Household poisoning cases from mercury brought from school.

Mercury has a number of unique and fascinating properties. It is present in the environment in several forms, both organic and inorganic. Each of these forms has somewhat unique properties that differentiate them from the other forms, but all are toxic to humans in one way or the others. Mercury has been proven to be a potential source of poisoning in children as a result of the inappropriate handling of a liquid mercury. The cases of metallic mercury vapor intoxication not associated with occupational exposure may occur in school science laboratories, from mercury dust and powders, from latex paint containing a mercury-based fungicide, and from normal wear or installation of dental amalgam fillings. Another source of toxic mercury exposure can be broken thermometers, barometers, or sphygmomanometers that may occur in the home, and children are often victims of environmental exposure. In this paper, we present three members of a family who were exposed to mercury brought home from school by a family member. Since the mercury exposure was not known, the initial presentation and clinical picture suggested a misdiagnosis, a contagious infectious disease, because the onset of symptoms occurred at different times in the same family members. A subsequent change to a diagnosis of mercury intoxication and chelation therapy with meso-2,3-dimercaptosuccinic acid was started.

Absence of exon 17 c.2970-2872delAAT mutation in Turkish NF1 patients with mild phenotype.

INTRODUCTION: Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder characterized by café-au-lait spots, neurofibromas, skinfold freckles, Lisch nodules, bone deformities, learning disabilities, and predisposition to neoplasms. It is caused by various mutations of the NF1 gene. Recently a 3-bp in-frame deletion in exon 17, c.2970-2972 delAAT mutation, has been associated with a milder phenotype of NF1 manifesting with pigmentary skin changes only. MATERIALS AND METHODS: We therefore analyzed 35 NF1 patients without neurofibromas, learning problems, or bone lesions (19 familial, 16 sporadic, age 7-44 years) for exon 17 mutations by DNA sequencing. RESULTS: We did not find the c.2970-2972 delAAT mutation in this group but identified two base changes in exon 17 (c.2989A>G and c.2894T>A), whether these two novel mutations are related to a mild phenotype remains to be confirmed in further studies. Our results suggest the reported phenotypic associations may not be valid for all populations.

Risk of recurrence after drug withdrawal in childhood epilepsy.

OBJECTIVES: After a reasonable seizure-free period, discontinuation of antiepileptic drugs (AED) is usually decided in epileptic patients despite the risk of seizure recurrence. In children, risk of recurrence after discontinuation of AED is generally 20-40%; however, there is still no general agreement on the criteria to predict safe discontinuation. This study was designed to determine the risk of recurrence and related risk factors after drug withdrawal in epileptic children. METHODS: 200 epileptic patients between 1 month and 15 years of age who were followed at least 1 year after drug withdrawal at a child neurology center between January 1993 and December 2005 formed the study population of this retrospective study. Patients were classified into groups according to defined risk factors for recurrence. RESULTS: Of 200 patients (118 boys, 82 girls), overall recurrence rate was 27%. Girls were more likely to have a seizure recurrence than boys, with the difference approaching statistical significance (p=0.058). EEG recordings after withdrawal (post-withdrawal EEG) in the follow-up were significantly different in the patients with recurrence with respect to presence of an abnormality (p=0.05). In the multivariate Cox regression analysis, female gender and abnormal post-withdrawal EEG were the risk factors influencing seizure recurrence, with female gender identified as the main risk factor. CONCLUSIONS: Although the decision to discontinue AED treatment necessitates evaluation of each patient individually, our study suggests that female patients and those with abnormal EEG after withdrawal require more cautious follow-up because of the high risk of recurrence.

Lamotrigine in children with refractory epilepsy.

We studied the efficacy and side effect profile oflamotrigine (LTG) in children with intractable epilepsy. We reviewed the database of our prolonged video-EEG laboratory to screen patients with intractable epilepsy who were on LTG either alone or in combination for three months or more. Of 75 patients, 28 patients (37%) had primary generalized seizures, 42 patients (56%) had partial onset seizures with or without secondary generalization, and 5 patients (7%) had two or more types of seizures. LTG reduced seizure frequency by at least 50% in 57.1% of patients with partial seizures and in 53.6% of patients with primary generalized seizures. The incidence of adverse events was relatively low (15%); the most common was skin rash. LTG should be considered in the treatment of pediatric patients with both partial onset and primary generalized seizures refractory to the major older antiepileptic drugs. LTG has a favorable side effect profile.

Neurofibromatosis: novel and recurrent mutations in Turkish patients.

Neurofibromatosis type 1 is an autosomal-dominant disorder affecting approximately 1 in 3500 births. It is characterized by café-au-lait spots, neurofibromas, axillary/inguinal freckling, and skeletal and neurologic signs. It exhibits full penetrance and a high mutation rate: 50% of neurofibromatosis type 1 patients represent a new mutation. The gene, located at 17q11.2, contains 60 exons that encode a 11-13-kb mRNA transcript. The mutation rate for neurofibromatosis type 1 is one of the highest known for human disorders, probably because of the large size of the gene, gene conversions mediated by pseudogenes, and the presence of repeated sequences. No clear genotype-phenotype correlation is established, except for patients with deletion of the entire neurofibromatosis type 1 gene. Neurofibromatosis type 1 mutations seem to be equally distributed along the gene. However, some exons in the neurofibromatosis type 1 gene may have a higher mutation rate, and the majority of these mutations are recurrent. We analyzed five exons (exons 4b, 16, 29, 31, and 37) for recurrent mutations and unknown mutations in 100 Turkish patients with neurofibromatosis type 1. We identified 496delGT and 499delTGTT mutations in exon 4b and 5866delA as a new mutation in exon 31 (Human Gene Mutation Database accession number Hd0524).

Significance of factor V, prothrombin, MTHFR, and PAI-1 genotypes in childhood cerebral thrombosis.

The aim of this study was to evaluate the significance of factor V (FV) G1691A, prothrombin G20210A, methylenetetrahydrofolate reductase (MTHFR) C677T, and plasminogen activator inhibitor-1 (PAI-1) 4G/5G genotypes in development of childhood cerebral thrombosis (CT). A total of 113 Turkish children with CT were studied and compared with the control group. The carrier frequency of the factor V G1691A mutation was found to be significantly higher in the patient group (17.7%) than controls (7.4%). The presence of this genotype was associated with a 2.7-fold increased risk of developing CT (95% confidence interval [CI], 1.0-7.0). The prevalence of prothrombin G20210A mutation in 110 patients (4.5%) was insignificantly higher than controls (2.3%) (odds ratio, 2.0; 95% CI, 0.4-10.7). A statistically significant increase in the frequency of homozygous MTHFR C677T genotype was observed in 62 patients (11.3%) compared to controls (4.3%), and this genotype was associated with 2.8-fold increased CT risk (95% CI, 1.0-8.0). The incidence of PAI-1 4G/4G genotype in 65 patients (21.5%) was slightly lower than that of controls (26.0%), but the differences did not reach statistical significance (odds ratio, 0.8; 95% CI, 0.4-1.5). The results of this study suggested that factor V G1691A and MTHFR C677T genotypes may be associated with an increased risk of developing CT in Turkish children.

Molecular genetic analyses in neurofibromatosis type 1 patients with tumors.

Neurofibromatosis type 1 (NF1) is one of the most common autosomal dominant disorders. NF1 is clinically characterized by neurofibromas, pigmentation anomalies, and an increased risk of malignant tumors. The NF1 gene product, neurofibromin, has a GTPase-activating protein domain (GRD) that interacts with the Ras protein, which is crucial in regulating signal transduction and cell proliferation/differentiation. We performed mutation analyses in the NF1-GRD region (exons 21-27a) and in exons 4b, 16, 29, and 37, and intron 28 in 17 NF1 patients with tumors. We identified a large deletion in the NF1 gene in a patient with a rhabdomyosarcoma as well as a variation in intron 22 in a patient with an optic glioma. We also found a 4-base pair deletion in another patient with optic glioma. In addition, allelic loss of the NF1 locus was shown in a pilocytic astrocytoma. Functional analyses of mutations in the NF1 gene may provide further insights into the pathogenesis of NF1 tumors.

Vigabatrin in pediatric patients with refractory epilepsy.

New generation antiepileptic medications have improved seizure outcome in patients with intractable epilepsy. We studied the efficacy and side effect profile of vigabatrin (VGB) in pediatric patients with intractable seizure disorder. We reviewed the database of our short-term video-EEG monitoring laboratory to screen patients with intractable epilepsy who were on VGB either alone or in combination for three months or more. We subsequently reviewed the medical records of these patients to abstract clinical information regarding age, sex, seizure type, epilepsy syndrome, efficacy and side effects of VGB. Of 111 patients, 75 (68%) were male and 36 (32%) female. Seizure onset was during the newborn period in 12 patients (11%), during the first year of life beyond the newborn period in 47 patients (42%), between 1-5 years in 23 patients (21%), and above five years in the remaining 29 patients (26%). Fifty-four patients (48.6%) had partial onset seizures with or without secondary generalization; 49 patients (44.1%) had primary generalized seizures; 8 patients (7.2%) had two or more types of seizure. Fifty-three percent of patients had mental retardation, and 35% had abnormal findings on physical/ neurological examination. Of 98 patients, 70 (71.4%) had abnormal magnetic resonance imaging (MRI) findings. Ninety-seven percent of patients had been on polytherapy before VGB was added to treatment. VGB reduced seizure frequency by at least 50% in 33.3% of patients with partial seizures, and in 30.6% of patients with primary generalized seizures. Six of the responders with partial seizures had complete resolution of their seizures. Most common side effects included visual field defects, increased appetite and obesity. Vigabatrin seems to be more effective in partial seizures in childhood intractable epilepsy. Patients should be closely monitored regarding side effects of VGB.

Reversible posterior leukoencephalopathy syndrome: report of three cases.

Reversible posterior leukoencephalopathy syndrome is characterized clinically by headache, abnormalities of mental status and visual perception, and seizures. Despite its diverse causes, common precipitating factors are defined as abrupt elevations of blood pressure, renal decompensation, fluid retention, and immunosuppressive therapy. We report three children with reversible posterior leukoencephalopathy syndrome presenting with generalized seizures and headache. The causes of reversible posterior leukoencephalopathy syndrome were considered to be acute hypertension and immunosuppressive therapy in case 1 with systemic lupus erythematosus, chemotherapy (vincristine and/or actinomycin-D) and hyponatremia in case 2, and acute hypertension in case 3, admitted with a familial Mediterranean fever attack. In light of these cases, we review the literature for the etiology, clinical and laboratory findings, and pathogenetic mechanisms of the disease.

Protective effects of valproic acid against hypoxic-ischemic brain injury in neonatal rats.

Although controversial, protective and therapeutic effects of valproic acid in various types of cellular injury suggest a potential role for this agent in hypoxic-ischemic brain injury. We therefore investigated the effects of valproic acid in an experimental model of neonatal hypoxic-ischemic brain injury. To examine the effect of valproic acid in this condition, hypoxic-ischemic brain injury was induced in 7-day-old rat pups by ligation of the right common carotid and then the pups were exposed to 1 hour of hypoxia in 8% oxygen. Low (200 mg/kg/day) and high (400 mg/kg/day) doses of valproic acid were administered in a 5-day regimen. Neuropathologic evaluation was performed using the hippocampus, cerebral cortex, and basal ganglia in the coronal plane. The 5-day regimen of valproic acid administration resulted in some protective and therapeutic effects on the brain damage and neuronal apoptosis in both hemispheres in a dose-dependent manner. Administration of valproic acid also decreased the percentage of apoptotic neurons in the contralateral hemisphere (P < .05). These results suggest that valproic acid can have therapeutic and protective effects in hypoxic-ischemic brain injury.

L-2-hydroxyglutaric aciduria: a report of 29 patients.

L-2-hydroxyglutaric aciduria (L2HGA) is a chronic slowly progressive neurodegenerative disease characterized mainly by psychomotor developmental delay and cerebellar dysfunction. We report the clinical, biochemical, and neuroimaging features of 29 patients from 22 families. The mean age at the time of diagnosis was 13.4 years (2.5-32 years). The mean follow-up period of patients was four years (1.5-16 years). The main clinical findings were mental retardation and cerebellar involvement with ataxic gait and intentional tremor. Additional findings were mental retardation, macrocephaly and seizures. Diagnosis was confirmed by increased urinary excretion of L-2-hydroxyglutaric acid in all patients and highly specific magnetic resonance imaging (MRI) pattern showing subcortical leukoencephalopathy with bilateral high signal intensity in dentate nuclei and putamens. During the follow-up period, all patients had a static encephalopathy course. The underlying metabolic defect and the possible role of L-2-hydroxyglutaric acid are studied in a subgroup of these families and under evaluation for publication.

Vertigo in childhood: a retrospective series of 100 children.

OBJECTIVE: Evaluation and management of vertigo in children vary between institutions and medical specialties. The aim of this study is to describe the characteristics of vertigo in children presenting to a pediatric neurology referral center and to investigate the relationship between vertigo and migraine. STUDY DESIGN: Patients <18 years old presenting with vertigo to Hacettepe University Ihsan Dogramaci Children's Hospital Neurology Unit between January 1996-January 2012 were included (n = 100). Data were obtained from patient files and phone interviews. RESULTS: Mean age was 7.5 years. The most common etiological groups were benign paroxysmal vertigo of childhood (BPVC) (39%), psychogenic vertigo (21%), epileptic vertigo (15%), and migraine-associated vertigo (MAV) (11%). BPVC was the most common diagnosis in children ≤5 years of age while psychogenic vertigo prevailed in children >5 years. Staring episodes characterized epileptic vertigo patients (p = 0.021) while headache was more often described by MAV patients (p < 0.001). Vertigo attacks >5 min were uncommon in BPVC patients compared to others (p = 0.013). Twenty percent of BPVC patients contacted through phone interviews were experiencing migraine type headaches that started at a median age of 7.5 years. An algorithm for evaluation of children with vertigo was formed based on data obtained from this study and the literature. When this algorithm was applied to 100 cases of this series, 88 (88%) were correctly diagnosed. CONCLUSION: While most vertigo cases in children can be diagnosed accurately by a detailed medical history, physical and neurological examination, a standard algorithm can help with the correct classification.

Familial segmental neurofibromatosis.

Segmental neurofibromatosis is considered to be the result of postzygotic NF1 gene mutations. We present a family in which the proband has generalized neurofibromatosis 1, whereas members of previous generations manifest segmental skin lesions. All, including the clinically asymptomatic grandmother, carry the same haplotype. This is the only case in the literature in which a parent with segmental skin findings has a child with full-blown neurofibromatosis 1 disease. The genetic mechanisms underlying this association are discussed. This family can be further investigated by examination of tissue samples from affected and unaffected sites for mutations.

Gender prevalence in childhood multiple sclerosis and myasthenia gravis.

Multiple sclerosis and myasthenia gravis are the most common autoimmune diseases affecting the nervous system, with generally a female predominance in adults. To determine the gender distribution in childhood, we reviewed 28 patients with definite multiple sclerosis and 44 patients with myasthenia gravis with onset before 16 years. In myasthenia gravis, a significant female preponderance was observed only with onset after 10 years of age; earlier disease showed no gender difference. Multiple sclerosis tended to affect boys more than girls before age 10 years and both sexes equally after this age. Gender prevalence in childhood multiple sclerosis and myasthenia gravis is different than in adult series; these results may provide insight into pathogenesis or clinical approach.

Molecular analysis of neurofibromatosis type 1 in Turkish families using polymorphic markers.

Neurofibromatosis type 1 (NF1) is a common autosomal dominant disorder characterized by multiple neurofibromas, café-au-lait spots, and Lisch nodules of iris. The NF1 gene is located on chromosome 17q11.2 and encodes an 11-13 kb mRNA containing 60 exons. The NF1 gene product neurofibromin is a large protein of 2818 amino acids which acts as a negative regulator in the ras signal transduction pathway. The disease has a high mutation rate and a wide range of expression. Because of the size and complexity of the gene, the variety of mutations and the need to identify the specific mutation in each family, indirect diagnosis using linked markers has an important part in genetic counseling. We analyzed 10 Turkish families with a total of 28 affected individuals and 34 non-affected relatives using polymorphic sequences, four intragenic and five flanking markers. Intragenic microsatellite markers were highly informative for all families. As a result, prenatal and presymptomatic diagnoses for familial cases are being made available.

Mutation analysis of TSC2 gene in 33 Turkish familial cases with tuberous sclerosis.

Tuberous sclerosis is an autosomal dominant multisystem disorder characterized by hamartomatous growths in different organs. Disease determining genes are localized to 9q34 (TSC1) and 16p13.3 (TSC2). Two-thirds of the cases are sporadic and result from new mutations. The aim of this study was to determine TSC2 gene mutations by Single Stranded Conformation Polymorphism (SSCP) analysis and direct sequencing in 33 familial cases with tuberous sclerosis who were followed up in the Pediatric Neurology Departments of Hacettepe University Ihsan Dogramaci and Ankara Social Security Children's Hospitals. Forty-one exons of TSC2 gene were amplified and subjected to SSCP, and sequence analysis was performed when an abnormal SSCP pattern was observed. As a result, six new mutations and nine gene polymorphisms were detected. The new mutations are G-->T mutation in exon 20, 16bp deletion in exon 29, 18bp deletion in exon 40, 538 G-->A mutation in exon 29, T-->C mutation in exon 21 and G-->A splice site mutation in exon 5. Although further studies on larger groups are needed, these results do not indicate a common region or type of mutation in the Turkish population.

Clinical, electrophysiological and neuropsychological findings of twenty-two children with mesial temporal sclerosis.

Twenty-two patients, followed with the diagnosis of epilepsy between the ages of 8.5 and 19 years who were found to have mesial temporal sclerosis (MTS) on brain magnetic resonance imaging (MRI) were evaluated according to their clinical, electrophysiological and neuropsychological characteristics, and assessed for the significance of neuropsychological tests on lateralization. In both MTS groups, a remarkable number of patients had their intial seizure before one year of age (45.5% in the right MTS group, and 36.4% in the left MTS group). Half of the patients were seizure-free for a period of two months-9.5 years (average 3.9 years). The duration between the febrile seizure and first non-febrile seizure was 6.2 years. Eleven patients had MTS on the left temporal lobe. Interictal EEG was normal in five (22.5%) patients; 10 (45.5%) had temporal spike on the corresponding side with MTS. Six (27.3%) patients had paroxysmal activity and voltage asymmetry on cortical areas other than temporal region. The Wechsler Memory Scale (WMS), Visual Reproduction Subtest and Auditory Verbal Learning Test (AVLT) Delayed Recall and Retrieval Subtest performances were poor in the right MTS group.

Evaluation of 36 patients from Turkey with neuronal ceroid lipofuscinosis: clinical, neurophysiological, neuroradiological and histopathologic studies.

Neuronal ceroid lipofuscinosis (NCL) is one of the most common progressive neurodegenerative diseases seen in childhood. NCL is inherited as autosomal recessive trait, and is characterized by the accumulation of 'ceroid lipofuscin' in neuronal and extraneuronal cells. Clinical features include seizures, ataxia, myoclonus, loss of vision, and mental and motor deterioration. Although the disease is widely seen across the world, there seems to be an information gap in Asian countries. To date, no comprehensive and detailed studies on NCL have been carried out in Turkey. However, one could predict that the disease is rather frequent in Turkey due to high rates of consanguineous marriages. Thirty-six Turkish patients were evaluated in this study. Sixteen (44.5%) patients were girls, and 20 (55.5%) were boys. Parents were consanguineous in 25 families (80%). In five families (14%), the disease was seen in two sibs. The diagnosis was based on clinical evaluation, and neurophysiological, neuroradiologic, enzymatic, and histopathological studies. Electron microscopic study was the main diagnostic laboratory test. Three patients were classified as infantile NCL, 11 were late infantile NCL, 5 were juvenile type NCL and 17 patients were Turkish variant NCL. In juvenile type, major initial symptom was visual impairment, whereas in all other types seizures were predominantly the first symptom at the onset of the disease. The initial symptoms of Turkish variant NCL were similar to those of late infantile type. Similar age at clinical symptoms and the presence of visual symptoms were common features of Turkish variant and juvenile NCL. Compared to late infantile NCL, Turkish variant, showed a more severe course regarding seizures. Electroencephalogram (EEG) showed abnormal features predominantly in Turkish variant, and were remarkable for occipital spikes. In patients with Turkish variant magnetic resonance imaging of the brain showed brainstem involvement, especially pons, in all patients except one; cerebral and cerebellar atrophy were seen with a slower course compared to late infantile NCL. Clinical picture of NCL in advanced stages of the disease was similar regardless of the subtype.

Hypomelanosis of Ito and Sturge-Weber syndrome without facial nevus: an association or a new syndrome?

Sturge-Weber syndrome without facial nevus is rare. Twenty-four cases were previously reported. Although hypomelanosis of Ito is a relatively common disorder, there was only one previous case in association with Sturge-Weber syndrome. We describe an 11-year-old boy with Sturge-Weber syndrome without facial nevus, coexistent with hypomelanosis of Ito.