Pediatric neurolisteriosis: A diagnosis to consider even in the absence of immunodeficiency

Neurolisteriosis is known to affect vulnerable groups, for example neonates or children with immunodeficiency. This is a key point of the current clinical guidelines regarding pediatric meningitis. We report a rare case of neurolisteriosis in an immunocompetent infant, without the typical signs of listeriosis, which led to a delay in administering the appropriate antibiotherapy. This case illustrates the clinical heterogeneity of neurolisteriosis and the relevance of appropriate polymerase chain reaction (PCR) tests when the clinical presentation differs from the current guidelines. This case also reminds us that raw or unpasteurized milk-based food products pose a risk even in immunocompetent infants or children.

Twenty-five novel mutations including duplications in the ATP7A gene

Twenty-five novel mutations including duplications in the ATP7A gene. Menkes disease (MD) and occipital horn syndrome (OHS) are allelic X-linked recessive copper deficiency disorders resulting from ATP7A gene mutations. MD is a severe condition leading to progressive neurological degeneration and death in early childhood, whereas OHS has a milder phenotype with mainly connective tissue abnormalities. Until now, molecular analyses have revealed only deletions and point mutations in both diseases. This study reports new molecular data in a series of 40 patients referred for either MD or OHS. We describe 23 point mutations (9 missense mutations, 7 splice site variants, 4 nonsense mutations, and 3 small insertions or deletions) and 7 intragenic deletions. Of these, 18 point mutations and 3 deletions are novel. Furthermore, our finding of four whole exon duplications enlarges the mutation spectrum in the ATP7A gene. ATP7A alterations were found in 85% of cases. Of these alterations, two thirds were point mutations and the remaining one third consisted of large rearrangements. We found that 66.6% of point mutations resulted in impaired ATP7A transcript splicing, a phenomenon more frequent than expected. This finding enabled us to confirm the pathogenic role of ATP7A mutations, particularly in missense and splice site variants.

Basal ganglia neuroprotection with anticonvulsants after energy stress: a comparative study

The 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model provides a valuable paradigm of the energy deficiency disorders found in childhood. In such disorders, anticonvulsants may provide neuroprotection by modulating cellular energy consumption and by exerting favorable pleiotropic effects on neuronal survival. To verify such hypothesis, we tested the effects of levetiracetam, vigabatrin, gabapentine, pregabaline, tiagabine, clonazepam and lamotrigine on neuroprotection in the MPTP mouse model. The membrane dopamine transporter (DAT) density, which provides a reliable index of dopaminergic neurons survival in the basal ganglia, was assessed by semi-quantitative autoradiography of the striatum. Unlike all other anticonvulsants tested, lamotrigine provided a significant and dose-dependent neuroprotection in these experimental conditions. Lamotrigine, a widely used and well-tolerated molecule in children, could provide neuroprotection in various energy deficiency disorders.

MPTP intoxication in mice: a useful model of Leigh syndrome to study mitochondrial diseases in childhood

The basal ganglia, which are interconnected in the striato-nigral dopaminergic network, are affected in several childhood diseases including Leigh syndrome (LS). LS is the most common mitochondrial disorder affecting children and usually arise from inhibition of the respiratory chain. This vulnerability is attributed to a particular susceptibility to energetic stress, with mitochondrial inhibition as a common pathogenic pathway. In this study we developed a LS model for neuroprotection trials in mice by using the complex I inhibitor MPTP. We first verified that MPTP significantly inhibits the mitochondrial complex I in the brain (p = 0.018). This model also reproduced the biochemical and pathological features of LS: MPTP increased plasmatic lactate levels (p = 0.023) and triggered basal ganglia degeneration, as evaluated through dopamine transporter (DAT) autoradiography, tyrosine hydroxylase (TH) immunohistochemistry, and dopamine dosage. Striatal DAT levels were markedly decreased after MPTP treatment (p = 0.003). TH immunoreactivity was reduced in the striatum and substantia nigra (p = 0.005), and striatal dopamine was significantly reduced (p < 0.01). Taken together, these results confirm that acute MPTP intoxication in young mice provides a reproducible pharmacological paradigm of LS, thus opening new avenues for neuroprotection research.

[Clinical variability and diagnosis steps in childhood mitochondrial disease]

OBJECTIVES

Mitochondrial respiratory chain deficiencies are known for their high clinical variability. Difficult to diagnose, the prevalence of these diseases is probably underestimated.

METHODS

We report 18 children diagnosed with respiratory chain deficiency at the Tours University Hospital over the past 10 years.

RESULTS

Three clinical profiles can be distinguished depending on the age at onset of the first symptoms: the neonatal period (4 cases), between 1 month and 2 years of age (10 cases), and after 10 years (4 cases). However, no clinical feature appears specific of any age group. In contrast, respiratory chain analysis on liver biopsy was very informative for all our patients at any age and with any clinical presentation, even with predominant neurological symptoms.

CONCLUSIONS

These biochemical analyses support the diagnosis of mitochondrial disorders in view of molecular analysis, which nevertheless frequently remains inconclusive. These investigations should benefit from the new molecular screening technologies based on DNA chips that can identify the genomic mutations responsible for these severe and relatively frequent diseases.

[Long-chain 3-hydroxyacyl CoA dehydrogenase deficiency and choroidal neovascularization]

We report the case of a 9-year-old girl with a long-chain 3-hydroxyacyl CoA dehydrogenase (LCHAD) deficiency. This enzyme participates in mitochondrial fatty acid B-oxidation. Genetic fatty acid oxidation defects induce cellular energetic deficiency, and thus early life-threatening manifestations. An appropriate diet prevents these severe disorders. Nevertheless, LCHAD deficiency is the only B-oxidation enzymatic disorder that induces a chorioretinopathy, predominating at the posterior pole. We describe the first case of bilateral macular choroidal neovascularization. One eye presented a fibrovascular lesion. The other eye presented an active neovascularization stabilized by two dynamic phototherapies. The specificity of choroidal degeneration related to LCHAD deficiency remains unknown. Reviewing of literature and biochemical mechanisms suggests that fatty acid oxidative stress rather than a mitochondrial energetic defect is involved. For practical purposes, this report emphasizes the importance of ophthalmological follow-up of these patients.

Complications de la neurofibromatose de type 1 chez l'enfant : à propos d'une série de 100 cas

Neurofibromatosis 1 (NF1) is a frequent genetic disease. Diagnostic criterias were established in 1988. The patients can exhibit various and unpredictable complications.

OBJECTIVES

To check the efficiency of a coordinated follow-up in specialized multidisciplinary centers providing a higher quality of management and to have a better knowledge of the complications including their true frequencies.

POPULATION AND METHODS

We report a serie of 100 NF1 children who were followed-up during 4 years in a specialized center at the Tours University Hospital. Three hospital check-up at 2-5, 6-7, 14-15 years of age were performed as well as an annual physical examination.

RESULTS

In our serie, the mean age was 7.8 years old with a sex ratio of 1. The mean age at diagnosis was 3.8 years old and the main diagnosis criteria were the café-au-lait spots and the family history for 80% of the patients. The optic nerve glioma has a low frequency of 5%. Learning disabilities clearly represent the most frequent complication (46% of the patients).

CONCLUSION

An early detection of these difficulties is a priority for the appropriate management of these children.

[Benefit of the extended-release methylphenidate formulations: a comparative study in childhood]

Methylphenidate (MPH) is a potential therapeutic tool for Attention Deficit with Hyperactivity Disorders (ADHD). In addition to the immediate-release formulation, Ritalin, two extended-release formulations, Ritalin LA and Concerta are available and allow a once-daily administration. We compared the respective benefits of both formulations for the patients and their family in terms of efficacy, handling and tolerance.

PATIENTS AND METHODS

This prospective study was based on 30 children aged 6 to 15 years. All patients had a confirmed ADHD and were efficiently treated with Ritalin. The children were consecutively treated with Ritalin LA and Concerta, with a comparable MPH daily dosage, during 2 months for each molecule. The 3 drugs were evaluated individually and comparatively through a battery of questionnaires submitted to the parents and the teachers of each child.

RESULTS

Extended-release MPH efficacy was comparable to the immediate-release formulation, Ritalin. For both of them, the once-daily administration appeared beneficial. Concerta was finally prescribed in 18 children, Ritalin LA in 8 cases and Ritalin in 4 cases. In each case the medical choice was consistent with the parents preference. Concerta was appreciated for its persisting efficacy in late afternoon during homework. Concerta and Ritalin LA did not induce significant adverse effects, especially regarding alimentation and sleep.

CONCLUSIONS

MPH therapy in ADHD carries an excellent risk/benefit ratio without addictive induced behaviours. The extended-release MPH formulations provide an improvement for the patients in keeping with Ritalin efficacy through a once-daily administration. Regardless of its formulation, MPH indications and guidelines must be respected.

[Diagnostic strategies for ischemic strokes in childhood]

Ischemic strokes represent a rare condition in childhood, mostly revealed by a motor deficit. In the pediatric age, strokes are different than in adulthood where atherosclerosis is the major cause. The etiologies of stroke in childhood are rather multiple and each of them is rare. In nearly half of the pediatric cases no cause can be found and usually no recurrence occurs. The aim of this presentation is to propose a diagnosis strategy for ischemic strokes in children. An extensive search should be performed in every children presenting a stroke episode even if the initial outcome appears favorable. Such investigations could improve our understanding and therapeutic strategies of stroke in childhood, a condition where the cognitive and functional prognosis can be severely compromised.

Stratégie diagnostique dans les accidents vasculaires cérébraux ischémiques de l'enfant

Ischemic strokes represent a rare condition in childhood, mostly revealed by a motor deficit. In the pediatric age, strokes are different than in adulthood where atherosclerosis is the major cause. The etiologies of stroke in childhood are rather multiple and each of them is rare. In nearly half of the pediatric cases no cause can be found and usually no recurrence occurs. The aim of this presentation is to propose a diagnosis strategy for ischemic strokes in children. An extensive search should be performed in every children presenting a stroke episode even if the initial outcome appears favorable. Such investigations could improve our understanding and therapeutic strategies of stroke in childhood, a condition where the cognitive and functional prognosis can be severely compromised.

Striatal and pontocerebellar hypoperfusion in Hallervorden-Spatz syndrome

Hallervorden-Spatz syndrome is a group of rare and severe disorders marked by extrapyramidal symptoms and iron accumulation in the globi pallidi, usually visible by magnetic resonance imaging. To assist in determining the functional correlates of these structural abnormalities, positron emission tomography was used to measure regional cerebral blood flows and dopaminergic function in a patient with Hallervorden-Spatz syndrome that manifested as progressive generalized dystonia, optic atrophy, and bilateral pallidal "eye of the tiger" sign. Voxel-by-voxel analysis of positron emission tomography images revealed no pallidal abnormalities but demonstrated significant hypoperfusion of the head of the right caudate nucleus, pons, and cerebellar vermis. Dopaminergic function of the basal ganglia, which was assessed based on visual- analysis of fixation of 18F-labeled fluoro-levodopa, was normal. These data suggest that Hallervorden-Spatz syndrome pathogenesis is not confined to the globi pallidi, and these data also may help to generate new pathogenic hypothesis.

Infantile spasms and Menkes disease

Epileptic seizures are a common feature in Menkes disease, an X-linked genetic disorder of copper metabolism. Details of type of seizures are rarely reported. We report the evolution of infantile spasms in two patients with Menkes disease and the relation with subcutaneous administration of copper-histidine.

Wolcott-Rallison syndrome: a case with endocrine and exocrine pancreatic deficiency and pancreatic hypotrophy

Clinical analysis and genetic investigations of new cases of Wolcott-Rallison syndrome are needed to evaluate the role of the gene(s) directly or indirectly implicated in pancreas development and in the aetiology of the syndrome.

Hyperinsulinemic hypoglycemia as a presenting sign in phosphomannose isomerase deficiency: A new manifestation of carbohydrate-deficient glycoprotein syndrome treatable with mannose

We report the case of a patient with carbohydrate-deficient glycoprotein syndrome type Ib who developed normally until 3 months of age, when she was referred to the hospital for evaluation of hypoglycemia that was found to be related to hyperinsulinism. She also had vomiting episodes, hepatomegaly, and intractable diarrhea, which evoked the diagnosis of carbohydrate-deficient glycoprotein syndrome. Oral mannose treatment at a dose of 0.17 g/kg body weight 6 times/d was followed by a clinical improvement and normalization of blood glucose, aminotransferases, and coagulation factor levels. Hyperinsulinemic hypoglycemia should be considered as a leading sign of carbohydrate-deficient glycoprotein syndrome type Ib, especially when it is associated with enteropathy and abnormal liver tests.

X-linked nonspecific mental retardation (MRX16) mapping to distal Xq28: linkage study and neuropsychological data in a large family

A genetic linkage study was performed on a large four-generation family with variable nonspecific X-linked mental retardation (MRX16), speech abnormalities, and retardation of all milestones. Significant linkage was found in the Xq28 region with loci DXS52, DXS15, BGN, and DXS1108 with maximum LOD scores of 4.86, 4.01, 4.83, and 5.43, respectively, at theta = 0.00. Recombination was observed at the locus DXS1113, thus mapping the gene in an 8-Mb interval between this marker and the Xq telomere. Linkage intervals of three other MRX families overlap with this interval in Xq28 where the RABGDIA gene, mutated in the MRX41 and MRX48 families, is also located. In MRX3, MRX28, but also in MRX16, no alteration of RABGDIA has been found, thus suggesting the existence of at least two MRX genes in distal Xq28.

Prion protein gene expression in cultured astrocytes treated by recombinant growth hormone and insulin-like growth factor

Cases of Creutzfeldt-Jakob disease recently occurred after long treatments with pituitary extracted human growth hormone (GH). Prion protein (PrP) and glial fibrillary acidic protein (GFAP), an astrocyte-specific marker, both accumulate in the central nervous systems of infected individuals during transmissible subacute spongiform encephalopathies (TSSE). PrP expression has been linked to susceptibility to and development of these diseases. We have investigated the effects of recombinant growth hormone, its main biological effector, insulin-like growth factor 1 (IGF-1), and two well known mitogens, epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF), on PrP and GFAP mRNA levels in primary cultures of murine astrocytes using Northern blot quantitation. After 48 h of exposure to these soluble factors, PrP mRNA levels remained unchanged relative to controls in all growth factor-treated cultures, whereas GFAP mRNA concentrations decreased markedly in EGF- and bFGF-treated cultures. These results suggest that GH and IGF-1 do not modulate PrP gene expression in astrocytes.

Modulation of prion protein gene expression by growth factors in cultured mouse astrocytes and PC-12 cells

The present study was performed on primary cultures of mouse astrocytes and cultures of rat pheochromocytoma PC-12 in order to investigate the regulation of the prion protein (PrP) gene expression in relation to proliferation and differentiation. Treatment of PC-12 cells with interleukin-6 (IL-6) and beta-nerve growth factor (NGF) resulted in induction of neuronal differentiation. Northern blot analysis demonstrated a 4-fold increase of PrP mRNA in relation to cellular differentiation, after 7 days of treatment with either of the two factors. In astrocytes, PrP and glial fibrillary acidic protein (GFAP) mRNA levels were found to be regulated in a similar manner during development in vitro. A 3-fold increase of their mRNAs was observed from 5 to 14 days of culture (proliferation period). Then, their gene expressions showed a slight decrease from 14 to 28 days (maturation period). Treatment of astrocytes with IL-6, basic fibroblast growth factor (bFGF), and epidermal growth factor (EGF) appeared to markedly down-regulate the expression of GFAP mRNAs, which might reflect cell maturation. In contrast, they had no significant effect on the expression of PrP gene. These results suggest that the PrP gene expression is differently regulated in neural cells. In neuronal cells, it is mainly associated with differentiation. On the other hand, in astrocytes, the PrP mRNA level seems to be not only related to the proliferation and differentiation stages.

Are pituitary and thyroid function tests useful for the monitoring of antithyroid drug treatment and the post therapeutic control of Graves' disease?

The control of Graves' disease patients treated with antithyroid drugs (ATD) involves monitoring the dose of ATD, the duration of therapy and the prediction of the long-term outcome of the disease. The sequential follow-up of free thyroid hormones and ultrasensitive TSH (USTSH) helps in monitoring of ATD therapy, except in patients complemented with thyroid hormones. The normalization of early thyroid uptake of radioiodine or pertechnetate, which seems to be closely related to circulating thyroid-stimulating immunoglobulins, confirms the remission that leads to stopping ATD therapy. The raise of plasma USTSH in a normal range within the six months following ATD withdrawal is another indicator of remission. However, the post therapeutic course of Graves' patients remains unpredictable: late relapses and hypothyroidism may occur despite the normalization of the pituitary-thyroid axis, leading to a yearly clinical control with USTSH evaluation.