What does an encephalocele refer to?

An encephalocele refers to a type of neural tube defect where brain tissue protrudes through an opening in the skull. This condition is a result of abnormal development of the neural tube during early fetal development, leading to a herniation of brain tissue into a sac-like structure. The herniated tissue can lead to significant neurological deficits and is often associated with other congenital abnormalities.

The other options represent different medical conditions. The bulging of spinal bones indicates a structural issue with the vertebrae, while a twisted spinal cord implies a deformity rather than a herniated tissue issue. Fluid collection around the brain, while clinically relevant, usually refers to conditions like hydrocephalus, which involves an accumulation of cerebrospinal fluid rather than the protrusion of brain tissue itself. Therefore, the definition of an encephalocele accurately describes the herniation of brain tissue through the skull.