Adam Kirton

The University of Calgary | HBI · Department of Paediatrics

Introduction Perinatal stroke affects millions of children and results in lifelong disability. Two forms prevail: arterial ischemic stroke (AIS), and periventricular venous infarction (PVI). With such focal damage early in life, neural structures may reorganize during development to determine clinical function, particularly in the contralesional he...

Background: Although much is known about cognitive dysfunction in attention-deficit/hyperactivity disorder (ADHD), few studies have examined the pathophysiology of disordered motor circuitry. We explored differences in neurometabolite levels and transcranial magnetic stimulation (TMS)-derived corticomotor representations among children with ADHD a...

Background: Children with severe motor impairment but intact cognition are deprived of fundamental human rights. Quadriplegic cerebral palsy is the most common scenario where rehabilitation options remain limited. Brain-computer interfaces (BCI) represent a potential solution, but pediatric populations have been neglected. Direct engagement of chi...

Transcranial magnetic stimulation (TMS) motor mapping is a safe, non-invasive method that can be used to study corticomotor organization. Motor maps are typically acquired at rest, and comparisons to maps obtained during muscle activation have been both limited and contradictory. Understanding the relationship between functional activation of the c...

BACKGROUND Data from the early pandemic revealed that 0.62% of children hospitalized with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) had an acute arterial ischemic stroke (AIS). In a larger cohort from June 2020 to December 2020, we sought to determine whether our initial point estimate was stable as the pandemic continued and to...

Brain stimulation combined with intensive therapy may improve hand function in children with perinatal stroke-induced unilateral cerebral palsy (UCP). However, response to therapy varies and underlying neuroplasticity mechanisms remain unclear. Here, we aimed to characterize robotic motor mapping outcomes in children with UCP. Twenty-nine children...

Perinatal stroke occurs early in life and often leads to a permanent, disabling weakness to one side of the body. To test the hypothesis that non-lesioned hemisphere sensorimotor network structural connectivity in children with perinatal stroke is different from controls, we used diffusion imaging and graph theory to explore structural topology bet...

Fatigue is prevalent in youth with perinatal stroke, but the causes are unclear. Predictive coding models of adult post-stroke fatigue suggest that fatigue may arise from dysfunction in predictive processing networks. To date, the association between fatigue and neural network connectivity in youth with perinatal stroke has not been examined. The p...

Perinatal stroke affects ∼1 in 1000 births and concomitant cognitive impairments are common but poorly understood. Rates of Attention Deficit/Hyperactivity Disorder (ADHD) are increased 5–10× and executive dysfunction can be disabling. We used diffusion imaging to investigate whether stroke-related differences in frontal white matter (WM) relate to...

Background Hemiparetic cerebral palsy impacts millions of people worldwide. Assessment of bilateral motor function in real life remains a major challenge. We evaluated quantification of upper extremity movement in hemiparetic children using bilateral actigraphy. We hypothesized that movement asymmetry correlates with standard motor outcome measures...

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal-dominant condition which is linked to a myriad of neurological complications arising from vascular malformations of the brain, spinal cord, and lungs. Our case describes a previously healthy 3-year-old male who presented to hospital with fever of unknown origin and was found to have a brai...

Aims In pediatric upper extremity rehabilitation, feasible repetition rates are unknown. Our objectives were to examine repetition rates during rehabilitation and their impact on outcomes. Methods Children with unilateral cerebral palsy due to perinatal stroke (n = 55, median 10 y 7 mo, 30 males) received Constraint-Induced Movement Therapy (CIMT)...

Introduction Tourette’s syndrome (TS) affects approximately 1% of children. This study will determine the efficacy and safety of paired comprehensive behavioural intervention for tics (CBIT) plus repetitive transcranial magnetic stimulation (rTMS) treatment in children with Tourette’s syndrome. We hypothesise that CBIT and active rTMS to the supple...

Children with severe physical disabilities are often unable to independently explore their environments, further contributing to complex developmental delays. Brain-computer interfaces (BCIs) could be a novel access method to power mobility for children who struggle to use existing alternate access technologies, allowing them to reap the developmen...

Introduction: Conventional transcranial direct current stimulation (tDCS) and high-definition tDCS (HD-tDCS) may improve motor learning in children. Mechanisms are not understood. Neuronavigated robotic transcranial magnetic stimulation (TMS) can produce individualised maps of primary motor cortex (M1) topography. We aimed to determine the effects...

Background: Children with severe physical disabilities and no expressive communication have few options for interaction and engagement with the world around them. There is a need for new technologies and programs dedicated to this population and brain computer interface (BCI) can provide new opportunities for independence. We established a novel, f...

Background Perinatal stroke causes hemiparetic cerebral palsy (HCP) and lifelong disability. Constraint-induced movement therapy (CIMT) and neurostimulation may enhance motor function, but the individual factors associated with responsiveness are undetermined. Objective We explored the clinical and neurophysiological factors associated with respon...

There is limited understanding of the effect of perinatal stroke on child and adolescent learning and memory abilities. This study sought to evaluate the clinical utility of the Child and Adolescent Memory Profile (ChAMP) in quantifying memory performance in youth with perinatal stroke. Children and adolescents aged 6–16 years old with a history of...

Aim To explore clinical factors associated with perinatal arterial ischemic stroke (AIS) and periventricular venous infarction (PVI) in infants who develop unilateral cerebral palsy (CP). Method This was a case–control study. Data current to 2019 was extracted from the Canadian Cerebral Palsy Registry (CCPR). Cases were infants born at term with c...

Background: Perinatal stroke injures motor regions of the brain, compromising movement for life. Early, intensive, active interventions for the upper extremity are efficacious, but interventions for the lower extremity (LE) remain infrequent and understudied. Objective: To determine the efficacy of ELEVATE – Engaging the Lower Extremity Via Active...

Background: Tic disorders may reflect impaired inhibitory control. This has been evaluated using different behavioural tasks, yielding mixed results. Our objective was to test inhibitory control in children with tics through simultaneous presentation of multiple, mobile stimuli. Methods: Sixty-four children with tics (mean age 12.4 years; 7.5-18...

Paediatric arterial ischaemic stroke is an important cause of neurological morbidity in children, with consequences including motor disorders, intellectual impairment, and epilepsy. The causes of paediatric arterial ischaemic stroke are unique compared with those associated with stroke in adulthood. The past decade has seen substantial advances in...

Perinatal ischemic stroke results in focal brain injury and life-long disability. Hemiplegic cerebral palsy and additional sequelae are common. With no prevention strategies, improving outcomes depends on understanding brain development. Reactive astrogliosis is a hallmark of brain injury that has been associated with outcomes but is unstudied in p...

Most cases of hemiparetic cerebral palsy are caused by perinatal stroke, resulting in lifelong disability for millions of people. However, our understanding of how the motor system develops following such early unilateral brain injury is increasing. Tools such as neuroimaging and brain stimulation are generating informed maps of the unique motor ne...

Background and Purpose Perinatal stroke is the leading cause of hemiparetic cerebral palsy resulting in lifelong disability for millions of people worldwide. Options for motor rehabilitation are limited, especially for the most severely affected children. Brain computer interfaces (BCIs) sample brain activity to allow users to control external devi...

Background: Studies using clinical measures have suggested that proprioceptive dysfunction is related to motor impairment of the upper extremity following adult stroke. We used robotic technology and clinical measures to assess the relationship between position sense and reaching with the hemiparetic upper limb in children with perinatal stroke....

Introduction: Transcranial magnetic stimulation (TMS) motor mapping can characterize the neurophysiology of the motor system. Limitations including human error and the challenges of pediatric populations may be overcome by emerging robotic systems. We aimed to show that neuronavigated robotic motor mapping in adolescents could efficiently produce...

Background and Purpose Because children often have lifelong morbidity after stroke, there is considerable enthusiasm to pursue mechanical thrombectomy in childhood stroke based on literature reports. However, current published data may reflect inconsistent reporting and publication bias, which limit the ability to assess safety and efficacy of mech...

Background Perinatal stroke is a leading cause of hemiparetic cerebral palsy and lifelong disability. Neurodevelopmental outcomes are difficult to predict and markers of long-term poor outcome continue to be investigated. Deceleration in growth of head circumference has been associated with worse developmental outcomes in neonatal brain injury. We...

Perinatal stroke is a focal vascular brain injury that occurs from the fetal period to 28 days of postnatal age. With an overall incidence of up to 1 in 1,000 live births, the most focused lifetime risk for stroke occurs near birth. Perinatal stroke can be classified by the timing of diagnosis, vessel involvement, and type of injury. Timing of diag...

Background: Placental abnormalities are associated with inflammation and have been linked to brain injury in preterm infants. We studied the relationship between placental pathology and the temporal profiles of cytokine levels in extremely pre-term infants. Study Design: We prospectively enrolled 55 extremely preterm infants born between June 2017...

Perinatal stroke causes most hemiparetic cerebral palsy and a lifetime of disability with no known prevention strategies. Two types of perinatal stroke predominate, arterial ischemic stroke (AIS) and periventricular venous infarction (PVI), dictating lesion-specific differences in outcomes. Executive functioning challenges and attention deficit hyp...

Perinatal stroke (PS) causes hemiparetic cerebral palsy (CP) and lifelong disability. Compensatory changes in the nonlesioned hemisphere may mediate residual function and represent targets for neuromodulation. Region-based approaches may reveal relationships between cortical thickness of nonlesioned primary motor/sensory cortices and motor function...

Acute neonatal stroke causes cerebral palsy, lifelong morbidity and mortality. Neonatal arterial ischemic stroke (NAIS) and hemorrhagic stroke (NHS) are most common. Pathophysiology is poorly understood and causation is often attributed to observed obstetrical factors such as instrumentation (forceps or vacuum) or operative delivery despite no empi...

Aim To explore the feasibility and possible effects of low‐frequency repetitive transcranial magnetic stimulation (rTMS) delivered to the supplementary motor area (SMA) on tic severity and motor system neurophysiology in children with Tourette syndrome. Method Ten children with Tourette syndrome (eight males, two females; 9–15y) participated in th...

Introduction: Perinatal stroke leads to cerebral palsy (CP) and lifelong disability for thousands of Canadian children. Hemiparesis, referring to impaired functionality in one side of the body, is a common complication of perinatal stroke. Standard long-term care for hemiparetic CP focuses on rehabilitation therapies. Early research suggests that...

Objective Continuous spike and wave in slow-wave sleep (CSWS), an epileptic encephalopathy, occurs after perinatal stroke where it is associated with cognitive decline. CSWS features a distinct EEG pattern, electrical status epilepticus in sleep (ESES). Biomarkers for the prediction of ESES have not been identified but will facilitate earlier diagn...

Aim To explore relationships between category classifications for children’s rehabilitation goals, outcomes, and participant characteristics. Method Children with hemiparetic cerebral palsy due to perinatal stroke rated self‐selected goals with the Canadian Occupational Performance Measure (COPM) and completed the Assisting Hand Assessment (AHA) a...

Objective Severe complications of SARS‐CoV‐2 include arterial ischemic stroke (AIS) in adults and pediatric multisystem inflammatory syndrome. Whether stroke is a frequent complication of pediatric SARS‐CoV‐2 is unknown. This study aimed to determine the proportion of pediatric SARS‐CoV‐2 cases with ischemic stroke and the proportion of pediatric s...

Aim To determine whether inequities in health outcomes for Indigenous Canadians are also present in cerebral palsy (CP) by comparing CP profiles between Indigenous and non‐Indigenous children. Method Using the Canadian Cerebral Palsy Registry, we conducted a cross‐sectional study. CP motor subtype, gross motor severity, comorbidities, perinatal ad...

Sensory phenomena (premonitory sensations/urges) are associated with tics. Noisier afferent signals may underlie tic disorders, possibly affecting proprioception. We compared 64 children with Tourette syndrome or chronic motor tic disorder with 155 typically developing controls in arm‐position matching using a robotic exoskeleton (Kinarm). Passive...

Thousands of youth suffering from acquired brain injury or other early-life neurological disease live, mature, and learn with only limited communication and interaction with their world. Such cognitively capable children are ideal candidates for brain-computer interfaces (BCI). While BCI systems are rapidly evolving, a fundamental gap exists betwee...

Objective: To develop consensus recommendations for the use of repetitive transcranial magnetic stimulation as an adjunct intervention for upper extremity motor recovery in stroke rehabilitation clinical trials. Methods: The Canadian Platform for Trials in Non-Invasive Brain Stimulation (CanStim) convened a multidisciplinary team of clinicians and...

Background and objectives: Developmental coordination disorder (DCD) is a neurodevelopmental motor disorder occurring in 5-6% of school-aged children. It is suggested that children with DCD show deficits in motor learning. Transcranial direct current stimulation (tDCS) enhances motor learning in adults and children but is unstudied in DCD. We aimed...

Developmental neuroplasticity allows young brains to adapt via experiences early in life and also to compensate after injury. Why certain individuals are more adaptable remains underexplored. Perinatal stroke is an ideal human model of neuroplasticity with focal lesions acquired near birth in a healthy brain. Machine learning can identify complex p...

Background: Transcranial direct current stimulation (tDCS) has been used extensively in patient populations to facilitate motor network plasticity. However, it has not been studied in patients with brain tumors. We aimed to determine the feasibility of a preoperative motor training and tDCS intervention in patients with glioma. In an exploratory ma...

Robotic Transcranial Magnetic Stimulation (TMS) is a non-invasive and safe tool that produces cortical motor maps using neuronavigation and neuroanatomical images. Motor maps are individualized representations of primary motor cortex (M1) topography that may reflect developmental and interventional plasticity. Results of TMS motor map reliability t...

Background: Perinatal stroke encompasses multiple disease-specific cerebrovascular syndromes that cause lifelong neurodevelopmental morbidity for millions worldwide. Acute presentations include neonatal arterial ischemic stroke (NAIS), neonatal cerebral sinovenous thrombosis, and neonatal hemorrhagic stroke (NHS). Delayed presentations include art...

Aim: To determine how the severity of antenatally diagnosed germinal matrix-intraventricular hemorrhage (GMH-IVH) relates to morbidity and mortality, and to explore potential risk factors. Method: We conducted a systematic review and individual patient data meta-analysis of antenatally diagnosed fetal GMH-IVH. The primary outcomes were mortality...

Sleep disturbances are commonly reported in children with persistent post-concussion symptoms (PPCS). Melatonin treatment is often recommended, yet supporting evidence is scarce. We aimed to evaluate the efficacy of treatment with Melatonin for sleep disturbance in youth with PPCS following mild traumatic brain injury (mTBI). Methods This paper is...

Objective: We aimed to employ diffusion imaging connectome methods to explore network development in the contralesional hemisphere of children with perinatal stroke and its relationship to clinical function. We hypothesized alterations in global efficiency of the intact hemisphere would correlate with clinical disability. Methods: Children with...

Objective To describe complementary and alternative medicine (CAM) use amongst children with cerebral palsy (CP) in Canada and to identify factors associated with CAM use. Methods We conducted a cross-sectional study, utilising data from the Canadian CP Registry. We explored the association between CAM use and regional, socioeconomic and CP phenot...

Background Perinatal stroke often leads to lifelong motor impairment. Two common subtypes differ in timing, location, and mechanism of injury: periventricular venous infarcts (PVI) are fetal white matter lesions while most arterial ischemic strokes (AIS) are cortical injuries acquired near term. Both alter motor system development and primary motor...

Perinatal stroke occurs around the time of birth and leads to lifelong neurological disabilities including hemiparetic cerebral palsy. Magnetic resonance imaging (MRI) has revolutionized our understanding of developmental neuroplasticity following early injury, quantifying volumetric, structural, functional, and metabolic compensatory changes after...

Objective To examine the relationship between neonatal inflammatory cytokines and perinatal stroke, using a systems biology approach analyzing serum and bloodspot cytokines from 47 patients. Methods This was a population-based, controlled cohort study with prospective and retrospective case ascertainment. Participants were recruited through the Al...

Background: Activities of daily living frequently require children to make rapid decisions and execute desired motor actions while inhibiting unwanted actions. Children with hemiparetic cerebral palsy due to perinatal stroke may have deficits in executive functioning in addition to motor impairments. The objective of this study was to use a roboti...

Aim Some conditions within specific populations are so rare rigorous evidence is unavailable. Childhood hyperkinesis is one example, yet presents an opportunity to examine sensation’s contribution to motor function. Methods The patient experienced functional difficulty from hyperkinesis as a result of childhood stroke. Home-based passive neuromusc...

Objective To determine that children with arterial ischemic stroke (AIS) due to an identifiable arteriopathy are distinct from those without arteriopathy and that each arteriopathy subtype has unique and recognizable clinical features. Methods We report a large, observational, multicenter cohort of children with AIS, age 1 month to 18 years, enrol...

Background The COVID-19 pandemic has broadly disrupted biomedical treatment and research including non-invasive brain stimulation (NIBS). Moreover, the rapid onset of societal disruption and evolving regulatory restrictions may not have allowed for systematic planning of how clinical and research work may continue throughout the pandemic or be rest...