Syndrome of the trephined (sinking skin flap syndrome) with and without paradoxical herniation: a series of case reports and review.

Decompressive craniectomy is gaining an increasing role in the neurosurgical treatment of intractable intracranial hypertension in patients with head injury, acute stroke, and severe brain edema. The conversion of the cranium from a "closed box" to an "open box" alters the barometric pressure, cerebrospinal fluid (CSF), and cerebral blood flow (CBF) and may or may not lead to syndrome of the trephined (sinking skin flap syndrome).