Spontaneous Otogenic Pneumocephalus: Case Series and Update on Management

Spontaneous Intraventricular Tension Pneumocephalus

Here, we report a very rare case of spontaneous intraventricular tension pneumocephalus. This case concerns a 40-year-old patient with medical history of a tumor of the pineal region and a secondary hydrocephalus treated by multiple ventriculoperitoneal shunts. He presented in the emergency room because of unusual headaches, nausea, and visual loss. In addition, he reported slight rhinorrhea in the past few weeks. The initial brain computed tomography scan revealed a spontaneous intraventricular tension pneumocephalus. There was no history of recent head trauma and no sign of disconnection of the shunt system. A complementary radiologic assessment including a thin-slice bone computed tomography scan and a radioisotope cisternography revealed an osseous defect and an isotope leakage at the junction between the tegmen tympani and the squamous part of the left temporal bone. A middle cranial fossa surgery was performed to repair the osteo-meningeal breach.

Extensive Pneumocephalus Secondary to Petrous Bone Cholesteatoma

Pneumocephalus refers to air inside the cranium; however, otogenic pneumocephalus is rarely reported in the literature. The neurological presentations of pneumocephalus include headache, lethargy, confusion, disorientation, and seizure. Here, we have reported a case of a 42-year-old woman with extensive pneumocephalus and cerebrospinal fluid leak secondary to petrous bone cholesteatoma. She presented to the emergency department with sudden headache and left ear discharge. Physical examination revealed watery otorrhea through a hole in the tympanic membrane. Radiological studies demonstrated extensive soft tissue in the left middle ear and mastoid extending to the internal auditory canal. Free intracranial air was observed, and bony destruction was seen in the cochlea, vestibule, and semicircular canals. The patient was managed surgically via the transotic approach and fully recovered. Although otogenic pneumocephalus is rarely encountered in clinical practice, early diagnosis and urgent management are important to prevent fatal complications.

Tandem cranial and spinal cerebrospinal fluid leaks presenting with otogenic tension pneumocephalus: illustrative case

BACKGROUND

Cranial and spinal cerebrospinal fluid (CSF) leaks are associated with opposite CSF fluid dynamics. The differing pathophysiology between spontaneous cranial and spinal CSF leaks are, therefore, mutually exclusive in theory.

OBSERVATIONS

A 66-year-old female presented with tension pneumocephalus. The patient underwent computed tomography (CT) scanning, which demonstrated left-sided tension pneumocephalus, with an expanding volume of air directly above a bony defect of the tegmen tympani and mastoideum. The patient underwent a left middle fossa craniotomy for repair of the tegmen CSF leak. In the week after discharge, she developed a recurrence of positional headaches and underwent head CT. Further magnetic resonance imaging of the brain and thoracic spine showed bilateral subdural hematomas and multiple meningeal diverticula.

LESSONS

Cranial CSF leaks are caused by intracranial hypertension and are not associated with subdural hematomas. Clinicians should maintain a high index of suspicion for intracranial hypotension due to spinal CSF leak whenever "otogenic" pneumocephalus is found. Close postoperative follow-up and clinical monitoring for symptoms of intracranial hypotension in any patients who undergo repair of a tegmen defect for otogenic pneumocephalus is recommended.

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 With Stroke-Like Symptoms: A Rare Complication of Mastoiditis

Pneumocephalus is defined as the presence of gas or air in the intracranial space and typically arises as a result of neurotrauma. Clinically, pneumocephalus most often presents asymptomatically but may cause headache, nausea, vomiting, and confusion. Pneumocephalus arising from mastoiditis is an unforeseen complication with only a handful of cases reported. We report a case of an elderly male who presented with stroke-like symptoms in the setting of erosive mastoiditis with pneumocephalus.

A rare case of spontaneous otogenic pneumocephalus with pictorial illustration of temporal evolution

Pneumocephalus is commonly seen on imaging in the setting of craniofacial trauma, skull base tumours, intracranial infection and after neurological intervention. Spontaneous pneumocephalus in the absence of these conditions is exceedingly rare, with only approximately 30 cases reported in the literature to date. Spontaneous otogenic pneumocephalus (SOP) is believed to occur as a result of anomalous communication between the intracranial space and a hyper-pneumatised temporal bone, with either positive extra-to-intracranial pressure or negative intracranial pressure gradient. These anomalous communicating channels may only become clinically apparent when triggered by episodes of acute increase in middle ear pressure during coughing, sneezing, Valsalva manoeuvre or significant change in atmospheric pressure. Patients may exhibit a wide range of neurological symptoms and the aim of treatment is to reduce the risk of complications such as infection and intracranial hypertension. Both conservative and neurosurgical approaches have been described. We report a case of SOP in which the patient was conservatively managed, and spontaneous resolution of pneumocephalus was documented on serial computed tomography (CT) scans. This unique case clearly demonstrates the natural history and temporal evolution of SOP without surgical intervention. This knowledge may potentially obviate the need for surgery, thus reducing morbidity and mortality in patients who are poor surgical candidates.

Tension Pneumocephalus From an Eroding Cholesteatoma: A Case Report and Review of the Literature

Pneumocephalus is defined as the presence of air inside the cranial vault. Benign and tension pneumocephalus are different ends of the same disease spectrum. Tension pneumocephalus leads to the formation of a pressure gradient, requiring emergent surgical decompression to prevent herniation of the intracranial structures. In this report, we present a rare case of tension pneumocephalus with essentially benign radiological findings secondary to a ruptured cholesteatoma. The patient was a 64-year-old woman with a history of end-stage renal disease on hemodialysis and hypertension. She presented to the emergency department (ED) with acute-onset weakness and decreased mentation. Physical exam findings were consistent with a cerebrovascular accident (CVA). CT scan and CT angiogram (CTA) were unremarkable for ischemia or hemorrhage but showed signs of free intracranial air, consistent with the diagnosis of pneumocephalus. After the activation of the code stroke, neurosurgery and neurology were consulted. Worsening respiratory status led to a decision to proceed with emergent intubation, but it was held based on the family’s decision to proceed with comfort measures. The patient’s status declined further within minutes and she died. Afterward, the case was discussed with the radiologist, who interpreted the cause as a cholesteatoma that had eroded through the temporal bone.

A Rare Case of Temporal Bone Pneumocephalus Tracking through the Internal Auditory Canal

A 39-year-old male with chronic hydrocephalus requiring biventricular shunts presented with progressive pneumocephalus over several years. He showed no improvement following ventriculoperitoneal (VP) shunt revision and anterior skull base repair for a sphenoid dehiscence. Imaging continued to show worsening pneumocephalus with air tracking along the right facial nerve from the geniculate ganglion to the internal auditory canal (IAC). The patient then underwent tympanomastoidectomy and skull base reconstruction. Based on a search of published literature, this appears to be the first reported case of temporal bone pneumocephalus coursing through the IAC, unlike most cases associated with tegmen defects and middle fossa pneumocephalus.

Severe Intracranial Hypotension After a Middle Fossa Approach for Spontaneous Otogenic Pneumocephalus

BACKGROUND

Spontaneous otogenic pneumocephalus is a rare condition caused by erosion of the tegmen tympani with subsequent entrance of air into the intracranial space. Its pathogenesis is thought to involve a previous state of intracranial hypotension, which pulls air into the intracranial cavity. The surgical management involves obliteration of the tegmen defect via a mastoidectomy or a middle fossa approach. Lumbar drainage has been used safely as an adjunct to middle fossa approaches so as to provide brain relaxation and decrease the incidence of postoperative cerebrospinal fluid leaks.

CASE DESCRIPTION

A 66-year-old male patient with otogenic pneumocephalus caused by nose blowing underwent repair of a tegmen tympani defect through a middle fossa approach, with the aid of intraoperative lumbar drainage. Progressive neurologic deterioration was seen postoperatively with obtundation and anisocoria. Computed tomography scans of the head demonstrated marked midline shift and transtentorial herniation. Recumbency and blood patch failed to improve the neurological condition. Intrathecal infusion of normal saline enabled clinical and radiological improvement.

CONCLUSIONS

Intraoperative lumbar drainage during a middle fossa approach for spontaneous otogenic pneumocephalus may dramatically aggravate a state of preexisting intracranial hypotension and lead to transtentorial herniation.