Presumed perinatal ischemic stroke: Vascular classification predicts outcomes

Imaging Developmental and Interventional Plasticity Following Perinatal Stroke

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 perinatal stroke. Such techniques can also be used to investigate how the brain responds to treatment (interventional neuroplasticity). Here, we review the current state of knowledge of how established and emerging neuroimaging modalities are informing neuroplasticity models in children with perinatal stroke. Specifically, we review structural imaging characterizing lesion characteristics and volumetrics, diffusion tensor imaging investigating white matter tracts and networks, task-based functional MRI for localizing function, resting state functional imaging for characterizing functional connectomes, and spectroscopy examining neurometabolic changes. Key challenges and exciting avenues for future investigations are also considered.

Association of neonatal inflammatory markers and perinatal stroke subtypes

OBJECTIVE

To examine the relationship between neonatal inflammatory cytokines and perinatal stroke using a systems biology approach analyzing serum and blood-spot cytokines from 47 patients.

METHODS

This was a population-based, controlled cohort study with prospective and retrospective case ascertainment. Participants were recruited through the Alberta Perinatal Stroke Project. Stroke was classified as neonatal arterial ischemic stroke (NAIS), arterial presumed perinatal ischemic stroke (APPIS), or periventricular venous infarction (PVI). Biosamples were stored blood spots (retrospective) and acute serum (prospective). Controls had comparable gestational and maternal ages. Sixty-five cytokines were measured (Luminex). Hierarchical clustering analysis was performed to create heat maps. The Fisher linear discriminant analysis was used to create projection models to determine discriminatory boundaries between stroke types and controls.

RESULTS

A total of 197 participants were analyzed (27 with NAIS, 8 with APPIS, 12 with PVI, 150 controls). Cytokines were quantifiable with quality control measures satisfied (standards testing, decay analysis). Linear discriminant analysis had high accuracy in using cytokine profiles to separate groups. Profiles in participants with PVI and controls were similar. NAIS separation was accurate (sensitivity 77%, specificity 97%). APPIS mapping was also distinguishable from NAIS (sensitivity 86%, specificity 99%). Classification tree analysis generated similar diagnostic accuracy.

CONCLUSIONS

Unique inflammatory biomarker signatures are associated with specific perinatal stroke diseases. Findings support an acquired pathophysiology and suggest the possibility that at-risk pregnancies might be identified to develop prevention strategies.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that differences in acute neonatal serum cytokine profiles can discriminate between patients with specific perinatal stroke diseases and controls.

Robotic assessment of rapid motor decision making in children with perinatal stroke

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 robotic object hit and avoid task to assess the ability of children with hemiparetic cerebral palsy to make rapid motor decisions.

Methods

Forty-five children with hemiparetic cerebral palsy due to perinatal stroke and 146 typically developing children (both groups ages 6–19 years) completed a robotic object hit and avoid task using the Kinarm Exoskeleton. Objects of different shapes fell from the top of the screen with increasing speed and frequency. Children were instructed to hit two specific target shapes with either hand, while avoiding six distractor shapes. The number of targets and distractors hit were compared between children with hemiparetic cerebral palsy and typically developing children, accounting for age effects. We also compared performance to a simpler object hit task where there were no distractors.

Results

We found that children with hemiparetic cerebral palsy hit a greater proportion of total distractors compared to typically developing children, demonstrating impairments in inhibitory control. Performance for all children improved with age. Children with hemiparetic cerebral palsy hit a greater percentage of targets with each arm on the more complex object hit and avoid task compared to the simpler object hit task, which was not found in typically developing children.

Conclusions

Children with hemiparetic cerebral palsy due to perinatal stroke demonstrated impairments in rapid motor decision making including inhibitory control, which can impede their ability to perform real-world tasks. Therapies that address both motor performance and executive functions are necessary to maximize function in children with hemiparetic cerebral palsy.

Precise neonatal arterial ischemic stroke classification with a three-dimensional map of the arterial territories of the neonatal brain

INTRODUCTION

Data regarding neonatal arterial ischemic stroke (NAIS) topography are still sparse and inaccurate. Despite the importance of locating NAIS to predict the long-term outcome of neonates, a map of arterial territories is not yet available. Our aim was therefore to generate the first three-dimensional map of arterial territories of the neonatal brain (ATNB) and test its usefulness.

METHODS

Three-dimensional time-of-flight magnetic resonance angiography images were acquired from four neonates without NAIS. Arteries were semi-automatically segmented to build a symmetric arterial template. This allowed us to delineate the volumetric extension of each arterial territory, giving rise to the ATNB map, which is publicly available. Its applicability was tested on a sample of 34 neonates with NAIS.

RESULTS

After applying the ATNB map to the neonatal sample, the posterior trunk of the middle cerebral artery, followed by its anterior trunk, were identified as the most affected arterial territories. When comparing the results obtained employing the map with the original diagnoses made during the standard clinical evaluation of NAIS, major diagnostic errors were found in 18% of cases.

CONCLUSION

The ATNB map has been proven useful to precisely identify the arterial territories affected by an NAIS, as well as to increase the accuracy of clinical diagnoses.

Unilateral Abducens Nerve Palsy Following Perinatal Stroke of the Middle Cerebral Artery

The authors describe a case of unilateral abducens nerve palsy following perinatal stroke of the middle cerebral artery. A 1-year-old boy presented with left eye esotropia but no other ocular abnormalities. The patient's history, examination, and diagnostic tests were consistent with abducens nerve palsy. He underwent left medial rectus recession of 5.5 mm and left lateral rectus resection of 7 mm followed by patching. At 15 months after surgery, primary gaze by prism alternate cover testing revealed a 4 prism diopter (PD) esophoria (small angle in left gaze with essentially no action of lateral rectus) and 2 PD right hyperphoria. Ophthalmologic management of abducens nerve palsy entails addressing neurological sequelae in a timely manner, treating the esotropia and strabismic amblyopia to optimize visual system development. [J Pediatr Ophthalmol Strabismus. 2020;57:e30-e33.].

Language development and brain reorganization in a child born without the left hemisphere

We present a case of a 14-year-old girl born without the left hemisphere due to prenatal left internal carotid occlusion. We combined longitudinal language and cognitive assessments with functional and structural neuroimaging data to situate the case within age-matched, typically developing children. Despite having had a delay in getting language off the ground during the preschool years, our case performed within the normal range on a variety of standardized language tests, and exceptionally well on phonology and word reading, during the elementary and middle school years. Moreover, her spatial, number, and reasoning skills also fell in the average to above-average range based on assessments during these time periods. Functional MRI data revealed activation in right fronto-temporal areas when listening to short stories, resembling the bilateral activation patterns in age-matched typically developing children. Diffusion MRI data showed significantly larger dorsal white matter association tracts (the direct and anterior segments of the arcuate fasciculus) connecting areas active during language processing in her remaining right hemisphere, compared to either hemisphere in control children. We hypothesize that these changes in functional and structural brain organization are the result of compensatory brain plasticity, manifesting in unusually large right dorsal tracts, and exceptional performance in phonology, speech repetition, and decoding. More specifically, we posit that our case's large white matter connections might have played a compensatory role by providing fast and reliable transfer of information between cortical areas for language in the right hemisphere.

Perinatal stroke

Perinatal stroke is a heterogeneous syndrome resulting from brain injury of vascular origin that occurs between 20 weeks of gestation and 28 days of postnatal life. The incidence of perinatal stroke is estimated to be between 1:1600 and 1:3000 live births (approximately 2500 children per year in the United States), though its actual incidence is difficult to estimate because it is likely underdiagnosed. Perinatal arterial ischemic stroke (PAIS) accounts for approximately 70% of cases of perinatal stroke. Cerebral sinovenous thrombosis, while less common, also accounts for a large proportion of the morbidity and mortality seen with perinatal stroke. Hemorrhagic stroke leads to disruption of neurologic function due to intracerebral hemorrhage that is nontraumatic in origin. While most cases of PAIS fall into one of these three categories, other patterns of injury should also be considered perinatal stroke. In some cases, the etiology of PAIS is not known but is idiopathic. This chapter will review the classification, risk factors, pathogenesis, clinical presentation, management, and long-term sequelae of perinatal stroke.

Perinatal Stroke

Perinatal strokes are a diverse but specific group of focal cerebrovascular injuries that occur early in brain development and affect an estimated 5 million people worldwide. The objective of this review is to describe the epidemiology, clinical presentations, pathophysiology, outcomes, and management for the 6 subtypes of perinatal stroke. Some perinatal strokes are symptomatic in the first days of life, typically with seizures, including neonatal arterial ischemic stroke, neonatal hemorrhagic stroke, and cerebral sinovenous thrombosis. The remaining subtypes present in the first year of life or later, usually with motor asymmetry and include arterial presumed perinatal ischemic stroke, presumed perinatal hemorrhagic stroke, and in utero periventricular venous infarction. The consequences of these injuries include cerebral palsy, epilepsy, and cognitive and behavioral challenges, in addition to the psychosocial impact on families. While there have been significant advances in understanding mechanisms of both injury and recovery, there is still a great deal to learn regarding causation and the optimization of outcomes.

Epileptic Spasms Predict Poor Epilepsy Outcomes After Perinatal Stroke

Perinatal stroke is a significant cause of severe epilepsy, including epileptic spasms. Although epileptic spasms due to underlying structural lesion often respond poorly to treatment and evolve into drug-resistant epilepsy, outcomes are not uniformly poor, and predictors of outcomes are not well described. We performed a single-institution retrospective review of epileptic spasms following perinatal stroke to determine if outcome depended on vascular subtype. We identified 24 children with epileptic spasms due to perinatal ischemic stroke: 11 cases of perinatal arterial stroke and 13 cases of perinatal venous infarct. Initial response to treatment was similar between groups; however, although children with perinatal arterial stroke who responded to epileptic spasms therapy had high rates of seizure freedom, many children with perinatal venous infarct, regardless of initial response, had residual drug-resistant epilepsy. We consider whether the mechanism for epileptogenesis may be different between arterial and venous strokes, and whether these 2 groups should be monitored for epileptic spasms, and subsequent epilepsy, differently.

Epileptic spasm and other forms of epilepsy in presumed perinatal arterial ischemic stroke in Turkey after more than 10 years follow-up: A single centre study

PURPOSE

To identify the frequency of epilepsy and whether the association of epilepsy with clinical and neuroimaging findings in children with presumed perinatal arterial ischemic stroke (PPAIS).

METHODS

We performed a retrospective analysis of 37 children with PPAIS followed-up at a tertiary referral center between January 1, 2000, and October 31, 2016. Clinical data including demographic features, age at onset of symptoms and seizures, initial clinical presentation, epilepsy features, used antiepileptic drugs, and thrombophilia screening results were abstracted from medical records. Brain magnetic resonance imaging scans were assessed for infarct laterality, location and affected brain regions.

RESULTS

The median age of the patients was 12 years (range 2-17.9 years) at last assessment. The initial symptom of PPAIS was early hand preference in 33 children (89%) and seizure in 4 children (11%). A total of 20 children (54%) developed epilepsy at a median age of 0.9 years. There were two peaks of epilepsy onset in infancy and adolescence. Fifteen children (41%) had focal epilepsy and 5 children (14%) had epileptic spasms. Twelve out of 20 children (60%) with epilepsy had drug resistant epilepsy. Cortical involvement was a statistically significant predictor of epilepsy (p = 0.021, relative risk 4.4, 95% confidence interval 0.7-27.7).

CONCLUSION

More than half of the children with PPAIS suffered from epilepsy during childhood, of whom developed drug resistant epilepsy in majority. Children with cortical lesion may have a higher risk to develop epilepsy.

Mirror movements in children with unilateral cerebral palsy due to perinatal stroke: clinical correlates of plasticity reorganization

AIM

We aimed to determine if the mirror movements that often result in children with unilateral cerebral palsy (CP) after perinatal stroke represent a clinical biomarker of developmental plasticity.

METHOD

This was a prospective, controlled cohort study. Mirror movements in children with unilateral CP from a population-based cohort were compared to those of typically developing controls. The population with stroke was assessed further via electromyography (EMG), motor function, and corticospinal organization investigations. Mirror movements were quantified (0-5) bidirectionally. EMG mirror movements were quantified during voluntary contraction. Motor function was quantified by validated measures including the Assisting Hand Assessment (AHA). Corticospinal organization was categorized as ipsilateral or contralateral using transcranial magnetic stimulation (TMS). The relationships between mirror movements, function, and corticospinal organization were assessed (t-tests, Pearson rank correlation coefficients).

RESULTS

Ninety-two participants were scored (55 males, 37 females, mean [SD] 12y [5y 6mo], range 4-17y), 63 with complete motor outcomes and 39 with TMS data. EMG ratios correlated with clinical mirror movements (r=0.562, p=0.008). Mild mirror activity in controls declined with age (r=-0.459, p<0.001). Mirroring was stronger with tasks performed by the affected hand (p<0.001). Mirror movements correlated with AHA scores (r=-0.255, p=0.04) and poor motor outcome (p<0.001). Unaffected hand mirror activity was higher in children with ipsilateral corticospinal tract arrangements (p<0.001).

INTERPRETATION

Clinical mirror movements correlate with disability and corticospinal organization in children with unilateral CP with perinatal stroke. This simple bedside biomarker could facilitate patient selection for personalized rehabilitation.

WHAT THIS PAPER ADDS

Mirror movements are a clinical indicator of corticospinal organization in children with unilateral cerebral palsy with perinatal stroke. Mirroring is strongest in children with ipsilateral corticospinal tract reorganization. The concept of a 'directionality factor' to mirror movements highlights additional, clinically relevant functional correlations.

Functional connectivity of language networks after perinatal stroke

Successful language acquisition during development is imperative for lifelong function. Complex language networks develop throughout childhood. Perinatal stroke may cause significant language disabilities but function can also be remarkably normal. Studying such very early brain injury populations may inform developmental plasticity models of language networks. We examined functional connectivity (FC) of language networks in children with arterial and venous perinatal stroke and typically developing controls (TDC) in a population-based, controlled, cohort study. Resting state functional MRI was performed at 3 T (TR/TE = 2000/30 ms, 150 volumes, 3.6mm3 voxels). Seed-based analyses used bilateral inferior frontal and superior temporal gyri. A subset of stroke participants completed clinical language testing. Sixty-six children participated (median age: 12.85±3.8y, range 6-19; arterial N = 17; venous N = 15; TDC N = 34]. Children with left hemisphere strokes had comparable FC in their right hemispheres compared to TDC. Inter- and intra-hemispheric connectivity strengths were similar between TDC and PVI but lower for AIS. Reduced FC was associated with poorer language comprehension. Language networks can be estimated using resting-state fMRI in children with perinatal stroke. Altered connectivity may occur in both hemispheres, is more pronounced with arterial lesions, and is associated with clinical function. Our results have implications for therapeutic language interventions after early stroke.

Perinatal stroke syndromes: Similarities and diversities in aetiology, outcome and management

With a birth-prevalence of 37-67/100,000 (mostly term-born), perinatal stroke encompasses distinct disease-states with diverse causality, mechanism, time of onset, mode of presentation and outcome. Neonatal primary haemorrhagic stroke and ischemic events (also divided into neonatal arterial ischemic stroke and neonatal cerebral sinus venous thrombosis) that manifest soon after birth are distinguished from presumed perinatal - ischemic or haemorrhagic - stroke. Signs of the latter become apparent only beyond the neonatal period, most often with motor asymmetry or milestones delay, and occasionally with seizures. Acute or remote MRI defines the type of stroke and is useful for prognosis. Acute care relies on homeostatic maintenance. Seizures are often self-limited and anticonvulsant agents might be discontinued before discharge. Prolonged anticoagulation for a few weeks is an option in some cases of sinovenous thrombosis. Although the risk of severe impairment is low, many children develop mild to moderate multimodal developmental issues that require a multidisciplinary approach.

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Sensory-motor network functional connectivity in children with unilateral cerebral palsy secondary to perinatal stroke

Background

Perinatal stroke is the most common cause of unilateral cerebral palsy. Mechanisms of post-stroke developmental plasticity in children are poorly understood. To better understand the relationship between functional connectivity and disability, we used resting-state fMRI to compare sensorimotor connectivity with clinical dysfunction.

Methods

School-aged children with periventricular venous infarction (PVI) and unilateral cerebral palsy were compared to controls. Resting-state BOLD signal was acquired on 3 T MRI and analyzed using CONN in SPM12. Functional connectivity was computed between S1, M1, supplementary motor area (SMA), and thalamus of the left/non-lesioned and right/lesioned hemisphere. Primary outcome was connectivity expressed as a Fisher-transformed correlation coefficient. Motor function was measured using the Assisting Hand Assessment (AHA), and Melbourne Assessment (MA). Proprioceptive function was measured using a robotic position matching task (VarXY).

Results

Participants included 15 PVI and 21 controls. AHA and MA in stroke patients were negatively correlated with connectivity (increased connectivity = poorer performance). Position sense was inversely correlated with connectivity (increased connectivity = improved performance) between the non-lesioned S1 and thalamus/SMA. In controls, VarXY was positively correlated with connectivity between the thalamus and bilateral sensorimotor regions.

Conclusions

Resting state fMRI measures of sensorimotor connectivity are associated with clinical sensorimotor function in children with unilateral cerebral palsy secondary to PVI. Greater insight into understanding reorganization of brain networks following perinatal stroke may facilitate personalized rehabilitation.

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Sensorimotor resting-state networks can be measured in children with PVI.

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Thalamic connectivity appears to be altered by PVI.

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Resting state connectivity is associated with motor performance in PVI.

Thalamic diaschisis following perinatal stroke is associated with clinical disability

BACKGROUND

Perinatal stroke causes most hemiparetic cerebral palsy and leads to lifelong disability. Understanding developmental neuroplasticity following early stroke is increasingly translated into novel therapies. Diaschisis refers to alterations brain structures remote from, but connected to, stroke lesions. Ipsilesional thalamic diaschisis has been described following adult stroke but has not been investigated in perinatal stroke. We hypothesized that thalamic diaschisis occurs in perinatal stroke and its degree would be inversely correlated with clinical motor function.

METHODS

Population-based, controlled cohort study. Participants were children (<19 years) with unilateral perinatal stroke (arterial ischemic stroke [AIS] or periventricular venous infarction [PVI]), anatomical magnetic resonance imaging (MRI) >6 months of age, symptomatic hemiparetic cerebral palsy, and no additional neurologic disorders. Typically developing controls had comparable age and gender proportions. T1-weighted anatomical scans were parcellated into 99 regions of interest followed by generation of regional volumes. The primary outcome was thalamic volume expressed as ipsilesional (ILTV), contralesional (CLTV) and thalamic ratio (CLTV/ILTV). Standardized clinical motor assessments were correlated with thalamic volume metrics.

RESULTS

Fifty-nine participants (12.9 years old ±4.0 years, 46% female) included 20 AIS, 11 PVI, and 28 controls. ILTV was reduced in both AIS and PVI compared to controls (p < .001, p = .029, respectively). Ipsilesional thalamic diaschisis was not associated with clinical motor function. However, CLTV was significantly larger in AIS compared to both controls and PVI (p = .005, p < .001, respectively). CLTV was inversely correlated with all four clinical motor assessments (all p < .003).

CONCLUSION

Bilateral thalamic volume changes occur after perinatal stroke. Ipsilesional volume loss is not associated with clinical motor function. Contralesional volume is inversely correlated with clinical motor function, suggesting the thalamus is involved in the known developmental plasticity that occurs in the contralesional hemisphere after early unilateral injury.

Crossed Cerebellar Atrophy in Perinatal Stroke

Background and Purpose- Perinatal stroke causes most hemiparetic cerebral palsy and lifelong disability. Crossed cerebellar atrophy (CCA) is chronic cerebellar volume loss following contralateral motor pathway injury. We hypothesized that CCA is quantifiable in perinatal stroke and associated with poor motor outcome. Methods- Term-born children with perinatal stroke, magnetic resonance imaging beyond 6 months of age, and no additional neurological disorders were recruited. Blinded scorers measured cerebellar volumes expressed as ratios (contralesional/ipsilesional), with values <1 suggesting CCA. Motor outcomes including perinatal stroke outcome measure (PSOM) motor and cognitive scores (good/poor), Assisting Hand Assessment, and Melbourne Assessment were compared with cerebellar volume measures. Results- Seventy-three children met criteria (53% male). Mean cerebellar ratios were <1.0 (0.975±0.04; range, 0.885-1.079; P<0.001) suggesting occurrence of CCA. Cerebellar ratios did not differ between stroke types or across PSOM motor outcomes. Larger ipsilesional cerebellar volume was associated with poor PSOM cognitive outcome (P=0.042), possibly with poor PSOM motor outcome (P=0.063), and overall PSOM score (P=0.034). Conclusions- CCA occurs in perinatal stroke but is not strongly associated with motor outcome. However, ipsilesional cerebellar volume is associated with poor cognitive and overall outcomes.

Perinatal arterial ischemic stroke

Perinatal arterial ischemic stroke is a relatively common and serious neurologic disorder that can affect the fetus, the preterm, and the term-born infant. It carries significant long-term disabilities. Herein we describe the current understanding of its etiology, pathophysiology and classification, different presentations, and optimal early management. We discuss the role of different brain imaging modalities in defining the extent of lesions and the impact this has on the prediction of outcomes. In recent years there has been progress in treatments, making early diagnosis and the understanding of likely morbidities imperative. An overview is given of the range of possible outcomes and optimal approaches to follow-up and support for the child and their family in the light of present knowledge.

Incidence of Epilepsy and Associated Risk Factors in Perinatal Ischemic Stroke Survivors

INTRODUCTION

Epilepsy is a serious and often lifelong consequence of perinatal arterial ischemic stroke (PAIS). Variable incidences and risk factors for long-term epilepsy in PAIS have been reported. To determine the incidence of epilepsy in PAIS survivors and report factors associated with the risk of developing epilepsy, a meta-analysis and systematic review of prior publications was performed.

METHODS

We examined studies on perinatal or neonatal patients (≤28 days of life) with arterial ischemic strokes in which the development of epilepsy was reported. EMBASE and MEDLINE/PubMed databases were systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

A meta-analysis of 10 studies revealed a summary incidence of epilepsy in PAIS patients of 27.2% (95% confidence interval 16.6% to 41.4%) over a mean study duration of 10.4 years (range 1.5 to 17). More recent studies generally reported a lower epilepsy incidence. A systematic review identified seven possible risk factors for epilepsy in PAIS patients: hippocampal volume reduction, infarct on prenatal ultrasound, a modified Alberta Stroke Program Early Computed Tomography score ≥9, family history of seizures, cerebral palsy, and initial presentation with cognitive impairment or seizures.

CONCLUSIONS

About a third of children with PAIS will develop epilepsy. While seven possible risk factors have been reported, further research is warranted to confirm the strength of their association with the development of epilepsy.

Current Therapeutic Management of Perinatal Stroke with a Focus on the Upper Limb: A Cross-Sectional Survey of UK Physiotherapists and Occupational Therapists

AIM

To determine current UK pediatric physiotherapist (PT) and occupational therapist (OT) management of perinatal stroke.

DESIGN

Web-based cross-sectional survey.

METHODS

Participants were members of the Association of Paediatric Chartered Physiotherapists and Occupational Therapists specialist section: children young people and families working with infants. Items covered prioritization of referrals, assessments, therapy approaches aimed at the upper limb, and parental support.

RESULTS

179 therapists responded. 87.2% of PTs and 63.0% of OTs managed infants with perinatal stroke. Infants with clinical signs of motor dysfunction at referral were prioritized for early initial assessment. The most frequently used assessments were the Alberta Infant Motor Scale (AIMS) and Bayley Scales of Infant Development (BSID). Of PTs and OTs, 41.9 and 40.0% used no standardized assessments. Frequently used therapy interventions were Bobath/Neurodevelopmental Therapy (NDT), positioning aids and passive movements. 88.1% of therapists would choose a bilateral rather than unilateral (affected side) therapy approach for infants with perinatal stroke aged up to 6 months. Of PTs and OTs, 56.9 and 57.1% provided psychological support to families.

CONCLUSIONS

Assessment and provision of therapy services following perinatal stroke is variable. Increased use of standardized assessments and centralized data collection regarding service provision for high-risk infants is recommended.

[Long term outcome of perinatal stroke]

Neonatal Arterial Ischemic Stroke (NAIS) affects 6-17 newborns on 100 000-birth term neonates, most of these children keeping long-term motor and cognitive impairments. Based on a literature review, the objectives of this paper are to describe motor and cognitive outcomes after a NAIS and to propose a consensual monitoring of these children to improve their management. About 30 % of children after a NAIS will develop a unilateral cerebral palsy requiring a management by a team with expertise in physical medicine and rehabilitation. Unlike adults, especially after a left NAIS, children will not present aphasia but between 50 and 90 % will present disorders of speech and language in expression and/or reception. After NAIS, the global intellectual efficiency is usually preserved except when the size of the lesion is very important or when severe epilepsy occurs. Several studies are also in favor of vulnerability in visuospatial functions. To quantify impairments, activity limitations and participation restrictions resulting from this NAIS, early and at least yearly evaluations with reliable tools must be carried out systematically until puberty. A multidisciplinary team with a longitudinal follow-up, in all the different developmental dimensions, must conduct these evaluations in term of motor skills, cognitive impairment, behavior, autonomy, quality of life, and participation. Consequences on family functioning need to be evaluate in order to help children and family coping with this event.

Imaging functional motor connectivity in hemiparetic children with perinatal stroke

Perinatal stroke causes lifelong disability, particularly hemiparetic cerebral palsy. Arterial ischemic strokes (AIS) are large, cortical, and subcortical injuries acquired near birth due to acute occlusion of the middle cerebral artery. Periventricular venous infarctions (PVI) are smaller, subcortical strokes acquired prior to 34 weeks gestation involving injury to the periventricular white matter. Both stroke types can damage motor pathways, thus, we investigated resulting alterations in functional motor networks and probed function. We measured blood oxygen level dependent (BOLD) fluctuations at rest in 38 participants [10 arterial patients (age = 14.7 ± 4.1 years), 10 venous patients (age = 13.5 ± 3.7 years), and 18 typically developing controls (TDCs) (age = 15.3 ± 5.1 years)] and explored strength and laterality of functional connectivity in the motor network. Inclusion criteria included MRI-confirmed, unilateral perinatal stroke, symptomatic hemiparetic cerebral palsy, and 6-19 years old at time of imaging. Seed-based functional connectivity analyses measured temporal correlations in BOLD response over the whole brain using primary motor cortices as seeds. Laterality indices based on mean z-scores in lesioned and nonlesioned hemispheres explored laterality. In AIS patients, significant differences in both strength and laterality of motor network connections were observed compared with TDCs. In PVI patients, motor networks largely resembled those of healthy controls, albeit slightly weaker and asymmetric, despite subcortical damage and hemiparesis. Functional connectivity strengths were not related to motor outcome scores for either stroke group. This study serves as a foundation to better understand how resting-state fMRI can assess motor functional connectivity and potentially be applied to explore mechanisms of interventional therapies after perinatal stroke.

Fetal stroke and cerebrovascular disease: Advances in understanding from lenticulostriate and venous imaging, alloimmune thrombocytopaenia and monochorionic twins

Fetal stroke is an important cause of cerebral palsy but is difficult to diagnose unless imaging is undertaken in pregnancies at risk because of known maternal or fetal disorders. Fetal ultrasound or magnetic resonance imaging may show haemorrhage or ischaemic lesions including multicystic encephalomalacia and focal porencephaly. Serial imaging has shown the development of malformations including schizencephaly and polymicrogyra after ischaemic and haemorrhagic stroke. Recognised causes of haemorrhagic fetal stroke include alloimmune and autoimmune thrombocytopaenia, maternal and fetal clotting disorders and trauma but these are relatively rare. It is likely that a significant proportion of periventricular and intraventricular haemorrhages are of venous origin. Recent evidence highlights the importance of arterial endothelial dysfunction, rather than thrombocytopaenia, in the intraparenchymal haemorrhage of alloimmune thrombocytopaenia. In the context of placental anastomoses, monochorionic diamniotic twins are at risk of twin twin transfusion syndrome (TTTS), or partial forms including Twin Oligohydramnios Polyhydramnios Sequence (TOPS), differences in estimated weight (selective Intrauterine growth Retardation; sIUGR), or in fetal haemoglobin (Twin Anaemia Polycythaemia Sequence; TAPS). There is a very wide range of ischaemic and haemorrhagic injury in a focal as well as a global distribution. Acute twin twin transfusion may account for intraventricular haemorrhage in recipients and periventricular leukomalacia in donors but there are additional risk factors for focal embolism and cerebrovascular disease. The recipient has circulatory overload, with effects on systemic and pulmonary circulations which probably lead to systemic and pulmonary hypertension and even right ventricular outflow tract obstruction as well as the polycythaemia which is a risk factor for thrombosis and vasculopathy. The donor is hypovolaemic and has a reticulocytosis in response to the anaemia while maternal hypertension and diabetes may influence stroke risk. Understanding of the mechanisms, including the role of vasculopathy, in well studied conditions such as alloimmune thrombocytopaenia and monochorionic diamniotic twinning may lead to reduction of the burden of antenatally sustained cerebral palsy.

Long-term neurodevelopmental outcome after perinatal arterial ischemic stroke and periventricular venous infarction

BACKGROUND

Long-term follow-up data after different vascular types of ischemic perinatal stroke is sparse. Our aim was to study neurodevelopmental outcomes following neonatal and presumed perinatal ischemic middle cerebral artery territory stroke (arterial ischemic stroke, AIS) and periventricular venous infarction (PVI).

METHODS

A prospective consecutive cohort of 40 term-born children with perinatal stroke (21 AIS, 19 PVI) was identified through the Estonian Paediatric Stroke Database. While 48% of the children with AIS were diagnosed during the neonatal period, all the children with PVI had presumed perinatal stroke. Outcomes based on the Paediatric Stroke Outcome Measure (PSOM) and Kaufman Assessment Battery for Children - Second Edition (K-ABC-II), in relation to extent and laterality of stroke, were defined.

RESULTS

At a median age of 7 years 6 months (range 3.6-13y), there was a trend towards worse neurodevelopmental outcome in participants with AIS when compared to PVI (mean total PSOM scores 3.1 and 2.2, respectively; p = 0.06). Combined deficits of motor, language and cognitive/behavioural functions were significantly more common among children with AIS (90%) when compared to children with PVI (53%, p = 0.007). General cognitive ability (by K-ABC-II) was significantly lower in the AIS subgroup (mean 79.6; 95% CI 72.3-87.0), but children with PVI (91.6; 95% CI 85.5-97.8) also had poorer performance than the age-equivalent normative mean. Large extent of stroke was associated with poorer neurodevelopmental outcome and lower cognitive performance in children following AIS but not in PVI.

CONCLUSION

In this national cohort, poor long-term neurodevelopmental outcome after perinatal ischemic stroke was seen irrespective of the vascular type or time of diagnosis of stroke. However, the spectrum of neurological deficits is different after perinatal AIS and PVI, with combined deficits more common among children following AIS.

Neurodevelopment After Perinatal Arterial Ischemic Stroke

BACKGROUND AND OBJECTIVES

Perinatal arterial ischemic stroke (PAIS) leads to cerebral palsy in ∼30% of affected children and has other neurologic sequelae. Authors of most outcome studies focus on middle cerebral artery (MCA) stroke without differentiating between site and extent of affected tissue. Our aim with this study was to report outcomes after different PAIS subtypes.

METHODS

Between 1990 and 2015, 188 term infants from 2 centers (London [n = 79] and Utrecht [n = 109]) had PAIS on their neonatal MRI. Scans were reevaluated to classify stroke territory and determine specific tissue involvement. At 18 to 93 (median 41.7) months, adverse neurodevelopmental outcomes were recorded as 1 or more of cerebral palsy, cognitive deficit, language delay, epilepsy, behavioral problems, or visual field defect.

RESULTS

The MCA territory was most often involved (90%), with posterior or anterior cerebral artery territory strokes occurring in 9% and 1%, respectively. Three infants died, and 24 had scans unavailable for reevaluation or were lost to follow-up. Of 161 infants seen, 54% had an adverse outcome. Outcomes were the same between centers. Main branch MCA stroke resulted in 100% adverse outcome, whereas other stroke subtypes had adverse outcomes in only 29% to 57%. The most important outcome predictors were involvement of the corticospinal tracts and basal ganglia.

CONCLUSIONS

Although neurodevelopmental outcome was adverse in at least 1 domain with main branch MCA stroke, in other PAIS subtypes outcome was favorable in 43% to 71% of children. Site and tissue involvement is most important in determining the outcome in PAIS.

The complex aetiology of cerebral palsy

Cerebral palsy (CP) is the most prevalent, severe and costly motor disability of childhood. Consequently, CP is a public health priority for prevention, but its aetiology has proved complex. In this Review, we summarize the evidence for a decline in the birth prevalence of CP in some high-income nations, describe the epidemiological evidence for risk factors, such as preterm delivery and fetal growth restriction, genetics, pregnancy infection and other exposures, and discuss the success achieved so far in prevention through the use of magnesium sulfate in preterm labour and therapeutic hypothermia for birth-asphyxiated infants. We also consider the complexities of disentangling prenatal and perinatal influences, and of establishing subtypes of the disorder, with a view to accelerating the translation of evidence into the development of strategies for the prevention of CP.

Evaluation and Acute Management of Ischemic Stroke in Infants and Children

PURPOSE OF REVIEW

This article provides an overview of stroke in neonates, infants, and children.

RECENT FINDINGS

Arterial ischemic stroke and cerebral venous sinus thrombosis are increasingly recognized in childhood as important causes of lifelong morbidity and mortality. Diagnosis of arterial ischemic stroke is frequently delayed, as acute neurologic deficits can be challenging to detect in the young child, and stroke is often not considered in the differential diagnosis. Neurologic sequelae following stroke are common, and strategies to minimize stroke size and optimize recovery are being developed. Recurrent arterial ischemic stroke is not uncommon, particularly in children with cerebral arteriopathy. Cerebral venous sinus thrombosis causes obstruction of venous outflow leading to venous infarcts. Complications include hemorrhagic conversion of infarcts and increased intracranial pressure. Without treatment, thrombus extension with increased symptoms is common. Robust guidelines of care that exist for adults do not exist for children, particularly for children with arterial ischemic stroke.

SUMMARY

The approach to stroke in infants and children can be informed by clinical experience in pediatric stroke and cerebral venous sinus thrombosis, the extensive literature on pediatric thrombosis, and extrapolation from data from adult patients.

Bilateral reaching deficits after unilateral perinatal ischemic stroke: a population-based case-control study

BACKGROUND

Detailed kinematics of motor impairment of the contralesional ("affected") and ipsilesional ("unaffected") limbs in children with hemiparetic cerebral palsy are not well understood. We aimed to 1) quantify the kinematics of reaching in both arms of hemiparetic children with perinatal stroke using a robotic exoskeleton, and 2) assess the correlation of kinematic reaching parameters with clinical motor assessments.

METHODS

This prospective, case-control study involved the Alberta Perinatal Stroke Project, a population-based research cohort, and the Foothills Medical Center Stroke Robotics Laboratory in Calgary, Alberta over a four year period. Prospective cases were collected through the Calgary Stroke Program and included term-born children with magnetic resonance imaging confirmed perinatal ischemic stroke and upper extremity deficits. Control participants were recruited from the community. Participants completed a visually guided reaching task in the KINARM robot with each arm separately, with 10 parameters quantifying motor function. Kinematic measures were compared to clinical assessments and stroke type.

RESULTS

Fifty children with perinatal ischemic stroke (28 arterial, mean age: 12.5 ± 3.9 years; 22 venous, mean age: 11.5 ± 3.8 years) and upper extremity deficits were compared to healthy controls (n = 147, mean age: 12.7 ± 3.9 years). Perinatal stroke groups demonstrated contralesional motor impairments compared to controls when reaching out (arterial = 10/10, venous = 8/10), and back (arterial = 10/10, venous = 6/10) with largest errors in reaction time, initial direction error, movement length and time. Ipsilesional impairments were also found when reaching out (arterial = 7/10, venous = 1/10) and back (arterial = 6/10). The arterial group performed worse than venous on both contralesional and ipsilesional parameters. Contralesional reaching parameters showed modest correlations with clinical measures in the arterial group.

CONCLUSIONS

Robotic assessment of reaching behavior can quantify complex, upper limb dysfunction in children with perinatal ischemic stroke. The ipsilesional, "unaffected" limb is often abnormal and may be a target for therapeutic interventions in stroke-induced hemiparetic cerebral palsy.

Perinatal stroke: mechanisms, management, and outcomes of early cerebrovascular brain injury

Perinatal stroke encompasses a heterogeneous group of focal neurological injuries early in brain development that probably affects more than 5 million people worldwide. Many such injuries are symptomatic in the first days of life, including neonatal arterial ischaemic stroke, cerebral sinovenous thrombosis, and neonatal haemorrhagic stroke. The remaining focal neurological injuries usually present later in the first year with motor asymmetry, such as arterial presumed perinatal ischaemic stroke, periventricular venous infarction, and presumed perinatal haemorrhagic stroke. The numerous sequelae of these injuries include hemiparesis (cerebral palsy), epilepsy, and cognitive, language, and behavioural challenges. In this Review we summarise each perinatal stroke disease, examining the epidemiology, pathophysiology, acute management, and outcomes, including the effect on parents and families, and emerging therapies to mitigate these lifelong morbidities.

Imaging the term neonatal brain

Brain imaging is important for the diagnosis and management of sick term neonates. Although ultrasound and computed tomography may provide some information, magnetic resonance imaging is now the brain imaging modality of choice because it is the most sensitive technique for detecting and quantifying brain abnormalities and does not expose infants to radiation. This statement describes the principles, roles and limitations of these three imaging modalities and makes recommendations for appropriate use in term neonates. The primary focus is the brain of term infants with neonatal encephalopathy, many of whom are diagnosed with hypoxic-ischemic encephalopathy.

Bihemispheric alterations in myelination in children following unilateral perinatal stroke

Background

Stroke is a leading cause of perinatal brain injury with variable outcomes including cerebral palsy and epilepsy. The biological processes that underlie these heterogeneous outcomes are poorly understood. Alterations in developmental myelination are recognized as a major determinant of outcome in preterm brain injury but have not been explored in perinatal stroke. We aimed to characterize myelination in hemiparetic children after arterial perinatal stroke, hypothesizing that ipsilesional myelination would be impaired, the degree of which would correlate with poor outcome.

Methods

Retrospective, controlled cohort study. Participants were identified through the Alberta Perinatal Stroke Project (APSP), a population-based research cohort (n > 400). Inclusion criteria were: 1) MRI-confirmed, unilateral arterial perinatal stroke, 2) T1-weighted MRI after 6 months of age, 3) absence of other neurological disorders, 4) neurological outcome that included at least one of the following tests - Pediatric Stroke Outcome Measure (PSOM), Assisting Hand Assessment (AHA), Melbourne Assessment (MA), neuropsychological evaluation (NPE), and robotic sensorimotor measurements. FreeSurfer software measured hemispheric asymmetry in myelination intensity (primary outcome). A second method using ImageJ software validated the detection of myelination asymmetry. A repeated measures ANOVA was used to compare perilesional, ipsilesional remote, and contralesional homologous region myelination between stroke cases and typically developing controls. Myelination metrics were compared to clinical outcome measures (t-test, Pearson's correlation).

Results

Twenty youth with arterial stroke (mean age: 13.4 ± 4.2yo) and 27 typically developing controls (mean age: 12.5 ± 3.7yo) were studied in FreeSurfer. Participants with stroke demonstrated lower myelination in the ipsilesional hemisphere (p < 0.0001). Myelination in perilesional regions had lower intensity compared to ipsilesional remote areas (p < .00001) and contralesional homologous areas (p < 0.00001). Ipsilesional remote regions had decreased myelination compared to homologous regions on the contralesional hemisphere (p = 0.016). Contralesional myelination was decreased compared to controls (p < 0.00001). Myelination metrics were not strongly associated with clinical motor, robotic sensorimotor, or neuropsychological outcomes though some complex tests requiring speeded responses had moderate effect sizes.

Conclusion

Myelination of apparently uninjured brain in both the ipsilesional and contralesional hemispheres is decreased after perinatal stroke. Differences appear to radiate outward from the lesion. Further study is needed to determine clinical significance.

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Myelination is altered in the lesioned hemisphere after perinatal stroke.

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The uninjured, contralesional hemisphere also demonstrates differences in myelination.

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Simple software can estimate MRI myelination abnormalities in children with perinatal brain injury.

Neuropsychological Outcome in Perinatal Stroke Associated With Epileptiform Discharges in Sleep

BACKGROUND

Patients with arterial perinatal stroke often suffer long-term motor sequelae, difficulties in language, social development, and behaviour as well as epilepsy. Despite homogeneous lesions, long-term behavioural and cognitive outcomes are variable and unpredictable. Sleep-related epileptic encephalopathies can occur after early brain injury and are associated with global developmental delays. We hypothesized that sleep-potentiated epileptiform abnormalities are associated with worse developmental outcomes after perinatal stroke.

METHODS

Participants were identified from a population-based cohort (Alberta Perinatal Stroke Project). Inclusion criteria were magnetic resonance imaging-confirmed arterial perinatal stroke, age 4 to 18 years, electroencephalogram (EEG) including sleep, and comprehensive neuropsychological evaluation. Sleep-related EEG abnormalities were categorized by an epileptologist blinded to the cognitive outcome. Associations between EEG classification and neuropsychological outcomes were explored (t tests, Bonferroni correction for multiple comparisons).

RESULTS

Of 128 potentially eligible participants, 34 (53% female) had complete EEG (mean age, 8.1 years; range, 0.2-16.4) and neuropsychology testing (mean age, 9.8 years; range 4.4-16.7). Twelve (35%) were classified as having electrical status epilepticus in sleep. Patients with abnormal EEGs were more likely to have statistically worse scores when corrected for multiple comparisons, in receptive language (median, 1st percentile; IQR 1-7th percentile; p<0.05), and externalizing behaviours (median, 82nd percentile; IQR, 79-97th percentile; p<0.05).

CONCLUSIONS

Developmental outcome in language and behaviour in children with arterial perinatal stroke is associated with electrical status epilepticus in sleep. Increased screening with sleep EEG is suggested, whereas further studies are necessary to determine if treatment of EEG abnormalities can improve outcome.

Epilepsy after perinatal stroke with different vascular subtypes

Objective

With an incidence up to 63 per 100,000 live births, perinatal stroke is an important cause of childhood epilepsy. The aim of the study was to find the prevalence of and predictive factors for epilepsy, and to describe the course of epilepsy in children with perinatal stroke with different vascular subtypes.

Methods

Patients were retrieved from the Estonian Paediatric Stroke Database with follow‐up time at least 24 months. Patients were divided into 5 perinatal stroke syndromes: neonatal arterial ischemic stroke (AIS), neonatal hemorrhagic stroke, neonatal cerebral sinovenous thrombosis, presumed AIS, and presumed periventricular venous infarction.

Results

The final study group included 73 children with perinatal stroke (39 boys). With a median follow‐up time of 8.6 years, epilepsy was diagnosed in 21/73 (29%) children, most of whom had AIS (17/21, 81%). The 18‐year cumulative poststroke epilepsy risk according to the Kaplan‐Meier estimator was 40.8% (95% confidence interval [CI] 20.7–55.9%). The median age at epilepsy diagnosis was 50 months (range 1 month to 18.4 years). Children with neonatal AIS had the highest risk of epilepsy, but children with presumed AIS more often had severe epilepsy syndromes. Cortical lesions (odds ratio [OR] 19.7, 95% CI 2.9–133), and involvement of thalamus (OR 9.8, 95% CI 1.8–53.5) and temporal lobe (OR 8.3, 95% CI 1.8–39.6) were independently associated with poststroke epilepsy.

Significance

The risk for poststroke epilepsy after perinatal stroke depends on the vascular subtype. Patients with perinatal AIS need close follow‐up to detect epilepsy and start with antiepileptic treatment on time.

Corticospinal tract diffusion properties and robotic visually guided reaching in children with hemiparetic cerebral palsy

Perinatal stroke is the leading cause of hemiparetic cerebral palsy (CP), resulting in life-long disability. In this study, we examined the relationship between robotic upper extremity motor impairment and corticospinal tract (CST) diffusion properties. Thirty-three children with unilateral perinatal ischemic stroke (17 arterial, 16 venous) and hemiparesis were recruited from a population-based research cohort. Bilateral CSTs were defined using diffusion tensor imaging (DTI) and four diffusion metrics were quantified: fractional anisotropy (FA), mean (MD), radial (RD), and axial (AD) diffusivities. Participants completed a visually guided reaching task using the KINARM robot to define 10 movement parameters including movement time and maximum speed. Twenty-six typically developing children underwent the same evaluations. Partial correlations assessed the relationship between robotic reaching and CST diffusion parameters. All diffusion properties of the lesioned CST differed from controls in the arterial group, whereas only FA was reduced in the venous group. Non-lesioned CST diffusion measures were similar between stroke groups and controls. Both stroke groups demonstrated impaired reaching performance. Multiple reaching parameters of the affected limb correlated with lesioned CST diffusion properties. Lower FA and higher MD were associated with greater movement time. Few correlations were observed between non-lesioned CST diffusion and unaffected limb function though FA was associated with reaction time (R = -0.39, p < .01). Diffusion properties of the lesioned CST are altered after perinatal stroke, the degree of which correlates with specific elements of visually guided reaching performance, suggesting specific relevance of CST structural connectivity to clinical motor function in hemiparetic children.

Interhemispheric motor interactions in hemiparetic children with perinatal stroke: Clinical correlates and effects of neuromodulation therapy

OBJECTIVE

Brain stimulation and constraint therapy may enhance function after perinatal stroke but mechanisms are unknown. We characterized interhemispheric interactions (IHI) in hemiparetic children and explored their relationship to motor function and neuromodulation.

METHODS

Forty-five hemiparetic perinatal stroke subjects aged 6-19 years completed a clinical trial of repetitive-transcranial magnetic stimulation (rTMS) and constraint therapy. Paired-pulse TMS measured IHI in cases and normal controls. Suprathreshold conditioning stimuli preceded contralateral test stimuli bidirectionally: stroke to non-stroke (SNS) and non-stroke to stroke (NSS). Primary outcome was the interhemispheric ratio (IHR) between conditioned and test only MEP amplitudes X100 (<100 implied inhibition). Motor outcomes at baseline and post-intervention were compared to IHR.

RESULTS

Procedures were well tolerated. IHI occurred bidirectionally in controls. Eighteen stroke participants had complete data. IHR were increased in stroke participants in both directions. SNS IHR was >100 (facilitation) in 39% of measurements and correlated with better motor function. NSS IHR correlated with poorer motor function. Intervention-induced clinical change was not associated with IHR.

CONCLUSIONS

Interhemispheric interactions are altered and related to clinical function, but not necessarily neuromodulation, in children with perinatal stroke.

SIGNIFICANCE

Adding interhemispheric interactions to evolving models of developmental plasticity following early injury may advance neuromodulation strategies.

Changes in spectroscopic biomarkers after transcranial direct current stimulation in children with perinatal stroke

BACKGROUND

Perinatal stroke causes lifelong motor disability, affecting independence and quality of life. Non-invasive neuromodulation interventions such as transcranial direct current stimulation (tDCS) combined with intensive therapy may improve motor function in adult stroke hemiparesis but is under-explored in children. Measuring cortical metabolites with proton magnetic resonance spectroscopy (MRS) can inform cortical neurobiology in perinatal stroke but how these change with neuromodulation is yet to be explored.

METHODS

A double-blind, sham-controlled, randomized clinical trial tested whether tDCS could enhance intensive motor learning therapy in hemiparetic children. Ten days of customized, goal-directed therapy was paired with cathodal tDCS over contralesional primary motor cortex (M1, 20 min, 1.0 mA, 0.04 mA/cm²) or sham. Motor outcomes were assessed using validated measures. Neuronal metabolites in both M1s were measured before and after intervention using fMRI-guided short-echo 3T MRS.

RESULTS

Fifteen children [age(range) = 12.1(6.6-18.3) years] were studied. Motor performance improved in both groups and tDCS was associated with greater goal achievement. After cathodal tDCS, the non-lesioned M1 showed decreases in glutamate/glutamine and creatine while no metabolite changes occurred with sham tDCS. Lesioned M1 metabolite concentrations did not change post-intervention. Baseline function was highly correlated with lesioned M1 metabolite concentrations (N-acetyl-aspartate, choline, creatine, glutamate/glutamine). These correlations consistently increased in strength following intervention. Metabolite changes were not correlated with motor function change. Baseline lesioned M1 creatine and choline levels were associated with clinical response.

CONCLUSIONS

MRS metabolite levels and changes may reflect mechanisms of tDCS-related M1 plasticity and response biomarkers in hemiparetic children with perinatal stroke undergoing intensive neurorehabilitation.

De novo and rare inherited copy-number variations in the hemiplegic form of cerebral palsy

Purpose

Hemiplegia is a subtype of cerebral palsy (CP) in which one side of the body is affected. Our earlier study of unselected children with CP demonstrated de novo and clinically relevant rare inherited genomic copy-number variations (CNVs) in 9.6% of participants. Here, we examined the prevalence and types of CNVs specifically in hemiplegic CP.

Methods

We genotyped 97 unrelated probands with hemiplegic CP and their parents. We compared their CNVs to those of 10,851 population controls, in order to identify rare CNVs (<0.1% frequency) that might be relevant to CP. We also sequenced exomes of “CNV-positive” trios.

Results

We detected de novo CNVs and/or sex chromosome abnormalities in 7/97 (7.2%) of probands, impacting important developmental genes such as GRIK2, LAMA1, DMD, PTPRM, and DIP2C. In 18/97 individuals (18.6%), rare inherited CNVs were found, affecting loci associated with known genomic disorders (17p12, 22q11.21) or involving genes linked to neurodevelopmental disorders.

Conclusion

We found an increased rate of de novo CNVs in the hemiplegic CP subtype (7.2%) compared to controls (1%). This result is similar to that for an unselected CP group. Combined with rare inherited CNVs, the genomic data impacts the understanding of the potential etiology of hemiplegic CP in 23/97 (23.7%) of participants.

Collagenosis of the Deep Medullary Veins: An Underrecognized Pathologic Correlate of White Matter Hyperintensities and Periventricular Infarction?

White matter hyperintensities (WMH) are prevalent. Although arteriolar disease has been implicated in their pathogenesis, venous pathology warrants consideration. We investigated relationships of WMH with histologic venous, arteriolar and white matter abnormalities and correlated findings with premortem neuroimaging. Three regions of periventricular white matter were sampled from archived autopsy brains of 24 pathologically confirmed Alzheimer disease (AD) and 18 age-matched nonAD patients. Using trichrome staining, venous collagenosis (VC) of periventricular veins (<150 µm in diameter) was scored for severity of wall thickening and occlusion; percent stenosis by collagenosis of large caliber (>200 µm) veins (laVS) was measured. Correlations were made between WMH in premortem neuroimaging and vascular and white matter pathology. We found greater VC (U(114) = 2092.5, p = 0.005 and U(114) = 2121.5, p = 0.002 for small and medium caliber veins, respectively) and greater laVS (t(110) = 3.46, p = 0.001) in patients with higher WMH scores; WMH scores correlated with VC (rs(114) = 0.27, p = 0.004) and laVS (rs(110) = 0.38, p < 0.001). By multiple linear regression analysis, the strongest predictor of WMH score was laVS (β = 0.338, p < 0.0001). VC was frequent in patients with periventricular infarcts identified on imaging. We conclude that periventricular VC is associated with WMH in both AD and nonAD patients and the potential roles of VC in WMH pathogenesis merit further study.

Clinical Manifestations, Outcomes, and Etiologies of Perinatal Stroke in Taiwan: Comparisons between Ischemic, and Hemorrhagic Stroke Based on 10-year Experience in A Single Institute

BACKGROUND

Perinatal stroke is a common cause of established neurological sequelae. Although several risk factors have been identified, many questions regarding causes and clinical outcomes remain unanswered. This study investigated the clinical manifestations and outcomes of perinatal stroke and identified its etiologies in Taiwan.

METHODS

We searched the reports of head magnetic resonance imaging and computed tomography performed between January 2003 and December 2012. The medical records of enrolled infants with perinatal stroke were also reviewed.

RESULTS

Thirty infants with perinatal stroke were identified; 10 infants had perinatal arterial ischemic stroke (PAIS) and 20 had perinatal hemorrhagic stroke (PHS). Neonatal seizure was the most common manifestation and presented in 40% of infants with PAIS and 50% of infants with PHS. All survivors with PAIS and 77% of the surviving infants with PHS developed neurological sequelae. Acute seizure manifestation was associated with poststroke epilepsy in infants with PHS but not in infants with PAIS (86% vs. 0%, p=0.005). PAIS was mostly caused by dysfunctional hemostasis (20%) and embolism (20%), whereas PHS was mostly attributable to birth asphyxia (30%).

CONCLUSION

Perinatal stroke is associated with high mortality and morbidity rates in infants. Clinically, it can be difficult to distinguish PAIS and PHS. One should keep a high level of suspicion, especially for PHS, if infants develop unexplained seizure, cyanosis, conscious change, anemia, and/or thrombocytopenia. A systematic diagnostic approach is helpful in identifying the etiologies of perinatal stroke.

Thrombophilia risk is not increased in children after perinatal stroke

Thrombophilia in children with perinatal stroke is rare, with rates similar to those in the normal population. Routine testing in childhood is not indicated.

Spatial Orientation and Navigation in Children With Perinatal Stroke

As a focal injury in an otherwise healthy child, perinatal stroke provides a clinical model of developmental brain plasticity. In this study, we report evidence that children with perinatal periventricular venous infarcts perform as well as control children on a video game that tests navigation abilities. In addition, children with a history of perinatal arterial strokes overcame initial deficits in navigation performance after additional practice. These findings lend support to the hypothesis that a complex cognitive skill dependent on a distributed neural network with prolonged maturation, such as navigation, may demonstrate resilience after early brain injury.