Clustering of Juvenile Canavan disease in an Indian community due to population bottleneck and isolation: genomic signatures of a founder event.

Mild/juvenile Canavan disease (M/JCD) is less frequently reported in the literature and little is known about its pathogenetic mechanisms. We report a comprehensive investigation into the pathogenetic mechanism of a novel NM_000049.4(ASPA):c.526G>A variant in two families. The families belong to Telugu Devanga Chettiar community (TDC) from southern India. TDC has a complex history of migration from their historical origin centuries ago with high endogamy. TDC probably has the highest clustering M/JCD recorded historically (around 24 cases). The pathogenic variant was shown to cause non-classical splicing defect resulting in two different transcripts. The splicing aberration, a loss of function mechanism coupled with a milder missense effect can explain the milder phenotype compared to the infantile-onset CD. The high clustering of an extremely rare form of neurodegenerative disorder with reduced fitness, led us to speculate the possibility of a founder event. Genotyping array of TDC and multiple distinct populations of Indian origin for several population genetic parameters was performed. It yielded robust signatures of a founder event in TDC, such as a high fixation index, increased runs of homozygosity and identity-by-descent in the absence of consanguinity; a large haplotype with high linkage disequilibrium among markers comprising the pathogenic variant; a robust population structure; mutation dating, estimating the age of the potential founder of TDC at around 375 years; possibly a high carrier rate in TDC. This study has not only focused its attention on natural history and pathogenetics but also paves way for carrier screening programs in TDC and future therapeutic studies.

Clinico-radiological phenotyping and diagnostic pathways in childhood neurometabolic disorders-a practical introductory guide.

Inborn errors of metabolism (IEM) although individually rare, together constitute a significant proportion of childhood neurological disorders. Majority of these disorders occur due to deficiency of an enzyme in a specific metabolic pathway, leading to damage by accumulation of a toxic substrate or deficiency of an essential metabolite. Early diagnosis is crucial in many of these conditions to prevent or minimise brain damage. Whilst many of the neuroimaging features are nonspecific, certain disorders demonstrate specific patterns due to selective vulnerability of different structures to different insults. Along with clinical and biochemical profile, neuroimaging thus plays a pivotal role in differentiating metabolic disorders from other causes, in providing a differential diagnosis or suggesting a metabolic pathway derangement, and on occasion also helps make a specific diagnosis. This allows initiation of targeted metabolic and genetic work up and treatment. Familiarity with the clinical features, relevant biochemical features and neuroimaging findings of common metabolic disorders to facilitate a prompt diagnosis cannot thus be overemphasized. In this article, we describe the latest classification scheme, the clinical and biochemical clues and common radiological patterns. The diagnostic algorithm followed in daily practice after clinico-radiological phenotyping is alluded to and illustrated by clinical vignettes. Focused sections on neonatal metabolic disorders and mitochondrial disorders are also provided. The purpose of this article is to provide a brief overview and serve as a practical primer to clinical and radiological phenotypes and diagnostic aspects of IEM.

Metabolic Stroke: A Novel Presentation in a Child with Succinic Semialdehyde Dehydrogenase Deficiency.

Succinic semialdehyde dehydrogenase (SSADH) deficiency is an autosomal recessive disorder of gamma-aminobutyric acid metabolism. Children with SSADH deficiency usually manifest with developmental delay, behavioral symptoms, language dysfunction, seizures, hypotonia, extrapyramidal symptoms, and ataxia. Diagnosis of SSADH deficiency is established by an abnormal urine organic acid pattern, including increased excretion of 4-hydroxybutyric acid and the identification of biallelic pathogenic variants in aldehyde dehydrogenase 5 family, member A 1 (ALDH5A1) gene. Here, we describe a 15-month-old girl with SSADH deficiency presenting with developmental delay, language deficits, and acute-onset right hemiparesis, following recovery from a diarrheal illness. Brain magnetic resonance imaging revealed hyperintense signal changes involving the left globus pallidus in T2-weighted images with restriction of diffusion in the diffusion-weighted images. Increased excretion of 4-hydroxybutyric acid, threo-4,5-dihydroxyhexanoic acid lactone and erythro-4,5-dihydroxyhexanoic acid lactone was detected by urine organic acid analysis and a diagnosis of SSADH deficiency was confirmed by the identification of homozygous pathogenic variant in ALDH5A1. Stroke mimic is a novel presentation in our patient with SSADH deficiency. She was initiated on treatment with vigabatrin and has shown developmental gains with the recovery of right hemiparesis. Follow-up neuroimaging shows near complete resolution of signal changes in the left globus pallidus, while there was subtle hyperintensity in the right globus pallidus. The phenotypic spectrum of SSADH deficiency is widely expanding, and this disorder should be considered in the differential diagnosis of children with metabolic stroke.

An Unusual Cause of Chronic Headache in an Adolescent Boy: A Case Report.

Spontaneous intracranial hypotension (SIH) is an under-diagnosed cause of headache in children and adolescents. SIH results from cerebrospinal fluid (CSF) leak due to breach in the dura mater and the etiology for dural breach is often diverse. We report an adolescent boy who presented with chronic episodic headache that later progressed to daily headache. There was a typical history of worsening of headache on upright position and relief of headache on lying down. He was treated with migraine prophylaxis in another hospital but there was no response. Marfanoid features and brisk deep tendon reflexes were observed on clinical examination. Brain magnetic resonance imaging (MRI) revealed sagging of the brain stem, pachymeningeal enhancement, and tonsillar herniation. MRI of spine myelogram confirmed multiple levels of CSF leak. He was initially managed with supportive measures and fluoroscopic-guided fibrin glue injection. Although child remained symptom-free for the next 6 months, he again developed headache. MRI and computed tomography spine myelogram revealed a meningeal diverticulum in the lumbar spine. He was managed with an autologous epidural blood patch and he has been well since then. In this report, we highlight the clinical and radiological pointers to the presence of SIH in children with recurrent headache.

Clinicoradiological Spectrum of L-2-Hydroxy Glutaric Aciduria: Typical and Atypical Findings in an Indian Cohort.

CONTEXT: Neurometabolic disorders form an important group of potentially treatable diseases. It is important to recognize the clinical phenotype and characteristic imaging patterns to make an early diagnosis and initiate appropriate treatment. L-2-hydroxy glutaric aciduria (L2HGA) is a rare organic aciduria with a consistent and highly characteristic imaging pattern, which clinches the diagnosis in most cases. AIMS: The study aims to describe the clinical profile, magnetic resonance imaging (MRI) patterns, and outcome in a cohort of children with L2HGA and to assess the clinicoradiological correlation. MATERIALS AND METHODS: This is a retrospective descriptive study done at the Department of Radiodiagnosis and Neurological Sciences of our institution. Clinical and radiological findings of children diagnosed with L2HGA over an 8-year period (2010-2017) were collected and analyzed. Descriptive statistical analysis of clinical and imaging data was performed. RESULTS: There were six girls and four boys. A total of 14 MRI brain studies in 10 patients with the diagnosis were analyzed. MRI of all patients showed a similar pattern with extensive confluent subcortical white-matter signal changes with symmetrical involvement of dentate nuclei and basal ganglia. In two children who presented with acute decompensation, there was asymmetric cortical involvement and restricted diffusion, which are previously unreported. There was no significant correlation between the radiological pattern with the disease duration, clinical features, or course of the disease. CONCLUSION: MRI findings in L2HGA are highly consistent and diagnostic, which helps in early diagnosis, particularly in resource-constraint settings, where detailed metabolic workup is not possible. The article also describes novel clinical radiological profile of acute encephalopathic clinical presentation.

Revisiting magnetic resonance imaging pattern of Krabbe disease - Lessons from an Indian cohort.

CONTEXT: Krabbe disease shows considerable heterogeneity in clinical features and disease progression. Imaging phenotypes are equally heterogeneous but show distinct age-based patterns. It is important for radiologists to be familiar with the imaging spectrum to substantially contribute toward early diagnosis, prognostication, and therapeutic decisions. AIMS: The study aims to describe different magnetic resonance imaging (MRI) patterns observed in a cohort of children with Krabbe disease and to assess correlation with age-based clinical phenotypes. MATERIALS AND METHODS: This is a retrospective descriptive study done at the Departments of Radiodiagnosis and Neurological Sciences of our institution, a tertiary care hospital in Southern India. Imaging features of children diagnosed with Krabbe disease over a 10-year period (2009-2018) were collected and analyzed. RESULTS: A total of 38 MRI brain studies from 27 patients were analyzed. Four distinct MRI patterns were recognizable among the different clinical subtypes. All patients from the early and late infantile group showed deep cerebral and cerebellar white matter and dentate hilum involvement. Optic nerve thickening was, however, more common in the former group. Adult-onset subtype showed isolated involvement of corticospinal tract, posterior periventricular white matter, and callosal splenium with the absence of other supra- and infra-tentorial findings. Juvenile subgroup showed heterogeneous mixed pattern with 78% showing adult subtype pattern and 22% showing patchy involvement of deep cerebral white matter with dentate hilum signal changes. CONCLUSION: Krabbe disease shows distinct imaging features which correspond to different clinical age-based subtypes. This article reemphasizes these distinct imaging phenotypes, highlights a novel imaging appearance in juvenile Krabbe, and also alludes to the rare variant of saposin deficiency. Awareness of these patterns is essential in suggesting the appropriate diagnosis and guiding conclusive diagnostic workup. Large multicenter longitudinal studies are needed to further define the role of imaging in predicting the clinical course and thus to guide therapeutic options.

Clinical Profile, Prognostic Indicators, and Therapeutic Outcomes of Pediatric Opsoclonus-Myoclonus-Ataxia Syndrome: A Single-Center Experience from South India.

BACKGROUND: Opsoclonus myoclonus syndrome (OMS) is a neuroinflammatory disorder. Indian literature on its clinical profile and outcome is sparse. OBJECTIVES: The objective of this study is to describe the clinical profile and analyze outcomes and prognostic predictors in a cohort of children with OMS. MATERIALS AND METHODS: This was a retrospective study of children with OMS between 2007 and 2017. RESULTS: Twenty-two children were included in the study. The mean age at onset of symptom was 20.9 months (standard deviation [SD]: 7.5). The mean duration of delay in diagnosis was 8.4 months (SD 1.26) with acute cerebellitis being the most common misdiagnosis. Eleven children (50%) were diagnosed with tumor during evaluation and follow-up and 11 children (50%) belonged to idiopathic/postinfectious group. Magnetic resonance imaging brain was normal in all children except for one revealing cerebellar atrophy on follow-up. One child in the paraneoplastic group (neuroblastoma) had a positive PNMA2/Ta onconeural antibody. Children in the tumor group had an earlier age of onset (mean 15.5 vs. 26.3 months), shorter time to onset of opsoclonus from initial symptom (2.54 vs. 7.27 weeks), and higher severity score at presentation (13.7 vs. 11.3) compared to the nontumor group. Children in the nontumor group attained their first remission with treatment earlier (10.9 weeks, SD: 4.5) than the children with tumor (18.72 weeks, SD: 5.8). There was no significant difference in the outcome between the groups. Children with multiple relapses (>3) and late surgical intervention for tumor (>6 months after symptom onset) had a poor outcome. DISCUSSION: A high index of suspicion coupled with early diagnosis and periodic tumor surveillance (even in the initially negative cases) along with aggressive combined multimechanistic immunotherapies is the key in improving outcomes. CONCLUSION: A high index of suspicion in appropriate clinical circumstances and early aggressive immunomodulation might lead to a better outcome.

Genomics and Radiogenomics in Inherited Neurometabolic Disorders - A Practical Primer for Pediatricians.

Advances in genetics has revolutionised the way we understand, diagnose and manage neurological disorders. Notwithstanding the fact that genetic confirmation has already become standard of care in routine clinical practice, radiological and clinical phenotyping has not diminished in value; in fact it has found an enhanced role in guiding and interpreting genetic test results. Inherited neurometabolic disorders are a prominent group of disorders which are seen commonly in clinical practice and many are potentially treatable. The concept of Radiogenomics is the bridge from phenotype to genotype and the strength of association varies widely across different inherited metabolic diseases. Understanding the strengths and limitations of these correlations forms the basis of success of multidisciplinary approach to diagnose these disorders. In this article authors give a brief overview of the genetic basis of a disease, available genetic tests and the prominent role of radiology in contemplating a diagnostic suspicion and guiding further confirmatory tests.

Reliability of Imaging-Based Diagnosis of Lateral Ventricular Masses in Children.

OBJECTIVE: We studied the accuracy of the radiologic diagnosis of lateral ventricular masses in children (<20 years of age). METHODS: In this retrospective study, data were collected from children with lateral ventricular masses managed in our unit between 2001 and 2016. There were 43 patients (26 boys and 17 girls; mean age, 12.1 years; range, 8 months to 20 years). Magnetic resonance imaging was available for 36 patients, whereas in 7 patients only a contrast-enhanced computed tomography scan was available. The images were read independently by 3 radiologists, who were blinded to the pathology. Two differential diagnoses were offered for each patient. The agreement between the 3 radiologists was calculated using the Fleiss κ statistic. RESULTS: The common pathologic diagnoses were subependymal giant cell astrocytoma (SEGA) (20.9%), low-grade astrocytoma (16.3%), high-grade astrocytoma (9.3%), choroid plexus papilloma (9.3%), and meningioma (9.3%). The sensitivity, specificity, and accuracy of the radiologic diagnoses were 62%, 96.7%, and 94.2%, respectively. Low-grade tumors such as low-grade gliomas, SEGAs, choroid plexus papillomas, and meningiomas were diagnosed with a high level of accuracy. High-grade gliomas, choroid plexus carcinomas, and other malignant neoplasms were difficult to diagnose on imaging. Cavernous angiomas were also difficult to diagnose. There was only fair agreement between the 3 radiologists (Fleiss κ = 0.24). CONCLUSIONS: The pathologic spectrum of lateral ventricular tumors in children is wide, and identifying the pathology on imaging is difficult for malignant tumors. Benign tumors such as SEGAs, low-grade astrocytomas, and choroid plexus papillomas are relatively easier to diagnose. There is significant interobserver variability in the radiologic diagnosis of these tumors.

Imaging of Childhood Inflammatory Brain Diseases.

Brain has been considered as an immune-privileged site for centuries owing to the presence of blood-brain barrier, absent lymphatic drainage, and antigen-presenting cells. However, the present prevailing concept is of immune surveillance where brain is continuously surveyed by immune cells. However, the presence of immune cells in central nervous system (CNS) brings the risk of inflammation and autoimmunity involving both T and B cell mediated pathways. These mechanisms form the underlying pathology in a wide spectrum of pediatric CNS diseases manifesting as acquired neurological deficits. Overlapping, heterogenous, and ambiguous clinical features often delays the diagnosis. Although not always pathognomonic, magnetic resonance imaging can be an important biomarker leading to early diagnosis, prognostication, and systematic follow-up pf these diseases. This review describes the spectrum of different pediatric inflammatory disorders and their pertinent imaging features illustrated with clinical examples.

Menkes disease and response to copper histidine: An Indian case series.

BACKGROUND: Menkes disease (MD) is an X-linked recessive neurodegenerative disorder caused by mutations in ATP7A gene. Depending on the residual ATP7A activity, manifestation may be classical MD, occipital horn syndrome, or distal motor neuropathy. Neurological sparing is expected in female carriers. However, on rare occasions, females may manifest with classical clinical phenotype due to skewed X-chromosome inactivation, X-autosome translocation, and XO genotype. Here, we describe a small series of probands with MD and their response to copper histidine therapy. This series also includes a female with X-13 translocation manifesting neurological symptoms. METHODS: The clinical profile, laboratory and radiological data, and follow-up of four children with MD were collected from the hospital database and are being presented. RESULTS: All the four children in our series had developmental delay, recurrent respiratory tract infections, hair and skeletal changes, axial hypotonia, tortuous vessels on imaging, low serum copper, ceruloplasmin, and elevated lactate. Fetal hypokinesia and fetal growth retardation were present in two cases. Failure to thrive was present in three children and only one child had epilepsy. Subcutaneous copper histidine was administered to all children. The average time lapse in the initiation of treatment was 20.3 months, and average duration of follow-up was 14.3 months. CONCLUSION: We conclude that copper histidine therapy is beneficial in reversing the skin and hair changes, improving appendicular tone, socio-cognitive milestones, and improving weight gain, and immunity. Early diagnosis and management of MD are essential to have a better clinical outcome. More research is needed to explore and devise new strategies in the management of patients with MD.

A tropical menace of co-infection of Japanese encephalitis and neurocysticercosis in two children.

Japanese encephalitis (JE) is a mosquito borne encephalitis caused by Flavivirus. Neurocysticercosis (NCC) is a parasitic disease of the central nervous system caused by Taenia solium. In this report, we describe the clinical profile, imaging findings, and outcome of two children with JE and coexisting NCC. Eleven and thirteen-year-old boys from the same town of Jharkhand state were brought with history of fever, seizures, altered sensorium, and extrapyramidal symptoms. Dystonia, hypomimia, bradykinesia, and dyskinesia were observed. Meige syndrome observed in one of the children is a novel finding. Magnetic resonance imaging of the brain revealed findings suggestive of JE with cysticercal granulomas. There are few reports of coexistence of JE and NCC in children. Both children were treated with ribavirin, and follow-up imaging had shown significant resolution of signal changes. Both the children had shown marked clinical improvement. Ribavirin was found to beneficial in reducing the morbidity in our patients.

Ocular Features and Visual Outcome in Children with Moyamoya Disease and Moyamoya Syndrome: A Case Series.

Moya Moya Disease (MMD) is characterised by idiopathic vasculopathy affecting the terminal internal carotid arteries resulting in the formation of extensive collaterals at the base of the brain, leptomeninges and parenchymal regions with resultant infarcts and bleeds. Four children presented with clinico-radiological features suggestive of Moyamoya disease/syndrome. This includes global developmental delay, recurrent seizures, transient ischaemic attacks and impaired vision. The first patient had vision of 6/15 in both eyes with bilateral optic disc pallor. Second case also had bilateral optic disc pallor with arteriolar attenuation, but had vision of perception of light only in both eyes. The third child had vision of 6/60 with alternate divergent squint and clinical features suggestive of Neurofibromatosis 1 (NF 1). Fourth patient presented with poor fixation in both eyes with bilateral total cataract. He underwent bilateral cataract surgery with intraocular lens implantation and vision improved to 2/60 with good fixation. We also describe their medical and neurosurgical interventions in this report.

Imaging in Pediatric Demyelinating and Inflammatory Diseases of Brain- Part 2.

Imaging plays an important role in diagnosis, management, prognostication and follow up of pediatric demyelinating and inflammatory diseases of brain and forms an integral part of the diagnostic criteria. This article reviews the spectrum of aquaporinopathies with an in-depth discussion on present criteria and differentiation from other demyelinating diseases with clinical vignettes for illustration; the latter part of article deals with the spectrum of CNS vasculitis.

Beta Propellar Protein-Associated Neurodegeneration: A Rare Cause of Infantile Autistic Regression and Intracranial Calcification.

Neurodegeneration with brain iron accumulation (NBIA) is a heterogeneous group of single gene disorders with distinguished clinical phenotypes and definitive imaging findings. Beta propeller protein-associated neurodegeneration (BPAN) is a subentity of NBIA with X linked dominant inheritance. In this report, we describe a girl with autistic regression, seizures, intracranial calcification, iron accumulation in substantia nigra, and globi pallidi, and diagnosis of BPAN was established based on the identification of previously described disease causing variant in WD repeat domain 45 (WDR45) gene encoding for ß propeller protein. This is the first genetically proven case from India. BPAN is an underrecognized disorder and must be considered as a differential diagnosis in children with atypical Rett features and should be enlisted among the causes for autistic regression and intracranial calcification. Pediatricians must be aware of this rare entity for establishing early diagnosis, prognostication, and genetic counseling. Treatment is usually supportive. More research is needed to explore drugs in the management of BPAN that can facilitate the autophagy and promotes cytoprotection.

Acute necrotising encephalopathy in a child with H1N1 influenza infection: a clinicoradiological diagnosis and follow-up.

Acute necrotising encephalopathy of childhood (ANEC) is a fulminant disorder with rapid progressive encephalopathy, seizures and poor outcome. It has been reported in association with various viral infections. We describe the clinicoradiological findings and short-term follow-up in a child with H1N1 influenza-associated ANEC. Laminar, target or tricolour pattern of involvement of the thalami was seen on apparent diffusion coefficient images. Our patient had significant morbidity at discharge despite early diagnosis and management with oseltamivir and immunoglobulin. Repeat imaging after 3 months had shown significant resolution of thalamic swelling, but there was persistence of cytotoxic oedema involving bilateral thalami. She was pulsed with intravenous steroids and maintained on a tapering schedule of oral steroids. This report emphasises the need for a high index of suspicion to establish early diagnosis, promotion of widespread immunisation strategies to prevent influenza outbreak, and more research to establish standard treatment protocols for this under-recognised entity.