Anemia of Prematurity - Portal Neonatal

Syringomyelia, the common finding associated with CM, is derived from the Greek words, syrinx
(meaning tube or pipe) and muelos (meaning marrow). Estienne, from France, first described the
spinal cord cavitation called syringomyelia in human cadavers in 1546. In 1824, Charles Ollivier
d'Angers provided the very descriptive name syringomyelia to the cylindrical dilatation of the spinal
cord, which in his illustrative case report, communicated with the fourth ventricle. In 1892, Abbe and
Coley from New York performed a myelotomy to drain the syrinx cavity. This was the first recorded
surgical procedure to treat syringomyelia.
Hindbrain malformations are the leading cause of syringomyelia. This cavitation of the spinal cord
usually is gradually progressive and can cause neurologic deterioration over time. The fluid in the
syrinx is identical to the CSF found elsewhere in the subarachnoid space; therefore, theories based
on aberrant CSF physiology are invoked to explain the relationship of syringomyelia in patients with
CM II. Nevertheless, the pathophysiologic mechanisms that cause these 2 disorders are not well
understood. Many excellent theories have been suggested, however, none have been conclusively
proven or universally accepted. Examination of the spinal cord in many neonates with
myelomeningocele reveals atrophic or poorly developed anterior horn cells, incomplete posterior
horns, and small nerve roots.
Initial examination
The initial neurologic examination of a neonate born with a neural tube defect should focus on the
neurologic sequelae of the NTD. Specifically, evaluate (1) site and level of the lesion, (2) motor and
sensory level, (3) presence of associated hydrocephalus, (4) presence of associated symptomatic
hindbrain herniation (eg, CM II), and (5) presence of associated orthopedic deformity.
The lesion is first examined after the birth of a neonate. Myelomeningocele is a consequence of failed
closure of the dorsal neural tube. Thus, the lesion appears as a red, raw neural plate structure devoid
of dura and skin covering. The sac comprising arachnoid laced with thin, fragile vessels can be filled
with CSF escaping from the central canal. A meningocele, in contradistinction, does not have neural
tissue in the sac and usually has a nearly complete skin covering.
Open neural tube defects should be immediately covered with a saline-moistened sponge to avoid
rupture of the sac and drying of the exposed neural placode. The neonate is maintained and
examined in the prone or lateral recumbent position. An IV is placed, and feedings are held until a full
assessment can be completed. The neonate is treated with systemic antibiotics consisting of
ampicillin at meningitic doses and gentamicin. Common neonatal organisms, such as group B
streptococci, and nosocomial organisms must be prevented from entering the CSF, especially
through a leaking myelomeningocele.
The neonatologist, pediatric geneticist, pediatric neurosurgeon, and pediatric orthopedist should
immediately evaluate the child. Possible cardiac abnormalities are evaluated with ultrasound. An
initial ultrasound of the head to evaluate for hydrocephalus also may be performed. Urologic
examination by ultrasound followed by a complete pediatric urologic evaluation may be performed
initially or at a later date. Orthopedic evaluation is performed shortly before discharge, as up to 10%
of neonates with an NTD may have hip dislocations. In addition, presence of a varus or valgus
extremity disorder is documented. A higher motor level lesion, such as L3-L4, can predispose some
children to hip dislocations due to the unopposed hip flexors.
The pediatric neurosurgeon carefully evaluates the patient to assess the site and type of lesion,
including assessment of lower extremity function. Evaluate the symmetry of the motor and sensory
levels affected by the NTD. Flaccid paralysis below the L4 level may reveal a strong psoas, but not
hip adduction, knee hyperextension, or foot inversion deformities. Flaccid paralysis of the foot with a
weak gastrocnemius-soleus complex may result in foot dorsiflexion deformities.
Attention to the anus helps to assess sacral nerve root function. Flaccid musculature in the S2-4
region often presents with a flat buttocks, absence of a well-developed gluteal cleft, and a patulous
anus with no anal wink. The thoracic or lumbar region may have a large hump due to kyphosis or
scoliosis of the spine; this can be so severe that it impedes the ability to place skin flaps over the NTD