Advances in diagnosis and treatment of syndrome of trephined and paradoxical herniation after decompressive craniectomy

The efficacy of decompressive craniectomy (DC) in reducing traumatic brain injury mortality has been affirmed, but there are also many serious complications. Syndrome of the trephined (ST) and paradoxical herniation (PH) are rare complications. ST is characterized by a series of neurological deterioration due to skin flaps subsidence from weeks to months after DC. These neurological impairments are closely related to the subsequent repair of skull defects. PH shows progressive decrease in consciousness on the basis of ST, changes in pupils on the side of skull defects, low touch pressure at the defect window, and obvious midline shift and brain stem compression on CT. ST and PH have common inducements in pathophysiology, including cerebrospinal fluid dynamics, atmospheric pressure, cerebral blood flow and brain material metabolism. There is no consensus on the diagnosis of ST and PH, and early cranioplasty is suggested in terms of treatment. This article reviews the clinical manifestations, pathophysiological changes, diagnosis and treatment of ST and PH after DC operation, so as to provide references for clinicians to further understand ST and PH. Key words: Encephalocele; Decompressive craniectomy; Syndrome of the trephined