Leukomalacia, Periventricular: Degeneration of white matter adjacent to the CEREBRAL VENTRICLES following cerebral hypoxia or BRAIN ISCHEMIA in neonates. The condition primarily affects white matter in the perfusion zone between superficial and deep branches of the MIDDLE CEREBRAL ARTERY. Clinical manifestations include VISION DISORDERS; CEREBRAL PALSY; PARAPLEGIA; SEIZURES; and cognitive disorders. (From Adams et al., Principles of Neurology, 6th ed, p1021; Joynt, Clinical Neurology, 1997, Ch4, pp30-1)Periventricular Nodular Heterotopia: A disorder resulting from a defect in the pattern of neuronal migration in which ectopic collections of neurons lie along the lateral ventricles of the brain or just beneath, contiguously or in isolated patches.Cerebral Ventricles: Four CSF-filled (see CEREBROSPINAL FLUID) cavities within the cerebral hemispheres (LATERAL VENTRICLES), in the midline (THIRD VENTRICLE) and within the PONS and MEDULLA OBLONGATA (FOURTH VENTRICLE).Echoencephalography: Use of reflected ultrasound in the diagnosis of intracranial pathologic processes.Infant, Newborn: An infant during the first month after birth.Encephalomalacia: Softening or loss of brain tissue following CEREBRAL INFARCTION; cerebral ischemia (see BRAIN ISCHEMIA), infection, CRANIOCEREBRAL TRAUMA, or other injury. The term is often used during gross pathologic inspection to describe blurred cortical margins and decreased consistency of brain tissue following infarction. Multicystic encephalomalacia refers to the formation of multiple cystic cavities of various sizes in the cerebral cortex of neonates and infants following injury, most notably perinatal hypoxia-ischemic events. (From Davis et al., Textbook of Neuropathology, 2nd ed, p665; J Neuropathol Exp Neurol, 1995 Mar;54(2):268-75)Infant, Premature: A human infant born before 37 weeks of GESTATION.Infant, Premature, DiseasesCerebral Palsy: A heterogeneous group of nonprogressive motor disorders caused by chronic brain injuries that originate in the prenatal period, perinatal period, or first few years of life. The four major subtypes are spastic, athetoid, ataxic, and mixed cerebral palsy, with spastic forms being the most common. The motor disorder may range from difficulties with fine motor control to severe spasticity (see MUSCLE SPASTICITY) in all limbs. Spastic diplegia (Little disease) is the most common subtype, and is characterized by spasticity that is more prominent in the legs than in the arms. Pathologically, this condition may be associated with LEUKOMALACIA, PERIVENTRICULAR. (From Dev Med Child Neurol 1998 Aug;40(8):520-7)Brain Diseases: Pathologic conditions affecting the BRAIN, which is composed of the intracranial components of the CENTRAL NERVOUS SYSTEM. This includes (but is not limited to) the CEREBRAL CORTEX; intracranial white matter; BASAL GANGLIA; THALAMUS; HYPOTHALAMUS; BRAIN STEM; and CEREBELLUM.Cerebral Hemorrhage: Bleeding into one or both CEREBRAL HEMISPHERES including the BASAL GANGLIA and the CEREBRAL CORTEX. It is often associated with HYPERTENSION and CRANIOCEREBRAL TRAUMA.Hypoxia-Ischemia, Brain: A disorder characterized by a reduction of oxygen in the blood combined with reduced blood flow (ISCHEMIA) to the brain from a localized obstruction of a cerebral artery or from systemic hypoperfusion. Prolonged hypoxia-ischemia is associated with ISCHEMIC ATTACK, TRANSIENT; BRAIN INFARCTION; BRAIN EDEMA; COMA; and other conditions.Gestational Age: The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.Oligodendroglia: A class of large neuroglial (macroglial) cells in the central nervous system. Oligodendroglia may be called interfascicular, perivascular, or perineuronal (not the same as SATELLITE CELLS, PERINEURONAL of GANGLIA) according to their location. They form the insulating MYELIN SHEATH of axons in the central nervous system.Bronchopulmonary Dysplasia: A chronic lung disease developed after OXYGEN INHALATION THERAPY or mechanical ventilation (VENTILATION, MECHANICAL) usually occurring in certain premature infants (INFANT, PREMATURE) or newborn infants with respiratory distress syndrome (RESPIRATORY DISTRESS SYNDROME, NEWBORN). Histologically, it is characterized by the unusual abnormalities of the bronchioles, such as METAPLASIA, decrease in alveolar number, and formation of CYSTS.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.Nerve Fibers, Myelinated: A class of nerve fibers as defined by their structure, specifically the nerve sheath arrangement. The AXONS of the myelinated nerve fibers are completely encased in a MYELIN SHEATH. They are fibers of relatively large and varied diameters. Their NEURAL CONDUCTION rates are faster than those of the unmyelinated nerve fibers (NERVE FIBERS, UNMYELINATED). Myelinated nerve fibers are present in somatic and autonomic nerves.Developmental Disabilities: Disorders in which there is a delay in development based on that expected for a given age level or stage of development. These impairments or disabilities originate before age 18, may be expected to continue indefinitely, and constitute a substantial impairment. Biological and nonbiological factors are involved in these disorders. (From American Psychiatric Glossary, 6th ed)Brain Damage, Chronic: A condition characterized by long-standing brain dysfunction or damage, usually of three months duration or longer. Potential etiologies include BRAIN INFARCTION; certain NEURODEGENERATIVE DISORDERS; CRANIOCEREBRAL TRAUMA; ANOXIA, BRAIN; ENCEPHALITIS; certain NEUROTOXICITY SYNDROMES; metabolic disorders (see BRAIN DISEASES, METABOLIC); and other conditions.Infant, Very Low Birth Weight: An infant whose weight at birth is less than 1500 grams (3.3 lbs), regardless of gestational age.Midline Thalamic Nuclei: Small, nonspecific nerve cells scattered in the periventricular GRAY MATTER, separating the medial part of the thalamus from the EPENDYMA of the THIRD VENTRICLE. The group includes the paraventricular nucleus, paratenial nucleus, reuniens nucleus, rhomboidal nucleus, and subfascular nucleus.Intracranial Hemorrhages: Bleeding within the SKULL, including hemorrhages in the brain and the three membranes of MENINGES. The escape of blood often leads to the formation of HEMATOMA in the cranial epidural, subdural, and subarachnoid spaces.Infant, Extremely Low Birth Weight: An infant whose weight at birth is less than 1000 grams (2.2 lbs), regardless of GESTATIONAL AGE.Infant, Low Birth Weight: An infant having a birth weight of 2500 gm. (5.5 lb.) or less but INFANT, VERY LOW BIRTH WEIGHT is available for infants having a birth weight of 1500 grams (3.3 lb.) or less.Gliosis: The production of a dense fibrous network of neuroglia; includes astrocytosis, which is a proliferation of astrocytes in the area of a degenerative lesion.Premature Birth: CHILDBIRTH before 37 weeks of PREGNANCY (259 days from the first day of the mother's last menstrual period, or 245 days after FERTILIZATION).Respiratory Distress Syndrome, Newborn: A condition of the newborn marked by DYSPNEA with CYANOSIS, heralded by such prodromal signs as dilatation of the alae nasi, expiratory grunt, and retraction of the suprasternal notch or costal margins, mostly frequently occurring in premature infants, children of diabetic mothers, and infants delivered by cesarean section, and sometimes with no apparent predisposing cause.Choristoma: A mass of histologically normal tissue present in an abnormal location.Anterior Thalamic Nuclei: Three nuclei located beneath the dorsal surface of the most rostral part of the thalamus. The group includes the anterodorsal nucleus, anteromedial nucleus, and anteroventral nucleus. All receive connections from the MAMILLARY BODY and BRAIN FORNIX, and project fibers to the CINGULATE BODY.Filamins: A family of crosslinking filament proteins encoded by distinct FLN genes. Filamins are involved in cell adhesion, spreading, and migration, acting as scaffolds for over 90 binding partners including channels, receptors, intracellular signaling molecules and transcription factors. Due to the range of molecular interactions, mutations in FLN genes result in anomalies with moderate to lethal consequences.Intensive Care Units, Neonatal: Hospital units providing continuing surveillance and care to acutely ill newborn infants.Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Kisspeptins: Intercellular signaling peptides that were originally characterized by their ability to suppress NEOPLASM METASTASIS. Kisspeptins have since been found to play an important role in the neuroendocrine regulation of REPRODUCTION.Myelin Basic Protein: An abundant cytosolic protein that plays a critical role in the structure of multilamellar myelin. Myelin basic protein binds to the cytosolic sides of myelin cell membranes and causes a tight adhesion between opposing cell membranes.Hyperoxia: An abnormal increase in the amount of oxygen in the tissues and organs.Ethamsylate: Benzenesulfonate derivative used as a systemic hemostatic.Hydrocephalus: Excessive accumulation of cerebrospinal fluid within the cranium which may be associated with dilation of cerebral ventricles, INTRACRANIAL HYPERTENSION; HEADACHE; lethargy; URINARY INCONTINENCE; and ATAXIA.Retrospective Studies: Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.Animals, Newborn: Refers to animals in the period of time just after birth.Preoptic Area: Region of hypothalamus between the ANTERIOR COMMISSURE and OPTIC CHIASM.