Duplication 2p16 is associated with perisylvian polymicrogyria.

Polymicrogyria (PMG) is a heterogeneous brain malformation that may result from prenatal vascular disruption or infection, or from numerous genetic causes that still remain difficult to identify. We identified three unrelated patients with polymicrogyria and duplications of chromosome 2p, defined the smallest region of overlap, and performed gene pathway analysis using Cytoscape. The smallest region of overlap in all three children involved 2p16.1-p16.3. All three children have bilateral perisylvian polymicrogyria (BPP), intrauterine and postnatal growth deficiency, similar dysmorphic features, and poor feeding. Two of the three children had documented intellectual disability. Gene pathway analysis suggested a number of developmentally relevant genes and gene clusters that were over-represented in the critical region. We narrowed a rare locus for polymicrogyria to a region of 2p16.1-p16.3 that contains 33-34 genes, 23 of which are expressed in cerebral cortex during human fetal development. Using pathway analysis, we showed that several of the duplicated genes contribute to neurodevelopmental pathways including morphogen, cytokine, hormonal and growth factor signaling, regulation of cell cycle progression, cell morphogenesis, axonal guidance, and neuronal migration. These findings strengthen the evidence for a novel locus associated with polymicrogyria on 2p16.1-p16.3, and comprise the first step in defining the underlying genetic etiology.

Somatic mutations in cerebral cortical malformations.

BACKGROUND: Although there is increasing recognition of the role of somatic mutations in genetic disorders, the prevalence of somatic mutations in neurodevelopmental disease and the optimal techniques to detect somatic mosaicism have not been systematically evaluated. METHODS: Using a customized panel of known and candidate genes associated with brain malformations, we applied targeted high-coverage sequencing (depth, ≥200×) to leukocyte-derived DNA samples from 158 persons with brain malformations, including the double-cortex syndrome (subcortical band heterotopia, 30 persons), polymicrogyria with megalencephaly (20), periventricular nodular heterotopia (61), and pachygyria (47). We validated candidate mutations with the use of Sanger sequencing and, for variants present at unequal read depths, subcloning followed by colony sequencing. RESULTS: Validated, causal mutations were found in 27 persons (17%; range, 10 to 30% for each phenotype). Mutations were somatic in 8 of the 27 (30%), predominantly in persons with the double-cortex syndrome (in whom we found mutations in DCX and LIS1), persons with periventricular nodular heterotopia (FLNA), and persons with pachygyria (TUBB2B). Of the somatic mutations we detected, 5 (63%) were undetectable with the use of traditional Sanger sequencing but were validated through subcloning and subsequent sequencing of the subcloned DNA. We found potentially causal mutations in the candidate genes DYNC1H1, KIF5C, and other kinesin genes in persons with pachygyria. CONCLUSIONS: Targeted sequencing was found to be useful for detecting somatic mutations in patients with brain malformations. High-coverage sequencing panels provide an important complement to whole-exome and whole-genome sequencing in the evaluation of somatic mutations in neuropsychiatric disease. (Funded by the National Institute of Neurological Disorders and Stroke and others.).

Effect of ankle-foot orthoses on gait in typically developing children: Developmental trend in segmental coordination.

OBJECTIVE: As orthoses, and particularly ankle-foot orthoses, are widely used in the management of children with motor disorders, including cerebral palsy, we aimed to study their effect in normal children in order to add to normative gait data, which are essential for diagnosing, understanding and treating abnormal gait patterns. DESIGN: We analyzed the effect of ankle-foot orthoses on classical gait parameters and lower limb segments coordination patterns in typically developing children in two age groups reflecting different neuromaturational/developmental situations. We recorded 3D kinematic gait patterns in 9 children (4-5 years) and 11 children (9-10 years) walking barefoot or wearing bilateral solid ankle-foot orthoses maintaining the ankle joint angle at a neutral position. RESULTS: Ankle-foot orthoses induced little change in cadence, step length, step width or walking velocity in younger children, though they altered intralimb coordination through the gait cycle. In older children, walking velocity was reduced, shank elevation amplitude increased, while lower limb coordination changed less significantly. In this age group, ankle-foot orthoses significantly reduced the variability of coordinative strategies. CONCLUSION: Ankle-foot orthoses affect the gait pattern in children with a typical development at different levels in younger and older subjects, but the resulting changes are minimal.

Opsoclonus-myoclonus associated with celiac disease.

Celiac disease may be associated with various neurologic manifestations, most commonly cerebellar ataxia. This report describes a 2-year-old male who presented with opsoclonus-myoclonus syndrome including action myoclonus, palpebral flutter, opsoclonus, and ataxia. Given the severity of ataxia, the child was unable to sit or walk independently. Brain magnetic resonance imaging was normal on two occasions (4-week interval). Oligoclonal bands were found in the cerebrospinal fluid. Blood and serum examinations were unremarkable, with no evidence of infectious seroconversion. However autoantibody testing indicated the presence of antigliadin antibodies of immunoglobulin A subtype, anti-endomysial antibodies, and anti-CV2 antibodies that were not, however, detected in the cerebrospinal fluid. Duodenal biopsy documented villous atrophy confirming the diagnosis of celiac disease. This case confirms that initial presentation of celiac disease may be restricted to neurologic features. We suggest that a search for evidence for celiac disease should be included in the evaluation of opsoclonus-myoclonus.

Reversible acute methotrexate leukoencephalopathy: atypical brain MR imaging features.

BACKGROUND: Unusual acute symptomatic and reversible early-delayed leukoencephalopathy has been reported to be induced by methotrexate (MTX). OBJECTIVE: We aimed to identify the occurrence of such atypical MTX neurotoxicity in children and document its MR presentation. MATERIALS AND METHODS: We retrospectively reviewed the clinical findings and brain MRI obtained in 90 children treated with MTX for acute lymphoblastic leukaemia or non-B malignant non-Hodgkin lymphoma. All 90 patients had normal brain imaging before treatment. In these patients, brain imaging was performed after treatment completion and/or relapse and/or occurrence of neurological symptoms. RESULTS: Of the 90 patients, 15 (16.7%) showed signs of MTX neurotoxicity on brain MRI, 9 (10%) were asymptomatic, and 6 (6.7%) showed signs of acute leukoencephalopathy. On the routine brain MRI performed at the end of treatment, all asymptomatic patients had classical MR findings of reversible MTX neurotoxicity, such as abnormal high-intensity areas localized in the deep periventricular white matter on T2-weighted images. In contrast, the six symptomatic patients had atypical brain MRI characterized by T2 high-intensity areas in the supratentorial cortex and subcortical white matter (n=6), cerebellar cortex and white matter (n=4), deep periventricular white matter (n=2) and thalamus (n=1). MR normalization occurred later than clinical recovery in these six patients. CONCLUSIONS: In addition to mostly asymptomatic classical MTX neurotoxicity, MTX may induce severe but reversible unusual leukoencephalopathy. It is important to recognize this clinicoradiological presentation in the differential diagnosis of acute neurological deterioration in children treated with MTX.

Gait control in spinal palsy.

Developmental motor impairment with lower limb spasticity most commonly corresponds to cerebral palsy of the spastic diplegia type. Here we describe a 4-year-old girl whose locomotor phenotype reflects early cortico-spinal lesion at the spinal level. This child has developmental spastic paraparesis secondary to D4-D8 cord compression. We analysed her gait using the ELITE optoelectronic system and compared it to that of six normal age-matched controls and six age-matched children with leucomalacic spastic diplegia. Gait characteristics of the patient included preservation of head orientation and arm swing similar to findings in normal controls and contrasting with children with spastic diplegia. She also had truncal instability and displayed lack of selectivity in lower limb movement as in spastic diplegia and in contrast with normal controls. This may reflect differences in locomotor control between developmental spasticity of cerebral and spinal origin. The latter might correspond to spinal palsy defined as abnormal movement and posture secondary to non-progressive pathological processes affecting the immature spinal cord.

Motor strategies in standing up in children with hemiplegia.

In spastic hemiplegia, the organization of whole body movements is impaired by deficient postural control. We studied segmental motor patterns involved in standing up from supine position in 15 children with spastic hemiplegic cerebral palsy and 14 unimpaired children using a visual analysis scale previously validated for developmental research. This approach examines specific movement patterns in upper limbs, axis, and lower limbs. We found that children with hemiplegia use movement patterns described in normal children but with reduced interindividual variability and a significant preponderance of asymmetric patterns. One previously undescribed stereotyped lower limb pattern was observed in two children with spastic hemiplegia. Emergence of these patterns is consistent with the referent body image theory. This approach can systematically characterize the limited repertoire of movement in patients with disorders of movement and posture and therefore contribute to a better understanding of motor control. The approach may guide management proposals with particular reference to variability and symmetry and might be used as a follow-up tool.

Nonsurgical cerebellar mutism (anarthria) in two children.

Cerebellar mutism (anarthria) is a well-described complication of posterior fossa tumor resection. It is accompanied by a characteristic behavior including irritability and autistic features. This syndrome is typically reversible within days to months. Underlying pathophysiology is unknown. We describe two children who presented with a similar clinical finding after nonsurgical cerebellar involvement, hemolytic-uremic syndrome in one and cerebellitis in the other. Postmortem pathologic findings in the first patient indicated cerebellar ischemic necrosis. Single-photon emission computed tomography in the second patient revealed diffuse cerebellar hypoperfusion with no supratentorial abnormalities, refuting a phenomenon of diaschisis between cerebellar and frontal connections. These findings confirm that this clinical syndrome may occur in a nonsurgical, nontraumatic context. They are consistent with recent integrative hypotheses explaining cerebellar anarthria.

Motor strategies in standing up in leukomalacic spastic diplegia.

In spastic diplegia impaired postural control jeopardizes the organization of whole-body movements. We studied segmental motor patterns involved in standing up from a supine position in ten children with spastic diplegia associated with periventricular leukomalacia and 14 unimpaired children using a visual analysis scale previously devised for developmental research. This approach examines specific movement patterns in upper limbs, axis and lower limbs. We found that children with spastic diplegia use movement patterns described in normal children but with markedly reduced intra- and interindividual variability. One previously undescribed stereotyped lower limb pattern was observed in four patients. This approach can systematically characterize the limited repertoire of movement in patients with spastic diplegia and therefore contribute to a better understanding of motor control.

Benign intracranial hypertension: atypical presentation of Miller Fisher syndrome?

Acute ocular paresis, nausea, vomiting, and headaches associated with high intracranial pressure without obvious intracranial pathology are typical features of benign intracranial hypertension. We describe two young children whose presentation, initially suggestive of idiopathic or benign intracranial hypertension, evolved to comprise ophthalmoplegia, ataxia, and areflexia. This triad characterizes Miller Fisher syndrome, a clinical variant of Guillain-Barré syndrome that occurs rarely among children. In both patients, this diagnosis was supported by the clinical course and neurophysiologic findings. Plasma serology was positive for Campylobacter jejuni and anti-GQ1b antibodies in one patient and for antimyelin antibodies in the other. This report of two children with Miller Fisher syndrome presenting with intracranial hypertension adds to the findings for a similar patient treated previously, which raises the question concerning the possible role or contribution of benign intracranial hypertension in Miller Fisher syndrome.