Roberto Horacio Caraballo

Mutations in GRIN2A cause idiopathic focal epilepsy with rolandic spikes

Idiopathic focal epilepsy (IFE) with rolandic spikes is the most common childhood epilepsy, comprising a phenotypic spectrum from rolandic epilepsy (also benign epilepsy with centrotemporal spikes, BECTS) to atypical benign partial epilepsy (ABPE), Landau-Kleffner syndrome (LKS) and epileptic encephalopathy with continuous spike and waves during slow-wave sleep (CSWS). The genetic basis is largely unknown. We detected new heterozygous mutations in GRIN2A in 27 of 359 affected individuals from 2 independent cohorts with IFE (7.5%; P = 4.83 × 10−18, Fishers exact test). Mutations occurred significantly more frequently in the more severe phenotypes, with mutation detection rates ranging from 12/245 (4.9%) in individuals with BECTS to 9/51 (17.6%) in individuals with CSWS (P = 0.009, Cochran-Armitage test for trend). In addition, exon-disrupting microdeletions were found in 3 of 286 individuals (1.0%; P = 0.004, Fishers exact test). These results establish alterations of the gene encoding the NMDA receptor NR2A subunit as a major genetic risk factor for IFE.

Atypical evolutions of benign localization-related epilepsies in children : Are they predictable?

Summary: Purpose: To emphasize that, in some patients, different atypical evolutions occur in the course of so‐called benign focal epilepsies of childhood (BFEC) and to promote interest in finding clinical and/or electroencephalographic (EEG) clues to which patients might be prone to these risky evolutions.

Linkage of benign familial infantile convulsions to chromosome 16p12-q12 suggests allelism to the infantile convulsions and choreoathetosis syndrome.

The syndrome of benign familial infantile convulsions (BFIC) is an autosomal dominant epileptic disorder that is characterized by convulsions, with onset at age 3-12 mo and a favorable outcome. BFIC had been linked to chromosome 19q, whereas the infantile convulsions and choreoathetosis (ICCA) syndrome, in which BFIC is associated with paroxysmal dyskinesias, had been linked to chromosome 16p12-q12. BFIC appears to be frequently associated with paroxysmal dyskinesias, because many additional families from diverse ethnic backgrounds have similar syndromes that have been linked to the chromosome 16 ICCA region. Moreover, one large pedigree with paroxysmal kinesigenic dyskinesias only, has also been linked to the same genomic area. This raised the possibility that families with pure BFIC may be linked to chromosome 16 as well. We identified and studied seven families with BFIC inherited as an autosomal dominant trait. Genotyping was performed with markers at chromosome 19q and 16p12-q12. Although chromosome 19q could be excluded, evidence for linkage in the ICCA region was found, with a maximum two-point LOD score of 3.32 for markers D16S3131 and SPN. This result proves that human chromosome 16p12-q12 is a major genetic locus underlying both BFIC and paroxysmal dyskinesias. The unusual phenotype displayed by one homozygous patient suggests that variability of the ICCA syndrome could be sustained by genetic modifiers.

Ketogenic diet in patients with Dravet syndrome.

Summary:  Purpose: The ketogenic diet (KD) has been used as a therapeutic alternative to antiepileptic drugs (AEDs) for refractory epilepsy. Severe myoclonic epilepsy in infants or Dravet syndrome (DS) is one of the most malignant epileptic syndromes. In this retrospective study, we evaluated the efficacy and tolerability of the KD in patients with diagnostic criteria of DS.

Panayiotopoulos syndrome : a consensus view

The aim of this paper is to promote the correct classification of, and provide guidelines on, the diagnosis and management of Panayiotopoulos syndrome (PS). An international consortium of established researchers in the field collaborated to produce a consensus document. The resulting document defines PS, characterizes its electro‐clinical features, considers its likely pathogenesis, and provides guidance on appropriate management. We conclude that PS is a common idiopathic, benign seizure disorder of childhood, which should be classified as an autonomic epilepsy, rather than an occipital epilepsy.

GRIN2B mutations in West syndrome and intellectual disability with focal epilepsy.

To identify novel epilepsy genes using a panel approach and describe the functional consequences of mutations.

Autonomic status epilepticus in panayiotopoulos syndrome and other childhood and adult epilepsies: A consensus view

Summary:  Purpose: To discuss and propose a definition of autonomic status epilepticus (SE), describe its clinical and EEG features, and review what is known about its epidemiology, pathophysiology, differential diagnosis, and management.

Panayiotopoulos-type benign childhood occipital epilepsy A prospective study

Objective: To characterize the clinical and EEG features of the syndrome of benign childhood partial seizures with ictal vomiting and EEG occipital spikes (Panayiotopoulos syndrome [PS]). Methods: Prospective study of children with normal general and neurologic examinations who had seizures with ictal vomiting and EEG with occipital spikes. Results: From February 1990 to 1997, the authors found 66 patients with PS and 145 children with benign childhood epilepsy with centrotemporal spikes. Peak age at onset of PS was 5 years. Ictal deviation of the eyes and progression to generalized seizures were common. One-third had partial status epilepticus. During sleep, all had seizures. While awake, one-third also had seizures. Five children with PS had concurrent symptoms of rolandic epilepsy and another five developed rolandic seizures after remission of PS. Prognosis was excellent: one-third had a single seizure, one-half had two to five seizures, and only 4.5% had frequent seizures. Conclusions: Panayiotopoulos-type benign childhood occipital epilepsy is less common than benign childhood epilepsy with centrotemporal spikes but is well defined and recognizable by clinical and EEG features.

Dravet syndrome: A study of 53 patients

OBJECTIVE We analyzed the electroclinical features, treatment and evolution of patients with Dravet syndrome (DS). MATERIAL AND METHODS We evaluated the clinical records of 53 patients that met the diagnostic criteria of DS according to the ILAE classification of 1989 seen at our center between February 1990 and December 2004. RESULTS Thirty-four male and 19 female patients met the diagnostic criteria of DS. Mean time of follow-up was 10 years. The mean age at onset was 6 months and in all patients the seizures were associated with febrile illness. Myoclonias were found in 39 children. These seizures appeared between the ages of 1 and 5.5 years, with an average of 1 year and 5 months. The seizures were difficult to control with AEDs. All patients presented some degree of mental delay. At the age of 6 years, one of the children in our series presented kinesigenic paroxysmal dyskinesias. Twenty patients were placed on the ketogenic diet (KD). Two did not tolerate the KD and the diet was ineffective in five cases. The other 13 showed different degrees of control of seizures. CONCLUSION The present study confirms the severity and intractability of the seizures and the difficulties to make an early diagnosis in DS. The onset of febrile seizures or seizures related to infectious disease or vaccination, focal or generalized, prolonged in time and during the first year of life, is especially suggestive of DS. The final diagnosis is usually made after 2 or 3 years when the electroclinical picture is complete, but earlier diagnosis is desirable. Myoclonias are the most representative type of non-febrile seizures in this syndrome but are not always present. Cognitive development is poor in all patients. Treatment with the KD should be considered early. A ion-channel disorder could explain the association between DS and paroxysmal diskinesias, as seen in one of our patients.

Status epilepticus in benign rolandic epilepsy manifesting as anterior operculum syndrome.

Summary: We report the fourth case of partial status epilepticus (SE) in benign epilepsy of childhood with rolandic spikes (BECRS). The child suffered long‐lasting attacks involving the mouth and pharynx, clinically manifest as speech arrest, sialorrhea, and drooling. Both clinical and electroencephalogram (EEG) data were compatible with the diagnosis of BECRS. Only during SE was the clinical picture similar to that observed in the operculum or Foix‐Chavany‐Marie syndrome. SE remission was obtained with the usual antiepileptic drug therapy (diazepam, clobazam, valproate). EEG records showed additional patterns of continuous spike‐waves during slow sleep and specific inhibition and blocking of interic‐tal centrotemporal spikes by mouth and/or tongue voluntary movements.