Never neglect the atmospheric pressure effect on a brain with a skull defect
A 65-year-old male patient was transferred to our hospital with a large, right-sided skull defect and severe scalp depression. He had suffered a traumatic brain injury 5 months earlier and undergone decompressive craniectomy and removal of an intracranial hemorrhage at that time. Hydrocephalus developed one month after the operation and he received a ventriculoperitoneal shunt. However, his level of consciousness progressively deteriorated thereafter. On neurological examination, he was drowsy with a Glasgow Coma Scale score of E1V1M4 and profound left hemiplegia. A computed tomography (CT) brain scan revealed marked concavity of the brain at the craniectomy site associated with midline shift to the left (). Transcranial Doppler sonography (Multi-Dop® X2, DWL; Elektronische Systeme GmbH, Schlotheim, Germany) was unable to detect the wave pattern of the blood flow in the middle cerebral artery of the concave brain. The impression was of sinking skin flap syndrome, so cranioplasty with bone cement was performed. Postoperatively, the patient was treated with hydration and bed rest for 3 days. Four days after his cranioplasty, follow-up CT images showed reversal of the midline shift with no significant complications in the underlying brain (). Follow-up transcranial Doppler revealed a mean velocity of 30 cm per second in the right middle cerebral artery. After the surgery, the patient’s mentality gradually improved to an alert state and he was discharged with a Glasgow Coma Scale score of E34V1M5–6 one month after cranioplasty.