Brain development

Proton MR spectroscopy of the brain allows noninvasive in vivo assessment of metabolites, which may be useful in understanding the biology of malformations of cortical development. The aim of this study was to determine the MR spectroscopic characteristics of polymicrogyria and heterotopia compared with those of normal frontal lobe white matter. We recruited 22 patients with radiographic findings characteristic of polymicrogyria, nine patients with radiographic findings characteristic of heterotopia, and 10 control subjects into the study. The MR imaging technique consisted of high-spatial-resolution axial dual-echo and gradient-echo 3D volume imaging. A single-voxel point-resolved technique (1600/135 [TR/TE]) was used to acquire spectra from the region of neocortical malformation and from frontal lobe white matter in control subjects. The differences in N-acetyl moieties (NA)/creatine (Cr), NA/choline (Cho), and Cho/Cr ratios among patients with heterotopia, those with polymicrogyr...

Neurological findings in a three-year-old child with meroacrania provide new insights into how the nervous system develops and functions in the absence of superior levels of control from the time of origin. The girl is the first child of a non-consanguineous white Brazilian couple, born at term, weighing 2650 g and measuring 44 cm in length. Upon examination at 43 months, she had quadriplegia, global hypotonia with occasional body hypertonia in a decorticate posture, hyperreflexia, ankle clonus, and extensor plantar response. This case allowed us to verify that, in the absence of upper structures and subcortical nuclei, there are clear signs that suggest corticospinal primacy in motor functions without a substitute pathway. Sound orientation responses suggest the independence of the vestibular-acoustic-ocular system, and manifestations of responsiveness to the environment raise questions about consciousness.

Insulin-like growth factors I and II (IGF-I and IGF-II) play an important role in normal growth and brain development and protect brain cells from several forms of injury. The effects of IGFs are mediated by type-I and type-II receptors and modulated by potentially six specific binding proteins that form high-affinity complexes with IGFs in blood and cerebrospinal fluid (CSF) and

Normal brain development throughout childhood and adolescence is usually characterized by decreased cortical thickness in the frontal regions as well as region-specific patterns of increased white matter myelination and volume. We investigated total cerebral volumes, neocortical surface area, and neocortical thickness in 16 children with a neural tube defect, spina bifida myelomeningocele (SB), and 16 age-matched typically developing controls using a semi-automated, quantitative approach to MRI-based brain morphometry. The results revealed no significant group differences in total cerebral volume. However, group differences were observed in the global distribution of distinct tissue classes within the cerebrum: the SB group demonstrated a significant 15% reduction in total white matter and a 69% increase in cerebrospinal fluid, with no differences in total gray matter. Group comparisons of neocortical surface area assessments were significantly smaller in the occipital regions for S...

Background: Several studies have investigated the biochemical remission rate of presurgical somatostatin analogs treatment on acromegaly, but the remission criteria were diversed and the results were contradicting. Objective: Aim of this paper is to provide enhanced evidence for the effectiveness of preoperative SSA treatment to improve on surgical results of macroadenomas in acromegaly. Data source: Literature is cited from the PubMed, Embase and Cochrane Library, dating from December, 1985 to August, 2013. Study eligibility criteria: Eligibility criteria included patients with acromegaly caused by GH-secreting pituitary macroadenomas, patients pretreated with somatostatin analogs versus direct surgery and a stricter remission criteria defined as the GH nadir<1μg/l during an oral glucose tolerance test (OGTT) and the age- and sex- adjusted IGF-1 concentration was normal. Primary end points included Short term and long term postoperative biochemical remission. Study appraisal and...

Across development children show marked improvement in their executive functions (EFs), including the ability to hold information in working memory and to deploy cognitive control, allowing them to ignore prepotent responses in favor of newly learned behaviors. How does the brain support these age-related improvements? Age-related cortical gray-matter thinning, thought to result from selective pruning of inefficient synaptic connections and increases in myelination, may support age-related improvements in EFs. Here we used structural MRI to measure cortical thickness. We investigate the association between cortical thickness in three cortical regions of interest (ROIs), and age-related changes in cognitive control and working memory in 5-10 year old children. We found significant associations between reductions in cortical thickness and age-related improvements in performance on both working memory and cognitive control tasks. Moreover, we observed a dissociation between ROIs typica...

To clarify the evolution of an augmented startle reflex in Tay-Sachs disease and compare the temporal relationship between this reflex and brainstem evoked potentials. Clinical and electrophysiological data from 3 patients with Tay-Sachs disease were retrospectively collected. The augmented startle reflex appeared between the age of 3 and 17 months and disappeared between the age of 4 and 6 years. Analysis of brainstem auditory evoked potentials revealed that poor segregation of peak I, but not peak III, coincided with the disappearance of the augmented startle reflex. A blink reflex with markedly high amplitude was observed in a patient with an augmented startle reflex. The correlation between the augmented startle reflex and the preservation of peak I but not peak III supports the theory that the superior olivary nucleus is dispensable for this reflex. The blink reflex with high amplitudes may represent augmented excitability of reticular formation at the pontine tegmentum in Tay-...