A prospective longitudinal study on visuo-cognitive development in Dravet syndrome: Is there a "dorsal stream vulnerability"?

A group of five DS patients whose first development was already reported were longitudinally followed up till the scholar age. Beside the general and epileptic clinical evolution, visual and cognitive functions were investigated in order to define their trajectory and possibly provide information about mechanisms of cognitive decline as well as to improve prognosis and tertiary prevention. Neuropsychological assessment was performed with a test battery investigating the development of visual function that progressively integrates into extrastriate components and higher cognitive skills (global form and motion coherence, stereopsis, crowding cards, ABCDEFV battery, general intelligence and specific cognitive tests). Main results showed a fall in visuo-motor items including global motion coherence and specific cognitive skills, presenting a continuity of the visual function deterioration extended from basic abilities to visuo-motor dorsal pathway skills. Moreover, a case whose previous visual and cognitive functions had been in the normal range began showing a visual deterioration with increasing age, followed by the cognitive decline; that prevents from excluding in early ages a poor development in presence of a normal visual function. A dorsal stream vulnerability seems thus shown in this sample of DS patients, like in other genetic syndromes (Williams, Prader Willi. fragile-X), providing new information about mechanisms underlying cognitive decline and suggesting a possible strategy to improve their neuropsychological outcome. Larger cohorts may confirm whether these findings are part of a specific pattern of DS neuropsychological phenotype.

Smith Lemli-Opitz syndrome: a contribution to the delineation of a cognitive/behavioral phenotype.

AIM: Smith-Lemli-Opitz syndrome (SLOS) is an autosomal recessive congenital malformation syndrome caused by an inborn error of cholesterol biosynthesis. The incidence is around 1:20000-1:70000. SLOS phenotype is very broad: severe phenotypes show exitus in perinatal period while milder phenotypes only show behavioral and learning problems. The purpose of this study is to further contribute to the delineation of a cognitive and behavioral phenotype in SLOS. METHODS: Nine patients with SLOS aged between 22 months and 25 years have been followed at the Department of Pediatrics, University of Naples "Federico II" for 2 years. A neuropsychologic study has been carried out in order to assess motor development, adaptive skills, social behavior, communication and language, temperament, aggressive behavior, symptoms typical of autism spectrum disorders (ASDs). RESULTS: The overall assessment of cognitive/behavioral phenotype showed severe / profound mental retardation in most of them (8/9) with a quite homogeneous neuropsychological profile. The language area was deficient both in expressive and receptive skills. Adaptive skills were in line with mental development. The presence of behavior problems (self-injury and stereotypies) was detected in 6 patients. The study of temperament showed a trend towards a sedentary lifestyle, lack of inhibition against novelty and danger, and reduced interest in the stimuli. None of our patients could be diagnosed as having ASDs. CONCLUSION: Although a specific behavioral phenotype for SLOS has gained support in the literature, we believe that many of the features described in individuals with SLOS are common to other mental retardation syndromes.

Epilepsy in inherited metabolic disorders: a pediatric series.

AIM: Our study aims at further defining the characteristics of epilepsy in Inherited Metabolic Disorders (IMDs). METHODS: We reviewed the medical records of 345 patients with IMDs followed at the Metabolic Diseases Unit of our Department of Pediatrics and found the presence of an epileptic syndrome in 45 cases. An overview is given based on various criteria such as pathogenetic background, seizure type, age of onset, EEG, neuroimaging data, treatability. Seizure types were: focal (24 patients), generalized (13 patients), febrile (3 patients), and hypoglycemic (8 patients with glycogenoses). Some patients presented with more than one type of seizures. Age of onset was mainly during the first year of life (N.=19), between 2 and 6 years in 13 patients, and after the 6th year in 9 patients. RESULTS: Available EEGs showed either focal (N.=21) or generalized epileptiform abnormalities (N.=11); multifocal paroxysms were evident in 3 patients while the remaining 3 patients had normal findings. Available neuroimages (CT/MRI) showed either normal findings (N.=6) or white matter abnormalities (N.=6), cerebral and/or cerebellar cortical atrophy (N.=11), hydrocephalus (N.=1), corpus callosum hypoplasia (N.=2), pontocerebellar hypoplasia (N.=1), gliosis in trigone area (N.=4). Most patients showed a favorable response to antiepileptic treatment (AEDs) with either complete control or reduced seizure frequency. CONCLUSION: IMDs are a relatively rare cause of epilepsy in children but their diagnosis is very important with respect to treatment, prognosis and genetic counselling.