Hydrocephalus is a common associated problem in spina bifida. It occurs in about what proportion of cases?

• A. 10%
• B. 30%
• C. 50%
• D. 90%

Answer: (D)

Hydrocephalus commonly accompanies spina bifida, especially with open defects like myelomeningocele, due to hindbrain herniation (Arnold-Chiari II) and disrupted CSF dynamics that lead to accumulation of CSF. Because of this strong association, most sources place the prevalence quite high—roughly nine out of ten children with spina bifida will develop hydrocephalus at some point and often require a shunt. So the best estimate among the options is about 90%.

The other figures underestimate how frequently hydrocephalus occurs in this condition; 10%, 30%, or 50% do not reflect the well-established link between spina bifida and hydrocephalus, especially in the more severe open forms.