Hydrocephalus and Myelomeningocele

Hydrocephalus complicates open spina bifida in 85-90% of patients. The key to understanding its etiology in this context is the Chiari (type II) malformation. In the fetus with open spina bifida, the meningocele sac acts as a CSF sump. The constant venting of CSF from the developing brain and spinal cord, beyond the time when the caudal neuropore should have closed, removes the distending force that is normally present within the cranial neurocele. This results in a constellation of features, termed the Chiari II malformation [6]. These include disorganization of brainstem topography, a small posterior fossa and, as cerebellar growth exceeds the confines of the small posterior fossa, herniation of the cerebellum through the foramen magnum and up through the incisura. As a consequence, the normal CSF pathways may be compromised at a number of sites, including the cerebral aqueduct, the fourth ventricular outlet and at the perimesencephalic region, resulting in hydrocephalus.

Hydrocephalus may only become apparent following closure of the myelomeningocele. In addition to the usual presenting features of infantile hydrocephalus, features unique to the myelomeningocele patient are bulging of the back wound, occasionally with CSF leakage and signs of brainstem compression due to the Chiari malformation. These latter signs can include stridor, lower cranial nerve palsies and upper-limb weakness and should prompt the search for progressive hydrocephalus. As well as being presenting signs of hydrocephalus in these infants, these signs may similarly herald a shunt malfunction in the older child. It is important to be aware of these atypical modes of presentation of raised intracranial pressure in the myelomeningocele population.

It is doubtful whether any child with myelomeningocele and shunted hydrocephalus can ever be considered to be truly shunt independent. Even in instances where it appears that the shunt is not being used, there are reports of sudden cardio-respiratory arrest attributable to the combination of raised ICP and the Chiari malformation.

Cure Your Yeast Infection For Good

Cure Your Yeast Infection For Good

The term vaginitis is one that is applied to any inflammation or infection of the vagina, and there are many different conditions that are categorized together under this ‘broad’ heading, including bacterial vaginosis, trichomoniasis and non-infectious vaginitis.

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