Hemiplegia and sinking flap syndrome within 2 hours of decompressive craniectomy: A rare case following intraoperative cardiac arrest.

Background: Sinking flap syndrome (SFS) is a well-documented but typically delayed complication of decompressive craniectomy (DC). Early-onset SFS, especially within hours of surgery, is extremely rare and may pose diagnostic and therapeutic challenges. In this report, we describe a unique case of SFS occurring just 2 h after DC in the context of an intraoperative air embolism and prolonged cardiopulmonary resuscitation, underscoring the impact of acute hemodynamic disturbances on SFS pathogenesis. Case Description: We present the case of an 84-year-old female with a history of hypertension and chronic aspirin use who underwent DC for a left temporo-parietal acute subdural hematoma. Intraoperatively, the patient experienced cardiac arrest requiring resuscitation. Postoperatively, she was intubated for 1 h and then extubated. At postoperative h 2, the scalp flap was observed to be sunken. On regaining consciousness, she was found to have new-onset right hemiplegia. Once hemodynamically stabilized, cranial computed tomography was performed at postoperative h 6 and confirmed SFS. Emergent cranioplasty was performed using the autologous bone flap. Neurological improvement was noted in the following days, and the patient was discharged with partial motor recovery and active rehabilitation plans. Conclusion: Although usually delayed, SFS can present as early as 2 h post-DC, particularly in the setting of intraoperative hypotension and cerebral hypoperfusion. Prompt recognition and intervention are crucial to prevent long-term neurological deficits.