Detection of copy number variations in epilepsy using exome data.

Epilepsies are common neurological disorders and genetic factors contribute to their pathogenesis. Copy number variations (CNVs) are increasingly recognized as an important etiology of many human diseases including epilepsy. Whole-exome sequencing (WES) is becoming a standard tool for detecting pathogenic mutations and has recently been applied to detecting CNVs. Here, we analyzed 294 families with epilepsy using WES, and focused on 168 families with no causative single nucleotide variants in known epilepsy-associated genes to further validate CNVs using 2 different CNV detection tools using WES data. We confirmed 18 pathogenic CNVs, and 2 deletions and 2 duplications at chr15q11.2 of clinically unknown significance. Of note, we were able to identify small CNVs less than 10 kb in size, which might be difficult to detect by conventional microarray. We revealed 2 cases with pathogenic CNVs that one of the 2 CNV detection tools failed to find, suggesting that using different CNV tools is recommended to increase diagnostic yield. Considering a relatively high discovery rate of CNVs (18 out of 168 families, 10.7%) and successful detection of CNV with <10 kb in size, CNV detection by WES may be able to surrogate, or at least complement, conventional microarray analysis.

Multicenter long-term follow-up of children with idiopathic West syndrome: ACTH versus vigabatrin.

BACKGROUND AND PURPOSE: Long-term follow-up of children with idiopathic West syndrome (WS) treated with adrenocorticotropic hormone (ACTH) or vigabatrin. METHODS: Records of 28 normal magnetic resonance imaging (MRI) WS cases were reviewed for seizure development and cognitive outcome in relation to treatment type and lag. RESULTS: Average age at disease onset was 5.5 months, and average lag time to treatment was 25 days. Fourteen patients were treated with ACTH (eight early and six late), and 14 with vigabatrin (without delay). Response rates were 88% for ACTH and 80% for vigabatrin. Short-term outcomes for seizure cessation and electroencephalography normalization were identical between the groups. In the long-term, early ACTH treatment was better than the rest combined. Average follow-up time was 9 years. A normal cognitive outcome was achieved in 100% of the early-ACTH group, 67% of the late-ACTH group and 54% of the vigabatrin group (P = 0.03). Seizures subsequently developed in 54% of the vigabatrin group, in 33% of the late ACTH group, and 0% of the early ACTH group (P < 0.05). CONCLUSIONS: Idiopathic WS with normal MRI is associated with a good cognitive outcome. Early ACTH treatment, administered within 1 month, yields a better cognitive and seizure outcome than vigabatrin or late ACTH.

Antibodies to glutamate receptor subtype 3 (GluR3) are found in some patients suffering from epilepsy as the main disease, but not in patients whose epilepsy accompanies antiphospholipid syndrome or Sneddon's syndrome.

Autoantibodies (Ab's) to the "B" peptide (amino acids 372-395) of glutamate/AMPA receptor subtype 3 (GluR3) are found in serum and cerebrospinal fluid of some patients with different types of epilepsy. Since such anti-GluR3B Ab's can activate and/or kill neurons in vitro and in vivo, they may contribute to epilepsy. To investigate whether anti-GluR3B Ab's may also be relevant to epilepsy when it accompanies some autoimmune-diseases, we tested for these Ab's in patients suffering from epilepsy that accompanies anti-phospholipid syndrome (APS) or Sneddon's syndrome (SNS), both being autoimmune-diseases with frequent neurological complications. We tested 77 pediatric patients whose epilepsy is their main disease; 31 adult patients whose epilepsy accompanies APS (primary or SLE-associated) or SNS; 45 epilepsy-free APS and SNS patients; and 90 healthy controls. Compared to the controls, significantly elevated anti-GluR3B Ab's were found in 22/77 (29%) patients whose epilepsy is their main disease, but in none of the patients whose seizures accompany APS or SNS. Yet, all the APS and SNS patients harbored the characteristic anti-phospholipid Ab's (aPL), directed against cardiolipin and beta2-glycoprotein I, and had lupus anti-coagulant. Thus, anti-GluR3B Ab's are not crossreactive with aPL, and not produced as a non-specific consequence of seizures on the one hand, or autoimmune-diseases on the other. Taken together with new findings accumulated recently in our lab, we suggest that anti-GluR3B Ab's are produced primarily in the periphery due to specific/non-specific "irritation" of the immune system, and that once they reach the brain via a leaky blood-brain barrier they may cause neuronal/glial damage and facilitate the outburst of epilepsy and additional neurological abnormalities. In contrast, the presence of anti-GluR3B Ab's does not seem to increase the probability of developing APS, SNS or the seizures that often accompany these autoimmune-diseases. These findings may have important diagnostic and therapeutic implications.

Estimation of the mutation frequencies in Charcot-Marie-Tooth disease type 1 and hereditary neuropathy with liability to pressure palsies: a European collaborative study.

A European collaboration on Charcot-Marie-Tooth type 1 (CMT1) disease and hereditary neuropathy with liability to pressure palsies (HNPP) was established to estimate the duplication and deletion frequency, respectively, on chromosome 17p11.2 and to make an inventory of mutations in the myelin genes, peripheral myelin protein 22 (PMP22), myelin protein zero (MPZ) and connexin 32 (Cx32) located on chromosomes 17p11.2, 1q21-q23 and Xq13.1, respectively. In 70.7% of 819 unrelated CMT1 patients, the 17p11.2 duplication was present. In 84.0% of 156 unrelated HNPP patients, the 17p11.2 deletion was present. In the nonduplicated CMT1 patients, several different mutations were identified in the myelin genes PMP22, MPZ and Cx32.

Machado-Joseph (Azorean) disease in a Yemenite Jewish family in Israel.

Machado-Joseph disease (MJD), an autosomal dominant, progressive, multisystem degeneration with cerebellar ataxia as the cardinal manifestation, usually affects individuals of Portuguese ancestry from the Azorean Islands. Cases have been reported in families from Japan, India, China, Brazil, and Australia. We report the first Israeli Jewish family with MJD, originating from a remote village near Ta'izz in Yemen.

Detection and measurement of an endogenous clonidine-displacing substance in human cerebrospinal fluid.

Clonidine-displacing substance (CDS) is a novel endogenous ligand for clonidine receptors previously detected in bovine brain and human serum. We examined for the first time whether CDS can be detected and measured in human cerebrospinal fluid (CSF). Using the [3H]clonidine displacement assay, we found that CDS could be identified and quantified in each of the CSF samples obtained from 81 patients with various neurological disorders. Mean level of CDS in CSF was 4.66 units/ml. Exceedingly high levels were observed in the CSF of patients with neoplastic meningitis (mean, 36.75 units/ml) and stroke (mean, 19.5 units/ml) (P < 0.0001). No correlation was found between CDS levels in CSF and age, gender, CSF protein or number of cells. CDS levels in CSF were higher than those in the serum (P < 0.01). We conclude that CDS is present and can be measured in human CSF. High CDS levels in CSF from patients with leptomeningeal metastases may serve as a tumor marker for malignant infiltration of the meninges. Additional studies in stroke patients will determine whether this endogenous ligand plays a role in the pathogenesis of cerebral ischemia.

Seizure frequency and characteristics in children with Down syndrome.

Seizures have not historically been considered a major component of Down syndrome. We examined the prevalence of epileptic seizures in 350 children and adolescents with Down syndrome evaluated at a regional center between 1985 and 1997. Results showed that 28 patients (8%) had epileptic seizures: 13 (47%) partial seizures; 9 (32%) infantile spasms, and 6 (21%) generalized tonic-clonic seizures. In the infantile spasm group, there was no relationship between the initial electroencephalogram (EEG) pattern and response to treatment or long-term seizure control, or between type of pharmacologic treatment (valproic acid, adrenocorticotropic hormone or both) and clinical remission, EEG normalization or long-term seizure control. Neurodevelopmental outcome was poor despite good seizure control in the infantile spasm group. This regional study reinforces the relative association of seizures and Down syndrome. A prospective study including a national/international registry with emphasis on developmental assessment and long-term follow up is warranted.

Neuropsychological aspects of benign childhood epilepsy with centrotemporal spikes.

PURPOSE: To establish whether the disability in benign epilepsy with centrotemporal spikes (BECTS) is the result of the number of seizures, the anti-epileptic therapy or is an inherent characteristic of the syndrome itself. METHODS: Thirty-six children with BECTS were tested for cognitive functions prior to commencing treatment with anti-epileptic drugs, and the findings were compared with those in 15 children with normal electroencephalograms, performed for unrelated reasons. The data in the study group were further correlated with the laterality of the epileptic focus and the number of seizures. RESULTS: Scores for verbal functioning on neuropsychological tests were significantly lower in the study group than the control group. There was no relationship between the neuropsychological scores in the patients and either lateralization of the epileptic focus or number of seizures. DISCUSSION: Children with BECTS have an impaired ability to process verbal information. The deficiency is apparently a result of the pathological electrical discharges that are part of the syndrome and are not dependent on the epileptic focus laterality, the number of seizures, or the anti-epileptic treatment.

Epilepsy in children with infantile thiamine deficiency.

OBJECTIVE: To report the follow-up findings of 7 children with severe epilepsy as a result of thiamine deficiency in infancy caused by a defective soy-based formula. METHODS: The medical records of 7 children aged 5-6 years with thiamine deficiency in infancy who developed epilepsy were reviewed and their clinical data, EEG tracings, and neuroimaging results were recorded. The clinical course and present outcome of these children, now 5 years after exposure to thiamine deficiency, are described. RESULTS: All infants displayed seizures upon presentation, either tonic, myoclonic, or focal. Six infants had an EEG recording at this stage and all showed slow background. Five of them had no epileptic activity and only 1 displayed focal activity. Following a seizure-free period of 1-9 months, the seizures recurred, and all 7 children displayed either myoclonic or complex partial seizures. Multifocal or generalized spike wave complexes were recorded on the EEGs of all 7 patients, and the tracings of 3 children evolved into hypsarrhythmia. The seizures were refractory to most antiepileptic drugs, and 4 children remain with uncontrolled seizures. All children have mental retardation and motor disabilities as well as symptoms of brainstem dysfunction. CONCLUSIONS: Our findings indicate that severe infantile thiamine deficiency may result in epilepsy.

Progressive spinocerebellar degeneration "plus" associated with Langerhans cell histiocytosis: a new paraneoplastic syndrome?

Langerhans cell histiocytosis (LCH), formerly known as histiocytosis-X, manifests by granulomatous lesions consisting of mixed histiocytic and eosinophilic cells. The hallmark of LCH invasion into the CNS is diabetes insipidus, reflecting local infiltration of Langerhans cells into the posterior pituitary or hypothalumus. In five patients who had early onset LCH with no evidence of direct invasion into the CNS, slowly progressive spinocerebellar degeneration accompanied in some by pseudobulbar palsy and intellectual decline was seen. Neurological impairment started 2.5 to seven years after the detection of LCH. No correlation was found between the clinical syndrome and location of LCH or its mode of treatment. An extensive search for metabolic, toxic, neoplastic, and hereditary aetiologies for progressive cerebellar degeneration was negative. It seems that the clinical entity described here may be considered a new paraneoplastic syndrome related to LCH. It may be induced by the eosinophil derived neurotoxin, which was shown to cause damage to Purkinje cells and pyramidal neurons.

The prognostic significance of glial fibrillary acidic protein staining in medulloblastoma.

Histologic and immunohistochemical properties of 53 medulloblastomas were analyzed with regard to clinical features and survival rate. No correlation was found between survival rate and histologic features of the tumor, such as desmoplastic reaction, number of mitoses, hemorrhages, necrosis, endothelial proliferation, glomerular arrangement, calcifications, rosettes, or oligodendroglial cells. However 82% of the patients with positive glial fibrillary acidic protein (GFAP) staining in numerous tumor cells survived more than 5 years; only 30% survived that long if their tumor cells were GFAP negative (P = 0.0093). This significant difference was not related to the mode of therapeutic protocol used. The authors suggest that GFAP staining may be a useful prognostic tool in medulloblastoma.

Parry-Romberg syndrome: follow-up imaging during suppressive therapy.

Parry-Romberg syndrome is a poorly--understood disorder characterized by progressive hemifacial atrophy involving the skin, soft tissue, and bone. Involvement of the central nervous system with impairment in neurologic function occurs infrequently. We describe a child with this syndrome in whom central nervous system involvement, documented on serial MRI, played a prominent role. We have attempted to correlate the clinical course with the radiologic findings, and to determine the impact of prednisone and methotrexate on the intracranial lesions.