Sinking Skin Flap Syndrome and Paradoxical Herniation After Hemicraniectomy for Malignant Hemispheric Infarction

Abstract

Background and Purpose— “Sinking skin flap” (SSF) syndrome is a rare complication after large craniectomy that may progress to “paradoxical” herniation as a consequence of atmospheric pressure exceeding intracranial pressure. The prevalence and characteristics of SSF syndrome after hemicraniectomy for malignant infarction of the middle cerebral artery are not well known. Methods— We analyzed a prospective cohort of 27 patients who underwent hemicraniectomy for malignant middle cerebral artery infarction. All had a clinical and brain imaging follow-up at 3 months and were followed until cranioplasty. Results— Three of 27 patients (11%) had, at 3 to 5 months posthemicraniectomy, SSF syndrome with severe orthostatic headache as the main symptom. In addition, 4 patients (15%) had radiological SSF syndrome but no clinical symptoms except partial seizures in one. Patients with SSF syndrome had a smaller surface of craniectomy (76.2 cm 2 versus 88.7 cm 2 , P =0.05) and a tendency toward larger infarct volume, an older age, and a longer delay to cranioplasty than those without this syndrome. Conclusions— SSF syndrome either clinically symptomatic or asymptomatic affects one fourth of patients 3 to 5 months after hemicraniectomy for malignant middle cerebral artery infarction. It should be diagnosed as early as possible to avoid progression to a paradoxical herniation.