LAUSR

© BMJ Publishing Group Limited 2022. No commercial reuse. See rights and permissions. Published by BMJ. DESCRIPTION Postoperative pseudomeningoceles are characterised by extradural accumulation of cerebrospinal fluid (CSF) leaked from a surgical wound into the subcutaneous space. Giant cranial pseudomeningoceles are extremely rare. Herein, we describe a case of focal seizures and haemiparesis caused by decompression of a giant cranial pseudomeningocele. An otherwise healthy man in his 40s presented with generalised tonicclonic seizures. Imaging demonstrated a 4.7×4.0×3.6 cm extraaxial right parasagittal lesion suggestive of a meningioma (figure 1A). His seizures were controlled with antiepileptic drugs and he underwent a right parietal craniotomy for resection of meningioma. The procedure was uneventful. Postoperatively, he developed a persistent large pseudomeningocele, with no features of hydrocephalus. We managed the pseudomeningocele conservatively, expecting it would settle with time. Histopathology confirmed a WHO grade 1 meningioma. He represented 3 months following his operation reporting problem of headache and a recent progressive increase in the size of the pseudomeningocele. On examination of the wound site, there was a very large fluctuant collection (>20 cm). He was neurologically intact. CT imaging of the brain confirmed the presence of a large subcutaneous CSF collection in communication with the surgical site. The pseudomeningocele had a large extracranial component and a relatively smaller intracranial component underlying the craniotomy site, causing mass effect on the underlying brain (figure 1B). We performed a highvolume lumbar puncture and applied a pressure bandage over the site of the pseudomeningocele. He had an opening pressure of 14 cmH2O, 45 mL of CSF was drained and closing pressure was 8 cmH20. Following the lumbar puncture, over the next 48 hours, he developed focal seizures affecting his left arm and leg and progressive left upper and lower limb weakness. On examination, he had power 0/5 in his left lower limb and 3/5 in his left upper limb. CT imaging demonstrated near complete resolution of the intracranial component of the pseudomeningocele; however, there was a new focal hypodensity in the underlying brain, suggestive of oedema (figure 2A). He was given highdose steroids. MR imaging, obtained the following day, confirmed T2 high signal in the right post central gyrus, extending into the paracentral lobule and corona radiata representing oedema (figure 2B). There were no areas of restricted diffusion to