====== Pneumocephalus ======

{{ ::pneumocephalusposttraumatic.jpg?250|}}

{{rss>https://pubmed.ncbi.nlm.nih.gov/rss/search/1rUyv9-0xUixl5iO_iYJhLAvyeFOIEhr64b4ORnpIsnYWcV1EH/?limit=15&utm_campaign=pubmed-2&fc=20240917132952}}

Pneumocephalus is defined as the presence of [[air]] within any of the [[intracranial]] [[compartment]]s. 

Pneumocephalus without a known underlying cause is defined as [[spontaneous pneumocephalus]]. 

When this circumstance causes [[increased intracranial pressure]] that leads to neurological deterioration, it is known as [[tension pneumocephalus]].
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At many [[academic center]]s, it is common to get a non-contrast [[CT scan]] within 6–12 hours of surgery to assess for acute complications (primarily blood—within the brain or epidural or subdural hematoma, amount of pneumocephalus, hydrocephalus...).

===== Epidemiology =====
It is a rare but potentially serious complication of [[spine surgery]] related in most cases with inadvertent [[dural tear]] during the operation. Most collections are small, behave benign, and respond to [[conservative therapy]]. 


A review of 295 patients indicates that trauma is the most common cause, accounting for 75% of cases. Infection, most common chronic otitis media, accounted for 9% of the cases reviewed
((Markham JW. The clinical features of pneumocephalus based upon a survey of 284
cases with report of 11 additional cases. Acta Neurochir (Wien). 1967;16(1):1-78.
PubMed PMID: 6032371.
)).

===== Etiology =====

[[Pneumocephalus Etiology]].

===== Classification =====

[[Pneumocephalus Classification]].

===== Clinical =====

[[Pneumocephalus clinical features]].


===== Diagnosis =====

[[Pneumocephalus diagnosis]]

===== Differential diagnosis =====

[[Pneumocephalus differential diagnosis]].

===== Complications =====

Intracranial abscess formation, traumatic skull base defects, and massive pneumocephalus are uncommon entities, which may be associated. It may be prudent to have heightened suspicion for the presence of intracranial abscess formation in patients with massive pneumocephalus secondary to anterior skull base trauma
((Becker SS, Russell PT. Intracranial abscess after anterior skull base defect: 
does pneumocephalus play a role? Rhinology. 2009 Sep;47(3):287-92. PubMed PMID:
19839252.
)).

see [[Tension pneumocephalus]].

===== Treatment =====

[[Pneumocephalus treatment]].

===== Case reports =====
A rare [[case]] of [[subdural]] [[pneumocephalus]], unassociated with [[CSF]] [[leak]], developed in the [[sella]]r and [[suprasellar region]]s. This [[complication]] was diagnosed in an adult male 1 week after the removal of a large tumor in the same site via ETSS. The patient presented with a severe [[headache]] and visual [[deterioration]]. He was diagnosed by a CT scan and managed emergently via ETSS. The headache was relieved immediately after surgery, and the recent visual deterioration was reversed the next day. As far as we have reviewed in the context of complications of ETSS, no previous study has reported such a complication of pneumocephalus unassociated with CSF leak following ETSS. As a conclusion, [[pneumocephalus]] can occur with or without CSF leakage as a complication of ETSS, and it may be avoided by a good (water-tight) sealing of the surgical site
((Awad A, Al-Ali A, Ahmad A, Al-Abdullah H. A suprasellar [[Aerocele]] as a Complication of [[Endoscopic Transsphenoidal Surgery]]: A Case Report. Ear Nose Throat J. 2024 Sep 17:1455613241276767. doi: 10.1177/01455613241276767. Epub ahead of print. PMID: 39286913.)).
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A 75-year-old man presented with bilateral lower [[limb]] [[weakness]]. Radiological [[examination]]s implied the possibilities of [[idiopathic normal pressure hydrocephalus]] (iNPH) and a suprasellar cyst, but both were observed conservatively at that time. Due to the progressive [[gait disturbance]], a [[lumboperitoneal shunt]] was implanted 1 year later. The clinical symptoms improved, but the cyst had grown after another year, causing [[visual impairment]]. [[Transsphenoidal]] [[drainage]] of the cyst was performed, but delayed pneumocephalus occurred. Repair surgery was performed with temporary suspension of [[shunt]] function, but pneumocephalus relapsed two and a half months after the resumption of shunt flow. In the second repair surgery, the shunt was removed because it was assumed that it would prevent the closure of the [[fistula]] by lowering [[intracranial pressure]]. Two and a half months later, after confirming the involution of the [[cyst]] and no pneumocephalus, a [[ventriculoperitoneal shunt]] was implanted, and cerebrospinal fluid (CSF) leakage has not relapsed since then. The coexistence of [[idiopathic normal pressure hydrocephalus]] (iNPH) and [[Rathke's cleft cyst]] (RCC) is rare, but it can occur. RCC can be cured by simple drainage but delayed [[pneumocephalus]] can occur in cases whose intracranial pressure decreases due to CSF shunting. When simple drainage without sellar reconstruction for RCC is attempted after CSF shunting for coexistent iNPH, attention should be paid to changes in intracranial pressure, and it is desirable to stop the flow of the shunt for a certain period
((Hashiba T, Nonaka M, Iwamura H, Kamei T, Takeda J, Asai A. Refractory Delayed Pneumocephalus after Transsphenoidal Cyst Drainage for Rathke's Cleft Cyst in a Patient with a Cerebrospinal Fluid Shunt. Asian J Neurosurg. 2023 Jun 6;18(2):342-346. doi: 10.1055/s-0043-1768573. PMID: 37397060; PMCID: PMC10310442.)).

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An 84-year-old man presented with dysarthria and incontinence. Computed tomography revealed an intraventricular pneumocephalus, thinning in the petrous bone, fluid in the air cells, and cleft in temporal lobe. A right subtemporal extradural approach was taken to detect bone-/-dural defects, and a reconstruction was performed using a musculo-pericranial flap.

This is the first patient of an isolated intraventricular spontaneous pneumocephalus without any other site air involved. Surgical approaches to repair such bone and dura defects should be considered an appropriate option
((Arai N, Tabuse M, Nakamura A, Miyazaki H. Spontaneous Intraventricular
Pneumocephalus. J Craniofac Surg. 2017 Jan 12. doi: 10.1097/SCS.0000000000003392.
[Epub ahead of print] PubMed PMID: 28085764.
)).

===== References =====