Brain & development
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Brain & development · Sep 2009
Vascular endothelial growth factor in neonates with perinatal asphyxia.
Vascular endothelial growth factor (VEGF) is a polypeptide growth factor that is activated by tissue hypoxia. The role of VEGF in perinatal asphyxia in human neonates is yet to be clarified. In infants who develop moderate to severe acute hypoxic ischemic encephalopathy (HIE) it is crucial to clearly understand physiologic and biochemical changes that accompany HIE before a novel treatment can be developed. ⋯ This study indicates that VEGF is increased in cord blood of neonates following birth asphyxia, and that VEGF is specifically most increased in infants who later developed encephalopathy. Further studies are required to determine the role of VEGF in brain insult. Such studies will help determine whether a therapeutic role for VEGF or VEGF inhibitors can exist for HIE infants.
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Brain & development · Sep 2009
Changing ictal-onset EEG patterns in children with cortical dysplasia.
Cortical dysplasia (CD) is intrinsically epileptogenic. We hypothesize that CDs clinically emerging in the early developing brain tend to extend into multifocal or larger epileptic networks to pronounce intractability in contrast to CDs which clinically emerge at a later age. ⋯ Ictal-onset EEG patterns change over time in children with early seizure onset and intractable epilepsy caused by CD. Younger epileptic children with CD more frequently have multifocal epileptogenic foci or larger epileptogenic foci. Early resection of CD, guided by MRI, MEG, and intracranial video EEG, resulted in seizure freedom despite changes in ictal-onset EEG patterns.
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Apoptosis occurs physiologically in the mammalian brain during the period of the growth spurt, which in human starts in the 3rd trimester of gestation and ends by the third year of life. Environmental factors can interact with programmed cell death mechanisms to increase the number of neurons undergoing apoptosis and thus produce neuropathological sequelae in the brain. In a series of studies it could be shown that classes of drugs which block N-methyl-D-aspartate (NMDA) glutamate receptors, promote gamma-aminobutyric-acid (GABA(A)) receptor activation or block voltage gated sodium channels, when administered to immature rodents during the period of the brain growth spurt, trigger widespread apoptotic neurodegeneration throughout the developing brain. ⋯ Pathomechanisms involved in the proapoptotic action of sedative and anticonvulsant drugs and oxygen include decreased expression of neurotrophins, inactivation of survival signaling proteins, activation of inflammatory cytokines as well as oxidative stress. These findings raise concerns pertaining to the treatment of infants and young children with sedative and anticonvulsant drugs and premature infants with oxygen. The experimental findings imply that new approaches should be developed for patients within these vulnerable age groups.
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Brain & development · Jun 2009
Changes in cerebral oxygenation and hemodynamics during cranial ultrasound in preterm infants.
To evaluate whether application of a transducer on the anterior fontanelle during cranial ultrasound (US) examination effects cerebral hemodynamics and oxygenation in preterm infants. STUDY DESIGN*: During cranial US examination, changes in cerebral blood oxygenation (cHbD) and cerebral blood volume (CBV) were assessed using near infrared spectrophotometry (NIRS) in 76 infants (GA 30.7 (4.1)wk, BW 1423 (717)g) within two days after birth. Ten of these infants (GA 29.1 (1.6)wk, BW 1092 (455)g) were studied again at a postnatal age of one week. RESULTS*: We obtained stable and consistent NIRS registrations in 54 infants within the first two days after birth. Twenty-eight of these infants showed a decrease in cHbD (0.59 (0.54) micromol/100g) during the scanning procedure while CBV did not change. Twenty-four infants showed no changes in NIRS and 2 infants showed an atypical NIRS response during cranial US examination. At the postnatal age of one week, stable and consistent NIRS registrations were obtained in 7 infants. None of these infants showed changes in NIRS variables during cranial US examination. ⋯ Application of an US transducer on the anterior fontanelle causes changes in cerebral oxygenation and hemodynamics in a substantial number of preterm infants. ( *values are expressed as median (interquartile range)).
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Brain & development · Jun 2009
Case ReportsUnilateral hypoglossal nerve palsy due to neurovascular conflict in a child.
A neurovascular conflict (NC) consists of a pathological contact between a vessel, generally an artery, and the root entry zone of a cranial nerve close to the brainstem. Even if NC of the V, VII and IX cranial nerve have been rarely described, to the best of our knowledge there is no report about the XII cranial nerve NC in the paediatric age. ⋯ The differential diagnosis of a peripheral unilateral cranial nerve palsy should include, even if rare in children, a neurovascular conflict. In this case a complete neuroimaging study is indicated.