A gyermeki agy fejlődése legújabb ismereteink tükrében, avagy hogyan lesz okos az óvodás?

Az agy az egyetlen olyan szervünk, amely születéskor még nem fejlődött ki teljesen. „Az agy felépül, nem születik.”(Brain Research, Jack Shonkoff, Harvard University) A sejtek többsége ugyan már jelen van, de a kapcsolatok, vagyis az „építményhez” szükséges hálózatrendszer csak később, a kisgyermekkorban fejlődik. A gyermek első néhány életéve kiemelkedően intenzív időszaka az agy, ill. a kognitív funkciók fejlődésének és érésének. Ennek az eredményeképpen válik az újszülött hamarosan a komplex mozgást, a beszédet és a gondolkodást is koordinálni képes gyermekké. Ennek az időszaknak a történései döntik el, hogy egész későbbi életünk, egészségünk és tanulási képességeink számára is milyen agy fejlődik. Az idegrendszer fejlődési folyamataink megismerése közelebb visz minket a kérdéshez, hogy vajon mitől és hogyan is lehet okos az óvodás

A Dravet-szindróma klinikai és genetikai diagnosztikájáról húsz esetünk kapcsán = Clinical and genetic diagnosis of Dravet syndrome: report of 20 cases

OBJECTIVE AND BACKGROUND: Severe myoclonic epilepsy in infancy (SMEI; Dravet's syndrome) is a malignant epilepsy syndrome characterized by prolonged febrile hemiconvulsions or generalized seizures starting in the first year of life. Later on myoclonic, atypical absence, and complex partial seizures appear. When one of these seizure forms is lacking the syndrome of borderline SMEI (SMEB) is defined. Psychomotor delay resulting in mental retardation is observed during the second year of life. In most patients a de novo sodium channel alpha-1 subunit (SCN1A) mutation can be identified. By reviewing the clinical, laboratory, and neuroimaging data of our SMEI patients diagnosed between 2000 and 2008, we would like to share our experiences in this rare but challenging syndrome. Our results will facilitate the earlier and better diagnosis of Hungarian children with SMEI. PATIENTS AND METHODS: Clinical, EEG, MRI and DNA mutation data of 20 SMEI patients treated in the Bethesda Children's Hospital (Budapest) were reviewed. RESULTS: The first seizure appeared at age 6.3+/-3.0 months. At least one of the first two seizures were complex febrile seizures in 19/20 and unilateral seizures in 12/20 children. All children except for one showed hemiconvulsions at least once; all children had seizures lasting longer than 15 minutes. Eight of twenty patients had SMEB. DNA diagnostics identified an SCN1A mutation in 17 patients (6 missense, 4 nonsense, 4 frameshift, 2 splice site, 1 deletion) while 3 children had no mutation. CONCLUSION: Early diagnosis of SMEI is important for the avoiding unnecessary examinations and false therapies as well as for genetic counselling. Typical symptoms of SMEI are early and prolonged febrile hemiconvulsions with neurological symptoms, mental retardation and secondary seizure types later on. The presence of an SCN1A mutation supports the diagnosis. We propose the availability of molecular diagnostics and stiripentol therapy for SMEI children in Hungar

The role of the northward-directed (sub)surface limb of the Atlantic Meridional Overturning Circulation during the 8.2 ka event

The so-called "8.2 ka event" is widely regarded as a major Holocene climate perturbation. It is most readily identifiable in the oxygen-isotope records from Greenland ice cores as an approximately 160-year-long cold interval between 8250 and 8090 years BP. The prevailing view has been that the cooling over Greenland, and potentially over the northern North Atlantic at least, was triggered by the catastrophic final drainage of the Agassiz–Ojibway proglacial lake as part of the remnant Laurentide Ice Sheet collapsed over Hudson Bay at around 8420 ± 80 years BP. The consequent freshening of surface waters in the northern North Atlantic Ocean and the Nordic Seas resulted in weaker overturning, and hence reduced northward ocean heat transport. We have reconstructed variations in the strength of the eastern branch of the Atlantic Inflow into the Nordic Seas around the time of the lake outbursts. While the initial freshwater forcing may have been even larger than originally thought, as the lake outbursts may have been accompanied by a major iceberg discharge from Hudson Bay, our proxy records from the mid-Norwegian Margin do not evidence a uniquely large slowdown in the eastern branch of the Atlantic Inflow at the time. Therefore, its main role in the 8.2 ka event may have been the (rapid) advection of fresh and cold waters to high northern latitudes, initiating rapid sea-ice expansion and an increase in surface albedo