Seizures induced by desloratadine, a second-generation antihistamine: clinical observations

Some clinical experiences indicate that H1-antihistamines, especially first-generation H1-antagonists, occasionally provoke convulsions in healthy children as well as epileptic patients. Desloratadine is a frequently used second-generation antihistamine considered to be effective and safe for the treatment of allergic diseases. We describe four children who experienced epilepsy associated with the nonsedating H(1)-antagonist desloratadine and discuss the neurophysiologic role of the central histaminergic system in seizure susceptibility. In conclusion, we recommend caution in treating epileptic patients with the histamine H(1)-antagonists, including second- and third-generation drugs that are frequently referred because they are considered to be nonsedating antihistamines.

Two epileptic syndromes, one brain: childhood absence epilepsy and benign childhood epilepsy with centrotemporal spikes

Childhood absence epilepsy (CAE) and benign childhood epilepsy with centrotemporal spikes (BCECTS), or benign rolandic epilepsy (BRE), are the most common forms of childhood epilepsy. CAE and BCECTS are well-known and clearly defined syndromes; although they are strongly dissimilar in terms of their pathophysiology, these functional epileptic disturbances share many features such as similar age at onset, overall good prognosis, and inheritance factors. Few reports are available on the concomitance of CAE and BCECTS in the same patients or the later occurrence of generalized epilepsy in patients with a history of partial epilepsy. In most cases described in the literature, absence seizures always started after the onset of benign focal epilepsy but the contrary has never occurred yet. We describe two patients affected by idiopathic generalized epileptic syndrome with typical absences, who experienced BCECTS after remission of seizures and normalization of EEG recordings. While the coexistence of different seizure types within an epileptic syndrome is not uncommon, the occurrence of childhood absence and BCECTS in the same child appears to be extremely rare, and this extraordinary event supports the hypothesis that CAE and BCECTS are two distinct epileptic conditions. However, recent interesting observations in animal models suggest that BCECTS and CAE could be pathophysiologically related and that genetic links could play a large role.

De novo mosaic ring chromosome 18 in a child with mental retardation, epilepsy and immunological problems

Ring chromosome 18 [r(18)] is a disorder in which one or both ends of chromosome 18 are lost and joined forming a ring-shaped figures. R(18) patients can therefore show features of 18q-, 18p- syndrome or a combination of both, depending on the size of the 18p and 18q deleted regions. The phenotype of the r(18) is characterized by developmental delay/mental retardation, typical facial dysmorphisms, major abnormalities and immunological problems. Here we report a case of de novo mosaic r(18) with a characterization by array-based comparative genomic hybridization analysis, and discuss the phenotypic correlation in r(18) also through a comparison with previously described cases of the literature.

"Idiopathic" mental retardation and new chromosomal abnormalities

Mental retardation is a heterogeneous condition, affecting 1-3% of general population. In the last few years, several emerging clinical entities have been described, due to the advent of newest genetic techniques, such as array Comparative Genomic Hybridization. The detection of cryptic microdeletion/microduplication abnormalities has allowed genotype-phenotype correlations, delineating recognizable syndromic conditions that are herein reviewed. With the aim to provide to Paediatricians a combined clinical and genetic approach to the child with cognitive impairment, a practical diagnostic algorithm is also illustrated. The use of microarray platforms has further reduced the percentage of "idiopathic" forms of mental retardation, previously accounted for about half of total cases. We discussed the putative pathways at the basis of remaining "pure idiopathic" forms of mental retardation, highlighting possible environmental and epigenetic mechanisms as causes of altered cognition.

Association of syndromic mental retardation and autism with 22q11.2 duplication

We describe a 5.3-year-old girl with autism, mental retardation, hypotonia, marked speech delay, and mild dysmorphic features with a 22q11.2 duplication. Her mother carries the same duplication and presents cleft palate, and normal intelligence. The clinical and behavioural phenotype of this relatively new syndrome is very heterogeneous, with high variability also in the familiar cases. Up till now, about 50 cases of 22q11.2 duplication have been reported, but only three of them are associated with autistic disorders. We propose that in addition to 22q13.3 deletion syndrome, also 22q11.2 duplication should be suspected in a patient with unspecified dysmorphisms, mental retardation, autism, hypotonia, and severe speech delay.