Subependymal Germinal Matrix Research Articles

Intraventricular Hemorrhage in Full‐term Neonates

The neuropathological and general pathological features of intraventricular hemorrhage are described in 32 neonates who had been born at term. Although the most common site of bleeding was the choroid plexus, a significant minority occurred in the subependymal germinal matrix. Associated neuropathological findings included meningeal venous congestion, periventricular white-matter necrosis and subarachnoid hemorrhage. Pulmonary hemorrhages, hyaline membranes and congenital heart-defects were common. Most of the infants had low Apgar scores at birth and lived for less than two days. Significant neurological findings included hypotonia, hyporeflexia, decreased activity level and seizures. Clinical signs had not been reliable enough to differentiate distressed neonates with intraventricular hemorrhage from those without. Intraventricular hemorrhage should be considered in both term and premature neonates who sustain perinatal asphyxia or who later develop evidence of neurological deterioration.

Seizures, hypoxic-ischemic brain injury, and intraventricular hemorrhage in the newborn.

The review deals with neonatal seizures, perinatal hypoxic-ischemic brain injury, and neonatal intraventricular hemorrhage. neonatal seizures are the most prominent signals of the largest number of neonatal neurological disorders. The convulsive phenomena may be subtle. The predominant etiological process is hypoxic-ischemic encephalopathy. Prognosis is related primarily to the neurological disease responsible for the seizures. Treatment may be specific for the underlying disorder (e.g., glucose or calcium) or less specific (i.e., therapy with anticonvulsant drugs). Prompt control of the seizures is important to avoid brain injury secondary to the effects of the seizures on ventilation, perfusion, and brain metabolism. Hypoxic-ischemic encephalopathy in the newborn most often is a consequence of intrauterine asphyxia. Diagnosis depends primarily on recognition of the clinical syndrome but also on a variety of neurodiagnostic techniques, including radionuclide and CT brain scans. Prognosis is estimated best by a combination of clinical analysis and specialized neurodiagnostic studies. management is based principally on vigorous support, particularly of ventilation and perfusion, maintenance of adequate glucose influx, and control of seizures. Intraventricular hemorrhage is the most common type of neonatal intracranial hemorrhage. The neuropathology is characterized by bleeding from capillaries of the subependymal germinal matrix. Secondary rupture of the ependymal lining then causes intraventricular hemorrhage. Pathogenesis relates to the anatomy of the germinal matrix, the distribution and regulation of cerebral blood flow, and the structure and vulnerability of periventricular capillaries. Precise diagnosis requires a brain imaging procedure; portable, real-time ultrasound is the preferred approach for critically ill infants. Prognosis relates to the severity of the hemorrhage as well as any preceding hypoxic-ischemic insults and the subsequent occurrence of hydrocephalus. Choice of therapy for posthemorrhagic ventricular dilatation depends upon severity and rapidity of progression and ranges from close observation only to ventriculoperitoneal shunting.

The role of sonography and the radiologist-ultrasonologist in the detection and follow-up of intracranial hemorrhage in the preterm neonate.

Intracranial hemorrhage (ICH), specifically hemorrhage in the subependymal germinal matrix, is a common disorder affecting preterm neonates. The authors discuss the relative virtues and limitations of portable, real-time ultrasonography (US) and computed tomography (CT) in detection and follow-up of sequelae of this disorder. The importance of cooperative effort on the part of the radiologist-ultrasonologist, neonatologist, pediatric neurologist, neurosurgeon and ultrasound technologist is emphasized.

Intraventricular hemorrhage and hydrocephalus in premature newborns: a prospective study with CT.

In a prospective study, 100 premature infants were studied with computed tomography (CT) brain scans within the first week of life. In 44 of these,hemorrhages originated from the subependymal germinal matrix, and ranged in severity from isolated germinal matrix hemorrhages to blood-filled, dilated ventricles with extension of hemorrhage into the brain parenchyma. A system of grading the severity of hemorrhage was developed. Grades I and II hemorrhages resolved spontaneously and grades III and IV were associated with progressive hydrocephalus. Asymptomatic hemorrhages that would not have been diagnosed on clinical grounds were detected by CT. This study offers a clearer understanding of the true incidence and natural history of cerebroventricular hemorrhage and associated hydrocephalus in premature neonates and may clarify etiologic factors and identify children at risk for subsequent neurologic abnormalities.

The fine structure of blood vessels of the telencephalic germinal matrix in the human fetus.

AbstractBlood vessels of the human telencephalic germinal matrix during the tenth through the twenty‐second week of gestation have been examined by light and electron microscopy. In all fetuses studied the ependymal and sub‐ependymal zones of the germinal matrix have a prominent vascular network. During the tenth and twelfth weeks of gestation, the endothelial cells are plump and display numerous organelles, junctional complexes, conspicuous luminal microvilli and stub‐like abluminal projections. Coated and micropinocytotic vesicles were found both in the cytoplasm and on luminal and abluminal surfaces. In endothelial cells intracytoplasmic, membrane‐limited, rod‐shaped bodies were frequently observed. These bodies have been linked to endothelial thromboplastic and clotting activities and related to abnormal clotting status. Their role in the pathogenesis of subependymal germinal matrix hemorrhage in premature infants remains unknown. Pericytes apposing the endothelial cells were recognized in all gestational periods. The endothelial basal lamina and astrocytic end‐feet are ill defined, and the extracellular space is pronounced. By the fifteenth and seventeenth weeks of gestation the endothelial cells are still large and now possess more numerous luminal microvilli and abluminal projections. At this stage the pericytes, basal lamina and astrocytic end‐feet are all well developed, resulting in a decrease in the surrounding extracellular space. By the twenty‐second week the endothelial cells possess few luminal and abluminal projections and the associated basal lamina, glia, pericytes and extracellular compartment appear mature. The relationship of the germinal matrix vasculature to the pathogenesis of subependymal hemorrhage is discussed.

Subependymal germinal matrix and intraventricular hemorrhage in premature infants: diagnosis by CT

Hemorrhage into the subependymal germinal matrix with rupture into the cerebral ventricles causes significant morbidity and mortality in premature infants. CT brain scanning was performed on eight premature infants on whom autopsy confirmation was obtained. Excellent sensitivity and accuracy in detecting germinal matrix hemorrhage and intraventricular hemorrhage were found. Germinal matrix hemorrhage appears as a parenchymal collection of blood adjacent to the foramen of Monroe and has a convex margin laterally. CT scanning of living premature infants is feasible in diagnosing nonfatal episodes of germinal matrix and intraventricular hemorrhage as well as subsequent development of hydrocephalus and porencephaly.