Paradoxical Herniation after Unilateral Decompressive Craniectomy: A Retrospective Analysis of Clinical Characteristics and Effectiveness of Therapeutic Measures.

AIM We aimed to investigate the importance of early diagnosis and proper management of paradoxical herniation based on the data of 13 patients who had 14 occurrences of paradoxical herniation. MATERIAL AND METHODS The characteristics and the effectiveness of treatments of 13 patients with paradoxical herniation were reviewed and analyzed retrospectively. RESULTS Paradoxical herniation occurred in eight patients (61.54%) during the postoperative 2 weeks and they presented with typical symptoms of brain herniation and a tense skin flap without sinking at the region of decompressive craniectomy. On the other hand, six patients developed paradoxical herniation in the postoperative period of 2 weeks to 2 months and presented with sinking skin flaps and delayed neurological deficits. Furthermore, all patients received emergency treatments, including sufficient hydration, clamping cerebrospinal fluid (CSF) drainage, and being placed in the Trendelenburg position. Six patients achieved full neurologic recovery after successful cranioplasty. CONCLUSION Intracranial hypotension causing paradoxical herniation can rapidly progress, especially along with CSF depletion. It is important for neurosurgeons to suspect paradoxical herniation in a subset of patients with large cranium defects and tense skin flap without sinking during the postoperative 2 weeks. Paradoxical herniation is rapidly reverted by improving CSF hydration, and performing early cranioplasty referred as the definitive treatment.