Pediatric Neurosurgical Surgery
The Pediatric Neurosurgical Service is an integral part of the Perinatal Center at the Weill Cornell. The Pediatric Neurosurgical Service is involved with interpretation of prenatal studies, prenatal parental consultations, and postnatal care of children with congenital malformations of the brain or spinal cord, also called the central nervous system (CNS). Pediatric Neurosurgical assessment is intended to offer parents a basis for better understanding the impact of the prenatal diagnosis of a congenital malformation. This education becomes essential in making decisions regarding the child's well being, selecting appropriate postnatal care, and planning for the birth of a child with some potential of disability. The numbers of congenital malformations that may affect the fetus are numerous, but many offer the opportunity for neurosurgical involvement with the potential for improving the long-term well being of the unborn child.
CNS Congenital Malformations
Hydrocephalus is the most common condition affecting the central nervous system of the unborn child. Normally, the cerebrospinal fluid (CSF) -- the fluid naturally found within the brain -- flows in a continuous fashion through compartments (ventricles) of the brain to the surface where the fluid gets reabsorbed into the blood stream. Any alteration of the normal circulation of CSF results in hydrocephalus. The most apparent manifestation of hydrocephalus in the fetus is an increase in the size of the ventricles and the head circumference. A blockage of the CSF circulation occurs either within the ventricles (noncommunicating hydrocephalus) or outside the ventricles (communicating hydrocephalus). Hydrocephalus can be caused by primary malformations of the brain such as aqueductal stenosis or is secondary to other lesions including congenital cysts, spinal dysraphism (see below), or hemorrhage. There are very effective treatment alternatives for children with hydrocephalus which have the potential of restoring normal function of the brain. These treatment options are all limited to the postnatal time period involving either a shunt or a third ventriculostomy. Treatment is based upon the cause of hydrocephalus and whether the type of hydrocephalus is communicating or noncommunicating. The eventual outcome of children with hydrocephalus is most strongly correlated with the cause of hydrocephalus.
Spinal Dysraphism (Myelodysplasia)
Congenital malformations of the spine, spina bifida, result in either open neural tube defects (myelomeningocele) or closed neural tube defects (tethered spinal cord, lipoma, etc.). Malformations of the spine are the second most common type of congenital disorder of the central nervous system diagnosed in the fetus. The incidence of myelodysplasia has decreased dramatically over the past several decades with the increasing use of pregestational folate supplementation. Spina bifida is accurately diagnosed with prenatal ultrasonography and sometimes confirmed with prenatal magnetic resonance imaging (MRI). The type of spinal dysraphism is widely varied, with the ultimate fate and prognosis of the child being dictated by the type of congential malformation, the location of the malformation, and any associated malformations of the central nervous system. Depending on the type of malformation, the child may require urgent postnatal surgery to repair the defect (myelomeningocele) or elective repair of a tethered spinal cord (lipoma). Children with the most common form of open neural tube defect, called myelomeningocele, have a high likelihood of having hydrocephalus (see above). The long-term outcome of children with spina bifida can range from a normal neurologic exam and functional status to one of significant disability with limited motor function of the legs and abnormal bladder function.
Intracranial Congenital Cysts
Congential cysts involving the brain are most commonly called arachnoid cysts. These cysts are fluid-filled structures containing normal fluid found in and around the brain called cerebrospinal fluid (CSF). The cyst can occur in different locations inside the head and result in either local compression of the brain with or without secondary hydrocephalus (see above). Most cysts are treated by way of surgically opening or fenestrating the cyst into the normal fluid-filled containers of the brain. This surgical procedure allows spontaneous restoration of flow and cessation of cyst growth. These procedures are typically performed on an elective basis in the postnatal time period. With the advent of endoscopic techniques, many of these children today avoid the implantation of shunts with the use of a minimally invasive technique for cyst fenestration. The long-term outcome of these children is dictated principally by the location and size of the cyst, with many children having full capacity with few limitations.
Congenital Brain Malformations
A wide variety of malformations of the brain can be detected in utero. These vary widely in the expected outcome. Dandy-Walker malformation, holoprosencephaly, and hydranencephaly are some of the more common primary malformations of the brain that are detected. Cephaloceles are also detected in utero. There are two main varieties of cephalocele: encephaloceles contain brain structure while meningoceles only contain cerebrospinal fluid. In both conditions, there is incomplete bone formation over the brain that results in various outpouchings of the brain and fluid. The results from the ultrasound, prenatal MRI scan, amniocentesis (cytogenetic analysis), and identification of any other associated malformations are all used in estimating a prognosis with respect to functional outcome. Depending on the type of malformation, the neurosurgical intervention may be done on an urgent or elective basis after delivery.
All prospective parents of the unborn child with the diagnosis of a malformation of the central nervous system are offered an evaluation by the Pediatric Neurosurgical Service as a component of the Perinatal Center at Weill Cornell. These consultations are intended to offer parents a clear understanding of the malformation, the potential functional implications, and the potential role of surgical intervention.
For appointments and information, visit the Weill Cornell Brain and Spine Center website.