Neural tube deficits

The majority of malformations of the spinal cord are the result of the failure of the caudal neuropore to properly close by the end of the fourth week of development. The defective closure of the caudal neuropore results in serious neural tube malformations known generally as spina bifida. There are many types of spina bifida, and the clinical presentation, including neurological deficits, can range from minor (e.g. spina bifida occulta) to severe (e.g. spina bifida with myeloschisis). Spina bifida cystica has been associated with exposure of the mother to large doses of retinoic acid, or vitamin A, via ingestion (Moore, 1988). 

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