Anemia of Prematurity - Portal Neonatal

ain. MRI is also useful during follow-up. In any newly diagnosed case of cerebral palsy, MRI
should be considered, since it may help in establishing the cause. However, the interpretation
of MRI in infants requires considerable expertise.
• Echocardiography: In infants requiring inotropic support, echocardiography (ECHO) helps to
define myocardial contractility and the existence of structural heart defects, if any.
Other Tests:
• Choice of tests depends on the evolution of symptoms.
• EEG: Even in the absence of obvious seizures, EEG should be obtained early, particularly in
moderately severe and severe cases. In infants on assisted ventilation, drugs such as
pancuronium bromide (for muscle paralysis) and morphine (for sedation) may mask the
symptoms of early seizures.
o Generalized depression of the background rhythm and voltage, with varying degrees
of superimposed seizures, are the early findings.
o A burst suppression pattern (ie, isoelectric EEG) is particularly ominous. If clinically
correlated, this EEG pattern usually is regarded as representing irreversible brain
injury, akin to the legal definition of brain death.
• Special sensory evaluation: Screening for hearing is now mandatory in many states in the
United States; in infants with HIE, a full-scale hearing test is preferable because of an
increased incidence of deafness among HIE infants requiring assisted ventilation.
• Retinal and ophthalmic examination: This examination may be valuable, particularly as part of
an evaluation for developmental abnormalities of the brain.
Histologic Findings: The neuropathology of neonatal HIE varies considerably. Depending on the
cause of HIE, more than one type of lesion may be seen in a single patient. Brain maturity at the time
of the insult is an important factor in the evolution of neuropathology. In the preterm infant, the
damage is at the germinal matrix area, leading to hemorrhage in the subependymal region, the
germinal matrix, or the intraventricular region. In the full-term infant, the pathology is mainly in the
cerebral cortex and in the basal ganglia. Selective neuronal necrosis is the most common
neuropathology. Major sites of necrosis are the cerebral cortex, diencephalon, basal ganglia, brain
stem, and cerebellum. The injuries correlate with clinical symptoms, such as disturbances of
consciousness, seizures, hypotonia, oculomotor-vestibular abnormalities, and feeding difficulties.
• Parasagittal cerebral necrosis: This lesion is bilateral, usually symmetrical, and occurs in the
cerebral cortex and the subcortical white matter, especially in the parietooccipital sides. These
regions represent the border zones of perfusion from major cerebral arteries.
• Status marmoratus: In this lesion, the basal ganglia, especially the caudate nucleus, putamen,
and thalamus, demonstrate neuronal loss, gliosis, and hypermyelination, leading to a marble
white discoloration of these regions. This is the least common type of neuropathology, and its
full evolution may take months to years.
• Focal and multifocal ischemic brain necrosis: These lesions are relatively large, localized
areas of necrosis of cerebral parenchyma, cortex, and subcortical white matter. The most
frequently affected region is the zone perfused by the middle cerebral artery.
• Periventricular leukomalacia: This lesion is characterized by necrosis of white matter, which is
seen grossly as white spots adjacent to the external angle of the lateral ventricles. These sites
are the border zones between penetrating branches of major cerebral arteries. These lesions
are more common in preterm than in term infants.