M.A. Farnetani

Childhood absence epilepsy: evolution and prognostic factors.

Summary:  Purpose: To evaluate how diagnostic criteria influence remission rates for patients with childhood absence epilepsy (CAE) and to assess clinical and EEG parameters as predictors of outcome.

Novel and recurrent tyrosine aminotransferase gene mutations in tyrosinemia type II.

Abstract Tyrosinemia typeII (Richner-Hanhart syndrome, RHS) is a disorder of autosomal recessive inheritance characterized by keratitis, palmoplantar hyperkeratosis, mental retardation, and elevated blood tyrosine levels. The disease results from deficiency in hepatic tyrosine aminotransferase (TAT). We have previously described one deletion and six different point mutations in four RHS patients. We have now analyzed the TAT genes in a further seven unrelated RHS families from Italy, France, the United Kingdom, and the United States. We have established PCR conditions for the amplification of all twelve TAT exons and have screened the products for mutations by direct sequence analysis or by first performing single-strand conformation polymorphism analysis. We have thus identified the presumably pathological mutations in eight RHS alleles, including two nonsense mutations (R57X, E411X) and four amino acid substitutions (R119W, L201R, R433Q, R433W). Only the R57X mutation, which was found in one Scottish and two Italian families, has been previously reported in another Italian family. Haplotype analysis indicates that this mutation, which involves a CpG dinucleotide hot spot, has a common origin in the three Italian families but arose independently in the Scottish family. Two polymorphisms have also been detected, viz., a protein polymorphism, P15S, and a silent substitution S103S (TCG→TCA). Expression of R433Q and R433W demonstrate reduced activity of the mutant proteins. In all, twelve different TAT gene mutations have now been identified in tyrosinemia typeII.

Efficacy and safety of topiramate in infants according to epilepsy syndromes

Studies of the efficacy of topiramate (TPM) in infants and young children are few. Here we report an open, prospective, and pragmatic study of effectiveness of TPM in terms of epilepsy syndromes, in children aged less than 2 years. The median follow-up period was 11 months. We enrolled 59 children in the study: 22 affected by localization-related epilepsy (LRE), 23 by generalized epilepsy, six by Dravets syndrome, and eight with unclassifiable epilepsy. TPM was effective (responders showed a decrease of more than 50% in seizure frequency) in 47% of patients, including 13% who were seizure-free at the last visit. TPM was more effective in localization-related epilepsy (48% of responders) than in generalized epilepsy (32% of responders). In the latter group, 19 patients suffered from infantile spasms. Four of six patients with cryptogenic infantile spasms became seizure-free. Of the 13 patients with symptomatic infantile spasms, only one was seizure-free. Results were poor for patients with Dravets syndrome. In general, TPM was well tolerated. The most frequently reported adverse effects were drowsiness, irritability, hyperthermia, and anorexia. The present study concludes that TPM is effective for a broad range of seizures in infants and young children and represents a valid therapeutic option in this population.

Facial hemangioma and malformation of the cortical development: A broadening of the PHACE spectrum or a new entity?

Facial hemangioma is usually isolated but its association with craniocervical arterial anomalies and structural brain malformations is well known. The acronym PHACE syndrome (posterior fossa malformation, facial hemangiomas, arterial anomalies, cardiac/aortic anomalies, and eye abnormalities) has been used to indicate that disorder in which brain anomalies are mainly represented by the Dandy–Walker malformation. We report on a 10‐month‐old boy affected by facial hemangioma and a complex cortical dysplasia located in the left frontal region. The lesion was characterized by a deeply infolding pachygyric cortex and a band of gray matter lining the wall of the lateral ventricle. The entire left cerebral hemisphere appeared hypoplastic. No anomalies of the posterior fossa structures or cardiac/aortic malformations were present. An overlapping clinical/pathological pattern was previously reported in another patient with facial hemangioma and cerebrovascular anomalies. These observations seem to indicate that the facial hemangiomas may be associated with disorders of the cortical development.

Malformations of cortical development in neurofibromatosis type 1.

The authors report three patients with neurofibromatosis type 1 and different types of malformations of cortical development: Patient 1 had a possible transmantle cortical dysplasia involving the right temporoinsuloparieto-occipital areas; Patient 2 had a periventricular band of heterotopic gray matter with an overlying pachygyric cerebral cortex; and Patient 3 had a left perisylvian polymicrogyria. Because all of these lesions result from different pathogenetic mechanisms, neurofibromin may play a role during several stages of cortical development.

Electroencephalographic and epileptic patterns in X chromosome anomalies.

Although epilepsy and mental retardation are commonly observed in individuals with chromosomal aberrations, the identification of EEG/epileptic profiles in those with specific chromosome anomalies remains difficult. A few syndromes seem to show peculiar clinical and EEG associations. The authors report an electroclinical investigation on a group of patients carrying X chromosome anomalies: 16 patients with Turners syndrome, 17 with Klinefelters syndrome, 1 with an X–autosomal rearrangement, 2 with Xq isochromosome [Xq(i)], and 7 with triple X syndrome. Epilepsy and/or EEG anomalies were found in three of the patients with Klinefelters syndrome, in one patient with an X–autosomal rearrangement, and in five of those with triple X syndrome. No epilepsy or EEG anomalies were detected in the other patients. Epilepsy may be associated with Klinefelters syndrome. In addition, the authors found that an electroclinical pattern, represented by paroxysmal activity in the posterior regions (temporo-parieto-occipital areas) with complex partial seizures and easily controlled by antiepileptic drugs, may be present in patients with triple X syndrome. In contrast, gross X–autosomal rearrangements are associated with polymorphic EEG/epileptic findings. Although further studies are needed to validate these observations, they clearly confirm the strict relationship between X chromosome anomalies and epilepsy.

Chromosome 18 aberrations and epilepsy: A review

Epilepsy is commonly observed in patients with chromosomal aberrations. We evaluated epilepsy and electroencephalographic (EEG) features in a group of patients carrying aberrations of chromosome 18. Fourteen patients were recruited: five with an 18p deletion syndrome (18pDS); six with an 18q deletion syndrome (18qDS); two with trisomy 18p syndrome; and one with a 45,XY,t(17‐18) (cen‐q11.2) karyotype. Patients with 18pDS had neither epilepsy nor EEG anomalies; four patients with 18qDS had epilepsy with partial seizures occurring during infancy or early childhood. Partial seizures were also present in both patients with trisomy 18p. By contrast, mixed seizures were observed in the patient carrying a translocation between chromosomes 17 and 18. Our data and a re‐evaluation of the literature suggest that epilepsy is infrequent in patients with 18pDS. Conversely, partial seizures and focal EEG anomalies may be observed in those with patients with 18qDS. Our observations suggest that the haplo‐insufficiency of genes located on the long arm of chromosome 18 is more likely to be associated with epilepsy, than is haplo‐insufficiency of genes located on the short arm. While further EEG/clinical investigations are needed to validate these observations, this study indicates a possible relationship between chromosome 18 genes and epilepsy.

Inter-ictal and post-ictal circulating levels of allopregnanolone, an anticonvulsant metabolite of progesterone, in epileptic children

Allopregnanolone belongs to a group of neuroactive steroid hormones, or neurosteroids, synthesized and acting within the brain and is as a potent endogenous positive modulator of GABA(A) receptor complex. Administration of allopregnanolone protects rats against pentylentetrazol, bicuculline, kainic acid, and picrotoxin-induced seizures. We investigated serum allopregnanolone levels in children with active epilepsy at pubertal Tanners stage I (n=52). Blood specimens were collected at least 12 h after a seizure (inter-ictal). In a subgroup of patients (n=11), specimens were also collected within 30 min from a seizure attack (post-ictal). Healthy age-matched children (n=18) served as controls. Serum allopregnanolone was measured by radioimmunoassay using a polyclonal antiserum. The inter-ictal serum allopregnanolone levels in the epileptic children were not statistically different from those detected in the control group, whereas post-ictal levels were significantly higher than the inter-ictal ones (P=0.0001). In this subgroup of patients allopregnanolone levels decreased to the basal values during the following 12 h. Serum allopregnanolone levels may therefore reflect changes in neuronal excitability, and allopregnanolone appears to be a reliable circulating marker of epileptic seizures. It is possible that increased post-ictal serum levels of allopregnanolone may play a role in modulating neuronal excitability and may represent an endogenous mechanism of seizure control.

EEG, PET, SPET and MRI in intractable childhood epilepsies: possible surgical correlations

Magnetic resonance imaging (MRI), single photon emission tomography (SPET), and positron emission tomography (PET) using [18F]fluorodeoxyglucose were used in combination with scalp and scalp-video EEGs in a group of 30 pediatric patients with drug resistant epilepsy (DRE) in order to identify patients who could benefit from neurosurgical approach. Seizures were classified according to the consensus criteria of The International League Against Epilepsy. In three patients infantile spasms (IS) were diagnosed; 13 subjects were affected by different types of generalized seizures, associated with complex partial seizures (CPS) in three. In the other 14 patients partial seizures, either simple (SPS) or complex, were present. A localized abnormality was demonstrated in one patient with IS and in three patients with generalized seizures. Of the group of 14 subjects with CPS, MRI and CT were normal in 7, but SPET or PET indicated focal hypoperfusion or hypometabolism concordant with the localization of the EEG abnormalities. In 5 of the other 7 patients anatomical and functional imaging and EEG findings were concordant for a localized abnormality. It can be concluded that functional imaging combined with scalp EEGs appears to be superior to the use of only CT and MRI for selecting children with epilepsy in whom a surgical approach can be considered, in particular when CPS resistant to therapy are present.

A comparative study of hydrocortisone versus deflazacort in drug-resistant epilepsy of childhood

Steroids are commonly used for the treatment of intractable epilepsy. Deflazacort has shown similar effects to prednisone, but with a less worrying adverse-effect profile. In this study, we first compared the efficacy, safety, and seizure relapse rate of deflazacort versus hydrocortisone in children affected by drug-resistant epilepsies. This was an open, non-blinded, randomized clinical study of 35 children affected by drug-resistant epilepsies. The study lasted 12 months. Group 1 (16 patients) received hydrocortisone for 6 months; group 2 (19 patients) was treated with deflazacort for the entire study period. Drug efficacy and tolerability were evaluated after 6 months of therapy. Seizure relapse rates were evaluated 12 months after the start of the study. After 6 months of therapy, hydrocortisone was effective in 44% of patients (responders, with a decrease in seizure frequency of >50%). Deflazacort was effective in 47% of patients (P=0.9). Adverse events occurred in 37% of patients using hydrocortisone and in none of those using deflazacort (P=0.002). At the end of the study, seizure relapse rate resulted significantly higher in group 1 than in group 2 (P=0.04). Hydrocortisone may be useful in the treatment of severely drug-resistant childhood epilepsies. However, its effects may be transient. Deflazacort should be considered in the therapeutic armamentarium for epileptic encephalopathies. The drug is as effective as hydrocortisone and may be used in therapy for a long period, with a less worrying adverse-effect profile.