Inherited Metabolic Causes of Stroke in Children: Mechanisms, Types, and Management

MRI in LARS1 deficiency-Spectrum, patterns, and correlation with acute neurological deterioration

Leucine aminoacyl tRNA-synthetase 1 (LARS1)-deficiency (infantile liver failure syndrome type 1 (ILFS1)) has a multisystemic phenotype including fever-associated acute liver failure (ALF), chronic neurologic abnormalities, and encephalopathic episodes. In order to better characterize encephalopathic episodes and MRI changes, 35 cranial MRIs from 13 individuals with LARS1 deficiency were systematically assessed and neurological phenotype was analyzed. All individuals had developmental delay and 10/13 had seizures. Encephalopathic episodes in 8/13 were typically associated with infections, presented with seizures and reduced consciousness, mostly accompanied by hepatic dysfunction, and recovery in 17/19 episodes. Encephalopathy without hepatic dysfunction occurred in one individual after liver transplantation. On MRI, 5/7 individuals with MRI during acute encephalopathy had deep gray matter and brainstem changes. Supratentorial cortex involvement (6/13) and cerebellar watershed injury (4/13) occurred with seizures and/or encephalopathy. Abnormal brainstem contour on sagittal images (8/13), atrophy (8/13), and myelination delay (8/13) were not clearly associated with encephalopathy. The pattern of deep gray matter and brainstem changes are apparently characteristic of encephalopathy in LARS1-deficiency, differing from patterns of hepatic encephalopathy or metabolic stroke in organic acidurias and mitochondrial diseases. While the pathomechanism remains unclear, fever and energy deficit during infections might be causative; thus, sufficient glucose and protein intake along with pro-active fever management is suggested. As severe episodes were observed during influenza infections, we strongly recommend seasonal vaccination.

Factors Associated with Pathway-Concordant Neuroimaging for Pediatric Ischemic Stroke

OBJECTIVE

To determine factors associated with magnetic resonance imaging (MRI) and noninvasive diagnostic angiography among children presenting to the emergency department (ED) with acute ischemic stroke.

STUDY DESIGN

We performed a cross-sectional study using data from >50 US children's hospitals. We included children 29 days through 17 years old hospitalized from the ED with an International Classification of Diseases, Tenth Revision, Clinical Modification, diagnosis code for acute ischemic stroke between October 1, 2015, and November 30, 2022. We excluded children with a principal diagnosis code of trauma/external injury, without neuroimaging on day of presentation, and into-ED transfers. Our outcomes were defined as acquisition of MRI (vs computed tomography only) and angiography (vs no angiography) on day of presentation. We performed generalized linear mixed modeling with hospital as a random effect to determine the association of demographics, known comorbidities, and treatment factors with each outcome.

RESULTS

We included 1601 children. In multivariable analysis, younger age, mechanical ventilation, and Black race were associated with lower odds of MRI acquisition, whereas history of moyamoya disease and sickle cell disease were associated with greater odds. Younger age, mechanical ventilation, Hispanic ethnicity, Black race, other races, history of metabolic disease, and history of seizures were associated with lower odds of angiography.

CONCLUSIONS

Younger and non-White children experienced lower odds of MRI and angiography, which may be driven by health system limitations or provider implicit biases or both. Our results expose risk factors for underdiagnosis of ischemic stroke and provide opportunities to tailor institutional pathways reflective of underlying pathophysiology.

Metabolic Stroke as a Clinical Manifestation of Zhu-Tokita-Takenouchi-Kim Syndrome: A Case Series

Objective

This study reports 2 unrelated individuals with Zhu-Tokita-Takenouchi-Kim (ZTTK) syndrome who presented with a metabolic stroke, which has not been commonly reported as a clinical manifestation of this syndrome.

Methods

Two female children were identified after presenting to our institution with a metabolic stroke and carried a diagnosis of ZTTK syndrome because of their clinical characteristics and previous genetic testing demonstrating pathogenic variants in SON.

Results

Both individuals presented with acute-onset left hemiplegia. They underwent workup, and corresponding metabolic stroke was identified on brain MRI. Both individuals recovered with good functional outcome. One individual was treated with l-arginine, ubiquinol, and levocarnitine. The other individual recovered without any intervention.

Discussion

ZTTK syndrome is a rare condition caused by pathogenic variants in SON. This syndrome is characterized by global developmental delay, short stature, facial dysmorphisms, seizures, hypotonia, and brain abnormalities. A metabolic stroke has not been reported as a common manifestation. SON has been reported to play a role in mitochondrial function. This can explain why metabolic stroke can be seen in individuals with ZTTK syndrome. It is important to recognize that metabolic stroke can be a clinical manifestation of ZTTK syndrome because it carries clinical and therapeutic implications.

Angiopathy and Stroke Associated with Homocystinuria in Childhood

A previously healthy 13 year-old boy presented with acute-onset headaches, aphasia and right-sided hemiparesis. Imaging showed cerebral ischemic infarction due to bilateral carotid occlusion, and investigation for stroke etiology diagnosed homocystinuria. Homocystinuria is an autosomal recessive condition that affects the metabolism of the amino acid methionine due to an enzyme deficiency. This disorder involves multiple organs systems, and complications include thromboembolic events, ectopia lentis, mental retardation, and skeletal abnormalities. The early diagnosis and treatment of hyperhomocystinemia can significantly improve outcomes. Therefore, metabolic screening for homocystinuria is strongly recommended for children presenting with stroke.

Cerebral Arteriopathies of Childhood - Current Approaches

Up to more than half of previously healthy children presenting with their first arterial ischemic stroke have a cerebral arteriopathy. Cerebral arteriopathies during childhood can be congenital, reflecting abnormal vessel development, or acquired when caused by disruption of vascular homeostasis. Distinguishing different types of cerebral arteriopathies in children can be challenging but of great clinical value as they may dictate different disease and treatment courses, and clinical and radiologic outcomes. Furthermore, children with stroke due to a specific arteriopathy exhibit distinctive features when compared to those with stroke due to other causes or a different type of arteriopathy. These features become crucial in the management of pediatric stroke by choosing appropriate diagnostic and treatment strategies. The objective of this article is to provide the reader with a comprehensive up-to-date review of the classification, symptoms, diagnosis, treatment, and outcome of cerebral arteriopathies in children.

Stroke-like Episodes in Inherited Neurometabolic Disorders

Stroke-like episodes (SLEs) are significant clinical manifestations of metabolic disorders affecting the central nervous system. Morphological equivalents presented in neuroimaging procedures are described as stroke-like lesions (SLLs). It is crucial to distinguish SLEs from cerebral infarction or intracerebral hemorrhage, mainly due to the variety in management. Another significant issue to underline is the meaning of the main pathogenetic hypotheses in the development of SLEs. The diagnostic process is based on the patient’s medical history, physical and neurological examination, neuroimaging techniques and laboratory and genetic testing. Implementation of treatment is generally symptomatic and includes L-arginine supplementation and adequate antiepileptic management. The main aim of the current review was to summarize the basic and actual knowledge about the occurrence of SLEs in various inherited neurometabolic disorders, discuss the possible pathomechanism of their development, underline the role of neuroimaging in the detection of SLLs and identification of the electroencephalographic patterns as well as histological abnormalities in inherited disorders of metabolism.

The Genetic Basis of Strokes in Pediatric Populations and Insight into New Therapeutic Options

Strokes within pediatric populations are considered to be the 10th leading cause of death in the United States of America, with over half of such events occurring in children younger than one year of life. The multifactorial etiopathology that has an influence on stroke development and occurrence signify the importance of the timely recognition of both modifiable and non-modifiable factors for adequate diagnostic and treatment approaches. The early recognition of a stroke and stroke risk in children has the potential to advance the application of neuroprotective, thrombolytic, and antithrombotic interventions and rehabilitation strategies to the earliest possible timepoints after the onset of a stroke, improving the outcomes and quality of life for affected children and their families. The recent development of molecular genetic methods has greatly facilitated the analysis and diagnosis of single-gene disorders. In this review, the most significant single gene disorders associated with pediatric stroke are presented, along with specific therapeutic options whenever they exist. Besides monogenic disorders that may present with stroke as a first symptom, genetic polymorphisms may contribute to the risk of pediatric and perinatal stroke. The most frequently studied genetic risk factors are several common polymorphisms in genes associated with thrombophilia; these genes code for proteins that are part of the coagulation cascade, fibrolysis, homocystein metabolism, lipid metabolism, or platelets. Single polymorphism frequencies may not be sufficient to completely explain the stroke causality and an analysis of several genotype combinations is a more promising approach. The recent steps forward in our understanding of the disorders underlying strokes has given us a next generation of therapeutics and therapeutic targets by which to improve stroke survival, protect or rebuild neuronal connections in the brain, and enhance neural function. Advances in DNA sequencing and the development of new tools to correct human gene mutations have brought genetic analysis and gene therapy into the focus of investigations for new therapeutic options for stroke patients.