ABSTRACT
We assessed the impact of unilateral epileptic foci in benign idiopathic partial epilepsy of childhood with rolandic discharges (BECT) on performance and hemispheric specialization in lateralized cognitive functions. Six children with BECT with a left-sided focus (BECT-L), 6 children with BECT with a right-sided focus (BECT-R), and 12 control children were tested in verbal, visual-spatial, and visual-attention tasks, with visual hemifield presentation. Children with BECT-R were impaired in the visual-spatial task relative to those with BECT-L, and the typical left-hemisphere (LH) advantage was not reported in the verbal task in children with BECT-L. Additionally, the classic global superiority effect was lacking in children with BECT-R, which may be due to impaired performance of the right hemisphere specialized in global (vs local)-level processing. These data argue for the deleterious effect of epileptic discharges per se on cognitive functions in the developing brain, and the decisive role of epileptic focus lateralization in specific cognitive impairments and hemispheric specialization.
Subject(s)
Cognition/physiology , Epilepsy, Rolandic/psychology , Functional Laterality/physiology , Visual Fields/physiology , Child , Electroencephalography , Epilepsy, Rolandic/physiopathology , Humans , Male , Neuropsychological Tests , Reaction TimeABSTRACT
Uranium is a heavy metal which, following accidental exposure, may potentially be deposited in human tissues and target organs, the kidneys and bones. A few published studies have described the distribution of this element after chronic exposure and one of them has demonstrated an accumulation in the brain. In the present study, using inductively coupled plasma mass spectrometry (ICP-MS) for the quantification of uranium, uranium transfer across the blood-brain barrier (BBB) has been assessed using the in situ brain perfusion technique in the rat. For this purpose, a physiological buffered bicarbonate saline at pH 7.4 containing natural uranium at a given concentration was perfused. After checking the integrity of the BBB during the perfusion, the background measurement of uranium in control rats without uranium in the perfusate was determined. The quantity of uranium in the exposed rat hemisphere, which appeared to be significantly higher than that in the control rats, was measured. Finally, the possible transfer of the perfused uranium not only in the vascular space but also in the brain parenchyma is discussed.
