Browsing by Author "Barlow, Karen"
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Item Open Access Alteration in, and recovery of, cerebral activation during a working memory task following pediatric mild traumatic brain injury(2018-01-12) Khetani, Aneesh; Barlow, Karen; Bray, Signe; Yeates, Keith; Lebel, CatherineIntroduction: Mild traumatic brain injuries (mTBIs) are most common in children and adolescents. For some, symptoms can persist for an extended duration, especially in the cognitive and working memory domains. The neurological changes that underlie these differences in children with persistent symptoms, and their recovery over time, have not been characterized at distinct time points. Objectives: To determine how cortical activation during a working memory task is different in children with persistent symptoms, relative to control and asymptomatic children, and to observe how that changes with time. Methods: This was a prospective, controlled cohort study of pediatric mTBI at approximately one- and two- months post-injury. Symptom status was determined by the post-concussion symptom inventory (PCSI). A visuospatial n-back working memory task was designed for use with functional magnetic resonance imaging (fMRI). The primary outcome measures were the blood oxygen level dependent (BOLD) signal and n-back working memory task performance. Results: 107 participants (60 symptomatic mTBI, 30 asymptomatic mTBI and 17 controls) were compared approximately one month following mTBI. Mean age was 14.2 years (SD 2.5) and 44% were male. During the n-back task, at approximately one month post-injury, symptomatic mTBI children had decreased activation in the posterior cingulate and precuneus regions compared to asymptomatic children, with no difference in performance. By approximately two months post-injury, we found that symptomatic children had less working memory related cortical activation compared to their own one month post-injury scan, and an improvement in task performance (n=45). Conclusions: Symptomatic mTBI children have cortical activation differences compared to asymptomatic children. Over time, there is a decrease in working memory functional activation within that symptomatic group. Our findings highlight the neurobiological consequences of pediatric mTBI on working memory cortical activation and recovery.Item Open Access Cortical Excitability after Mild Traumatic Brain Injury in Children(2015-12-04) Seeger, Trevor; Barlow, Karen; Kirton, Adam; Dunn, Jeff; Gallagher, Clare; Esser, MichaelIntroduction: Mild traumatic brain injury is frequently complicated by post-concussive syndrome. It is unknown why these symptoms persist, but recent research suggests that cortical excitability may play a role. Objectives: To determine if cortical excitability is different in pediatric mTBI, and if it correlates with symptom persistence. Methods:This was a cross-sectional controlled cohort study. Cortical excitability was measured using a variety of TMS paradigms in children with (symptomatic) and without (asymptomatic) persistent symptoms at one month post injury. The primary outcome measure was the corticalsilent period (cSP) (thought to represent GABAergic inhibition). Results: 57 children with mTBI (44% male; age 14.23 (SD:2.49)) and 28 controls were compared. cSP was similar between groups (F(2, 70)=0.53, p=0.591). There were no other significant group differences in cortical excitability. Conclusions: TMS was well tolerated in children with mTBI. Cortical excitability is similar to normal children at one-month following the injury.Item Open Access Experts’ opinion about the pediatric secondary headaches diagnostic criteria of the ICHD-3 beta(2017-11-29) Özge, Aynur; Abu-Arafeh, Ishaq; Gelfand, Amy A; Goadsby, Peter J; Cuvellier, Jean C; Valeriani, Massimiliano; Sergeev, Alexey; Barlow, Karen; Uludüz, Derya; Yalın, Osman Ö; Faedda, Noemi; Lipton, Richard B; Rapoport, Alan; Guidetti, VincenzoAbstract Background The 2013 International Classification of Headache Disorders-3 was published in a beta version to allow clinicians to confirm the validity of the criteria or suggest improvements based on field studies. The aim of this work was to review the Secondary Headache Disorders and Cranial Neuralgias and Other Headache Disorders sections of ICHD-3 beta data on children and adolescents (age 0–18 years) and to suggest changes, additions, and amendments. Methods Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the available literature on pediatric headache, they made observations and proposed suggestions for the mentioned headache disorders on children and adolescents. Results Some headache disorders in children have specific features, which are different from adults that should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psychosocial basis in children and adolescents making primary headache disorders in children distinct from those in adults. Conclusions Several recommendations are presented in order to make ICHD-3 more appropriate for use in children.Item Open Access Experts’ opinion about the primary headache diagnostic criteria of the ICHD-3rd edition beta in children and adolescents(2017-11-23) Özge, Aynur; Faedda, Noemi; Abu-Arafeh, Ishaq; Gelfand, Amy A; Goadsby, Peter J; Cuvellier, Jean C; Valeriani, Massimiliano; Sergeev, Alexey; Barlow, Karen; Uludüz, Derya; Yalın, Osman Ö; Lipton, Richard B; Rapoport, Alan; Guidetti, VincenzoAbstract Background The 2013 International Classification of Headache Disorders-3 (ICHD-3) was published in a beta version to allow the clinicians to confirm the validity of the criteria or to suggest improvements based on field studies. The aim of this work was to review the Primary Headache Disorders Section of ICHD-3 beta data on children and adolescents (age 0-18 years), and to suggest changes, additions, and amendments. Methods Several experts in childhood headache across the world applied different aspects of ICHD-3 beta in their normal clinical practice. Based on their personal experience and the literature available on pediatric headache, they made observations and proposed suggestions for the primary headache disorders section of ICHD-3 beta data on children and adolescents. Results Some headache disorders in children have specific features which are different from those seen in adults and which should be acknowledged and considered. Some features in children were found to be age-dependent: clinical characteristics, risks factors and etiologies have a strong bio psycho-social basis in children and adolescents making primary headache disorders in children distinct from those in adults. Conclusions Several recommendations are presented in order to make ICHD-3 more appropriate for use with children.Item Open Access Limited somatosensory functional connectivity differences in youth with ASD, at rest(2017) Cechmanek, Brian; Bray, Signe; Lebel, Catherine; Dunn, Jeff; McCrimmon, Adam; Barlow, Karen; Curtin, SuzanneChildren and adolescents with autism spectrum disorder typically experience sensory sensitivities, involving over- and/or under-reactions to sensory stimuli. Tactile hyper-reactivity, in particular, is implicated in negative outcomes such as aversion to oral hygiene, dietary issues, and self-harm. Presently, there is no established overarching neurological basis for these sensitivities in autism. Understanding the underlying causes of these sensitivities may help guide pharmacological and behavioural interventions. Motivated by suggested linkages between over-connectivity measures and negative outcomes in ASD, this thesis used resting-state functional-MRI to examine somatosensory functional connectivity differences in youth with autism. Connectivity differences, arising in the somatosensory region, may represent a good marker of sensory sensitivities in ASD. Our findings show limited functional connectivity differences in ASD, and scarce changes in age by diagnosis interaction or autism symptom severity. This suggests that functional connectivity of the somatosensory network in youth with autism is not disrupted, at rest, compared to neurotypical controls.Item Open Access Neurophysiological and diffusion tensor imaging correlates of mild traumatic brain injury in children(2018-07-24) King, Regan; Kirton, Adam; Barlow, Karen; Lebel, Catherine A.; Esser, Michael J.; Federico, PaoloChildren typically recover quickly following a mild traumatic brain injury (mTBI), however up to 15% of children continue to experience symptoms past three months post injury. Currently, underlying mechanisms of persistent post-concussive symptoms (PPCS) in children are unknown. The present thesis uses transcranial magnetic stimulation (TMS) and diffusion tensor imaging (DTI) to characterize the structural and functional characteristics of PPCS in 98 children (aged 8-18) with mTBI, over time. The Post-concussive Symptom Inventory (PCSI) was used to classify post-concussive symptoms in participants as symptomatic or asymptomatic. Twenty-six healthy controls were included for comparison. Neurophysiological data assessing cortical inhibition and facilitation were evaluated alongside symptom status. Associations between symptom status and DTI measures of water diffusion and anisotropy were also assessed in the corticospinal tract (CST), motor fibers of the corpus callosum (CC), and uncinate fasciculus (UF). Differences in neurophysiology were noted between healthy controls and children with mTBI in both inhibitory and excitatory TMS paradigms, further differentiating by symptom status. Differences in inhibitory paradigms were also noted over time. Fractional anisotropy (FA) differed as well in the UF, but not in the CST or CC, of symptomatic children compared to controls. No differences in diffusion metrics were observed over time. In summary, these findings suggest an indirect association of neurophysiology and white matter structure in mTBI recovery. Further exploration of neurophysiological and imaging correlates of PPCS are required to improve recovery and treatment outcomes of mTBI.Item Open Access Pain in Children Following Mild Traumatic Brain Injury: A Longitudinal Analysis in Association with Post-Concussive Symptoms(2017) Kwan, Vivian; Yeates, Keith; Noel, Melanie; Barlow, Karen; Kirton, AdamUp to 57% of youth report pain 3 to 36 months after a mild traumatic brain injury (TBI; Tham et al., 2013). Importantly, pain may be related to post-concussive symptoms (PCS). Thus our objective was to examine pain as a time-varying covariate of PCS. The current study recruited children ages 8 to 16 following mild TBI (n = 112) or orthopedic injury (OI; n = 67) at the time of injury and up to 6 months post-injury. Participants provided weekly ratings of their pain intensity and PCS frequency. Results showed that children with mild TBI and OI do not have significantly different trajectories of pain decline over time. However, relative increases in an individual’s pain ratings were related to increases in cognitive and somatic PCS, and this relationship was stronger in children with mild TBI than OI. Future research to better understand this closer association after mild TBI is warranted.Item Open Access The Neural Correlates of Motor Functioning in Preschool-Aged Children(2017) Grohs, Melody; Dewey, Deborah; Lebel, Catherine; Barlow, Karen; Kirton, AdamAlthough researchers have spent decades characterizing typical brain and motor development, limited research has bridged these two fields by examining the associations between brain structure and motor behavior. The current study uses both diffusion and T1-weighted magnetic resonance imaging (MRI) to investigate the relationships between brain microstructure, macrostructure, and motor abilities in 68 typically developing preschool children, aged 3 to 5 years. The Movement Assessment Battery for Children-2nd edition (MABC-II) was used to assess motor functioning in children. Associations between MABC-II total test standard scores and white matter anisotropy and diffusivity in callosal motor fibers (CC) and corticospinal tracts (CST) were examined. Associations of MABC-II scores and whole brain structural properties (i.e., cortical thickness and volume) in canonical motor regions were also examined. Motor scores were found to correlate with measures of anisotropy and diffusivity in CC motor fibers. No associations were found between motor performance and measures of anisotropy or diffusivity in either the left or right CST. Finally, no associations were observed between cortical and subcortical macrostructure and motor abilities in preschool-aged children. These findings suggest a relationship between callosal fiber white matter structure and motor performance in typically developing preschool-aged children, and that structural variation in callosal motor fibers but not corticospinal tracts, may partially account for the natural variability in motor performance seen across typically developing preschool children. Clarifying brain-motor behavior relationships in typically developing children could help to inform future studies on the etiology and physiology of developmental motor impairments in pediatric populations.Item Open Access “What is the actual goal of the pathway?”: examining emergency department physician and nurse perspectives on the implementation of a pediatric concussion pathway using the theoretical domains framework(2021-02-05) Ly, Anh; Zemek, Roger; Wright, Bruce; Zwicker, Jennifer; Schneider, Kathryn; Mikrogianakis, Angelo; Conradi, Alf; Johnson, David; Clark, Brenda; Barlow, Karen; Burey, Joseph; Kolstad, Ash; Yeates, Keith OAbstract Background Multiple evidence-based clinical practice guidelines (CPGs) exist to guide the management of concussion in children, but few have been translated into clinical pathways (CP), which operationalize guidelines into accessible and actionable algorithms that can be more readily implemented by health care providers. This study aimed to identify the clinical behaviours, attitudinal factors, and environmental contexts that potentially influence the implementation of a clinical pathway for pediatric concussion. Methods Semi-structured interviews were conducted from October 2017 to January 2018 with 42 emergency department clinicians (17 physicians, 25 nurses) at five urban emergency departments in Alberta, Canada. A Theoretical Domains Framework (TDF)-informed interview guide contained open-ended questions intended to gather feedback on the proposed pathway developed for the study, as well as factors that could potentially influence its implementation. Results The original 14 domains of the TDF were collapsed into 6 clusters based on significant overlap between domains in the issues discussed by clinicians: 1) knowledge, skills, and practice; 2) professional roles and identity; 3) attitudes, beliefs, and motivations; 4) goals and priorities; 5) local context and resources; and 6) engagement and collaboration. The 6 clusters identified in the interviews each reflect 2–4 predominant topics that can be condensed into six overarching themes regarding clinicians’ views on the implementation of a concussion CP: 1) standardization in the midst of evolving research; 2) clarifying and communicating goals; 3) knowledge dissemination and alignment of information; 4) a team-oriented approach; 5) site engagement; and 6) streamlining clinical processes. Conclusion Application of a comprehensive, evidence-based, and theory-driven framework in conjunction with an inductive thematic analysis approach enabled six themes to emerge as to how to successfullly implement a concussion CP.