Postoperative tension pneumocephalus resulting in encephalopathy and seizure activity: Answer

Abstract

A.CSF leakage Tension pneumocephalus—symptomatic intracranial air, confirmed by head CT—is a rare phenomenon that has been reported in multiple settings (e.g., trauma, infection) [[1]Schirmer C.M. Heilman C.B. Bhardwaj A. Pneumocephalus: case illustrations and review.Neurocrit Care. 2010; 13: 152-158Crossref PubMed Scopus (123) Google Scholar]. Additionally, air accumulation has been linked to post-operative CSF leakage [[2]Banu M.A. Szentirmai O. Mascarenhas L. et al.Pneumocephalus patterns following endonasal endoscopic skull base surgery as predictors of postoperative CSF leaks.J Neurosurg. 2014; 121: 961-975Crossref PubMed Scopus (42) Google Scholar]. A few cases have attributed seizures to pneumocephalus, but corresponding EEG findings have not been reported [[3]Lam K.K. Prasad A. Fehlings M.G. Venkatraghavan L. Pneumocephalus: an unusual case of postoperative seizure after intradural spine surgery.Can J Anaesth. 2014; 61: 969-970Crossref PubMed Scopus (9) Google Scholar]. CSF leakage after supratentorial tumor resection is often due to hydrocephalus. As this patient's preoperative and postoperative imaging did not show gross hydrocephalus, increased intracranial pressure secondary to edema combined with intraoperative involvement of the temporal horn of the lateral ventricle are most likely responsible for CSF leakage, which then permitted one-way entry and accumulation of air (“ball-valve” mechanism), eventually causing symptoms. The most likely explanation for new onset persistent right-sided weakness three days following a clinical seizure is recurrent left hemisphere-onset focal subclinical electrographic seizures. The weakness cannot be explained by Todd’s paresis as this does not correlate with ictal activity on EEG. This patient’s EEG was consistent with focal non-convulsive status epilepticus (NCSE), with electrographic seizures emerging from cerebral regions of complex structural pathology secondary to tumor resection. The patient continued to be in NCSE despite receiving adequate anticonvulsive therapy. Following shunt placement, the patient improved cognitively, and right-sided weakness/sensation and NCSE resolved, suggesting that mass effect of pneumocephalus contributed to patient’s clinical course. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The authors report no disclosures. Postoperative tension pneumocephalus resulting in encephalopathy and seizure activity: QuestionJournal of Clinical NeuroscienceVol. 47PreviewA 46-year-old man underwent subtotal resection of a 2.8 × 2.7-cm left temporoparietal glioblastoma (Fig. 1A-B). Levetiracetam 500 mg BID was started prophylactically for seizures. He was discharged home in good condition. Five days later and following staple removal, he presented with headache, gait ataxia, and confusion. On exam, he was disoriented but showed no motor or sensory deficits. Head CT revealed extensive intracranial air with a 4-mm midline shift (Fig. 1C-D). Two subgaleal angiocatheters were placed to relieve air pressure. Full-Text PDF