Anna Rita Ferrari

Idiopathic Epilepsies with Seizures Precipitated by Fever and SCN1A Abnormalities

Summary:  Purpose: SCN1A is the most clinically relevant epilepsy gene, most mutations lead to severe myoclonic epilepsy of infancy (SMEI) and generalized epilepsy with febrile seizures plus (GEFS+). We studied 132 patients with epilepsy syndromes with seizures precipitated by fever, and performed phenotype–genotype correlations with SCN1A alterations.

Idiopathic photosensitive occipital lobe epilepsy.

Summary: We studied 10 neurologically normal patients (8 females, 2 males) aged 8–30 years (mean 17 years) who had recurrent episodes of visually induced occipital seizures. Television and computer screens were the main triggers. Seizure onset occurred between the ages of 5 and 17 years (mean 11 years). All seizures were stimulus related and began with elementary visual symptoms, followed in most patients by a slow clustering of cephalicpain, epigastric discomfort, and vomiting, with either normal or only mildly impaired responsiveness. EEG fea‐tures included normal background activity, occipital spikes and waves, and a photoparoxysmal response which could be occipital, generalized, or both. Four pa‐tients also showed spontaneous generalized epileptiform abnormalities, and 3 had rolandic spikes. An Oz electrode was critical in identifying epileptiform activity in some patients. Complete seizure control was achieved in most patients with monotherapy, although occasional stimulus‐related seizures occurred in 3 patients who showed a wider range of photosensitivity. These patients have an idiopathic localization‐related epilepsy with age‐related onset and specific mode of precipitation. Although this type of epilepsy has been reported previously, it has remained underrecognized, probably because it is difficult to differentiate clinically from migraine or from nonreflex childhood idiopathic occipital epilepsy.

Xp22.3 genomic deletions involving the CDKL5 gene in girls with early onset epileptic encephalopathy

Purpose:  Mutations of the X‐linked gene cyclin‐dependent kinase‐like 5 (CDKL5) cause an X‐linked encephalopathy with early onset intractable epilepsy, including infantile spasms and other seizure types, and a Rett syndrome (RTT)–like phenotype. Very limited information is available on the frequency and phenotypic spectrum associated with CDKL5 deletions/duplications. We investigated the role of CDKL5 deletions/duplications in causing early onset intractable epilepsy of unknown etiology in girls.

Generalized Epilepsy with Febrile Seizures Plus (GEFS+): Clinical Spectrum in Seven Italian Families Unrelated to SCN1A, SCN1B, and GABRG2 Gene Mutations

Summary:  Purpose: We describe seven Italian families with generalized epilepsy with febrile seizures plus (GEFS+), in which mutations of SCN1A, SCN1B, and GABRG2 genes were excluded and compare their clinical spectrum with that of previously reported GEFS+ with known mutations.

Influence of dosage, age, and co-medication on plasma topiramate concentrations in children and adults with severe epilepsy and preliminary observations on correlations with clinical response.

The influence of dosage, age, and co-medication on plasma topiramate (TPM) concentrations at steady state was investigated in 51 patients aged 3 to 30 years. All patients had chronic active epilepsy, and most were receiving concomitant medication with enzyme-inducing anticonvulsants (carbamazepine and phenobarbital). Plasma TPM concentrations were determined by a specific immunoassay in samples obtained before the morning dose. Thirty-five patients could be evaluated prospectively at different dose levels, and the relationship between plasma TPM concentration and dosage was linear over the assessed dose range (1.8 to 10.0 mg/kg) both in adults and in children. The influence of age on pharmacokinetic parameters could be assessed only for the 42 patients co-medicated with enzyme inducers. In these patients dose-normalized plasma TPM concentrations correlated positively with age (r = 0.59, P < 0.0001), where apparent oral clearance values (CL/F) were inversely related to age (r = 0.73, P < 0.0001). In particular, CL/F values in children aged less than 10 years (112 ± 82 mL/kg/h, mean ± SD, n = 14) were almost three times as high as those observed in patients aged >15 to 30 years (42 ± 16 mL/kg/h, n = 17), whereas the CL/F value in children aged 10 to 15 years (66 ± 22 mL/kg/h, n = 11) was intermediate between those found in the two other age groups. Patients not receiving enzyme-inducing AEDs showed lower CL/F values than did age- and gender-matched patients on enzyme-inducing co-medication. A preliminary evaluation of the relationship between plasma TPM concentration and therapeutic response could be made in 41 patients. No significant difference in drug concentration was detected between patients showing a greater than 50% reduction in seizure frequency compared with baseline (5.9 ± 2.2 &mgr;g/mL, n = 30) and those having no clinical improvement (5.2 ± 2.2 &mgr;g/mL, n = 11). Likewise, there was no consistent relationship between plasma TPM concentration and appearance of adverse effects. These results indicate that plasma TPM concentrations are linearly related to dosage both in adults and in children and that children aged <10 years require much greater body weight-adjusted dosage to achieve drug levels comparable to those observed in young adults. The marked increase in TPM clearance caused by enzyme-inducing co-medication was confirmed.

CDKL5 gene-related epileptic encephalopathy: electroclinical findings in the first year of life

Aim  Cyclin‐dependent kinase‐like 5 (CDKL5) gene abnormalities cause an early‐onset epileptic encephalopathy. We performed video‐electroencephalography (video‐EEG) monitoring early in the course of CDKL5‐related epileptic encephalopathy in order to examine the early electroclinical characteristics of the condition.

Bilateral frontoparietal polymicrogyria, Lennox‐Gastaut syndrome, and GPR56 gene mutations

Purpose:  Bilateral frontoparietal polymicrogyria (BFPP) has been reported in sporadic patients and in recessive pedigrees. Eleven mutations in GPR56, a gene encoding an evolutionarily dynamic G‐protein–coupled receptor, have been identified in 29 patients from 18 families. The clinical features of BFPP include severe mental retardation, motor and language impairment, and epilepsy. No detailed description of the epilepsy is available for the patients reported to date. We report three consanguineous families in which four affected individuals with BFPP and GPR56 mutations had Lennox‐Gastaut syndrome.

Plasma gabapentin concentrations in children with epilepsy: Influence of age, relationship with dosage, and preliminary observations on correlation with clinical response

The influence of age and administered daily dosage on the plasma concentrations of gabapentin (GBP) at steady state was evaluated in a group of 41 children and young adults (aged 3–30 years) receiving long-term adjunctive treatment with GBP for the management of refractory partial-onset seizures. For each patient, peak and trough concentrations were determined by a specific high-performance liquid chromatography (HPLC) method in samples obtained before the morning dose and 2.5 hours later, respectively. To assess within-subject relationship between plasma concentration and dosage, 30 patients were evaluated at more than one dosage level. Within the assessed dose range, plasma GBP concentrations were linearly related to dose. Apparent oral clearance values (mean ± SD) in children aged 6 years or less (4.8 ± 0.9 mL/kg/min) were comparable with those observed in children aged 7 to 15 years (4.6 + 1.5 mL/kg/min) and moderately higher than those found in young adults (3.9 + 0.9 mL/kg/min), even though differences among groups failed to reach statistical significance. There was, however, a significant difference in CL/F between children aged 10 years or less and older children (5.1 ± 1.1 vs. 3.8 ± 1.2 mL/kg/min, P < 0.005). Of the 41 patients who entered the study, 22 discontinued treatment, mostly due to insufficient efficacy. No significant difference in plasma GBP concentration was detected between patients showing a greater than 50% reduction in seizure frequency (4.1 ± 1.9 &mgr;g/mL, n = 11, mean ± SD) and those having no significant clinical improvement (4.4 ± 1.7 &mgr;g/mL, n = 30). These results indicate that in children given dosages up to 50 mg/kg/d (mean, 25 mg/kg/d), GBP pharmacokinetic analyses show no important deviation from linearity. The data also suggest that, on average, children may need moderately higher dosages to reach plasma GBP concentrations comparable with those found in adults. There seems to be a large variation in the plasma concentrations of the drug associated with a favorable therapeutic response.

Epilepsy in Mowat-Wilson syndrome: delineation of the electroclinical phenotype.

Mowat–Wilson syndrome (MWS) is a genetic disease caused by heterozygous mutations or deletions of the ZEB2 gene and is characterized by distinctive facial features, epilepsy, moderate to severe intellectual disability, corpus callosum abnormalities and other congenital malformations. Epilepsy is considered a main manifestation of the syndrome, with a prevalence of about 70–75%. In order to delineate the electroclinical phenotype of epilepsy in MWS, we investigated epilepsy onset and evolution, including seizure types, EEG features, and response to anti‐epileptic therapies in 22 patients with genetically confirmed MWS. Onset of seizures occurred at a median age of 14.5 months (range: 1–108 months). The main seizure types were focal and atypical absence seizures. In all patients the first seizure was a focal seizure, often precipitated by fever. The semiology was variable, including hypomotor, versive, or focal clonic manifestations; frequency ranged from daily to sporadic. Focal seizures were more frequent during drowsiness and sleep. In 13 patients, atypical absence seizures appeared later in the course of the disease, usually after the age of 4 years. Epilepsy was usually quite difficult to treat: seizure freedom was achieved in nine out of the 20 treated patients. At epilepsy onset, the EEGs were normal or showed only mild slowing of background activity. During follow‐up, irregular, diffuse frontally dominant and occasionally asymmetric spike and waves discharges were seen in most patients. Sleep markedly activated these abnormalities, resulting in continuous or near‐to‐continuous spike and wave activity during slow wave sleep. Slowing of background activity and poverty of physiological sleep features were seen in most patients. Our data suggest that a distinct electroclinical phenotype, characterized by focal and atypical absence seizures, often preceded by febrile seizures, and age‐dependent EEG changes, can be recognized in most patients with MWS.

Somatic Overgrowth Predisposes to Seizures in Autism Spectrum Disorders

Background Comorbidity of Autism Spectrum Disorders with seizures or abnormal EEG (Autism-Epilepsy Phenotype) suggests shared pathomechanisms, and might be a starting point to identify distinct populations within the clinical complexity of the autistic spectrum. In this study, we tried to assess whether distinct subgroups, having distinctive clinical hallmarks, emerge from this comorbid condition. Methods Two-hundred and six individuals with idiopathic Autism Spectrum Disorders were subgrouped into three experimental classes depending on the presence of seizures and EEG abnormalities. Neurobehavioral, electroclinical and auxological parameters were investigated to identify differences among groups and features which increase the risk of seizures. Our statistical analyses used ANOVA, post-hoc multiple comparisons, and the Chi-squared test to analyze continuous and categorical variables. A correspondence analysis was also used to decompose significant Chi-squared and reduce variables dimensions. Results The high percentage of children with seizures (28.2% of our whole cohort) and EEG abnormalities (64.1%) confirmed that the prevalence of epilepsy in Autism Spectrum Disorders exceeds that of the general population. Seizures were associated with severe intellectual disability, and not with autism severity. Interestingly, tall stature (without macrocephaly) was significantly associated with EEG abnormalities or later onset seizures. However, isolated macrocephaly was equally distributed among groups or associated with early onset seizures when accompanied by tall stature. Conclusions Tall stature seems to be a phenotypic “biomarker” of susceptibility to EEG abnormalities or late epilepsy in Autism Spectrum Disorders and, when concurring with macrocephaly, predisposes to early onset seizures. Growth pattern might act as an endophenotypic marker in Autism-Epilepsy comorbidity, delineating distinct pathophysiological subtypes and addressing personalized diagnostic work-up and therapeutic approaches.