A 73-year-old man presented with intermittent unresponsiveness and fevers. He had extensive squamous cell carcinoma (SCC) of the scalp on the right, treatment of which had resulted in radiation-induced osteonecrosis (Figure 1). He had no neurologic deficits on admission. Non-contrasted head CT demonstrated vasogenic edema in the right frontal lobe. Seventy-two hours later, he developed acute left hemiparesis. Repeat head CT (Figure 2) demonstrated a new large air-filled cavity in the right frontal lobe with mass effect.
Figure 1. Large Area of Exposed Calvarium.
Figure 2. Large Air-filled Cavity in the Right Posterior Frontal Lobe with Mass Effect.
‘Pneumocephalus’ describes intracranial gas in any location. ‘Tension pneumocephalus’ refers to subdural gas which exerts a mass effect. Intraparenchymal air with mass effect is consistent with ‘tension pneumatocele’.1–3 The mechanisms of intracranial air under tension can include a one- way valve phenomenon wherein air can enter but cannot leave, or the inverted soda-bottle effect where air is sucked in to replace leaked CSF.1,2 Tension pneumocephalus has been described most commonly in the setting of cranio-facial fractures while tension pneumatoceles are rarer.4 Two 3 mm bubbling holes were found on the patient’s calvarium and this air intake opening was occluded by dressings. He was placed on 100% oxygen and underwent craniectomy, debridement of necrotic bone, drainage of an abscess, and reconstruction. He ultimately passed away after two months.
The patient had an acute tension pneumatocele, resulting from a calvarial bone defect and infection related to SCC. Clinicians should be mindful of this possibility when caring for patients with extensive scalp defects and neurologic symptoms.
CONFLICTS OF INTEREST
None
AUTHORSHIP
All authors had access to the data and participated in the preparation of the manuscript.
CORRESPONDING AUTHOR
Warren Gavin MD, FACP
Assistant Professor of Clinical Medicine
Indiana University School of Medicine
1800 N. Capitol Ave, Suite E 140
Indianapolis, IN 46202
Phone: 317-962-3925
wgavin@iuhealth.org
Funding Statement
No funding was received.
References
- Causes of pneumocephalus and when to be concerned about it. Cunqueiro A., Scheinfeld M.H. 2018Emerg Radiol. 25:331–340. doi: 10.1007/s10140-018-1595. https://doi.org/10.1007/s10140-018-1595 [DOI] [PubMed] [Google Scholar]
- Tension pneumocephalus after skull base surgery. A case report and review of literature. Biju R.D., Wu J., Hussain Z. May;2020 J Clin Neurosci. 75:218–220. doi: 10.1016/j.jocn.2020.03.041. [DOI] [PubMed] [Google Scholar]
- Outcome of Posttraumatic Delayed Intracerebral Tension Pneumatocele: Prospective Study of Four Cases: Single Institutional Experience. Kankane Vivek Kumar, Gupta Tarun Kumar. 2018Asian journal of neurosurgery. 13(4):1087–1095. doi: 10.4103/ajns.ajns_226_17. https://doi.org/10.4103/ajns.ajns_226_17 [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tension pneumocephalus: a case report with review of the literature. Sweni Shah, Senthilkumaran Subramanian, Balamurugan Namasivayam, Thirumalaikolundusubramanian Ponniah. Jun 11;2013 Emergency Radiology. 20(6):573–578. doi: 10.1007/s10140-013-1135-7. https://doi.org/10.1007/s10140-013-1135-7 [DOI] [PubMed] [Google Scholar]