1/91. Characterization of nodular neuronal heterotopia in children.Neuronal heterotopia are seen in various pathologies and are associated with intractable epilepsy. We examined brain tissue from four children with subcortical or periventricular nodular heterotopia of different aetiologies: one with severe epilepsy following focal brain trauma at 17 weeks gestation, one with hemimegalencephaly and intractable epilepsy, one with focal cortical dysplasia and intractable epilepsy, and one dysmorphic term infant with associated hydrocephalus and polymicrogyria. The connectivity of nodules was investigated using histological and carbocyanine dye (DiI) tracing techniques. DiI crystal placement adjacent to heterotopic nodules revealed numerous DiI-labelled fibres within a 2-3 mm radius of the crystals. Although we observed labelled fibres closely surrounding nodules, the majority did not penetrate them. Placement of DiI crystals within nodules also identified a limited number of projections out of the nodules and in one case there was evidence for connectivity between adjacent nodules. The cellular and neurochemical composition of nodules was also examined using immunohistochemistry for calretinin and neuropeptide y (NPY), which are normally expressed in GABAergic cortical interneurons. Within heterotopic nodules from all cases, numerous calretinin-positive neurons were identified, along with a few cell bodies and many processes positive for NPY. Calretinin-positive neurons within nodules were less morphologically complex than those in the cortex, which may reflect incomplete differentiation into an inhibitory neuronal phenotype. There were also abnormal clusters of calretinin-positive cells in the overlying cortical plate, indicating that the migratory defect which produces heterotopic nodules also affects development of the cortex itself. Thus, heterotopic nodules consisting of multiple neuronal cell types are associated with malformation in the overlying cortical plate, and have limited connectivity with other brain regions. This abnormal development of connectivity may affect neuronal maturation and consequently the balance of excitation and inhibition in neuronal circuits, leading to their epileptogenic potential.- - - - - - - - - - ranking = 1keywords = neuronal (Clic here for more details about this article) |
2/91. Periventricular brain heterotopias in a child with adrenocortical insufficiency, achalasia, alacrima, and neurologic abnormalities (Allgrove syndrome).We describe a previously unreported finding of periventricular heterotopias in a brain magnetic resonance imaging (MRI) study, in a girl with adrenocortical insufficiency, alacrima, achalasia, and neurologic deterioration (Allgrove syndrome). This finding could indicate that the underlying mechanism in this syndrome can be traced to the first half of fetal life and also might cause abnormal neuronal migration. This disorder recently has been linked to chromosome 12q13. There could be several explanations for the clinical heterogeneity in this syndrome: a contiguous gene syndrome involving multiple genes, including one whose deletion causes heterotopias, or a deficiency of a gene for a neurotrophic factor active during pre- and postnatal life and responsible for both migration and survival of neurons could be the cause. The identification of the responsible gene(s) will lead to further understanding of this multisystem disorder.- - - - - - - - - - ranking = 32.245197429038keywords = neuronal migration, neuronal, migration (Clic here for more details about this article) |
3/91. Intracranial extracerebral neuroglial heterotopia: A case report and review of the literature.Heterotopic masses of neuroglial tissue are uncommon and most frequently involve extracranial midline structures. We report an unusual case of an intracranial, extracerebral neuroglial heterotopia involving the middle and anterior cranial fossae of a 5-year-old girl who presented with facial asymmetry. The lesion was composed of mature but disorganized gray and white matter admixed with surrounding soft tissues and exhibited histologic features reminiscent of cortical dysplasia. These rare lesions have been postulated to arise from a protrusion of tissue from the neuraxis through a pial defect, from abnormalities in the migration of embryonic neuroepithelial tissue, or from an accessory evagination of the neural tube inferior to the telencephalic vesicles. Regardless of the underlying pathogenic mechanism, these lesions must be histologically distinguished from both teratomas and primary central nervous system neoplasms.- - - - - - - - - - ranking = 0.12267374809921keywords = migration (Clic here for more details about this article) |
4/91. Pituitary adenoma with neuronal choristoma: a report of two rare cases.Two rare cases of pituitary adenoma with neuronal choristoma are described. Both patients were female and presented with features of acromegaly with elevated growth hormone and prolactin levels. Radiologically, both lesions were predominantly intrasellar in location with extension into suprasellar region, but hypothalamus was not involved. Histopathological examination revealed a mixture of chromophobe pituitary adenoma cells and neuronal cells. In both cases, the adenoma component was positive for growth hormone and prolactin. Interestingly, immunopositivity for alpha-subunit, cytokeratin and prolactin was seen in the adenoma and neuronal cells in one case. Our findings support the hypothesis that the neuronal cells possibly arise from adenoma cells as a result of metaplasia.- - - - - - - - - - ranking = 1keywords = neuronal (Clic here for more details about this article) |
5/91. Functional imaging in schizencephaly using [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET) and single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT).We analyzed interictal [18F]fluoro-2-deoxy-D-glucose positron emission tomography (FGD-PET) and single photon emission computed tomography with technetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT) in a 23-year-old female with schizencephaly. She had epilepsy and mild left hemiparesis, but was otherwise developmentally normal. We found the glucose metabolism and perfusion of the wall of the schizencephalic cleft to be identical to those of normal cerebral cortex. The wall of the transcerebral clefts, which were observed to be lined by abnormally organized gray matter as a result of a migration disorder, demonstrated gray matter metabolic activity and perfusion. FDG-PET and HMPAO-SPECT were thus found to be a useful complement to magnetic resonance imaging for evaluating schizencephaly.- - - - - - - - - - ranking = 42.018931453627keywords = migration disorder, migration (Clic here for more details about this article) |
6/91. Congenital thyroid disease revisited: migrational anomalies and dyshormonogenesis.nuclear medicine scintigraphy, in conjunction with other diagnostic tools, plays a vital role in assessing patients with congenital migrational anomalies. We present 5 patients, 4 of whom were hypothyroid and 1 patient who was euthyroid. Scintigraphic and ultrasonographic images were examined and correlated with laboratory results. These patients demonstrate the spectrum of migrational anomalies of the thyroid. nuclear medicine scintigraphy was a valuable aid in establishing the location of the ectopic thyroid as well as its function.- - - - - - - - - - ranking = 0.73604248859525keywords = migration (Clic here for more details about this article) |
7/91. Graves' disease and recurrent ectopic thyroid tissue.Ectopic thyroid tissue is the result of abnormal migration of the gland as it travels from the floor of the primitive foregut to its destined pretracheal position. The prevalence of ectopic thyroid tissue ranges between 7%-10%. patients with ectopic thyroid tissue are usually euthyroid, but can present with signs and symptoms of upper aerodigestive tract obstruction. We report a case in which ectopic mediastinal thyroid tissue was removed surgically because of substernal chest pain. It recurred 9 years later when the patient developed Graves' disease. We propose that the recurrence of the ectopic thyroid tissue was due to the influence of thyroid stimulating immunoglobulins (TSI).- - - - - - - - - - ranking = 0.12267374809921keywords = migration (Clic here for more details about this article) |
8/91. thyrotoxicosis in a patient with submandibular thyroid.Ectopic thyroid glands generally appear in the midline due to abnormal median migration; their presence lateral to the midline is rare. We report the case of a 42-year-old female who presented with symptoms of thyrotoxicosis and an expanding submandibular swelling. Tc-99m-sodium pertechnetate scanning showed thyroid tissue in the left submandibular region, while no thyroid tissue was seen in the normal site. The patient was treated with 10 mCi of 131I and subsequently became euthyroid. literature review revealed seven cases of lateral aberrant thyroid tissue. The theories to explain lateral aberrant thyroid are presented.- - - - - - - - - - ranking = 0.12267374809921keywords = migration (Clic here for more details about this article) |
9/91. Adrenal tissue in the placenta: a heterotopia caused by migration and embolism?Heterotopic adrenal tissue is not uncommon, especially in the urogenital system. Adrenocortical tissue in the placenta, however, is presumably very rare. To our knowledge, four cases have been published. There are several different theories to explain such a heterotopia. According to our findings, an embolic spread of adrenal precursor cells via fetal vascular shortcuts is the most likely mechanism. Apart from that hypothesis, the possibility of a monodermal teratoma as well as of an aberrant differentiation of cells of the extraembryonic mesoderm are considered in the literature.- - - - - - - - - - ranking = 0.49069499239683keywords = migration (Clic here for more details about this article) |
10/91. Bilateral periventricular nodular heterotopia associated with coeliac disease and palatoschisis.periventricular nodular heterotopia (PNH) is considered a distinct entity in relation to the other forms of neuronal migration disorders (NMD), because PNH patients usually have normal neurological and mental examination results. We report the case of a 48-year-old woman with bilateral periventricular nodular heterotopia associated with epilepsy, coeliac disease, palatoschisis and other dysmorphic features. Her intelligence quotient (I.Q.) and the results of a neurological examination were normal, but she suffered from a drug-resistant epileptic syndrome characterised by predominantly generalised and sporadic partial seizures. It has recently been suggested that an X-linked dominant inheritance may play a role in bilateral periventricular nodular heterotopia, and it is thought that a genetic defect is probably responsible for coeliac disease. In our patient, a genetic disorder may have produced both diseases and the dysmorphic syndrome, although the coexistence of PNH, epileptic seizures, coeliac disease and palatoschisis could be coincidental. Further observations are needed to ascertain whether the simultaneous presence of these disorders is simply an unusual association of unrelated pathologies or a new and distinct pathological entity.- - - - - - - - - - ranking = 278.74960980748keywords = neuronal migration disorder, migration disorder, neuronal migration, neuronal, migration (Clic here for more details about this article) |
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