LOSED NEURAL TUBE DEFECT WITH HYDROCEPHALUS - A CASE REPORT

Neural tube defects (NTDs) are the second common birth defects next to congenital heart defects. Global Incidence of NTDs is 1-10 per 1000 pregnancies and in India it is about 4.5 per 1000 pregnancies. NTDs are classified clinicoradiologically into open and closed and embryologically into primary and secondary. Neural tissue is exposed to environment in open NTDs whereas closed NTDs are covered by skin. Primary neural tube defects constitutes majority of NTDs resulting from failure of primary neurulation. Eg anencephaly, encephalocoele and myelomeningocoele. They are mostly open NTDs and hydrocephalus occurs in 90 percent of cases. Secondary neural tube defects constitutes 5 percent of all NTDs. They result from abnormal development of lower sacral or coccygeal elements due to failure of secondary neurulation Eg-lipomeningocoele, meningocoele and tethered cord. These are closed NTDs and skin is typically intact over these lesions. In these cases Arnold Chiari type-2 malformation should be ruled out if associated with hydrocephalus by Magnetic Resonance Imaging. Closed neural tube defects are rarely associated with hydrocephalus (about 0.5 percent only). Here we report a Term IUGR baby born with a hyperpigmented patch in the midline of lumbosacral region. There was no mass or defect palpable over the lesion. MRI spine at birth showed tethered cord. Ultrasonography at birth showed normal ventricles. Baby was advised to follow up at 3 months for surgery of tethered cord. Parents failed to show up and child presented at 7 months for another medical problem and found to have large head. MRI brain showed obstructive hydrocephalus due to aqueductal stenosis. Third ventriculostomy and spinal cord detethering procedures have been planned. Hydrocephalus is usually associated with open NTDs. We report this case owing to a rare but possible association of hydrocephalus with closed neural tube defects.