Comprehensive molecular screening strategy of OCLN in band-like calcification with simplified gyration and polymicrogyria.

Occludin (OCLN) is an important component of the tight junction complex, providing apical intercellular connections between adjacent cells in endothelial and epithelial tissue. In 2010 O'Driscoll et al reported mutations in OCLN to cause band-like calcification with simplified gyration and polymicrogyria (BLC-PMG). BLC-PMG is a rare autosomal recessive syndrome, characterized by early onset seizures, progressive microcephaly, severe developmental delay and deep cortical gray matter and basal ganglia calcification with symmetrical, predominantly fronto-parietal, polymicrogyria. Here we report 4 additional cases of BLC-PMG with novel OCLN mutations, and provide a summary of the published mutational spectrum. More generally, we describe a comprehensive molecular screening strategy taking into account the technical challenges associated with the genetic architecture of OCLN, which include the presence of a pseudo-gene and copy number variants.

Treatment of Gastrointestinal Bleeding in a Probable Case of Cerebroretinal Microangiopathy with Calcifications and Cysts.

Cerebroretinal microangiopathy with calcifications and cysts (CRMCC) is a highly pleiotropic disorder, particularly affecting the eye, brain, bone, and gut. The potential catastrophic sequelae of the associated gastrointestinal phenotype, variably characterised by both chronic bleeding and liver failure, is becoming increasingly apparent. Here we report a probable case of CRMCC with pre- and postnatal growth restriction, bilateral exudative retinopathy, a pathognomonic pattern of intracranial calcification, white matter disease, osteopenia with a tendency to fractures, and chronic gastrointestinal bleeding secondary to abnormal dilated vasculature. The gastrointestinal endoscopic findings were characteristic of gastric antral vascular ectasia (GAVE). Treatment with a combination of oral oestrogen and progesterone ameliorated the gastrointestinal blood loss such that monthly blood transfusions could be stopped. The benefit of this relatively benign therapy in managing the potentially life-limiting consequences of an abnormal gastrointestinal vasculature in CRMCC is of great interest.

Novel POLG1 mutations associated with neuromuscular and liver phenotypes in adults and children.

BACKGROUND: The POLG1 gene encodes the catalytic subunit of DNA polymerase gamma, essential for mitochondrial DNA replication and repair. Mutations in POLG1 have been linked to a spectrum of clinical phenotypes, and may account for up to 25% of all adult presentations of mitochondrial disease. METHODS AND RESULTS: We present 14 patients, with characteristic features of mitochondrial disease including progressive external ophthalmoplegia (PEO) and Alpers-Huttenlocher syndrome and laboratory findings indicative of mitochondrial dysfunction, including cytochrome c oxidase (COX) deficiency and multiple deletions or depletion of the mitochondrial DNA. Four novel POLG1 missense substitutions (p.R597W, p.L605R, p.G746S, p.A862T), are described, together with the first adult patient with a recently described polymerase domain mutation (p.R1047W). All novel changes were rare in a control population and affected highly conserved amino acids. CONCLUSION: The addition of these substitutions-including the first report of a dinucleotide mutation (c.1814_1815TT>GC)-to the growing list of defects further confirms the importance of POLG1 mutations as the underlying abnormality in a range of neurological presentations.

Prolonged recovery of consciousness in children following symptomatic epileptic seizures.

INTRODUCTION: There is little published data on the duration of depressed consciousness following epileptic seizures. A prolonged recovery time may be a symptom of underlying brain pathology. This prospective paediatric cohort study investigates whether recovery is prolonged following symptomatic seizures. METHODS: Children aged 1-16 years, who had a witnessed seizure in which consciousness was impaired, were recruited. One hundred and twenty eight children (158 seizures) were studied. Seizure aetiology was classified as febrile, idiopathic, remote symptomatic, acute symptomatic and acute on remote symptomatic. At least hourly Paediatric Coma Scale recordings were used to assess recovery time. RESULTS: Recovery time was longest for children with acute on remote symptomatic seizures (4.0 h, range 0.89-10.5), followed by those with acute symptomatic seizures (1.94 h, range 0-35.27), remote symptomatic seizures (1.5h, range 0.07-85.5) and idiopathic seizures (0.83 h, range 0.07-13.13). Children with febrile seizures recovered the quickest (0.3h, range 0.05-9). Recovery time was significantly longer (p<0.001, CI 1.96-5.38) following seizures for which rescue antiepileptic drugs were administered compared to those for which it was not. Age, sex, type and duration of seizure did not independently affect recovery time. DISCUSSION: Symptomatic seizures take longer to recover than seizures of other aetiologies. It is recommended that a febrile child who presents with a seizure, who has not fully recovered within 30 min, should be investigated for an acute symptomatic aetiology. A high index of suspicion is also needed if children with apparent idiopathic seizures have not fully recovered within 1.5h.

Band-like intracranial calcification with simplified gyration and polymicrogyria: a distinct "pseudo-TORCH" phenotype.

The combination of intracranial calcification and polymicrogyria is usually seen in the context of intrauterine infection, most frequently due to cytomegalovirus. Rare familial occurrences have been reported. We describe five patients-two male-female sibling pairs, one pair born to consanguineous parents, and an unrelated female-with a distinct pattern of band-like intracranial calcification associated with simplified gyration and polymicrogyria. Clinical features include severe post-natal microcephaly, seizures and profound developmental arrest. Testing for infectious agents was negative. We consider that these children have the same recognizable "pseudo-TORCH" phenotype inherited as an autosomal recessive trait.

Recovery of consciousness after epileptic seizures in children.

OBJECTIVE: To investigate the duration of postictal impairment of consciousness and the factors that affect it. PATIENTS AND METHODS: 90 children aged 1-16 years (37 male, 53 female, median age 6 years), attending the accident and emergency department, and inpatients of Leeds General Infirmary, Leeds, UK, who had experienced seizures involving impairment of consciousness. Interventions-hourly modified paediatric coma scores were determined, until a coma score of 15 was obtained. Linear regression analysis was used to determine the factors influencing recovery time. RESULTS: 49 children were excluded owing to incomplete coma scoring, lost notes and refusal of consent. Median time for full recovery of consciousness was 38 min (0.63 h, range 0.05-17 h). Median recovery time was 18 min (0.3 h, range 0.05-9 h) from febrile seizures, which was significantly shorter than for seizures of other aetiologies (p<0.05), 1.35 h (range 0.07-13.13 h) from idiopathic seizures, 1.25 h (0.07-12.1 h) from remote symptomatic seizures and 4.57 h (0.25-17 h) from acute symptomatic seizures. Median recovery time after the use of benzodiazepines was 3.46 h (range 0.08-14.25 h), and was significantly longer (p<0.05) than for seizures not treated with benzodiazepines (median 0.47 h, range 0.05-17 h). Age, sex, seizure type and duration did not significantly affect recovery time. CONCLUSIONS: Most children experiencing febrile seizures recover within 30 min. An acute symptomatic aetiology should be considered if recovery takes >1 h.

Aggravation of epilepsy by anti-epileptic drugs.

The possibility that so-called anti-epileptic drugs (AEDs) may aggravate epilepsy must always be borne in mind by the clinician. Many reports of such aggravation of seizures have been published. Most such reports are anecdotal and speculative, and suggest that many such reactions are idiosyncratic. However, for some there is a sufficient body of evidence to suggest that some AEDs used in certain epilepsies may consistently cause worsening of seizures. Seizure aggravation may include increase in the frequency or severity of existing seizures, emergence of new types of seizure, or the occurrence of status epilepticus. The pathophysiology of seizure aggravation is poorly understood including non-specific effects such as those associated with sedation, drug-induced encephalopathy, and paradoxical or inverse pharmacodynamic effects. For some epilepsies the choice of AEDs may be inappropriate, and although the mechanism of seizure aggravation is not clear, its occurrence may be fairly predictable. This is best documented for the use of carbamazepine in idiopathic generalized and myoclonic epilepsies. Most other AEDs have been reported occasionally to cause seizure aggravation. The lowest risk of seizure aggravation appears to be with valproate. Risk factors for worsening of seizures are epileptic encephalopathy, polytherapy, high frequency of seizures, and cognitive impairment. Advances in pharmacogenomics may in the future enable such adverse effects to be predicted for individual patients. Meanwhile, a systematic approach to reporting AED-induced seizure aggravation should be developed.

Congenital glaucoma and brain stem atrophy as features of Aicardi-Goutières syndrome.

We report on three children from two families with Aicardi-Goutières syndrome. All three had congenital glaucoma. Additionally, neuroimaging demonstrated significant brain stem atrophy in the affected sib-pair. These features have not been previously described in Aicardi-Goutières syndrome and expand the phenotypic spectrum.

Topiramate for drug-resistant epilepsies.

Topiramate is a new anti-epileptic drug with proven efficacy against partial seizures in adults. A retrospective assessment of the use of topiramate in drug-resistant childhood epilepsy was undertaken. Thirty-four children (median age of 10 years; range 2-18 years) were treated for a median of 9 months (range 6-18 months). The starting dose was 0.25-2.0 mg/kg/day increasing to a maximum of 13 mg/kg/day. Generalized seizures occurred in 27 patients, partial seizures in 15 and infantile spasms in two. Epilepsies were localization-related in 15 patients and generalized in 18. One patient had severe myoclonic epilepsy in infancy. Two patients had Lennox-Gastaut syndrome, five (two currently and three previously) had West syndrome and one had epilepsy with myoclonic absences. Twenty patients had a substantial (> 50%) reduction in seizure frequency; two of whom became seizure-free. Two-patients had an increase in seizures. Efficacy was seen against simple and complex partial seizures, generalized tonic-clonic seizures (primarily generalized), atonic and tonic seizures, myoclonic seizures and infantile spasms. There was no response in the one patient with myoclonic absence seizures. Adverse effects were reported in nine patients; appetite suppression occurred in five patients, behaviour disturbances in three, somnolence in two and poor concentration in one patient. Topiramate is efficacious in a wide spectrum of childhood epilepsies and is well tolerated.

Overexpression of an unstable intrinsic factor-cobalamin receptor in Imerslund-Gräsbeck syndrome.

Two sisters with Imerslund-Gräsbeck syndrome who presented with clinical features of cobalamin deficiency are described. Intrinsic factor-cobalamin receptor (IFCR) activity and protein levels were determined in ileal biopsy specimens by using radioisotope assay and immunoblotting, respectively. IFCR activities in ileal homogenates expressed as femtomoles of ligand binding per milligram of protein were 38 +/- 4 in control tissue, 494 +/- 24 in patient 1, and 94 +/- 7 in patient 2. However, when assayed in the presence of IFCR antiserum, the ligand binding was inhibited by > 90% in both normal control and the patients with Imerslund-Gräsbeck syndrome. Immunoblotting of total membranes from the biopsy specimen of these 2 patients failed to detect an immunoreactive band of molecular mass of 185 kilodaltons. These findings are at variance with reports of decreased IFCR activity and indicate a new phenotype in which an active but an unstable receptor is overexpressed in Imerslund-Gräsbeck syndrome.

Protein C and S deficiency causing childhood stroke.

The annual incidence of cerebrovascular disease in children is 2.5/100,000 and cerebral infarction is being increasingly recognised in neonates. Deficiency of proteins C and S and their roles in thrombosis have only recently been recognised. Immunologic and functional assays of these proteins now make it possible to determine whether deficiency of them is associated in any particular case of childhood cerebrovascular accident (CVA). We describe two patients, both presenting with stroke in childhood, who were found to be deficient, one in protein C and one in protein S.

Unusual MRI appearance of diffuse subcortical heterotopia or "double cortex" in two children.

Two children with mild epilepsy and learning and behaviour problems had magnetic resonance imaging (MRI) scans showing an almost identical generalised disorders of neuronal migration. Their computer tomography (CT) scans showed abnormal hypodense white matter. The MRI showed a four layered appearance of the cerebral parenchyma extending from the frontal to the occipital region. There was a normal appearance to the white matter in the periventricular region which had an abnormally smooth junction with a thick diffuse layer of heterotopic grey matter. This was surrounded by a thin layer of white matter which had normal digitations with the overlying cortex. The appearance of the overlying cortex was normal. These and other recently described cases broaden the concept of generalised disorders of neuronal migration and illustrate that it is possible to have a generalised cerebral malformation with few clinical consequences.

Cerebrospinal fluid nucleotide metabolites following short febrile convulsions.

Cerebrospinal fluid (CSF) markers of cerebral energy depletion were measured in 32 infants and children following short (less than 10 minutes) febrile convulsions, and in 19 controls. Specific and sensitive indices of high-energy phosphate compound depletion (hypoxanthine, xanthine and uridine) showed no marked changes. Values for patients and febrile controls were significantly higher than for afebrile controls, which is consistent with increased cerebral metabolism in febrile patients. There were no differences in pH, lactate or creatine kinase levels in the CSF of patients and controls. The results suggest that short febrile convulsions are benign and that in the absence of risk factors for the subsequent development of epilepsy, prophylactic anticonvulsant treatment is not indicated.

Cerebrospinal fluid nucleotide metabolites following non-convulsive status epilepticus.

The authors studied specific and sensitive indicators of neuronal adenosine triphosphate (ATP) depletion--hypoxanthine, xanthine and uridine levels--in the cerebrospinal fluid (CSF) of nine children during non-convulsive status epilepticus. No evidence of ATP depletion was found and CSF pH and creatine kinase levels were similar to those of controls. Hypoxanthine, xanthine and uridine had a tendency to be low, but this was significant only for xanthine. The authors speculatively link this reduction to a reduction in neuronal protein synthesis. This might be a mechanism whereby non-convulsive status epilepticus could lead to intellectual deterioration and dementia.

Vigabatrin in the treatment of epilepsy in children.

1. This study presents the results of the preliminary screening of vigabatrin as add-on therapy in an open, non-controlled multicentre study in children with refractory epilepsy. 2. There were 135 children, with an age range of 2 months-12 years. Main seizure type was partial in 42%, generalized in 29%, Lennox-Gastaut syndrome in 19% and West syndrome in 10%. 3. Vigabatrin was added onto current antiepileptic treatment in an initially recommended dose of 40-80 mg kg-1 day-1. However, the doses were frequently increased when tolerance allowed it, and the final mean dose used was 87 mg kg-1 day-1 (27-600). 4. A 75% to 100% reduction in seizure frequency was observed in 25% of patients (11 patients became seizure free) and 50 to 75% decrease in a further 13%. Efficacy was better in partial seizures, with good to excellent results in 49% of patients. The use of high doses, above 100 mg kg-1 day, was not associated with greater efficacy in this preliminary study. 5. No side effects were reported in 79% of patients. Agitation and insomnia were observed in 8.8% and somnolence in 6%. Other adverse events included ataxia (2.2%), nausea (2.2%) and increased appetite (1%). A moderate and transient decrease in haemoglobin was reported in six patients from the same centre; these patients were all receiving very high doses of vigabatrin (250 to 600 mg kg-1 day-1). 6. Vigabatrin thus appears to be a safe antiepileptic drug that may be effective in the treatment of severe epilepsy in children.