Exploratory Investigation of Brain MRI Lesions According to Whole Sample and Visual Function Subtyping in Children With Cerebral Visual Impairment

BACKGROUND: There is limited research on brain lesions in children with cerebral visual impairment (CVI) of heterogeneous etiologies and according to associated subtyping and vision dysfunctions. This study was part of a larger project establishing data-driven subtypes of childhood CVI according to visual dysfunctions. Currently there is no consensus in relation to assessment, diagnosis and classification of CVI and more information about brain lesions may be of potential diagnostic value. Aim: This study aimed to investigate overall patterns of brain lesions and associations with level of visual dysfunction and to compare the patterns between the classification subgroups in children with CVI. METHODS: School-aged children with CVI received ophthalmological and neuro-psychological/developmental assessments to establish CVI-related subtyping. Other pediatric information was collected from medical records. MRI scans were coded according to a semi-quantitative template including brain regions (right hemisphere, left hemisphere, visual pathways) and summed for total scores. Non-parametric analyses were conducted. RESULTS: 28 children had clinical brain MRI scans available [44% of total sample, Group A (lower severity of visual dysfunctions) n = 16, Group B (higher severity) n = 12]. Total brain scores ranged between 0 and 18 (Group A mdn = 7, IQR = 0.8–10.0, Group B mdn = 10, IQR = 6.5–11.8) and were widespread across regions. 71 per cent had post-geniculate visual pathway damage. The median total brain and hemisphere scores of Group B were higher than subgroup A but differences did not reach statistical significance. No statistically significant associations were found between brain scores and vision variables (acuity, contrast sensitivity). CONCLUSION: This study found a spread of lesions across all regions on the brain scans in children with congenital CVI. The majority had damage in the postgeniculate visual pathways and visual cortex region suggesting this is an area of interest and potentially informative for diagnosis. However the subtyping classification did not show differences in number or region of lesions though the trend was higher toward Group B. This study confirms the complex diffuse and variable nature of brain lesions in children with congenital CVI, many of whom have other neurological impairments

Brain malformations associated to Aldh7a1 gene mutations: Report of a novel homozygous mutation and literature review

Background: The ALDH7A1 gene is known to be responsible for autosomal recessive pyridoxine-dependent epilepsy (OMIM 266100). The phenotypic spectrum of ALDH7A1 mutations is very heterogeneous ranging from refractory epilepsy and neurodevelopmental delay, to multisystem neonatal disorder. Aim: The present study aims at describing the phenotype associated with a novel homozygous ALDH7A1 mutation and the spectrum of brain malformations associated with pyridoxine-dependent epilepsy. Methods: We conducted a literature review on the Internet database Pubmed (up to November 2017) searching for ALDH7A1 mutations associated with brain malformations and brain MRI findings. Results: We present the case of two siblings, children of related parents. The proband presented neonatal focal seizures not responding to conventional antiepileptic drugs. Electroencephalography showed a suppression burst pattern and several multifocal ictal patterns, responsive to pyridoxine. Brain MRI was normal. Molecular analysis by targeted next-generation sequencing panel for epileptic encephalopathy disclosed a homozygous missense mutation of ALDH7A1. The same mutation was then found in a stored sample of DNA from peripheral blood of an older sister dead 3 years earlier. This girl presented a complex brain malformation diagnosed with a foetal MRI and had neonatal refractory seizures with suppression burst pattern. She died at 6 months of age. Literature review: The brain abnormalities most frequently reported in pyridoxine-dependent epilepsy include: agenesia/hypoplasia of the corpus callosum, not specific white matter abnormalities, large cisterna magna, ventriculomegaly, haemorrhages, cerebellum hypoplasia/dysplasia, and, more rarely, dysplasia of the brainstem and hydrocephalus. Discussion and conclusions: ALDH7A1 mutations have been associated to different brain abnormalities, documented by MRI only in few cases. The study cases expand the clinical spectrum of ALDH7A1 associated conditions, suggesting to look for ALDH7A1 mutations not only in classical phenotypes but also in patients with brain malformations, mainly if there is a response to a pyridoxine trial

Moyamoya syndrome and 6p chromosome rearrangements: Expanding evidences of a new association

Background: Moyamoya syndrome represents an etiologically heterogeneous cerebral evolutive angiopathy. It can be associated with both well-characterized and recently described genetic conditions with mendelian inheritance. Case report: We report the case of a moyamoya angiopathy in a prematurely born girl affected by congenital heart defect, mild facial dysmorphism, mild neurodevelopmental delay and borderline cognitive profile, associated to a de novo complex rearrangement involving the terminal segment of the short arm of chromosome 6. Conclusion: To the best of our knowledge, this is the second case described of pediatric moyamoya syndrome associated with a 6p complex rearrangement. Adding this case to the pertinent literature, we discuss the pathogenic role of rearrangements in 6p region in moyamoya syndrome and suggest to investigate in this region potential genes involved in angiogenesis or vascular homeostasis. (C) 2016 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved

Temporal bone and intracranial abnormalities in syndromic causes of hearing loss: an updated guide.

To describe in detail the temporal bone and brain findings in both common and rare syndromic causes of hearing loss, with the purpose of broadening among radiologists and enhance the current understanding of distinct imaging features in paediatric patients with syndromic hearing loss. A detailed search of electronic databases has been conducted, including PubMed, Ovid Medline, Scopus, Cochrane Library, Google Scholar, National Institute for Health and Care Excellence (NICE), Embase, and PsycINFO. Syndromic causes of hearing loss are characterised by different and sometimes specific abnormalities in the temporal bone. A complete knowledge of the image findings in the temporal bones, brain, skull and other body regions is critical for the optimal assessment and management of these patients

Neonatal mitochondrial leukoencephalopathy with brain and spinal involvement and high lactate: expanding the phenotype of ISCA2 gene mutations

A homoallelic missense founder mutation of the iron-sulfur cluster assembly 2 (ISCA2) gene has been recently reported in six cases affected by an autosomal recessive infantile neurodegenerative mitochondrial disorder. We documented a case of a 2-month-old girl presenting with severe hypotonia and nystagmus, who rapidly deteriorated and died at the age of three months. Increased cerebral spinal fluid level of lactate, documented also at the brain spectroscopy, involvement of the cortex, restricted diffusion of white and gray matter abnormalities, sparing of the corpus callosum and extensive involvement of the spinal cord were observed. Her clinical presenting features and course as well as some neuroradiological findings mimicked those of early-onset leukoencephalopathy with brainstem and spinal cord involvement and high brain lactate (LBSL). The analysis of the mitochondrial respiratory chain function showed a reduced activity of complexes II and IV. The girl harboured two heterozygous mutations in the ISCA2 gene. A comprehensive review of the literature and a comparison with the cases of early onset LBSL enabled us to highlight significant differences in the clinical, biochemical and neuroradiological phenotype between the two conditions, which also emerged from the comparison with the other 6 reported cases of ISCA2 gene mutation previously reported. In summary, this represents the second report ever published associating ISCA2 gene mutation with a mitochondrial leukoencephalopathy, with a different genetic mechanism to the previous cases. Molecular analysis of ISCA2 should be included in the genetic panel for the diagnosis of early onset mitochondrial leukoencephalopathies

Neonatal Arterial Ischemic Stroke Secondary to Carotid Artery Dissection: A Case Report and Systematic Literature Review

Background: Carotid artery (CA) dissection is a rare etiology of neonatal arterial ischemic stroke (NAIS). Methods: We describe one novel case and conduct a systematic literature review on NAIS attributed to CA dissection, to collect data on its clinical-radiological presentation, treatment, and outcome. Results: Eight published cases of NAIS attributed to CA dissection were identified and analyzed with our case. All patients (nine of nine) were born at term, and eight of nine experienced instrumental/traumatic delivery or urgent Caesarean section. None had fetal problems during pregnancy or thrombophilia. Signs and symptoms at presentation (between days of life 0 and 6) included seizures (eight of nine), respiratory distress or irregular breathing (five of nine), hyporeactivity, decreased consciousness or irritability (four of nine), and focal neurological signs (two of nine). At magnetic resonance imaging (MRI), stroke was unilateral in seven of nine and extensive in five of nine. CA dissection was documented by neuroimaging or at postmortem studies (seven of nine), and hypothesized by the treating physicians based on delivery and neuroradiology characteristics (in the remaining two of nine). Antithrombotic treatment was used in two of nine. According to available follow-up, one of eight died at age seven days, seven of eight had neurological/epileptic sequelae, and CA recanalization occurred in three of four. Conclusions: NAIS attributed to CA dissection is rarely identified in the literature, often preceded by traumatic/instrumental delivery, presenting with seizures and systemic signs/symptoms, and often characterized by extensive MRI lesions and neurological sequelae. Definite evidence and recommendations on antithrombotic treatment are lacking