Hydrocephalus Hydrocephalus is not a specific disease; rather, it represents a diverse group of conditions. In the case of myelomeningocele it results from impaired circulation and

SB216763 order absorption of cerebral spinal fluid. Myelomeningocele and cerebral hemorrhage of prematurity are the leading causes.43,44 Hydrocephalus occurs in approximately 85% of children with myelomeningocele and bears little relationship to intelligence.45,46 Generally the chance of developing hydrocephalus is greater in upper lesions. It Inhibitors,research,lifescience,medical is uncommon in the closed forms of spinal dysraphism. Clinical manifestations of hydrocephalus vary with age and include enlargement of the head, vomiting, irritability, and lethargy. Headache may be present in older children. An ultrasound or a computed tomography scan or magnetic resonance imaging (MRI) can confirm the diagnosis. Hydrocephalus does not directly Inhibitors,research,lifescience,medical affect the urologic course of the patient, other than when major intra-abdominal procedures

are performed in the presence of an indwelling ventriculoperitoneal shunt. The risk of infecting the shunt should be considered in these cases. Chiari II Malformation In Chiari II malformation the posterior fossa is small, and the cerebellum, pons, and medulla are displaced to varying degrees into the cervical Inhibitors,research,lifescience,medical canal, leading to a variable degree of compression of the brainstem, which may be caused by an abnormal development of the ventricular system because of the open dysraphism.47 Some element of Chiari II malformation is present in most children with a myelomeningocele. Respiratory and swallowing difficulties associated with Chiari II are the primary Inhibitors,research,lifescience,medical causes of morbidity and mortality in the first 2 decades of life in this group of patients.48 Shunt dysfunction or untreated hydrocephalus can mimic all the symptoms of hindbrain compression. Differential diagnosis has to be made before starting management. The treatment for Chiari II malformations

is surgical decompression of the hindbrain in the cervical canal. Patients with occult Inhibitors,research,lifescience,medical spinal dysraphism or the closed form of neural tube defects rarely have the changes else of the Chiari II malformation, and less than 3% will have caudal descent of the cerebellar tonsils (Chiari I) without any change in the cortical architecture. Tethered Spinal Cord During normal fetal development the bony spine grows at a greater rate than the spinal cord. This difference in rate results in a progressive disparity between the termination of the spinal cord and that of the bony spine. At 8 weeks’ gestation the conus medullaris ends at the coccygeal vertebral level. By 24 weeks’ gestation it lies at the L3–L4 level. Not until approximately 2 months after birth does the conus medullaris come to lie at the permanent adult vertebral level of L1–L2.