Core Terms & Classification
Cranium bifidum
Cranium bifidum is a congenital opening or cleft in the skull bone through which intracranial contents can herniate.
In short: Cranium bifidum
- It describes the bony defect that makes an encephalocele possible.
- "Bifidum" means split or divided.
- When tissue protrudes through it, the result is a cephalocele or encephalocele.
- The opening itself is repaired and reconstructed during surgery.
What it is
Cranium bifidum is the skull-bone counterpart to the more familiar "spina bifida" of the spine. It refers to the gap in the bone; an encephalocele is what happens when tissue protrudes through that gap. The term "cranium bifidum cysticum" is sometimes used when a fluid-filled sac is present.
Understanding Cranium bifidum
The opening is the structural problem at the heart of an encephalocele, but whether and what protrudes through it determines the diagnosis and the repair needed. Surgeons close and reconstruct this bony defect during surgery, often using imaging like CT and 3D reconstruction to map its size and shape beforehand.
Why it matters
Distinguishing the bony opening (cranium bifidum) from the protruding tissue (encephalocele) helps families understand the two parts of a repair: closing the membranes watertight and rebuilding the bone. Both are necessary to protect the brain and restore the head's contour.
Common questions
Is cranium bifidum the same as encephalocele?
Not exactly — it is the bony opening; an encephalocele is tissue protruding through it.
Can the opening be closed?
Yes — repairing the bony defect (cranioplasty) is part of surgery.
How is the opening's size measured?
Usually with CT imaging and 3D reconstruction.
Bottom line
Cranium bifidum is the skull opening underlying an encephalocele, closed and reconstructed during surgical repair.
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