Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Myelomeningocele ?
    ### Response:
    Myelomeningocele is the most severe form of spina bifida. It happens when parts of the spinal cord and nerves come through the open part of the spine. It causes nerve damage and other disabilities. Seventy to ninety percent of children with this condition also have too much fluid on their brains (hydrocephalus).
    