Bilateral (opercular and paracentral lobular) polymicrogyria and neurofibromatosis type 1.

Anecdotal cases of polymicrogyria (PMG; a malformation of cortical development consisting of an excessive number of small gyri with abnormal lamination) in patients with neurofibromatosis type 1 (NF1) have been described; however, the cases were unilateral and had negative NF1 genetic testing. We describe an 11-year-old girl with NF1 manifesting as a complex epileptic syndrome, including partial seizures secondarily generalized and status epilepticus, who had in association, bilateral, asymmetrical (opercular and paracentral lobular) PMG. She had a 1-bp deletion (c.1862delC) in exon 12b of the NF1 gene. It is notable that, given the key role played by the NF1 gene product, neurofibromin, in normal brain development, and the relatively high frequency of other brain findings in NF1, there are not more NF1 cases with brain malformations manifesting as PMG.

Neurocardiogenic syncope and epilepsy in pediatric age: the diagnostic value of electroencephalogram-electrocardiogram holter.

Neurocardiogenic syncope is induced by a hyperrecruitment of parasympathetic nerve tone elicited by emotional stress or pain. The presence of a transient loss of consciousness associated with involuntary motor activity or with urinary incontinence and the misinterpretation of anamnestic data or of electroencephalogram (EEG) abnormalities often leads to wrong diagnosis of epilepsy in children with this disorder.Careful and systematic history taking, pressure measurement, electrocardiogram (ECG), and, in selected cases, head-up tilt table testing are generally enough to rule out a cardiogenic or a neurocardiogenic syncope. Simultaneous EEG-ECG Holter represents a useful instrument for differential diagnosis between neurocardiogenic syncope and epilepsy.We report 3 case reports to demonstrate how simultaneous EEG-ECG Holter can contribute to characterize functional heart-brain interactions and the exact sequence of the physiopathologic events leading to the loss of consciousness in cases in which the clinical borders with epileptic disorders are particularly subtle.

Dysembryoplastic neuroepithelial tumors: a prospective clinicopathologic and outcome study of 13 children.

Dysembryoplastic neuroepithelial tumors (DNETs) are benign intracortical masses that are typically observed in children and young adults and are classified as glioneuronal tumors (WHO grade I). Large and retrospective series of patients with DNETs have been reported, but prospective studies on pediatric cohorts of patients with DNETs have been lacking. In the present study, 13 children (8 boys, 5 girls; age 8-18 years) who had simple (n = 2) or complex (n = 11) partial seizures (seizure duration range, 2-4 years; mean, 1.5 years; mode, 1.2 years) were prospectively enrolled and monitored over 13 years. The DNETs were located in the frontal (n = 2), temporal (n = 9), or occipital (n = 2) cortex. In 11/13 cases, the seizures were resistant to drug therapy, and all the children had surgery consisting of extended lesionectomy coupled with neuronavigation. Pathology examination revealed cortical dysplasia (n = 8), glial nodules (n = 11), calcification (n = 4), cellular atypia (n = 3), endothelial proliferation (n = 1), perivascular inflammation (n = 3), and meningeal involvement (n = 6). All children were seizure free throughout postsurgical follow-up of 2-11 years. This first prospective study with follow-up monitoring of a childhood population with DNETs confirms, on a long-term basis, that the coupled strategy of extended lesionectomy and neuronavigation has good outcome for long-term seizure control.

Usefulness of diffusion tensor imaging and fiber tractography in neurological and neurosurgical pediatric diseases.

INTRODUCTION: Diffusion tensor imaging (DTI) with fiber tractography (FT) is a recently introduced imaging technique that is unique in providing detailed imaging of white matter (WM) tracts and connectivity between different regions of the brain not easily appreciated with other imaging methods. DISCUSSION: DTI has been used in recent years to investigate several disease conditions involving WM, including brain malformations, cerebral ischemia, multiple sclerosis, neurocutaneous syndromes, and brain tumors. CONCLUSION: In this paper, we focus our attention on the main applications of DTI-FT in the field of pediatric neurology, adding our personal experience.

New trends in neuronal migration disorders.

Neuronal migration disorders are an heterogeneous group of disorders of nervous system development and they are considered to be one of the most significant causes of neurological and developmental disabilities and epileptic seizures in childhood. In the last ten years, molecular biologic and genetic investigations have widely increased our knowledge about the regulation of neuronal migration during development. One of the most frequent disorders is lissencephaly. It is characterized by a paucity of normal gyri and sulci resulting in a "smooth brain". There are two pathologic subtypes: classical and cobblestone. Classical lissencephaly is caused by an arrest of neuronal migration whereas cobblestone lissencephaly caused by overmigration. Heterotopia is another important neuronal migration disorder. It is characterized by a cluster of disorganized neurons in abnormal locations and it is divided into three main groups: periventricular nodular heterotopia, subcortical heterotopia and marginal glioneural heterotopia. Polymicrogyria develops at the final stages of neuronal migration, in the earliest phases of cortical organization; bilateral frontoparietal form is characterized by bilateral, symmetric polymicrogyria in the frontoparietal regions. Bilateral perisylvian polymicrogyria causes a clinical syndrome which manifests itself in the form of mild mental retardation, epilepsy and pseudobulbar palsy. Schizencephaly is another important neuronal migration disorder whose clinical characteristics are extremely variable. This review reports the main clinical and pathophysiological aspects of these disorders paying particular attention to the recent advances in molecular genetics.

Pigmentary mosaicism, subcortical band heterotopia, and brain cystic lesions.

A 10-year-old boy presented with a severe and diffuse mosaic skin hypopigmentation running (in narrow bands) along the lines of Blaschko associated with mosaic areas of alopecia, facial dysmorphism with midface hypoplasia, bilateral punctate cataract, microretrognathia, short neck, pectus excavatum, joint hypermobility, mild muscular hypotonia, generalized seizures, and mild mental retardation. Cranial magnetic resonance imaging revealed hypoplastic corpus callosum (primarily posterior), subcortical band heterotopia, and diffuse subcortical, periventricular cystic-like lesions. Similar dysmorphic features were observed in the child's mother, but with no imaging abnormalities. The facial phenotype coupled with the cysts in the brain was strongly reminiscent of the oculocerebrorenal Lowe syndrome. Full chromosome studies in the parents and the proband and mutation analysis on peripheral blood lymphocytes (and on skin cultured fibroblasts from affected and unaffected skin areas in the child) in the genes for subcortical band heterotopia (DCX (Xq22.3-q23)], lissencephaly (PAFAH1B1, alias LIS1, at 17p13.3), and oculocerebrorenal syndrome of Lowe (OCRL at Xq23-q24)] were unrevealing. This constellation of multiple congenital anomalies including skin hypopigmentation and eye, musculoskeletal, and nervous system abnormalities was sufficiently characterized to be regarded as a novel example of pigmentary mosaicism of the Ito type (i.e., hypomelanosis of Ito).

Complex epileptic (Foix-Chavany-Marie like) syndrome in a child with neurofibromatosis type 1 (NF1) and bilateral (opercular and paracentral) polymicrogyria.

The association of brain malformations and symptomatic epilepsy in the setting of neurofibromatosis type 1 (NF1) is rarely reported. When it occurs, patients can present clinically with infantile spasms, focal seizures, generalized tonic clonic seizures or atypical absences. We report on a 10-year-old (molecularly proven) NF1 girl manifesting a complex epileptic syndrome resembling the Foix-Chavany-Marie spectrum (also known as opercular syndrome) associated with bilateral (opercular and paracentral lobular) polymicrogyria (PMG). Anecdotal cases of unilateral PMG in the setting of NF1 have been described in association with other-than-opercular epileptic syndromes. The typical clinical opercular syndrome consisting in mild mental retardation, epilepsy and pseudobulbar palsy is usually associated to bilateral perisylvian PMG (BPP) CONCLUSION: To the best of our knowledge, the complex epileptic syndrome hereby reported has not been previously recorded in the setting of NF1. In addition, the present girl manifested all the clinical features of an opercular syndrome but had an asymmetrical PMG (not a BPP).

Neuronal migration disorders: clinical, neuroradiologic and genetics aspects.

UNLABELLED: Disorders of neuronal migration are a heterogeneous group of disorders of nervous system development. One of the most frequent disorders is lissencephaly, characterized by a paucity of normal gyri and sulci resulting in a 'smooth brain'. There are two pathologic subtypes: classical and cobblestone. Six different genes could be responsible for this entity (LIS1, DCX, TUBA1A, VLDLR, ARX, RELN), although co-delection of YWHAE gene with LIS1 could result in Miller-Dieker Syndrome. Heterotopia is defined as a cluster of normal neurons in abnormal locations, and divided into three main groups: periventricular nodular heterotopia, subcortical heterotopia and marginal glioneural heterotopia. Genetically, heterotopia is related to Filamin A (FLNA) or ADP-ribosylation factor guanine exchange factor 2 (ARFGEF2) genes mutations. Polymicrogyria is described as an augmentation of small circonvolutions separated by shallow enlarged sulci; bilateral frontoparietal form is characterized by bilateral, symmetric polymicrogyria in the frontoparietal regions. Bilateral perisylvian polymicrogyria results in a clinical syndrome manifested by mild mental retardation, epilepsy and pseudobulbar palsy. Gene mutations linked to this disorder are SRPX2, PAX6, TBR2, KIAA1279, RAB3GAP1 and COL18A1. Schizencephaly, consisting in a cleft of cerebral hemisphere connecting extra-axial subaracnoid spaces and ventricles, is another important disorder of neuronal migration whose clinical characteristics are extremely variable. EMX2 gene could be implicated in its genesis. Focal cortical dysplasia is characterized by three different types of altered cortical laminations, and represents one of most severe cause of epilepsy in children. TSC1 gene could play a role in its etiology. CONCLUSION: This review reports the main clinical, genetical and neuroradiological aspects of these disorders. It is hoped that accumulating data of the development mechanisms underlying the expanded network formation in the brain will lead to the development of therapeutic options for neuronal migration disorders.

MTHFR homozygous mutation and additional risk factors for cerebral infarction in a large Italian family.

Several cases with cerebral infarctions associated with the C677T mutation in the methylenetetrahydrofolate reductase gene (MTHFR) have been reported. Given the large number of asymptomatic individuals with the MTHFR mutation, additional risk factors for cerebral infarction should be considered. This study describes a large family with the MTHFR mutation and a combination of heterozygous factor V Leiden mutations and different additional exogenous and endogenous thrombogenic risk factors. Psychomotor retardation and a left fronto-insular infarct associated with the MTHFR mutation together with diminished factor VII and low level of protein C was documented in the first patient. In the second patient, generalized epilepsy and a malacic area in the right nucleus lenticularis was associated with the MTHFR mutation and a low level of protein C. In the third patient, right hemiparesis and a left fronto-temporal porencephalic cyst were documented, together with the MTHFR mutation and hyperhomocysteinemia. An extensive search of additional circumstantial and genetic thrombogenic risk factors should be useful for prophylaxis and prognosis of infants with cerebral infarctions associated with the MTHFR mutation and of their related family members.

Infantile spasms in the setting of Sturge-Weber syndrome.

INTRODUCTION: The prevalence and outcome of the most frequent type of epilepsy in infancy-infantile spasms (IS)-are well characterized in the setting of most neurocutaneous disorders. By contrast, still there is no study describing the natural history of IS in the setting of Sturge-Weber syndrome (SWS). MATERIALS AND METHODS: Two patients with SWS and IS were identified in our series and five in the literature. The aim of study is to evaluate the clinical, electroencephalographic (EEG) and imaging features of our cases and to compare our cases with those described in the literature. IS in the setting of SWS is an uncommon but possible event (2/19 patients seen over 13 years in our institutions). RESULTS: We confirmed the correlation between IS and severity of SWS cutaneous and neural (extension of leptomeningeal capillary malformation) phenotype. IS in SWS seems to be atypical both from a clinical viewpoint (they are asymmetric) and from a laboratory viewpoint (EEG is not classically hypsarrhythmic).

Neurofibromatosis type 1 and infantile spasms.

BACKGROUND: There is no agreement on the prevalence, natural history and outcome of infantile spasms (IS) in neurofibromatosis type 1 (NF1). By contrast, its prevalence and outcome are well characterised in the setting of other neurocutaneous disorders (e.g. tuberous sclerosis). MATERIALS AND METHODS: The aim of the present study was to try to establish a genotype-phenotype correlation in IS in the setting of NF1. A retrospective (years 1990-2000) and prospective (years 2000-2006) study in three paediatric centres in Italy were taken as referral populations for: (1) children with NF1 and (2) neurological problems in childhood. RESULTS: Ten NF1 patients have had IS. The calculated population-based: (1) prevalence of IS in NF1 (0.76%) was higher than the reported frequency of IS in the general population (0.02-0.05%) and (2) frequency of NF1 in the IS series in two out of three centres (0.62-0.90%) was lower than the estimated frequencies in the literature (1.5-3.0%). Patients had psychomotor delay preceding the spasms (50%), symmetrical spasms (50%), typical (80%) and modified (20%) hypsarrhythmia and foci of spikes and waves and a good response to corticosteroid treatment (50%). Outcome was good in 30%. Imaging revealed high-signal foci in atypical locations (sub-cortical and central brain regions). Deoxyribonucleic acid analysis revealed three novel NF1 gene mutations without genotype-phenotype correlation. CONCLUSION: Even though the combination of IS and NF1 does not seem to be coincidental, it is certainly an unusual event in NF1--rarer than in other neurocutaneous disorders. Spasms in NF1 are not associated with specific genetic defects.

Bilateral periventricular nodular heterotopia with amniotic band syndrome.

The amniotic (constriction) band syndrome is characterized by distal ring constrictions, intrauterine amputations, and acrosyndactyly. External constriction by amniotic bands is the generally accepted mechanism: early amniotic rupture leads to formation of mesodermal fibrous strands that constrict, entangle, and amputate distal portions of limbs. Etiology is heterogeneous. Anecdotal cases involving central nervous system abnormalities (e.g., acrania, anencephaly, polymicrogyria, congenital bilateral perisylvian syndrome, neuronal heterotopia, septo-optic dysplasia, and spinal cord tethering) have been reported. We describe a 9-year-old girl with typical features of constriction band syndrome localized to the lower limbs who had also profound mental retardation and drug-resistant epilepsy associated with bilateral periventricular nodular heterotopia (a brain malformation of neuronal migration and proliferation caused by mutations in the X-linked filamin 1 gene [FLN1] on chromosome Xq28). The karyotype was normal, as was mutational screening for FLN1. The occurrence of bilateral periventricular nodular heterotopia in the context of amniotic band syndrome is novel (chance occurrence of both: 0.000004%).

Bilateral perysilvian polymicrogyria in Chiari I malformation.

CASE REPORT: We report on a 7-year-old girl with generalized epilepsy and mental retardation. DISCUSSION: Neurologic examination was normal and only facial dysmorphic features, compatible with frontonasal dysplasia, were observed. However, magnetic resonance imaging (MRI) revealed Chiari I malformation together with bilateral opercular polymicrogyria. To our knowledge, this is the first report of the association of these developmental disorders. This condition raises questions regarding the ethiopathogenetic classification of Chiari spectrum and as to whether embryologic and genetic causes could be potentially interconnected.

Septo-optic dysplasia complex: a heterogeneous malformation syndrome.

Septo-optic dysplasia is defined by a variable combination of dysgenesis of midline brain structures including optic nerve hypoplasia and hypothalamic-pituitary dysfunction often associated with a wide variety of brain malformations of cortical development. Multiple congenital anomalies have been reported only sporadically. Despite recent demonstration of the possible pathogenic role of HESX1/Hesx1 gene (a homeobox gene important for development of prosencephalon), the etiology of most cases of septo-optic dysplasia still remains unclear. This report describes eight children (4 males, 4 females; age 2 to 17 years) with septo-optic dysplasia who manifested dysmorphic features (involving not only the midline facial structures) and a spectrum of additional clinical and imaging features including autism, facial hemangioma, and holoprosencephaly. Full mutational screening for the HESX1 gene in seven of eight children was negative. Based on the extreme variability of the clinical and imaging phenotypes hereby observed, on literature review, and on septo-optic dysplasia animal models, this study confirmed that the phenotypic heterogeneity in septo-optic dysplasia is high. We suggest that: (1) dysmorphic features are more frequent than previously thought--they may represent a relevant part of the phenotype; (2) septo-optic dysplasia should be recategorized as an heterogeneous malformation syndrome (septo-optic dysplasia complex) (encompassing multiple brain, endocrine, and systemic anomalies) rather than a single precisely defined entity.

Delineation of a newly recognized neurocutaneous malformation syndrome with "cutis tricolor".

The term "cutis tricolor" describes the combination of congenital hyper- and hypo-pigmented lesions, in close proximity to each other with a background of normal skin. Cutis tricolor represents twin spotting and has been reported as an isolated skin disorder or as part of a neurocutaneous malformation syndrome. We report on an 11-year-old girl with diffuse pigmentary changes of the cutis tricolor type, facial anomalies, mental retardation, epileptic seizures, EEG anomalies, small skull, progressive double-curved thoracolumbar/lumbar scoliosis with vertebral scalloping and dysplastic vertebral pedicles and ribs, and tibial bowing. These abnormalities are similar to those observed in cases reported by Happle et al. [1997: J Med Genet 34:676-678] and Ruggieri [2000: Eur J Pediatr 159:745-749]. Additionally, our patient had altered behavior and hypoplasia of the corpus callosum. This constellation of abnormalities represents a newly recognized neurocutaneous malformation syndrome. The phenotype could be explained by somatic mutation. Loss of heterozygosity at an early developmental stage would give rise to one single mosaic skin disorder (e.g., generalized skin manifestations of the cutis tricolor type in association to extracutaneous anomalies). Postzygotic recombination occurring later during embryogenesis would give rise to solitary lesions confined to the skin.

Convulsive disorder and the genetics of signal transduction; a study of a low molecular weight protein tyrosine phosphatase in a pediatric sample.

Recent studies point to an involvement of kinases and phosphatases in ionic channel regulation and in physiopathologic mechanisms leading to convulsive disorders. Acid phosphatase locus 1 (ACP1), also named cytosolic low molecular weight phosphotyrosine phosphatase, is a highly polymorphic phosphatase that is especially abundant in the central nervous system and is known to be involved in several signal transduction pathways. We studied ACP1 in 122 children with idiopathic generalized tonic-clonic seizures, 80 children with febrile convulsions, and 417 controls from the population of Rome. Low activity phenotypes of ACP1 (*A/*A and *A/*B) were found to be over-represented while high activity phenotypes (*C/*C and *B/*C) were under-represented in generalized seizures cases compared to controls (P < 0.005). No significant difference was observed between febrile convulsion cases and controls. These observations suggest a protective role of the high activity ACP1 phenotypes against seizures in children.

Periventricular nodular heterotopia: report of a pediatric series.

Periventricular nodular heterotopia is a malformation that occurs in both males and females and is associated with a variety of clinical and neuroradiologic signs. A gene called filamin-1 (FLN-1) has recently been identified. We review the clinical and imaging findings from a series of pediatric patients with periventricular nodular heterotopia. Five patients (three males and two females; age range = 4-18 years) were investigated. In our series, periventricular nodular heterotopia can be the common denominator in different conditions. Periventricular nodular heterotopia can occur alone or be associated with cortical malformations. Epilepsy was present in three of the five patients and was resistant to drugs in one female. Mental retardation was present in three of the five patients. Two male patients had normal intelligence, with no cortical anomalies; patient 3 had unilateral periventricular nodular heterotopia. The associated malformations were more severe in the female patients and slight only in patient 1. The two females showed anomalies rarely reported in association with bilateral periventricular nodular heterotopia. We believe that other genes can be involved in children with atypical neuroradiologic periventricular nodular heterotopia. No mutations were detected in 6 of the 48 exons of the FLN-1 gene, although this does not allow any definitive conclusions to be reached. We conclude that our series of patients with periventricular nodular heterotopia clearly highlights the complexity of the clinical, neurologic, and neuroradiologic characteristics associated with this malformation.