Radiological Evaluation of Hypoxic Ischemic Encephalopathy

To compare between Transcranial Ultrasound , MRI and CT in patients with Hypoxic Ischemic Encephalopathyas regards diagnostic accuracy and prognostic value .

* Hypoxic Ischemic Encephalopathy (HIE) is an injury to the brain, occurring in the neonatal period (under 28 days old) in which there is deprivation of oxygen supply to brain. It is a common cause of neonate mortality and developmental psychomotor disorders in the pediatric population worldwide.This is one of the major causes of cerebral palsy." * Hypoxic ischemic encephalopathy (HIE) is one of the most serious birth complications affecting full term infants. It occurs in 1.5 to 2.5 per 1000 live births in developed countries and 2.3-26.5 per 1000 live births in developing countries . The incidence of HIE has not declined even with advances in obstetric care (i.e. fetal monitoring) aimed at preventing the hypoxicischemic event; thus much of the current neonatal research about HIE focuses on minimizing the extent of subsequent brain injury. * HIE is a disorder in which clinical manifestations indicate brain dysfunction.While the exact cause is not always identified, antecedents include cord prolapse, uterine rupture, abruptio placenta, placenta previa, maternal hypotension, breech presentation, or shoulder dystonia. The manifestations of perinatal HIE in early postnatal life include abnormal fetal heart rate tracings, poor umbilical cord gases (pH \< 0.7 or base deficit ≥ 12 mmol/L),low Apgar scores, presence of meconium stained fluid,or the need for respiratory support within the first several minutes of postnatal life. * The infant usually develops seizure within first 24 h of life. Children with periventricular leukomalacia (PVL) may develop spastic CP in the form of diplegia, quadriplegia, or hemiplegia.Involvement of subcortical white matter produces severe mental retardation and impaired vision.Basal ganglia (BG) and thalamic involvement result in extrapyramidal symptoms. Multicystic encephalopathy is associated with quadriplegia, bulbar and choreoathetoid symptoms, microcephaly and mental retardation. Abnormal electroencephalographic (EEG) findings may predict adverse clinical outcome such as long-term neurologic sequelae or impending death. * Multiple neuroimaging techniques are available to visualize brain injury in the neonatal period. Cranial ultrasonography is a helpful noninvasive tool to detect antenatal onset of injury and abnormalities that may mimic HIE. Abnormalities related to HIE can be recognized with ultrasonography as well, but it will take 48-72 h to see these changes develop in the white matter or deep gray nuclei . Magnetic resonance imaging (MRI) which includes diffusion-weighted imaging (DWI) is the preferred imaging modality during the first week after birth to determine the extent of brain injury and predict neurodevelopmental outcome in infants with symptoms of HIE, without its prognostic utility being altered by therapeutic hypothermia . * CT image could be used as important diagnostic indication in the assessment of HIE neonate CT could identify subarachnoid hemorrhage. It is valuable in clinical application