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The chromosomal loci for seven epilepsy genes have been identified in chromosomes 1q, 6p, 8q, 16p, 20q, 21q, and 22q. In 1987, the first epilepsy locus was mapped in a common benign idiopathic generalized epilepsy syndrome, juvenile myoclonic epilepsy (JME). Properdin factor or Bf, human leukocyte antigen (HLA), and DNA markers in the HLA-DQ region were genetically linked to JME and the locus, named EJM1, was assigned to the short arm of chromosome 6. Our latest studies, as well as those by Whitehouse et al., show that not all families with JME have their genetic locus in chromosome 6p, and that childhood absence epilepsy does not map to the same EJM1 locus. Recent results, therefore, favor genetic heterogeneity for JME and for the common idiopathic generalized epilepsies. Heterogeneity also exists in benign familial neonatal convulsions, a rare form of idiopathic generalized epilepsy. Two loci are now recognized; one in chromosome 20q (EBN1) and another in chromosome 8q. Heterogeneity also exists for the broad group of debilitating and often fatal progressive myoclonus epilepsies (PME). The gene locus (EPM1) for both the Baltic and Mediterranean types of PME or Unverricht-Lundborg disease is the same and is located in the long arm of chromosome 21. Lafora type of PME does not map to the same EPM1 locus in chromosome 21. PME can be caused by the juvenile type of Gaucher's disease, which maps to chromosome 1q, by the juvenile type of neuronal ceroid lipofuscinoses (CLN3), which maps to chromosome 16p, and by the "cherry-red-spot-myoclonus" syndrome of Guazzi or sialidosis type I, which has been localized to chromosome 10. A point mutation in the mitochondrial tRNA(Lys) coding gene can also cause PME in children and adults (MERFF).

Epilepsy secondary to active or inactive neurocysticercosis (NCC) is a major public health problem in Latin American countries. In an open-label pilot trial, we evaluated and followed (mean = 13 months) 16 patients with epilepsy resulting from active NCC which was treated with anticisticercal (ACC) drugs. These patients were aged 12-68 years with confirmed active NCC and seizures not controlled by adequate antiepileptic drug (AED) therapy. Patients were treated with albendazole or praziquantel (ALB and PZQ, ACC drugs) and AED monotherapy. The number of NCC cysts was markedly reduced by ACC therapy. Thirteen patients remained seizure-free and 2 had only one seizure during follow-up. Our data suggest a positive effect of ACC treatment on the prognosis of epilepsy caused by active NCC, but a prospective, double-blind, controlled study with long-term follow-up must be performed to determine whether ACC therapy improves long-term seizure control.

We studied 100 consecutive Mexican patients with epilepsy that started after the age of 25 years. All patients underwent clinical evaluation, computed tomography, and electroencephalography; additionally, cerebrospinal fluid analysis was performed in 82 of them. Neurocysticercosis or its sequelae were diagnosed in 50 patients (50%); 36 of these patients had partial seizures, 41 had parenchymal calcifications, and 15 had two or more lesions. Our results are in contrast with those of most studies from countries with a low incidence of neurocysticercosis, where brain tumors, cerebrovascular disease, trauma, and alcoholism are the main causes of tardive epilepsy.

DeGiorgio C, Pietsch-Escueta S, Tsang V, Corral-Leyva G, Ng L, Medina MT, Astudillo S, Padilla N, Leyva P, Martinez L, Noh J, Levine M, del Villasenor R, Sorvillo F. Sero-prevalence ofTaenia soliumCysticercosis andTaenia soliumTaeniasis in California, USA.Acta Neurol Scand 2005: 111: 84–88.© Blackwell Munksgaard 2005.Taenia soliumCysticercosis is a leading cause of epilepsy and neurological disability in the developing world. It is caused by ingestion of the eggs of the tapeworm,T. soliumTaeniasis. The prevalence of eitherT. soliumCysticercosis orT. soliumTaeniasis in the United States in populations at risk is poorly understood. The primary objectives of this study are to perform the first study of the sero-prevalence ofT. soliumCysticercosis andT. soliumTaeniasis in an at-risk community in the USA, specifically rural Southern California; identifyT. soliumTaeniasis positive individuals, and treat positive individuals for the tapewormT. soliumTaeniasis.Community based sero-prevalence study of antibodies toT. soliumCysticercosis andT. soliumTaeniasis in 449 subjects living in a federally funded, predominantly Hispanic residential community; and in two migrant farm worker camps in rural Ventura County, California, USA. For this study, fingerstick blood samples were obtained. Serum immunoblots for bothT. soliumCysticercosis andT. soliumTaeniasis were performed.The sero-prevalence ofT. soliumCysticercosis was 1.8% and the sero-prevalence ofT. soliumTaeniasis by serum immunoblot was 1.1%.Taenia soliumCysticercosis andT. soliumTaeniasis antibodies were not detected in children. The sero-prevalence ofT. soliumTaeniasis was highest in the migrant farm worker community. Handwashing frequency was correlated withT. soliumTaeniasis sero-positivity.The sero-prevalence ofT. soliumCysticercosis andT. soliumTaeniasis in this population, as detected by serum immunoblot, approximates the prevalence in some endemic areas of Latin America. Importantly, most patients likely had prior exposure, not active infection. This study establishes for the first time, the relative sero-prevalence ofT. soliumCysticercosis andT. soliumTaeniasis in at-risk populations in the United States. [ABSTRACT FROM AUTHOR]

Background: In juvenile myoclonic epilepsy, data are limited on the genetic basis of networks promoting convulsions with diffuse polyspikes on electroencephalography (EEG) and the subtle microscopic brain dysplasia called microdysgenesis.Methods: Using Sanger sequencing, we sequenced the exomes of six members of a large family affected with juvenile myoclonic epilepsy and confirmed cosegregation in all 37 family members. We screened an additional 310 patients with this disorder for variants on DNA melting-curve analysis and targeted real-time DNA sequencing of the gene encoding intestinal-cell kinase ( ICK). We calculated Bayesian logarithm of the odds (LOD) scores for cosegregating variants, odds ratios in case-control associations, and allele frequencies in the Genome Aggregation Database. We performed functional tests of the effects of variants on mitosis, apoptosis, and radial neuroblast migration in vitro and conducted video-EEG studies in mice lacking a copy of Ick.Results: A variant, K305T (c.914A→C), cosegregated with epilepsy or polyspikes on EEG in 12 members of the family affected with juvenile myoclonic epilepsy. We identified 21 pathogenic ICK variants in 22 of 310 additional patients (7%). Four strongly linked variants (K220E, K305T, A615T, and R632X) impaired mitosis, cell-cycle exit, and radial neuroblast migration while promoting apoptosis. Tonic-clonic convulsions and polyspikes on EEG resembling seizures in human juvenile myoclonic epilepsy occurred more often in knockout heterozygous mice than in wild-type mice (P=0.02) during light sleep with isoflurane anesthesia.Conclusions: Our data provide evidence that heterozygous variants in ICK caused juvenile myoclonic epilepsy in 7% of the patients included in our analysis. Variant ICK affects cell processes that help explain microdysgenesis and polyspike networks observed on EEG in juvenile myoclonic epilepsy. (Funded by the National Institutes of Health and others.). [ABSTRACT FROM AUTHOR]