Pneumocephalus as a rare complication: a systematic review plus clinical vignette

Sudden-onset, non-traumatic large volume pneumocephalus following presentation of acute bacterial meningitis

A man in his 30s, with sinonasal undifferentiated carcinoma status post resection 6 years prior, presented with acute onset of fever, headache and altered mentation. The patient was diagnosed with bacteremia and meningitis due to Streptococcus pneumoniae A standard antibiotic and corticosteroid regimen was started. Brain MRI showed an encephalocele abutting the superolateral nasopharynx mucosa. After several days of clinical improvement, the patient's mental status and headache acutely relapsed. A CT head venogram showed a large volume pneumocephalus originating from the region of a surgical defect. Management included external ventricular drain placement followed by right pterional craniotomy with skull base packing. Skull base defects increase the risk of life-threatening conditions such as bacterial meningitis and pneumocephalus. It is crucial for clinicians to be aware of the possibility of cranial surgical defects developing years after surgery.

Otogenic Enterobacter cloacae meningitis complicated with pneumocephalus

Pneumocephalus refers to a pathologic collection of gas within the cranial cavity and is mostly caused by head trauma and neurosurgical procedures. Spontaneous nontraumatic pneumocephalus is a very rare condition. We herein report an unusual case of community-acquired bacterial meningitis with a combination of acute otitis media, Enterobacter cloacae, and nontraumatic pneumocephalus. A 75-year-old woman presented with fever, mental change, and neck stiffness. Brain imaging demonstrated pneumocephalus and fluid collection in the left mastoid air cells. E. cloacae was isolated from both blood and otorrhea cultures, and the patient was successfully treated with intravenous ceftazidime for 3 weeks. Although E. cloacae is a very rare cause of community-acquired bacterial meningitis in adults, it should be considered as a possible pathogen in otogenic meningitis complicated with pneumocephalus.

Spontaneous Otogenic Intracranial Pneumocephalus: A Case Report

Spontaneous otogenic pneumocephalus (SOP) is a rare condition. We report a case of SOP that may be related to repeated Valsalva maneuvers. A young woman underwent repeated Valsalva maneuvers to restore Eustachian tube function and subsequently developed symptoms that included otalgia, headache, and nausea. A temporal bone computed tomography scan was performed and a diagnosis of SOP was made. Subsequent surgical treatment was performed and no recurrence was found during the 1-year follow-up period. The rarity of SOP and its potential for misdiagnosis pose significant challenges in clinical practice. The Valsalva maneuver is 1 of the contributing factors to this phenomenon. Otologists should be familiar with the potential complications of the Valsalva maneuver and use it with greater caution.

Pneumocephalus; a rare cause of coma

We report the case of an 84-years old female patient who developed cerebral air embolism in association with the indwelling hemodialysis central venous catheter. Pneumocephalus, even though rare, should be included in the differential diagnosis of acute manifestation of neurologic deficits, especially in association with central venous access, surgical interventions or trauma, and requests prompt management. Brain computed tomography scanning remains the investigation of choice.

Retrograde Cerebral Air Embolism Associated With Bronchovenous Fistula

Cerebral air embolism is a rare event and predominantly iatrogenic. Here we present a case of spontaneous intravascular cerebral air embolism caused by lung cancer, which is among the other previously reported cases worldwide. A 69-year-old man with small cell lung carcinoma presented after being found unconscious. Computed tomography (CT) of the chest revealed a lung mass eroding into the superior vena cava (SVC) and with communication to the right upper lobe bronchus. As the patient's neurologic status deteriorated further, serial CT scans of the brain noted multiple air emboli with development of left cerebral infarction, and death followed shortly after. This case highlights the rapid progression of this rare condition and thereby the need to be familiar with the clinical setting in which the presence of cerebral air embolism can occur.