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New Treatments in Newborn Neurology

Hypoxic ischemic injury is a major cause of mortality and morbidity. Usually it is a combination of hypoxia and ischemia that basically results in decreased supply of oxygen to the tissue, and that’s the cause of it. Hypercapnia and acidosis also contribute significantly.

The most common causes include intrauterine asphyxiation secondary to placenta abruptio. This is a very common cause of bleeding just prior to labor or delivery process, and is usually associated with a lot of abdominal pain as well. Respiratory distress such as those patients who had meconium staining or hyaline membrane disease.

In the next three days they go back into a state of decreased level of consciousness, either become stuporous or comatose again. Again having respiratory arrests. They now begin to show some brainstem dysfunction. Some of the clinical manifestations of these five different syndromes - we’ll talk first about the neuronal necrosis - they tend to have stupor of comatose. They have seizures, hypotonic, they have oculomotor disturbances as well and they have depressed lower brainstem function. Long term sequelae include mental retardation, spastic quadriparesis, seizure disorders, some of them may develop ataxia. They may have bulbar or pseudobulbar palsy. And ADHD.

EEG pattern also gives you an indication of how severe the injury has been. Having birth suppression or persistent marked suppression or an isolette, electric EEG would signify diffuse cortical neuronal necrosis. Having positive vertex and rolandic sharp waves in the neonatal period is suggestive of periventricular leukomalacia. Focal blebs, would indicate focal ischemic necrosis.

In terms of their intellectual function, this was a question that actually came out in terms of trying to differentiate between those who had spastic diplegia and quadriplegia, in terms of their IQ. They didn’t give numbers but the majority of the kids that have spastic diplegia will have a more or less normal IQ. Normal IQ actually being between 85-100, 70 is still not two standard deviations below.

Talk now about intracranial hemorrhage. The location of intracranial hemorrhage is also very important. In full term they tend to get subdurals, however it is really uncommon, but it is much more common in full terms as opposed to pre-terms if it does occur. Primary subarachnoid hemorrhage again is much more common in preterm as opposed to full term. Intracerebellar hemorrhage tends to occur more in preterm infant as opposed to full term.

In terms of subdural, usually what happens is that the infant is usually large and has a difficult delivery and the birth canal is small, so the mother may have CPD, cephalic pelvic disproportion. The skull is usually very compliant, especially if it is in a preterm child and then the pelvic structure is usually rigid. The two factors that are involved in this bleeding are usually precipitous labor or prolonged labor. So the extremes cause problems. So if the labor is very short in duration, for example this mother delivered eight children.

Subarachnoid hemorrhage. They tend to present with seizures in the first 72 hours. You need to watch for hydrocephalus in these patients. They are associated with mild hypoxic ischemic injury. Remember, as I said earlier, especially in the preterm, their white matter is not as compliant as ours, obviously, as we grow older.

In terms of intraparenchymal hemorrhage, underlying factors; AVM is rare in this age group. They may have a vitamin K deficiency or it may be an extension of intraventricular hemorrhage.

Cephalhematoma. Now these are outside the brain itself and these are more related to scalp lesions. What happens is you have blood in the subperiosteal space and usually related to birth trauma, again from molding or from prolonged delivery.

There are three main neurological syndromes, in terms of preterm intraventricular hemorrhage. The catastrophic ones usually involve within minutes to hours. They may be depressed, in terms of their consciousness or alertness. They end up having apneic episodes and they usually have tonic seizures and will be noted to be quite flaccid, have a flaccid quadriparesis. The second type is that of a slow deterioration that may take hours to days to occur, and there are some - in about 10 to 20% of them - that may be clinically silent. Those are usually associated with very small IVH bleeds.

In terms of the sequelae, those that have - in terms of the severity of the hemorrhage - severe to severe plus hemorrhagic PVL, there’s about a 70% mortality rate. Another 80% of them will end up having hydrocephalus and therefore required shunt, and long term sequelae in terms of mental retardation, behavioral disorders, learning difficulties, etc. is pretty high. If it’s just mild to moderate chances of a near normal life is very possible.

Neonatal seizures. The problem with this is it is very difficult to diagnose. They are based, basically just like any other seizures, on stereotypic activity and they usually have a normal eye movement. If you really watch the baby closely and actually sit down … actually, Dr. Konigsberger at UMDNJ, from stories I’ve been told, during his younger days would actually sit down by the neonatal isolette and actually just look at the baby for hours to see what exactly is going on. There are basically five clinical patterns, which was put out by Volpe in 2006.

Some other metabolic disturbances that occur, or commonly occur with these infants, especially with preterm infants, is hypoglycemia. You’ve got to be careful and make sure the patient doesn’t have hypocalcemia or hypomagnesemia as well.

One of the more common causes of seizures in this age group, depending on time. If they occur in the first 24 hours, top on your list should always be meningitis and sepsis. The second thing you’ve got to think about is, is the mom receiving any medication that might cause seizures in this neonate. Hypoxic ischemic injury, especially if it was already in utero that it occurred. Intrauterine infections such as TORCH, CMV or herpes. Intraventricular hemorrhage, pyridoxine deficiency.

Galactosemia; it’s an autosomal recessive disorder. The defect is galactose 1 phosphate uridyl transferase deficiency. A percent more of systemic findings, growth failure, mental retardation, cataract formation. This is one cue that should put you to galactosemia. Cataract formation. The other thing that will cause congenital cataract is Rubella embryopathy.

Urea cycle defects; symptoms. They are typically normal in the first few days of life then they present with poor feeding, vomiting, lethargy and may present with seizures. They may also have respiratory problems and bulging fontanelle and hepatomegaly. Later on in life, with adequate treatment, they still end up having developmental disabilities and their hypoammoniemic state.

This is a condition that you need to know about, the transient hyperammonemia of the newborn. It is a fulminant disorder, usually more commonly seen in premature and is seen in the first day of life. This can be fatal. You’ve got to recognize it earlier.