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Biomedical subjects

H Stroink

Publications and source records attributed to H Stroink.

At least 19 recordsLinked to original sources
PubMed2006

Severe episodic neurological deficits and permanent mental retardation in a child with a novel FHM2 ATP1A2 mutation.

OBJECTIVE: Attacks of familial hemiplegic migraine (FHM) are usually associated with transient, completely reversible symptoms. Here, we studied the ATP1A2 FHM2 gene in a young girl with episodes of both very severe and transient neurological symptoms that were triggered by mild head trauma as well as permanent mental retardation. Her family members suffered from hemiplegic and confusional migraine attacks. METHODS: Mutation analysis of the ATP1A2 gene was performed by direct sequencing of all exons and flanking intronic regions, using genomic DNA of the proband. Functional consequences of the mutation were analyzed by cellular survival assays. RESULTS: We identified a novel G615R ATP1A2 mutation in the proband and several of her family members. Functional analysis of mutant Na,K-ATPase in cellular survival assays showed a complete loss-of-function effect. INTERPRETATION: Permanent mental retardation in children may be caused by ATP1A2 mutations.

Arginine↗
PubMed2005

Four-year outcome after early withdrawal of antiepileptic drugs in childhood epilepsy.

Four-year follow-up of children with epilepsy included in a randomized trial of early withdrawal of antiepileptic drugs showed that 51% achieved a terminal remission of at least 2 years without medication and 21% with medication; 15% had seizures during the fourth year. Early medication withdrawal is not recommended as standard practice in children with a rapid response to medication. The authors developed a model to predict outcome if withdrawal is considered.

Adolescent↗
PubMed2005

Removal of epileptogenic sequences from video material: the role of color.

BACKGROUND: After Pokémon viewing triggered an epidemic of seizures in Japan, many efforts have been made to design safety guidelines and systems to protect subjects with photosensitivity. The authors developed a new method based upon nonlinear diffusion techniques capable of filtering the epileptogenic content of a video sequence related to color without altering its spatial and luminance content. METHODS: The authors showed to 25 photosensitive patients (18 women, mean age: 22 years) the original Pokémon sequence and a modified one in an ABBA protocol using two television (TV) sets (100 and 50 Hz). RESULTS: Twenty-three patients had a photoparoxysmal response (PPR) according to Waltz classification with at least one of the scenes. The modified sequence triggered fewer and less severe PPRs than the original version in both TVs (p < 0.001). Original sequences elicited generalized PPRs in 56.5% of the trials for the 50 Hz TV and in 41.3% for the 100 Hz TV, whereas modified sequences elicited these responses in only 8.7% (50 Hz) and 4.3% (100 Hz TV) of the trials (p < 0.001). Sensitivity to the modified version on the 50 Hz TV correlated with pattern sensitivity (p < 0.05). CONCLUSION: Specific manipulations of the color modulation-depth could be enough to decrease dramatically the risk of triggering seizures in susceptible subjects exposed to provocative visual scenes. This new method can be implemented in protective devices able to filter out the epileptogenic video sequences in which color plays a fundamental role while leaving intact the spatial content, frequency, and average luminance.

Adolescent↗
PubMed2004

Alternating hemiplegia of childhood: no mutations in the second familial hemiplegic migraine gene ATP1A2.

Alternating hemiplegia of childhood (AHC) is a rare disorder mainly characterised by attacks of hemiplegia and mental retardation. AHC has often been associated with migraine. Previously, we have excluded the involvement of the familial hemiplegic migraine (FHM) CACNA1A gene in four patients with AHC. A second gene for FHM was discovered recently: the ATP1A2 gene on chromosome 1q23, coding for the alpha 2 subunit of Na+,K+-ATPase. We performed a mutation analysis of the ATP1A2 gene in six patients, using direct sequencing, but found no mutations in any of the 23 exons. Other cerebral ion channel genes remain candidate genes for AHC.

Adolescent↗
PubMed2004

Interrater agreement of the diagnosis and classification of a first seizure in childhood. The Dutch Study of Epilepsy in Childhood.

OBJECTIVE: To assess the interrater agreement of the diagnosis and the classification of a first paroxysmal event in childhood. METHODS: The descriptions of 100 first paroxysmal events were submitted to two panels each consisting of three experienced paediatric neurologists. Each observer independently made a diagnosis based on clinical judgment and thereafter a diagnosis based on predefined descriptive criteria. Then, the observers discussed all patients within their panel. The agreement between the six individual observers was assessed before discussion within each panel and after that, between the two panels. RESULTS: Using their clinical judgement, the individual observers reached only fair to moderate agreement on the diagnosis of a first seizure (mean (SE) kappa 0.41 (0.03)). With use of defined descriptive criteria the mean (SE) kappa was 0.45 (0.03). The kappa for agreement between both panels after intra-panel discussion increased to 0.60 (0.06). The mean (SE) kappa for the seizure classification by individual observers was 0.46 (0.02) for clinical judgment and 0.57 (0.03) with use of criteria. After discussion within each panel the kappa between the panels was 0.69 (0.06). In 24 out of 51 children considered to have had a seizure, agreement was reached between the panels on a syndrome diagnosis. However, the epileptic syndromes were in most cases only broadly defined. CONCLUSIONS: The interrater agreement on the diagnosis of a first seizure in childhood is just moderate. This phenomenon hampers the interpretation of studies on first seizures in which the diagnosis is only made by one observer. The use of a panel increased the interrater agreement considerably. This approach is recommended at least for research purposes. Classification into clinically relevant syndromes is possible only in a very small minority of children with a single seizure.

Child↗
PubMed2003

The accuracy of the diagnosis of paroxysmal events in children.

OBJECTIVE: To assess the accuracy of the diagnosis of epileptic seizures in children. METHODS: The Dutch Study of Epilepsy in Childhood is a prospective hospital-based study of 881 children referred because of possible seizures. The diagnosis was based on predefined descriptive criteria, as applied by a panel of three pediatric neurologists. Children with a definite other diagnosis were excluded. All children with unclear events were followed up for 1 year and children with seizures were followed up for 2 years to assess the accuracy of the diagnosis. RESULTS: In 170 of 224 children seen after a single event, the incident was classified initially as epileptic, in 54 as unclear. In none of the 170 children did the diagnosis prove to be wrong. In four of the 54 children, recurrent episodes enabled a definite diagnosis of epilepsy. In 412 of the 536 children seen with multiple events, an initial diagnosis of epilepsy was made. After follow-up, this initial diagnosis was probably incorrect in 19. In contrast, seven of 124 children with multiple unclear episodes at intake later received the diagnosis epilepsy. CONCLUSIONS: A false-positive diagnosis of epilepsy was made in 4.6%, whereas a definite diagnosis of epilepsy or seizure was delayed in 5.6% of children with multiple unclear events and in 7.4% of children with one unclear event.

Adolescent↗
PubMed2003

Immunoglobulins in children with epilepsy: the Dutch Study of Epilepsy in Childhood.

In an unselected cohort of 282 children, serum immunoglobulin (Ig) concentrations were determined shortly after the first presentation with one or more unprovoked epileptic seizures and before the start of treatment with anti-epileptic drugs (AEDs), and after 9-18 months of AEDs use. At intake, IgA, IgG1, IgG2 and IgG4 concentrations were significantly higher than published reference values in healthy age-matched controls. In a subset of 127 children, Ig levels at intake were compared with those after AEDs use for 9-18 months. IgA and IgG4 levels had decreased significantly to normal concentrations, but IgG1 and IgG3 levels increased significantly. To determine the influence of AEDs, Ig levels in children who used carbamazepine or valproic acid monotherapy were analysed separately. The use of carbamazepine was associated with a significant decrease of IgA and IgG4 levels, and the use of valproic acid with a significant decrease of IgA and increase of IgG1 levels. In conclusion, humoral immunity is already altered in children shortly after the first presentation with epileptic seizures. Whether this is the consequence of an exogenous event, and to what extent this is related to an interaction of the central nervous system and the immune system, remains to be evaluated. Treatment with AEDs, such as carbamazepine and valproic acid, is associated with significant changes of Ig (sub)class concentrations.

Adolescent↗
PubMed2002

[Television, children and epilepsy].

Two girls and one boy suffered seizures caused by television and other visual stimuli from 11, 12 and 12 years of age onwards, respectively. EEG recording revealed that intermittent photic stimulation (IPS) provoked epileptiform activity. Technological progress (video games, computer, disco, car, train) has considerably increased the risk for visually-induced seizures. A comprehensive clinical history with special attention to the environmental circumstances is important. For correct diagnosis an EEG with standardised IPS is necessary. Treatment consists of avoidance of strong visual stimuli. Patients may need prophylaxis with valproic acid, which should only be withdrawn after clear reduction of the EEG response to IPS. Repeating the EEG after the dosage has been lowered will help avoiding unnecessary recurrence of seizures.

Adolescent↗
PubMed2002

Nonsymptomatic generalized epilepsy in children younger than six years: excellent prognosis, but classification should be reconsidered after follow-up: the Dutch Study of Epilepsy in Childhood.

PURPOSE: To assess the prognosis and the accuracy of the epilepsy classification in young children with nonsymptomatic generalized epilepsy. METHODS: Of the cohort of the Dutch Study of Epilepsy in Childhood (n = 466), all children younger than 6 years with a diagnosis of idiopathic (IGE) or cryptogenic (CGE) generalized epilepsy either at intake (n = 108) and/or after 2 years of follow-up (n = 102) were included. The number of reclassifications after 2 years was determined, and the reasons for reclassification were analyzed. All children receiving a diagnosis of IGE or CGE at 2 years were followed up for 5 years to study their outcome in terms of terminal remission (TR). Data on their level of intellectual functioning were collected at the start of this analysis. RESULTS: The epilepsy syndrome was reclassified in 17 children. In 14 of them, the seizure type also was reclassified, and in three, the course of the epilepsy determined the new epilepsy type. Two other children had a reclassification of their seizure types without a change of the epilepsy type. Many children were categorized as having IGE not otherwise specified. In all probability, this is a heterogeneous group, containing patients with various epilepsy syndromes, with generalized tonic-clonic seizures as a common hallmark. Of the 102 children with IGE or CGE at 2 years of follow-up, 75% had a TR of >6 months after 2 years, and 85% a TR of >or=1 year after 5 years. CONCLUSIONS: In a fair proportion of children with nonsymptomatic generalized epilepsy in this age group, it is not possible to classify firmly the epilepsy and/or the seizures immediately after the intake. Instead, they are reclassified during the course of the disease. This and the apparent heterogeneity of the category IGE not otherwise specified point to inherent drawbacks of the current International League Against Epilepsy (ILAE) classification of epilepsy and epileptic syndromes. The prognosis of IGE at this young age is generally excellent.

Age Factors↗
PubMed2001

First-trimester diagnosis of late-infantile neuronal ceroid lipofuscinosis (LINCL) by tripeptidyl peptidase I assay and CLN2 mutation analysis.

Late-infantile neuronal ceroid lipofuscinosis (LINCL) is a progressive neurodegenerative disorder caused by the deficiency of lysosomal tripeptidyl peptidase I (TPP-I) encoded by the CLN2 gene. We report the first case of early prenatal diagnosis of LINCL by combined enzyme and mutation analysis. TPP-I activity in chorionic villi (CV) was less than 2% of the mean normal control level and g.1946A > G and g.3670C > T mutations were demonstrated, as in the two previously affected children. After termination of pregnancy, TPP-I deficiency was confirmed in cultured CV cells and in the fetal skin fibroblasts. The expression of unequivocal TPP-I deficiency in CV demonstrates that enzyme assay is a reliable option for prenatal diagnosis of LINCL.

Aminopeptidases↗
PubMed2001

Pitfalls in the diagnosis of multiple sulfatase deficiency.

Multiple sulfatase deficiency (MSD, OMIM 272200) is an autosomal recessive leukodystrophy associated with the deficiency of several, in total seven, sulfatases. The disorder is clinically and biochemically variable. The clinical picture combines features of mucopolysaccharidosis and metachromatic leukodystrophy (MLD, OMIM 250100) in a variable spectrum. Here we report a 3-year old Iranian girl with an MLD-like presentation of MSD. Arylsulfatase A deficiency and sulfatide excretion were found. Differently from what was previously reported in the literature, this girl never showed abnormal mucopolysaccharide excretion in the urine. There were no additional visceral or skeletal signs. She was originally diagnosed as having MLD. Only when she developed ichthyosis were seven additional sulfatases measured. In leukocytes, arylsulfatase A, steroid sulfatase and N-acetylglucosamine-6 sulfatase were profoundly deficient, while iduronate-2 sulfatase and arylsulfatase B were moderately reduced. In fibroblasts, N-acetylglucosamine-6 sulfatase was deficient, while arylsulfatase A was moderately reduced. This case illustrates the possible pitfalls in the clinical and laboratory diagnosis of MSD.

Brain↗
PubMed2001

Mortality risk in children with epilepsy: the Dutch study of epilepsy in childhood.

OBJECTIVE: Long-term follow-up studies of patients with epilepsy have revealed an increased mortality risk compared with the general population. Mortality of children who have epilepsy in modern times is as yet unknown. Therefore, the objective of this study was to determine mortality of children who have epilepsy in comparison with the general population. METHODS: Between August 1988 and August 1992, 472 children, aged 1 month to 16 years, who presented in 1 of the participating hospitals with 2 or more newly diagnosed unprovoked seizures or at least 1 status epilepticus were enrolled in the study. All children were followed for 5 years or until death. The number of deaths observed during follow-up was compared with the expected number of deaths in the same age group in the general population in the Netherlands. RESULTS: Nine children died during follow-up, amounting to a mortality rate of 3.8/1000 person-years, which is sevenfold higher than expected (95% confidence interval = 2.4-11.5). No deaths were observed among the 328 children who had epilepsy of nonsymptomatic cause. All deceased children had epilepsy that was caused by a static or progressive neurologic disorder (mortality risk = 22.9; 95% confidence interval = 7.9-37.9). None of them died from sudden unexpected and unexplained death of epilepsy. CONCLUSIONS: In our cohort, we found no indication that children who have nonsymptomatic epilepsy have an increased mortality risk compared with the general population, whereas children who have symptomatic epilepsy have a 20-fold increased mortality risk. These data provide guidance for counseling parents of children who have epilepsy.

Adolescent↗
PubMed2001

Alexander disease: diagnosis with MR imaging.

BACKGROUND AND PURPOSE: To date, the demonstration of Rosenthal fibers on brain biopsy or autopsy specimens is considered a prerequisite for a definitive diagnosis of Alexander disease. We initiated a multiinstitutional survey of MR abnormalities in both presumed and confirmed cases of Alexander disease to assess the possibility of an MR-based diagnosis. METHODS: MR imaging studies in three patients with an autopsy-based diagnosis of Alexander disease were analyzed to define MR criteria for the diagnosis. These criteria were then applied to 217 children with leukoencephalopathy of unknown origin. RESULTS: Five MR imaging criteria were defined: extensive cerebral white matter changes with frontal predominance, a periventricular rim with high signal on T1-weighted images and low signal on T2-weighted images, abnormalities of basal ganglia and thalami, brain stem abnormalities, and contrast enhancement of particular gray and white matter structures. Four of the five criteria had to be met for an MR imaging-based diagnosis. In a retrospective analysis of the MR studies of the 217 patients, 19 were found who fulfilled these criteria. No other essentially new MR abnormalities were found in these patients. In four of the 19 patients, subsequent histologic confirmation was obtained. The clinical symptomatology was the same in the patients with and without histologic confirmation and correlated well with the MR abnormalities. MR abnormalities were in close agreement with the known histopathologic findings of Alexander disease. CONCLUSION: The defined criteria are sufficient for an in vivo MR imaging diagnosis of Alexander disease; only in atypical cases is a brain biopsy still necessary for a definitive diagnosis.

Brain↗
PubMed2000

Clinical and biochemical characteristics of congenital disorder of glycosylation type Ic, the first recognized endoplasmic reticulum defect in N-glycan synthesis.

We report on 8 patients with a recently described novel subtype of congenital disorder of glycosylation type Ic (CDG-Ic). Their clinical presentation was mainly neurological with developmental retardation, muscular hypotonia, and epilepsy. Several symptoms commonly seen in CDG-Ia such as inverted nipples, abnormal fat distribution, and cerebellar hypoplasia were not observed. The clinical course is milder overall, with a better neurological outcome, than in CDG-Ia. The isoelectric focusing pattern of serum transferrin in CDG-Ia and CDG-Ic is indistinguishable. Interestingly, beta-trace protein in cerebrospinal fluid derived from immunoblot analysis of the brain showed a less pronounced hypoglycosylation pattern in CDG-Ic patients than in CDG-Ia patients. Analysis of lipid-linked oligosaccharides revealed an accumulation of Man9GlcNAc2 intermediates due to dolichol pyrophosphate-Man9GlcNAc2 alpha-1,3 glucosyltransferase deficiency. All patients were homozygous for an A333V mutation.

Amino Acid Substitution↗
PubMed1999

The early prognosis of epilepsy in childhood: the prediction of a poor outcome. The Dutch study of epilepsy in childhood.

PURPOSE: To examine which variables available early in the course of childhood epilepsy are associated with a poor short-term outcome and to develop models to predict such an outcome. METHODS: We prospectively followed up 466 children with newly diagnosed epilepsy for 2 years. Variables were collected at intake and after 6 months. Outcome was defined as the duration of the terminal remission (TR): poor (<6 months) and not poor (> or =6 months). RESULTS: Of the subjects, 31% had a poor outcome. Multivariate analysis based on the intake variables identified number of seizures, seizure type, and etiology as risk factors for a poor outcome. With the intake and 6-month variables combined, seizure type, etiology, the number of seizures, and not attaining a 3-month remission during these 6 months, and the EEG at 6 months were predictive variables. A predictive model based on the multivariate logistic-regression analysis with the intake variables was correct in 56% of the children in whom it predicted a poor outcome and in 73% of the children in whom it predicted a not-poor outcome. With the intake and 6-month variables together, these percentages were 66 and 79%, respectively. The sensitivity of these models was low (29 and 47%, respectively); the specificity was good (90 and 89%). CONCLUSIONS: The 2-year outcome of childhood epilepsy is closely related to its early course. The prognosis is poor in approximately 30% of patients. By using our data, the prediction of a poor outcome is correct in almost two thirds of the patients; however, the models produce many false-negative predictions.

Age Factors↗
PubMed1998

Epilepsy in childhood: an audit of clinical practice.

BACKGROUND: It is not known how many children with epilepsy may not need treatment with antiepileptic drugs (AEDs), how many respond unsatisfactorily to subsequent treatment regimens, and how many achieve "acceptable control" despite lack of remission. METHODS: In a prospective multicenter hospital-based study, 494 children with a broad range of seizure types and types of epilepsy were followed up for at least 2 years. There was no standard treatment protocol. We describe the treatment strategies applied to these children by the neurologists in charge and outcome with respect to remission from seizures. RESULTS: Treatment was initially withheld in 29% of the children, and after 2 years 17% still had not received any AEDs. There were no serious complications caused by withholding treatment. Of the children treated with AEDs, 60% were still using the first AED after 2 years; 80% received monotherapy and 20%, polytherapy. Children with severe symptomatic epilepsies, such as the West or Lennox-Gastaut syndrome, received polytherapy early on in the course of treatment. When 3 regimens had failed, the chance of achieving a remission of more than 1 year with subsequent regimens was 10%. Nevertheless, 15 of 50 children receiving AEDs in whom the "longest remission ever" was less than 6 months did achieve acceptable seizure control according to the neurologist in charge of treatment. Hence, of 494 children, only 35 (7%) developed an intractable form of epilepsy, defined as failure to bring seizures under acceptable control. CONCLUSIONS: A substantial percentage of children with new-onset epilepsy did not need treatment with AEDs. Chances of achieving a good outcome declined with subsequent treatment regimens. Not all children with recurrent seizures were suffering from intractable epilepsy; some had achieved acceptable control of seizures.

Adolescent↗
PubMed1998

A novel frameshift mutation 840delA and a novel polymorphism D203A in the steroidogenic acute regulatory protein gene in a Japanese patient with congenital lipoid adrenal hyperplasia. Mutations in brief no. 117. Online.

Congenital lipoid adrenal hyperplasia (CLAH) is an autosomalrecessive disorder characterized by impaired production of all steroids including glucocorticoids, mineralocorticoids and sexsteriods. It has recently been reported that mutations in the steriodogenic acute regulatory protein (StAR) gene cause CLAH. We analyzed the StAR gene in a Japanese patient with CLAH. The patient was revealed to be a compound heterozygote bearing a nonsense mutation Q258X, changing codon 258 (CAG) encoding Gln to the stop codon TAG, and a novel framshift mutation 840delA resulting from deletion of one of the three adenosines normally present in codon 238 (AAA), thus leading to a frameshift after codon 237 (Thr) in the StAR gene. The patient was also revealed to be homozygous for a novel missense point mutation D203A, changing codon 203 (GAC) encoding Asp to GCC encoding Ala in the StAR gene. To elucidate the significance of the D203A mutation, we analyzed the StAR gene sequence in twenty normal subjects, and found that all of them were homozygous for the D203A mutation, indicating that the D203A mutation is an innocent polymorphism. In conclusion, we have identified a novel frameshift mutation 840delA which seems to cause 840delA and the first polymorphism D203A in the human StAR gene.

Adrenal Hyperplasia, Congenital↗