiden tyytyväisyyttä hoitoon. Kaiken kaikkiaan kuitenkin aivovammapotilaat tässä aineistossa olivat subjektiivisesti keskimäärin varsin tyytyväisiä hoitopolkuunsa sekä kokivat, että heillä oli mahdollisuuksia vaikuttaa esimerkiksi hoidon suunniteluun

Behavioral Deficits and Axonal Injury Persistence after Rotational Head Injury Are Direction Dependent

Pigs continue to grow in importance as a tool in neuroscience. However, behavioral tests that have been validated in the rodent model do not translate well to pigs because of their very different responses to behavioral stimuli. We refined metrics for assessing porcine open field behavior to detect a wide spectrum of clinically relevant behaviors in the piglet post-traumatic brain injury (TBI). Female neonatal piglets underwent a rapid non-impact head rotation in the sagittal plane (n=8 evaluable) or were instrumented shams (n=7 evaluable). Open field testing was conducted 1 day prior to injury (day −1) in order to establish an individual baseline for analysis, and at days +1 and +4 after injury. Animals were then killed on day +6 after injury for neuropathological assessment of axonal injury. Injured piglets were less interested in interacting with environmental stimuli and had a lower activity level than did shams. These data were compared with previously published data for axial rotational injuries in neonatal piglets. Acute behavioral outcomes post-TBI showed a dependence on the rotational plane of the brain injury, with animals with sagittal injuries demonstrating a greater level of inactivity and less random usage of the open field space than those with axial injuries. The persistence of axonal injury is also dependent on the rotational plane, with sagittal rotations causing more prolonged injuries than axial rotations. These results are consistent with animal studies, finite element models, and studies of concussions in football, which have all demonstrated differences in injury severity depending upon the direction of head impact rotation

A Combined Therapeutic Regimen of Buspirone and Environmental Enrichment is more Efficacrious than Either Alone in Enhancing Spatial Learning in Brain-Injured Rats

Abstract Buspirone, a 5-HT1A receptor agonist, and environmental enrichment (EE) enhance cognition and reduce histopathology after traumatic brain injury (TBI) in adult rats, but have not been fully evaluated after pediatric TBI, which is the leading cause of death in children. Hence, the aims of this study were to assess the efficacy of buspirone alone (Experiment 1) and in combination with EE (Experiment 2) in TBI postnatal day-17 male rats. The hypothesis was that both therapies would confer cognitive and histological benefits when provided singly, but their combination would be more efficacious. Anesthetized rats received a cortical impact or sham injury and then were randomly assigned to receive intraperitoneal injections ofbuspirone (0.08 mg/kg, 0.1 mg/kg, and 0.3 mg/kg) or saline vehicle (1.0 mL/kg) 24 h after surgery and once daily for 16 days (Experiment 1). Spatial learning and memory were assessed using the Morris water maze (MWM) on post-operative days 11-16, and cortical lesion volume was quantified on day 17. Sham controls for each condition were significantly better than all TBI groups. In the TBI groups, buspirone (0.1 mg/kg) enhanced MWM performance versus vehicle and buspirone (0.08 mg/kg and 0.3 mg/kg) (p\u3c0.05) and reduced lesion volume relative to vehicle (p=0.038). In Experiment 2, buspirone (0.1 mg/kg) or vehicle was combined with EE after TBI, and the data were compared to the standard (STD)-housed groups from Experiment 1. EE lead to a significant enhancement of spatial learning and a reduction in lesion size versus STD. Moreover, the combined treatment group (buspirone+EE) performed markedly better than the buspirone+STD and vehicle+EE groups, which suggests an additive effect and supports the hypothesis. The data replicate previous studies assessing these therapies in adult rats. These novel findings may have important rehabilitation-relevant implications for clinical pediatric TBI