Intragenic rearrangements in LARGE and POMGNT1 genes in severe dystroglycanopathies

Dystroglycanopathies are a heterogeneous group of muscular dystrophies with autosomal recessive inheritance characterized by abnormal glycosylation of alpha-dystroglycan. The most severe phenotypes are Walker-Warburg Syndrome (WWS) and muscle-eye-brain disease (MEB) presenting with lissencephaly type II (LIS II) and in which muscular dystrophy is associated with mental retardation and eye abnormalities. To date, six distinct genes, POMT1, POMT2, POMGNT1, FKTN, FKRP, LARGE and recently in one case DPM3, have been shown to be involved in dystroglycanopathies. Genomic sequencing alone is still frequently used for diagnosis purpose, not allowing detection of intragenic rearrangements at the heterozygous state contrarily to RNA analysis, quantitative PCR and CGH array analysis. These latter methods enabled us to identify four new intragenic rearrangements in the LARGE gene in three fetuses with WWS, born to two unrelated families: deletion of exons 9-10 and duplication of introns 1-4 for the first family and deletion of exons 4 and 7 for the second one; and a deletion of the last six exons of the POMGNT1 gene in two unrelated MEB patients. Genomic dosage studies using emerging tools such as CGH array should be included in routine molecular analysis of dystroglycanopathies, not only for the screening of the LARGE gene in which this kind of mutation seems to be more frequent than point mutations, but also for the other involved genes, especially in severe clinical cases.

Febrile brain stroke and tuberculous meningitis: persisting threat in non-endemic countries

Tuberculous meningitis is uncommon in western countries and its outcome is poor when it is not diagnosed and treated in good time. Here, we present a case of febrile brain stroke revealing a tuberculous arachnoiditis in a 13-month-old infant living in a non-endemic country. Thanks to prompt specific antibiotherapy, the clinical outcome was globally favourable in spite of the occurrence of an asymptomatic brain tuberculoma, which disappeared spontaneously. Although tuberculous meningitis is rare in non-endemic countries, it must be evoked in strokes occurring in a febrile context.

A common pattern of brain MRI imaging in mitochondrial diseases with complex I deficiency

OBJECTIVE

To identify a consistent pattern of brain MRI imaging in primary complex I deficiency. Complex I deficiency, a major cause of respiratory chain dysfunction, accounts for various clinical presentations, including Leigh syndrome. Human complex I comprises seven core subunits encoded by mitochondrial DNA (mtDNA) and 38 core subunits encoded by nuclear DNA (nDNA). Moreover, its assembly requires six known and many unknown assembly factors. To date, no correlation between genotypes and brain MRI phenotypes has been found in complex I deficiencies.

DESIGN AND SUBJECTS

The brain MRIs of 30 patients carrying known mutation(s) in genes involved in complex I were retrospectively collected and compared with the brain MRIs of 11 patients carrying known mutations in genes involved in the pyruvate dehydrogenase (PDH) complex as well as 10 patients with MT-TL1 mutations.

RESULTS

All complex I deficient patients showed bilateral brainstem lesions (30/30) and 77% (23/30) showed anomalies of the putamen. Supratentorial stroke-like lesions were only observed in complex I deficient patients carrying mtDNA mutations (8/19) and necrotising leucoencephalopathy in patients with nDNA mutations (4/5). Conversely, the isolated stroke-like images observed in patients with MT-TL1 mutations, or the corpus callosum malformations observed in PDH deficient patients, were never observed in complex I deficient patients.

CONCLUSION

A common pattern of brain MRI imaging was identified with abnormal signal intensities in brainstem and subtentorial nuclei with lactate peak as a clue of complex I deficiency. Combining clinico-biochemical data with brain imaging may therefore help orient genetic studies in complex I deficiency.

Insidious peripheral neuropathy occurring under treatment in infantile MTHFR deficiency

5,10-Methylenetetrahydrofolate reductase (MTHFR) deficiency was diagnosed in a 1-month-old baby with signs of cerebral distress. Under a classic treatment using methionine supplementation, methyl donor (betaine) folinic acid, vitamin B(6) and vitamin B(12), the neuromotor development was satisfactory. At 15 years of age, however, despite no clear modification of the biochemical markers in body fluids, she developed a clinically overt peripheral axonal neuropathy. Only partial clinical improvement was obtained after reinforcement of betaine doses. Surveillance of the peripheral nerve is indicated in MTHFR deficiency, including in the infantile form with a good therapeutic compliance.

[Arterial ischemic stroke in the healthy child. Practical approach (neonate and foetus excluded)]

Primary stroke can be due to embolism or an obstructive process of the vascular wall. Embolism may come from a parietal lesion of a large artery in the neck (traumatic dissections), from a cryptic cardiopathy, from a venous thrombosis associated with a right-left shunt. Among pathologies of endocranial arteries, the most frequent is the acute, postviral arteriopathy of the sus-clinoïd carotid, which evolves toward stabilisation or regression. Insidious obstructive arteriopathies of the Willis circle, including development of a transparenchymal suppletive circulation (Moya-Moya disease), cumulate chronic circulatory insufficiency and repetitive strokes. Inflammatory multifocal cerebral arteriopathies mainly involve mean and small arteries. Most of them are secondary to a multisystemic disease, but some are primary. The basic investigation is anatomical and begins with MRI. Emergency conventional cerebral angiography is discussed when heparinotherapy is difficult to decide (evolutive thrombosis), or when an endovascular intervention appears possible (anoeuvrism). Secondarily, conventional angiography is indicated in any chronic situation where a precise anatomical follow-up is necessary. Investigations of the cardiovascular system, of the thrombophilic risk, of a dysimmune process are discussed according to the clinico-anatomical diagnosis.

The association between developmental handicaps and traumatic brain injury during pregnancy: an issue that deserves more systematic evaluation

AIMS

Trauma during pregnancy is commonly viewed as benign for the foetus when the delivery occurs normally. This study revisits that point of view.

METHOD

We included eighteen patients having a neurological handicap with an anamnesis of an accident during pregnancy and a follow-up sufficient to determine a definite outcome.

RESULTS

Pregnancy outcome and observed management. Foetal abnormalities were detected in six cases between the first and the thirteenth day after the trauma. Emergency delivery or rapid birth after signs of foetal distress occurred in five cases. One baby died soon after birth. One-third of cases were not submitted to any investigation. VARIOUS NEUROLOGICAL HANDICAPS WERE RECORDED: Congenital microcephaly (three patients), congenital hydrocephalus (three), Infantile cerebral hemiplegy (six), quadriplegy with severe encephalopathy (four), diplegy (one), clumsiness with cerebellar atrophy (one), Moebius syndrome (one), mental retardation with autistic features (two), learning disability (one) auditory agnosia (one). Cerebral imaging showed macroscopic abnormalities in fourteen patients, evoking various pathogenetic hypotheses.

CONCLUSION

The association between maternal trauma and foetal brain lesions lacks sufficient investigation in many cases. Prospective studies are needed to clarify both medical and legal issues. Guidelines are proposed for obstetrical and paediatric management after significant maternal trauma.

Manifestations neurologiques spectaculaires après traumatisme crânien bénin : étude rétrospective de 51 enfants

Mild head traumas, as a rule, remain a- or paucisymptomatic. In a few cases however, spectacular manifestations develop despite absence of intracerebral lesion. POPULATION, METHODS: We have studied retrospectively 51 such children and contacted their family in order to clarify the follow-up.

RESULTS

The dominant symptoms allowed to categorize the following situations: syncope-like loss of consciousness (11 cases), seizures (6), severe headaches with neurologic signs (15), confusion (8), visual disorders (6), amnesic ictus (5). Recurrences were possible but benign: in 8/11 children in the group "syncopes", in 1/6 in the group "seizures", in 5/21 in the 4 other groups. In the latter 4 groups, 11/21 children developed common migraine. Except for the only case who developed epilepsy later on, scholarship was normal in the 25 cases with sufficient follow-up.

DISCUSSION

Beside syncopes and seizures, the long-lasting episodes suggested a migrainous pathogeny, perhaps at a maturative stage where the trigger of migrainous mechanism is at a low level in the brain.

CONCLUSION

The mildness of the knock, the normality of CT scan including when the symptoms are present and the normality of both consciousness and examination once the symptoms have disappeared allow to avoid further investigations.

Thrombose néonatale des veines jugulaires : retentissement à long terme sur le développement cérébral (à propos de deux cas)

Bilateral obstruction of the internal jugular veins is rare in the neonatal period and no long-term follow-up has been reported yet. We report two cases. The first developped an extensive thrombosis of superior veina cava related to a central veinous line, the second an unilateral thrombosis of the transverse-sigmoid sinus associated to a constitutional hypoplasia of the contralateral jugular vein. In the latter case, no cause or risk factor was noticeable, except for a forceps delivery. In both cases the clinical course was dominated by the development of a prominent collateral network of cervico-facial veins and by a progressive macrocrania. According to MRImaging, the latter was not related to a dilation of CSF spaces, but to a macro-encephaly, either by inflation of the vascular veinous compartment inside the parenchyma or by genuine brain's overgrowth. Long-term follow-up showed a grossly normal course, both from the neurological and the scholar point of view. However, slight neuropsychological anomalies were noticed, bringing some shade on the prognosis.

Allelic heterogeneity of SMARD1 at the IGHMBP2 locus

Spinal Muscular Atrophy with Respiratory Distress (SMARD) is an autosomal recessive disorder characterized by neurogenic muscular atrophy due to progressive anterior horn cell degeneration and early life-threatening respiratory failure ascribed to diaphragmatic dysfunction. SMARD is clinically and genetically heterogeneous. SMARD type 1 is characterized by onset of respiratory failure within the first weeks of life and has been ascribed to mutations in the immunoglobulin mu-binding protein 2 (IGHMBP2) gene on chromosome 11q13-q21. We report here the identification of nine novel IGHMBP2 mutations in five SMARD1 patients, including seven missense [ c.587A>G (p.Gln196Arg), c.647C>T (p.Pro216Leu), c.752T>C (p.Leu251Pro), c.1693G>A (p.Asp565Asn), c.1730T>C (p.Leu577Pro), c.1807C>T (p.Arg603Cys), c.1909C>T (p.Arg637Cys)] and two nonsense mutations [ c.1488C>A (p.Cys496X), c.2368C>T (p.Arg790X)]. Interestingly, 7 of 9 mutations occurred at highly conserved residues of the putative DNA helicase domain. The identification of novel IGHMBP2 variants will hopefully help diagnosing SMARD1 and contribute to a better functional characterization of IGHMBP2 gene product.

Phoneme perception in a neonate with a left sylvian infarct

We report the case of a neonate tested three weeks after a neonatal left sylvian infarct. We studied her perception of speech and non-speech stimuli with high-density event-related potentials. The results show that she was able to discriminate not only a change of timbre in tones but also a vowel change, and even a place of articulation contrast in stop consonants. Moreover, a discrimination response to stop consonants was observed even when syllables were produced by different speakers. Her intact right hemisphere was thus able to extract relevant phonetic information in spite of irrelevant acoustic variation. These results suggest that both hemispheres contribute to phoneme perception during the first months of life and confirm our previous findings concerning bilateral responses in normal infants.

[At the crossroads between developmental and degenerative diseases: the cerebellar disorders of early infancy. Classification and practical approach]

The developmental characteristics of the cerebellum, including its histogenesis which persists well beyond birth, explain, at least in part,why the mechanisms of cerebral disorders of infancy remain equivocal. The nosology of certain congenital ataxias, especially those with cerebellar hypoplasia, remains ambiguous, at the crossroads between early degenerative disease and congenital non-progressive anomalies. We have revisited the clinical approach to the most frequent situations: (1) the careful dysmorphology work-up must search for any element of various recognizable syndromes, especially those transmitted by autosomal recessive inheritance. An update of list of such syndromes is provided. (2) Cerebellum imaging must be obtained as early as possible and re-documented with a long-term follow-up. Emerging 3D techniques should help improve morphological evaluation. (3) One the contrary, a complex biochemical work-up, looking for metabolic diseases, is required only when the clinical and radiological evaluations provide unusual data. (4) Mental status is always the most relevant element of prognosis. t is frequently compromised, including in congenital non-progressive ataxia with normal imaging. Beyond the classical strategies, the genetic approach must take into consideration possible phenotypic homologies with natural or experimental animal models. This approach is illustrated by the recent discovery of mutations with the human homolog of the Reeler gene in a subset of cerebellar agenesis associated with other dysgenetic elements.

[Encephalopathy associated with severe bacterial infections: "presuppurative encephalitis" or "toxi-infectious disorder"?]

Three children are reported, exhibiting encephalopathic symptoms in the course of a severe bacterial infection, though they had no sign of intracranial purulent collection nor metabolic disturbances: the first was associated with a appendicular peritonitis, the second with a purulent knee arthritis, the third with a pneumoccus septicemia. The elements are reviewed that favor either a true septic encephalitis, i.e. microscopic presuppurative foci, versus a toxiinfectious process, either by direct action of toxins or through intracerebral activation of pre-inflammatory cytokines. Whatever the mechanism involved in individual cases, the treatment is mainly based on prompt administration of the convenient antibiotics.

[SPECT-identified hypoperfusion of the left temporomesial structures in a Kleine-Levin syndrome]

A 13-year-old boy developed typical features of Kleine-Levin syndrome. Routine investigations and MRI were normal. SPECT, performed both during an attack and during a symptom-fee period, demonstrated clear hypoperfusion of the left mesiotemporal structures. The possible implications of this finding are discussed.

Critical illness neuromuscular disease: clinical, electrophysiological, and prognostic aspects

BACKGROUND

Critical illness neuromuscular disease, which has been recognised as a distinct clinical entity in adults, remains poorly described in children.

AIMS

To assess retrospectively the clinical, electrophysiological, and prognostic features of the disease.

METHODS

Retrospective study in a children's university hospital.

RESULTS

Five critically ill patients presented with generalised paralysis, associated with long lasting failure to breathe in three. The cause of the generalised paralysis was critical illness neuropathy in two, acute myopathy in two, and mixed neuromyopathy in one.

CONCLUSIONS

Neuromuscular disease should be suspected in critically ill children with muscle weakness. Because corticosteroids and muscle relaxants appear to trigger some types of intensive care unit neuromuscular disease in children, their use should be restricted or administered at the lowest doses possible.

Familial and sporadic forms of central core disease are associated with mutations in the C-terminal domain of the skeletal muscle ryanodine receptor

Central core disease (CCD) is an autosomal dominant congenital myopathy. Diagnosis is based on the presence of cores in skeletal muscles. CCD has been linked to the gene encoding the ryanodine receptor (RYR1) and is considered to be an allelic disease of malignant hyperthermia susceptibility. However, the report of a recessive form of transmission together with a variable clinical presentation has raised the question of the genetic heterogeneity of the disease. Analyzing a panel of 34 families exclusively recruited on the basis of both clinically and morphologically expressed CCD, 12 different mutations of the C-terminal domain of RYR1 have been identified in 16 unrelated families. Morphological analysis of the patients' muscles showed different aspects of cores, all of them associated with mutations in the C-terminal region of RYR1. Furthermore, we characterized the presence of neomutations in the RyR1 gene in four families. This indicates that neomutations into the RyR1 gene are not a rare event and must be taken into account for genetic studies of families that present with congenital myopathies type 'central core disease'. Three mutations led to the deletion in frame of amino acids. This is the first report of amino acid deletions in RYR1 associated with CCD. According to a four-transmembrane domain model, the mutations concentrated mostly in the myoplasmic and luminal loops linking, respectively, transmembrane domains T1 and T2 or T3 and T4 of RYR1.

Efficacy of high dose steroid therapy in children with severe acute transverse myelitis

No effective treatment has been demonstrated for patients with acute transverse myelopathy. In a multicentre controlled study, 12 children with severe acute transverse myelopathy were treated with intravenous methylprednisolone (IVMP) and compared with a historical group of 17 patients. The treatment had a significant effect on the proportion of patients walking independently at 1 month and on the proportion with full recovery at 1 year, with no differences in the frequency of complications between the two groups.

Respiratory chain deficiency in Alpers syndrome

Alpers syndrome is a progressive encephalopathy of early onset, characterized by rapid and severe developmental delay, intractable seizures and liver involvement in a previously healthy child. Here, we report on respiratory chain enzyme deficiency in the liver of four unrelated children presenting with epileptic encephalopathy and liver involvement diagnosed as Alpers syndrome. Interestingly, oxidative phosphorylation in skeletal muscle was normal in 4/4 and blood and CSF lactate in 3/4 patients. Liver involvement had a late clinical onset in patients with previously isolated epileptic encephalopathy. Based on these observations, we suggest 1. to give consideration to respiratory chain deficiency in the diagnosis of severe epileptic encephalopathy in childhood, even when no clinical or biological evidence of liver involvement or lactic acidosis is noted, and 2. to investigate the respiratory chain in a needle biopsy of the liver in children with epileptic encephalopathy prior to valproate administration if biochemical indications for respiratory chain disease or hepatic disturbance are noted, as this drug is believed to occasionally trigger hepatic failure and fatal outcome.

Organization of the mevalonate kinase (MVK) gene and identification of novel mutations causing mevalonic aciduria and hyperimmunoglobulinaemia D and periodic fever syndrome

Mevalonic aciduria (MA) and hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) are two autosomal recessive inherited disorders both caused by a deficient activity of the enzyme mevalonate kinase (MK) resulting from mutations in the encoding MVK gene. Thus far, disease-causing mutations only could be detected by analysis of MVK cDNA. We now describe the genomic organization of the human MVK gene. It is 22 kb long and contains 11 exons of 46 to 837 bp and 10 introns of 379 bp to 4.2 kb. Three intron-exon boundaries were confirmed from natural splice variants, indicating the occurrence of exon skipping. Sequence analysis of 27 HIDS and MA patients confirmed all previously reported genotypes based on cDNA analysis and identified six novel nucleotide substitutions resulting in missense or nonsense mutations, providing new insights in the genotype/phenotype relation between HIDS and MA.

Arthrogryposis and multicystic encephalopathy after acute fetal distress in the end stage of gestation

The natural history of the rare association "multicystic encephalopathy-arthrogryposis" was traced in a fetus carefully followed after artificial insemination. The fetus exhibited normal viability and brain morphology up to the 32nd week. At 36 weeks, active movements diminished and at 37 weeks, hydramnios and signs of fetal distress led to cesarean section. The infant presented with severe arthrogryposis of the limbs and spine, but not with the other elements of a long-lasting akinesia. US showed multicystic encephalopathy. Both the clinical and the neuropathological findings established that multicystic encephalopathy was neither the cause nor the sequential consequence of the fetal akinesia, but the result of a recent diffuse, acute malacic process that also involved the anterior horn cells. Acute fetal distress, responsible for major ischemic damage to CNS but compatible with fetal survival, remains an obscure condition which allows for the development of severe arthrogryposis in a few weeks.

The gene encoding gigaxonin, a new member of the cytoskeletal BTB/kelch repeat family, is mutated in giant axonal neuropathy

Disorganization of the neurofilament network is a prominent feature of several neurodegenerative disorders including amyotrophic lateral sclerosis (ALS), infantile spinal muscular atrophy and axonal Charcot-Marie-Tooth disease. Giant axonal neuropathy (GAN, MIM 256850), a severe, autosomal recessive sensorimotor neuropathy affecting both the peripheral nerves and the central nervous system, is characterized by neurofilament accumulation, leading to segmental distension of the axons. GAN corresponds to a generalized disorganization of the cytoskeletal intermediate filaments (IFs), to which neurofilaments belong, as abnormal aggregation of multiple tissue-specific IFs has been reported: vimentin in endothelial cells, Schwann cells and cultured skin fibroblasts, and glial fibrillary acidic protein (GFAP) in astrocytes. Keratin IFs also seem to be alterated, as most patients present characteristic curly or kinky hairs. We report here identification of the gene GAN, which encodes a novel, ubiquitously expressed protein we have named gigaxonin. We found one frameshift, four nonsense and nine missense mutations in GAN of GAN patients. Gigaxonin is composed of an amino-terminal BTB (for Broad-Complex, Tramtrack and Bric a brac) domain followed by a six kelch repeats, which are predicted to adopt a beta-propeller shape. Distantly related proteins sharing a similar domain organization have various functions associated with the cytoskeleton, predicting that gigaxonin is a novel and distinct cytoskeletal protein that may represent a general pathological target for other neurodegenerative disorders with alterations in the neurofilament network.

Peripheral neuropathy with hypomyelination, chronic intestinal pseudo-obstruction and deafness: a developmental "neural crest syndrome" related to a SOX10 mutation

We describe the case of a girl with an unusual congenital phenotype, combining peculiar peripheral nerve lesions with hypomyelination, chronic intestinal pseudoobstruction, and deafness. She was found to have a de novo heterozygous frameshift mutation in the gene encoding the SOX10 transcription factor. The likely role of SOX10 in determining the fate of Schwann cells during early embryogenesis may explain the peripheral nervous system developmental disorder observed in this patient.

[Epilepsy presenting as life-threatening events in infants]

OBJECTIVE

This study was aimed at assessing the frequency and features of epilepsy presenting as life-threatening events in infancy.

PATIENTS AND METHODS

Fifteen cases were collected over eight years. Subtle symptoms suggestive of epilepsy were rare (9/15) in the retrospective analysis; the clinical context and cerebral imaging were occasionally contributive (5/15); interictal EEG was useful but inconstantly contributive, including when the epileptic nature of the episodes had become clinically probable (10/15). Though it had no clear relationships with epileptic episodes but contributed to mislead diagnosis, gastroesophageal reflux was frequently associated. Uncovered epilepsies were not homogeneous, ranging from severe epileptic encephalopathy to benign epilepsy of infancy.

CONCLUSION

Epilepsy presenting as life-threatening events is sometimes a diagnostic challenge. When an infant develops recurrent critical episodes during a several-week follow-up, with neurological and general investigations not providing more information, the immediate success of antiepileptic treatment might support diagnosis.

Giant axonal neuropathy locus refinement to a < 590 kb critical interval

Giant axonal neuropathy (GAN) is a rare autosomal recessive neurodegenerative disorder, characterised clinically by the development of chronic distal polyneuropathy during childhood, mental retardation, kinky or curly hair, skeletal abnormalities and, ultrastructurally, by axons in the central and peripheral nervous systems distended by masses of tightly woven neurofilaments. We recently localised the GAN locus in 16q24.1 to a 5-cM interval between the D16S507 and D16S511 markers by homozygosity mapping in three consanguineous Tunisian families. We have now established a contig-based physical map of the region comprising YACs and BACs where we have placed four genes, ten ESTs, three STSs and two additional microsatellite markers, and where we have identified six new SSCP polymorphisms and six new microsatellite markers. Using these markers, we have refined the position of our previous flanking recombinants. We also identified a shared haplotype between two Tunisian families and a small region of homozygosity in a Turkish family with distant consanguinity, both suggesting the occurrence of historic recombinations and supporting the conclusions based on the phase-known recombinations. Taken together, these results allow us to establish a transcription map of the region, and to narrow down the GAN position to a < 590 kb critical interval, an important step toward the identification of the defective gene.

[Progress in pediatric neurology]

A central part of Pediatric Neurology is currently dominated by the search for genetic factors involved in developmental disorders of the nervous system, including cases where the cytogenetic examination remains uncontributive. The prerequisite for a good definition of the malformative phenotypes leads to distinguish: 1 cerebral malformations that can be identified at the macroscopic scale, by imaging. 2 polymalformative syndromes including mental retardation where cerebral imaging is not contributive, thus the syndromatic definition is based on associated somatic anomalies. 3 Non-syndromatic mental retardation, where a genetic origin is clear only in the familial forms. Various methodological approaches have included genetic linkage studies, search for inframicroscopic chromosomal rearrangements in the critical region and investigation of candidate genes. A great number of syndromes have been connected with a great diversity of genetic mechanisms, whose many examples are presented: genopathies with regular or variable expression, unstable mutations, contiguous gene syndromes or other complex infracytogenetic rearrangements, chromosomal or genic mosaicisms, mutations submitted to parental imprinting. New methods of genomic screening will be necessary to progress in this field, given the great number of genes involved in cerebral development. As for the early developmental disorders of the PNS and muscle, their diagnosis becomes frequent during the intrauterine life, raising the problem of a better definition of the fetopathological phenotypes.

Stroke in childhood: outcome and recurrence risk by mechanism in 59 patients

This paper describes 59 patients, 3 months to 16 years of age, who were seen consecutively in the same center for cerebral arterial infarction. It focuses on the mechanism of stroke. The pathophysiologic process could be established for 78% of the children. Arteriopathic stroke (31 patients, or 53%) was the most common. The arteriopathies were either progressive (moyamoya in 4 patients, or 7%) or nonprogressive (27 patients, or 46%). The latter form occurred in two patterns: dissection of cervicocephalic arteries (12 patients, or 20%) and transient cerebral arteriopathy of unknown origin but probably angiitis (15 patients, or 25%). Cardiac or transcardiac embolic stroke occurred in 12% of the series and systemic diseases in 14%. There was a favorable outcome in 70% of patients having stroke due to nonprogressive arterial disease and stroke due to unidentified mechanisms. In contrast, only 26% of patients with embolic stroke, systemic disease, or moyamoya had a favorable outcome. Recurrences were more frequent and severe in this latter group. It is concluded that it is important to determine the mechanism of childhood stroke, because it strongly influences outcome, the recurrence risk, and treatment choice.

[What is new in pediatric neurology?]

Some significant advances in the field of pediatric neurology are reviewed. For many constitutional disorders, concepts and diagnostic procedures have progressed from various genetic techniques or from protein labeling in situ. Many neurodegenerative disorders, some poorly-defined metabolic diseases, and several syndromes associating mental retardation with neurologic or extraneurologic malformations have been characterized. In addition, for many disorders viewed as 'poorly specific' (mental retardation, epilepsy, migraine), familial forms have permitted us to define the first genes involved. In 'acquired' disorders, new data come from clinical trials (antiepileptic, anti-inflammatory drugs) rather than definite conceptual advances. Finally, clinics and biology are no longer the only approaches to brain functions, and clinical neurophysiology could encounter a second wind thanks to the techniques of functional imaging, especially in the fields of developmental neuropsychology.

Hematologic involvement in mitochondrial cytopathies in childhood: a retrospective study of bone marrow smears

We retrospectively analyzed the bone marrow (BM) smears of 10 children with mitochondrial cytopathies. Light microscopic examination showed large and coalescent cytoplasmic vacuolization of some BM precursors in nine cases, including two children with normal peripheral blood counts and four with sideroblastic anemia. BM ultrastructural study showed abnormal mitochondria in the erythroid lineage in all three children studied. Ultrastructural studies in two cases revealed a population of giant mitochondria with abnormal ultrastructure coexisting with a population of normal mitochondria in proerythroblasts, basophil erythroblasts, and less commonly in more mature erythroblasts. In a third child, mitochondria were normal in size with cristae either absent or exhibiting abnormal longitudinal orientation. Heteroplasmic segregation of mitochondria during cell division could account for the finding of a double population of cells on ultrastructural examination. These features suggest that cytologic and ultrastructural BM examination could be useful for the diagnosis of mitochondrial disorders. That is, when large and coalescent cytoplasmic vacuoles of BM precursor cells are present, the clinician should search for mitochondrial cytopathy in a child with unexplained cytopenia(s).

Haemorrhagic shock and encephalopathy syndrome: neurological course and predictors of outcome

The haemorrhagic shock and encephalopathy syndrome (HSES) is a devastating disease. The aetiology of this syndrome is unknown, and, despite intensive treatment, the outcome is often fatal or associated with severe neurological sequelae.

OBJECTIVE

To assess the neurological features and potential prognostic markers of the disease.

DESIGN

Retrospective study.

SETTING

Division of Neuropaediatrics in a children's university hospital.

PATIENTS AND METHODS

Fourteen patients fulfilling the HSES criteria out of 42 children admitted with fever and shock to the Paediatric Intensive Care Unit between 1986 and 1994, were analysed for clinical, biological, neuroradiological, EEG and neuropathological findings.

RESULTS

The patients (age range from 2 to 33 months) were found at night or in the morning either comatous (n = 3) or convulsing (n = 11). All but one were healthy before admission, although eight had had a brief prodromal infectious disease. All were febrile (mean body temperature 39.9 degrees C +/-0.9 degrees). Seasonal clustering during the winter months was observed. Coma and seizures with frequent status epilepticus were the main neurological manifestations. All children recovered from their multiple organ failure within a few days. Seven died (50%); four survivors had neurological sequelae (29%) with a developmental quotient (DQ) of 50% or less in three and a DQ of 75% in one and three infants (21%) had normal outcomes. Computed tomography (CT) displayed a diffuse area of low density mainly in the cerebral cortex and intraventricular and parenchymal haemorrhages. Magnetic resonance imaging (MRI) showed haemorrhagic cortical lesions. Postmortem examination of the brain conducted in three patients showed necrotic and haemorrhagic lesions, mainly in cortical areas. Comparison of the children with adverse outcome (death or neurological sequelae) with those with normal outcome revealed that predictors of poor outcome were status epilepticus (p = 0.003) and coma for more than 24 h (p = 0.01). Infants without disseminated intravascular coagulation, without a biphasic course and without brain hypodensities or haemorrhages on CT scans performed at least 4 days after onset had a normal neurodevelopmental outcome.

CONCLUSION

The central nervous system appeared to be the main target of the HSES lesions. The most common outcome was brain death or severe brain damage. Further studies with a larger sample are necessary to determine whether the prognostic indicators we identified are reliable.

Acute inflammatory demyelinating polyradiculopathy in children: clinical and electrodiagnostic studies

Clinical and electrophysiological features in 43 children with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) were retrospectively studied. More than one-third of these children were less than 3 years old. Some distinctive clinical features specific to adults or to children were identified. Initial symptoms such as ataxia and severe limb or back pain were more frequent in children. By using the criteria suggested here, according to our neurophysiological findings, the diagnosis of AIDP could be proposed as early of the first days of illness in 90% of the children and is confirmed during the second week. The neurophysiological evolution was very similar in children and adults except that recovery occurred sooner in children. Prognosis was better in childhood (complete recovery in all but 2 patients with minor disabilities).

Bone marrow transplantation in metachromatic leukodystrophy caused by saposin-B deficiency: a case report with a 3-year follow-up period

A 2-year-old child had a metachromatic leukodystrophy-variant phenotype mainly involving the peripheral nervous system (PNS) that was caused by saposin-B deficiency. Bone marrow transplantation resulted in transient deterioration then continuous improvement of PNS functions. These findings were supported by nerve conduction velocity measurements, but the symptoms ultimately worsened. Magnetic resonance imaging showed persistent white matter lesions and progressive pontocerebellar atrophy.

[Neurogenic bladder in children with acute transverse myelopathy]

BACKGROUND

Neurogenic sphincter dysfunction may result from acute transverse myelopathy. The aim of this paper is to study the course of such a dysfunction and to propose management techniques.

PATIENTS AND METHODS

The files of 21 children admitted at the mean age of 8 years 5 months (2 to 14 years, 8 months) for acute transverse myelopathy were retrospectively studied.

RESULTS

Bladder sphincter dysfunction occurred in the first days of disease in 85% of these patients. Abnormal perception of micturition was one of the most constant and specific symptoms. Anorectal function was also impaired. Complete regressive course was noted in 38% of patients, minor sequellae in 39% and major sequellae beyond 6 months of course in 23%. None upper tract deterioration was noted after 3 years of course. Factors of favorable prognosis were early motor function recovery (especially recommencement of walking before 20 days) and early management of bladder dysfunction (inability to void had better prognosis than urinary incontinence).

CONCLUSION

Early systematic bladder drainage in case of inability to void might be essential for improved prognosis.

MRI-neuropathological correlations in type 1 lissencephaly

Although imperfect, MRI is the best way of distinguishing type 1 lissencephaly from other, less classical lissencephalic malformations. We reported a case in which correlation of MRI and neuropathology was possible. Besides the classical radiological features of lissencephaly, i.e., agyria and excessive thickness of the cortex, an additional sign was observed: a thin cortical band, which gave high signal on T2-weighted images, represented a paucicellular and partially myelinated band, 1500 microns thick, lying under the true superficial cortex. This MRI feature could be characteristic of the particular cortical lamination observed in true type 1 lissencephaly.

Transient cerebral arteriopathy: a disorder recognized by serial angiograms in children with stroke

Repeated clinical evaluation and cerebral arteriography during the evolution of ischemic strokes of idiopathic origin allowed us to characterize a transient cerebral arteriopathy. We retrospectively studied the clinical characteristics, course, and neuroimaging features of this disorder in nine children. Of 34 children with ischemic strokes seen consecutively between 1984 and 1995, 9 (26%) were diagnosed as having transient attack of the cerebral arterial wall, termed transient cerebral arteriopathy. All of these patients had previously been in good health. The mean age at the time of the first stroke was 6 years (range, 2 9/12 years to 13 4/12 years). All children presented with acute hemiplegia. A recurrence of the stroke took place 3 months at the latest after the initial infarct in three children (mean clinical follow-up 2 7/12 years). Cerebral imaging in all the patients showed small subcortical infarcts located in basal ganglia or internal capsule. Arteriography revealed multifocal lesions of the arterial wall (focal stenosis or segmental narrowing), mostly located in the initial parts of basal arteries of the carotid system. Longitudinal arteriographic follow-up showed initial worsening of these arterial lesions (n = 5) for a maximum duration of 7 months followed by complete regression (n = 2), improvement (n = 5), or stabilization of the lesions (n = 2). Five patients had a complete clinical recovery. Further studies are necessary to confirm a presumed inflammatory cause of this arteriopathy.

Segregation of the G8993 mutant mitochondrial DNA through generations and embryonic tissues in a family at risk of Leigh syndrome

We identified the T8993G mitochondrial mutation in a female infant who died of Leigh syndrome. The proportion of mutant mitochondrial DNA increased to near homoplasmy in three generations of the pedigree. A similarly high proportion of mutant mitochondrial DNA was found in the chorionic villi and in fetal tissues from a pregnancy interrupted because of the risk of Leigh syndrome. This study supports the concept that prenatal diagnosis can be used for Leigh syndrome with the T8993G mitochondrial DNA mutation.

[Ischemic cerebral vascular accident caused by vertebral artery dissection]

BACKGROUND

Strokes due to vertebral artery lesions are not yet well known in children.

CASE REPORT

We report on a case of post-traumatic vertebral artery dissection responsible for ischemic stroke in a 8-year old boy. Headache, vomiting and a brief loss of consciousness were the main initial signs. Neurological examination showed a locked-in syndrome. Cerebral imaging revealed lesions in cortical cerebellar hemisphere, cerebral pedoncular and protuberance. An arteriogram performed on day 10 showed left vertebral artery occlusion at C2 levels consistent with vertebral dissection. Antiagregants treatment was given. Neurological recovery was good. Pertinent clinical data of 24 children who had strokes due to a vertebral artery dissection are analysed.

CONCLUSION

Vertebral artery dissection is presently a well-known cause of childhood strokes. Benefits from anticoagulants are now established.

High dose methylprednisolone in severe acute transverse myelopathy

No effective treatment has been shown for patients with acute transverse myelopathy. In an open study five children with severe acute transverse myelopathy were treated with intravenous methylprednisolone and compared with a historical group of 10 patients. The results show that in the methylprednisolone treatment group compared with the historical group of 10 patients: the median time to walk independently was significantly reduced (23 v 97 days); the proportion of patients with a full recovery within 12 months was significantly higher (80 v 10%); all patients had complete motor recovery within one year in contrast with only two of 10 patients in the historical group; and serious adverse effects did not occur. This pilot study suggests that high dose methylprednisolone is effective in the treatment of acute transverse myelopathy.

[Primary amenorrhea revealing congenital hydrocephalus]

Among the various endocrine manifestations of chronic hydrocephaly, amenorrhea is not exceptional, whereas late puberty and obesity are the most frequent. The hypothalamic gonadotropic function usually returns to normal within the few months following the ventricular shunt.

CASE REPORT

A 16 year-old girl, with a von Recklinghausen's disease, developed amenorrhea 2 years after the onset of puberty. X-rays of her skull showed an enlarged sella turcica and a diagnosis of hydrocephalus due to aqueductal stenosis was finally made. As her head circumference was retrospectively shown at +3 SD as early as the first month of life, the stenosis was certainly congenital, a feature known to occur in 2% of patients with von-Recklinghausen's disease.

CONCLUSION

In symptomatic forms of aqueductal stenosis, the preferred surgical procedure is ventriculocisternostomy under endoscopy. Recovery of intellectual functions is often incomplete. Early diagnosis of hydrocephalus is of paramount importance; ultrasonography through anterior fontanel should be proposed to any infant with head circumference reaching +3 SD.

Survival motor neuron gene deletion in the arthrogryposis multiplex congenita-spinal muscular atrophy association

The survival motor neuron (SMN) gene was lacking in 6/12 patients with arthrogryposis multiplex congenita (AMC) associated with spinal muscular atrophy (SMA). Neither point mutation in the SMN gene nor evidence for linkage to chromosome 5q13 were found in the other patients. Hitherto, arthrogryposis was regarded as an exclusion criterion in SMA. Our data strongly suggest that AMC of neurogenic origin is genetically heterogeneous, with a subgroup being allelic to SMA. Absence or interruption of the SMN gene in the AMC-SMA association will make the diagnosis easier and genetic counselling will now become feasible.