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Perinatal stroke causes most hemiparetic cerebral palsy and cognitive dysfunction may co-occur. Compensatory developmental changes in the intact contralesional hemisphere may mediate residual function and represent targets for neuromodulation. We used morphometry to explore cortical thickness, grey matter volume, gyrification, and sulcal depth of the contralesional hemisphere in children, adolescents, and young adults after perinatal stroke and explored associations with motor, attention, and executive function. Participants aged 6–20 years (N = 109, 63% male) with unilateral perinatal stroke underwent T1-weighted imaging. Participants had arterial ischemic stroke (AIS; n = 36), periventricular venous infarction (PVI; n = 37) or were controls (n = 36). Morphometry was performed using the Computational Anatomy Toolbox (CAT12). Group differences and associations with motor and executive function (in a smaller subsample) were assessed. Group comparisons revealed areas of lower cortical thickness in contralesional hemispheres in both AIS and PVI and greater gyrification in AIS compared to controls. Areas of greater grey matter volume and sulcal depth were also seen for AIS. The PVI group showed lower grey matter volume in cingulate cortex and less volume in precuneus relative to controls. No associations were found between morphometry metrics, motor, attention, and executive function. Cortical structure of the intact contralesional hemisphere is altered after perinatal stroke. Alterations in contralesional cortical morphometry shown in perinatal stroke may be associated with different mechanisms of damage or timing of early injury. Further investigations with larger samples are required to more thoroughly explore associations with motor and cognitive function. [ABSTRACT FROM AUTHOR]

Transcranial magnetic stimulation (TMS) motor mapping is a safe, non-invasive method used to study corticomotor organization and intervention-induced plasticity. Reliability of resting maps is well established, but understudied for active maps and unestablished for active maps obtained using robotic TMS techniques. The objective of this study was to determine the reliability of robotic neuro-navigated TMS motor map measures during active muscle contraction. We hypothesized that map area and volume would show excellent short- and medium-term reliability. Twenty healthy adults were tested on 3 days. Active maps of the first dorsal interosseous muscle were created using a 12 × 12 grid (7 mm spacing). Short- (24 h) and medium-term (3–5 weeks) relative (intra-class correlation coefficient) and absolute (minimal detectable change (MDC); standard error of measure) reliabilities were evaluated for map area, volume, center of gravity (CoG), and hotspot magnitude (peak-to-peak MEP amplitude at the hotspot), along with active motor threshold (AMT) and maximum voluntary contraction (MVC). This study found that AMT and MVC had good-to-excellent short- and medium-term reliability. Map CoG (x and y) were the most reliable map measures across sessions with excellent short- and medium-term reliability (p < 0.001). Map area, hotspot magnitude, and map volume followed with better reliability medium-term than short-term, with a change of 28%, 62%, and 78% needed to detect a true medium-term change, respectively. Therefore, robot-guided neuro-navigated TMS active mapping is relatively reliable but varies across measures. This, and MDC, should be considered in interventional study designs. [ABSTRACT FROM AUTHOR]

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 between these populations. Children underwent diffusion and anatomical 3T MRI. Whole-brain tractography was constrained using a brain atlas creating an adjacency matrix containing connectivity values. Graph theory metrics including betweenness centrality, clustering coefficient, and both neighbourhood and hierarchical complexity of sensorimotor nodes were compared to controls. Relationships between these connectivity metrics and validated sensorimotor assessments were explored. Eighty-five participants included 27 with venous stroke (mean age = 11.5 ± 3.7 years), 26 with arterial stroke (mean age = 12.7 ± 4.0 years), and 32 controls (mean age = 13.3 ± 3.6 years). Non-lesioned primary motor (M1), somatosensory (S1) and supplementary motor (SMA) areas demonstrated lower betweenness centrality and higher clustering coefficient in stroke groups. Clustering coefficient of M1, S1, and SMA were inversely associated with clinical motor function. Hemispheric betweenness centrality and clustering coefficient were higher in stroke groups compared to controls. Hierarchical and average neighbourhood complexity across the hemisphere were lower in stroke groups. Developmental plasticity alters the connectivity of key nodes within the sensorimotor network of the non-lesioned hemisphere following perinatal stroke and contributes to clinical disability. [ABSTRACT FROM AUTHOR]

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 networks that emerge following perinatal stroke. As a focal injury of defined timing in an otherwise healthy brain, perinatal stroke represents an ideal human model of developmental plasticity. Here, we provide an introduction to perinatal stroke epidemiology and outcomes, before reviewing models of developmental plasticity after perinatal stroke. We then examine existing therapeutic approaches, including constraint, bimanual and other occupational therapies, and their potential synergy with non-invasive neurostimulation. We end by discussing the promise of exciting new therapies, including novel neurostimulation, brain-computer interfaces and robotics, all focused on improving outcomes after perinatal stroke. [ABSTRACT FROM AUTHOR]

As leaders of the global consortia of professional experts dedicated to improving outcomes from stroke in neonates and children, we strongly urge rational and cautious application of available therapies in neonatal stroke. Recurrent ischemic events are exceedingly rare after neonatal stroke; hence antithrombotic therapy for secondary stroke prevention is not indicated. Additional tools applied in adults with stroke to select candidates for recanalization therapies including perfusion studies and MRI sequences such as fluid attenuated inversion recovery (FLAIR) are unvalidated in newborns and not applicable given developmental differences in brain structure, such that biomarkers of stroke evolution in adults are often not visible. [Extracted from the article]

Introduction: Large/medium vessel vasculitis is an important etiology of childhood stroke. Early research suggests vessel wall enhancement on postcontrast MRI may be a marker of intracranial vasculitis yet no systematic descriptions of normal periarterial enhancement exist in the literature. The aim was to describe normal periarterial enhancement in the pediatric population. Methods: We included all children who had an MR scan between January 2007 and December 2010, with normal parenchymal imaging, no clinical concern of vasculopathy, and axial and coronal postcontrast fat-saturated T1-weighted images with 3-mm slice thickness. Intensity of periarterial enhancement was graded on a three-point scale by two investigators for all intracranial large and medium arteries. Results: A total of 44 patients aged 4 months to 16 years were included. Inter- and intra-rater reliability in enhancement grading was high (all kappa >0.65). Thin, linear, noncircumferential periarterial enhancement was common and usually symmetrical. It was most commonly prominent in the cavernous and petrous segments of the internal carotid artery and the M1 segment of the middle cerebral artery. Periarterial enhancement was rarely observed at segments surrounded by CSF, including supraclinoid segments of the internal carotid arteries, P1 segments of the posterior cerebral arteries, V4 segments of the vertebral artery, and the basilar arteries. Conclusion: Normal periarterial enhancement is common and usually symmetrical along major intracranial arteries but rarely seen around arterial segments bordered by CSF. Knowledge of these findings may be useful for a sensitive and specific interpretation of MR scans of patients with clinical concerns of vasculitis. [ABSTRACT FROM AUTHOR]

Introduction: Pediatric stroke, while increasingly recognized among practitioners as a clinically significant, albeit infrequent entity, remains challenging from the viewpoint of clinicians and researchers. Discussion: Advances in neuroimaging have revealed a higher prevalence of pediatric stroke while also provided a safer method for evaluating the child's nervous system and vasculature. An understanding of pathogenic mechanisms for pediatric stroke requires a division of ages (perinatal and childhood) and a separation of mechanism (ischemic and hemorrhagic). This article presents a review of the current literature with the recommended divisions of age and mechanism. Conclusion: Guidelines for treatment, though limited, are also discussed. [ABSTRACT FROM AUTHOR]

Background After a year of unsuccessful treatment for hypertension, a young boy underwent a stenting procedure for aortic hypoplasia and awoke with hemiparesis and language deficits. Investigations Neuroimaging, echocardiography, craniocervical vascular imaging and prothrombotic testing. Diagnosis Procedure-related acute arterial ischemic stroke and malignant cerebral edema with herniation. Management Anticoagulation with heparin, seizure prophylaxis and neuroprotective care, including external cooling for hyperthermia. Medical management of increased intracranial pressure and hemicraniectomy at 48 h for malignant cerebral edema. Treatment of deep vein thrombosis with inferior vena cava filter was also required. Long term treatments included extensive rehabilitation, aspirin, antiepileptics, antidyskinetics, antidepressants, antihypertensives and cosmetic skull reconstruction. [ABSTRACT FROM AUTHOR]

Summary: Evidence-based therapeutic interventions for pediatric ischemic cerebrovascular disease are beginning to emerge. The primary therapeutic target is usually the pathological prothrombotic disturbance that underlies the majority of pediatric stroke. A battle between anticoagulation and anti-platelet therapies continues to provide controversy and is the inspiration for upcoming randomized trials. Supportive care and neuroprotective strategies are an important consideration in children with stroke. Attempts to determine the safety of acute thrombolytic interventions are also underway. Finally, unique medical and surgical treatments for specific diseases leading to stroke in children continue to evolve. After briefly summarizing the epidemiology, pathophysiology, diagnosis, and outcomes of ischemic strokes in children, treatment approaches and alternatives will be reviewed in detail with emphasis placed on current areas of controversy and future directions for clinical research. [Copyright &y& Elsevier]