- Email: [email protected]
Tension pneumocephalus: A case report of spontaneous decompression into the ventricular system
146
Correspondences
[5] Dashti SR, Fiorella D, Spetzler RF, et al. Transorbital endovascular embolization of dural carotid-cavernous fistula: access to cavernous sinus through direct puncture: case examples and technical report. Neurosurgery 2011;68(1 Suppl Operative):75—83. [6] Patel DV, Rangaswamy R, Lesley WS, et al. Transvenous embosurgery of a left sigmoid sinus dural arteriovenous fistula via a retrograde approach from the superior ophthalmic vein, cavernous and inferior petrosal sinuses. J Neurointervent Surg 2011;3:229—32.
Jean-Christophe Gentric a,b Jean-Christophe Ferré b,∗ Hélène Raoult b Franc ¸ois Eugène b Jean-Yves Gauvrit b a CHU de Brest, Cavale Blanche Hospital, Department of Radiology, boulevard Tanguy-Prigent, 29200 Brest, France b CHU de Rennes, Pontchaillou Hospital, Department of Neuroradiology, 2, rue Henri-Le-Guilloux, 35033 Rennes, France ∗
Corresponding author. Tel.: +33 02 99 28 43 67; fax: +33 02 99 28 43 64. E-mail address: [email protected] (J.-C. Ferré) doi:10.1016/j.neurad.2012.03.009
Tension pneumocephalus: A case report of spontaneous decompression into the ventricular system Case report A 25-year-old man underwent right orbitozygomatic approach resection of a right sphenoid wing osteosarcoma. Routine postoperative computed tomography (CT) demonstrated the expected postoperative findings of a small amount of gas and blood products in the right temporal region. On postoperative day 7, the patient complained of clear-fluid drainage from the right orbit and nasal cavity. A CT scan of the head demonstrated an interval increase in the volume of intraparenchymal and extra-axial gas in the right frontal region with a mass effect on the right frontal lobe (Fig. 1). Repair using dural sealant and intranasal packing was performed, but the packing fell out after a further 7 days, with recurrence of the cerebrospinal fluid (CSF) leak. Subsequent CT revealed a further increase of the right frontal intraparenchymal pneumocephalus with interval partial decompression into the lateral and third ventricles. Small bubbles of gas were also visible throughout the subarachnoid space (Fig. 2). Concern was raised over the possible extension of the gas collection into the nasal cavity, sphenoid sinuses and/or ethmoid air cells. Magnetic resonance imaging (MRI) of the brain was thus performed, and demonstrated air—fluid levels in the intraparenchymal and intraventricular pneumocephalus (Fig. 3). The patient was initially treated with bed rest and oxygen therapy, and returned 10 days later for definitive surgical repair. The
Figure 1 Non-contrast axial head CT of a 25-year-old man with tension pneumocephalus shows a large right frontal intraparenchymal gas collection and a small amount of bifrontal subdural pneumocephalus. Midline shift and effacement of the interhemispheric fissure are also evident.
patient subsequently followed an uneventful postoperative course.
Discussion Tension pneumocephalus is defined as the entrapment of intracranial air under pressure, which can result in brain compression, thereby potentially leading to brain herniation and death [1,2]. Two primary mechanisms of the development of tension pneumocephalus are known: the ball-valve effect; and inverted soda-bottle effect. The ball-valve effect occurs when air is forced out of an air-containing extracranial space (such as a paranasal sinus) through a fistulous connection into an intracranial cavity. The inverted soda-bottle effect occurs when negative intracranial pressure is induced by a loss of CSF through a leak. As a result, air is drawn into the intracranial cavity through a bony or dural defect in the skull base and replaces the CSF until the pressure in the two cavities is equalized [3]. The present patient had both a CSF leak and a defect in the ethmoid air cells. Two CT findings of increased tension of intracranial gas were noted: the ‘‘Mount Fuji sign’’, in which subdural air with increased tension separates and compresses the frontal lobes [4]; and the ‘air-bubble sign’, wherein small air bubbles are diffusely spread throughout a variety of cisterns rather than clustered together in the subarachnoid space [5]. Our patient’s CT demonstrated the latter sign. It is unusual for tension pneumocephalus to spontaneously decompress and, in this case, decompression via the ventricular system afforded the patient extra time during which definitive surgery could be planned to repair the CSF leak. It is important for radiologists to recognize the diagnosis of tension pneumocephalus because, if left untreated, it can lead to rapid clinical deterioration and even death.
Correspondences
147
Figure 2 a: non-contrast axial maxillofacial CT shows a right frontal intraparenchymal pneumocephalus with partial decompression of the lateral ventricles; b: another non-contrast axial maxillofacial CT reveals small bubbles of gas, which were also visible throughout the subarachnoid space.
Figure 3 a: axial T2-weighted (1.5-T magnet) MRI scan shows air-fluid levels in the intraparenchymal and intraventricular pneumocephalus. Right-to-left midline shift is again present. There is also a small left frontal subdural fluid collection; b: sagittal T2-weighted (1.5-T magnet) MRI scan shows air-fluid levels in the intraparenchymal and intraventricular pneumocephalus.
Disclosure of interest The authors have not supplied their declaration of conflict of interest.
References [1] Öge K, Akpinar G, Bertan V. Traumatic subdural pneumocephalus causing rise in intracranial pressure in the early phase of head trauma: report of two cases. Acta Neurochir 1998;140:655—8. [2] Gönül E, Yetis¸er S, ¸ Sirin S, et al. Intraventricular traumatic tension pneumocephalus: a case report. Kulak Burun Bogaz Ihtis Derg 2007;17(4):231—4. [3] Lunsford LD, Maroon JC, Sheptak PE, et al. Subdural tension pneumocephalus. Report of two cases. J Neurosurg 1979;50(4):525—7. [4] Ishiwata Y, Fujitsu K, Sekino T, et al. Subdural tension pneumocephalus following surgery for chronic subdural hematoma. J Neurosurg 1988;68:58—61.
[5] Dandy WE. Pneumocephalus (Intracranial pneumatocele or aerocele). Arch Surg 1926;132(5):949—82.
J.N. Kucera a,∗ N. Dragicevic b F.R. Murtagh c a University of South Florida College of Medicine, Tampa, Florida, USA b Mount Sinai School of Medicine, Department of medicine, New York, USA c Moffitt Cancer Center and Research Institute, Tampa, Florida, USA ∗
Corresponding author. E-mail address: [email protected] (J.N. Kucera) doi:10.1016/j.neurad.2012.05.001
Correspondences
[5] Dashti SR, Fiorella D, Spetzler RF, et al. Transorbital endovascular embolization of dural carotid-cavernous fistula: access to cavernous sinus through direct puncture: case examples and technical report. Neurosurgery 2011;68(1 Suppl Operative):75—83. [6] Patel DV, Rangaswamy R, Lesley WS, et al. Transvenous embosurgery of a left sigmoid sinus dural arteriovenous fistula via a retrograde approach from the superior ophthalmic vein, cavernous and inferior petrosal sinuses. J Neurointervent Surg 2011;3:229—32.
Jean-Christophe Gentric a,b Jean-Christophe Ferré b,∗ Hélène Raoult b Franc ¸ois Eugène b Jean-Yves Gauvrit b a CHU de Brest, Cavale Blanche Hospital, Department of Radiology, boulevard Tanguy-Prigent, 29200 Brest, France b CHU de Rennes, Pontchaillou Hospital, Department of Neuroradiology, 2, rue Henri-Le-Guilloux, 35033 Rennes, France ∗
Corresponding author. Tel.: +33 02 99 28 43 67; fax: +33 02 99 28 43 64. E-mail address: [email protected] (J.-C. Ferré) doi:10.1016/j.neurad.2012.03.009
Tension pneumocephalus: A case report of spontaneous decompression into the ventricular system Case report A 25-year-old man underwent right orbitozygomatic approach resection of a right sphenoid wing osteosarcoma. Routine postoperative computed tomography (CT) demonstrated the expected postoperative findings of a small amount of gas and blood products in the right temporal region. On postoperative day 7, the patient complained of clear-fluid drainage from the right orbit and nasal cavity. A CT scan of the head demonstrated an interval increase in the volume of intraparenchymal and extra-axial gas in the right frontal region with a mass effect on the right frontal lobe (Fig. 1). Repair using dural sealant and intranasal packing was performed, but the packing fell out after a further 7 days, with recurrence of the cerebrospinal fluid (CSF) leak. Subsequent CT revealed a further increase of the right frontal intraparenchymal pneumocephalus with interval partial decompression into the lateral and third ventricles. Small bubbles of gas were also visible throughout the subarachnoid space (Fig. 2). Concern was raised over the possible extension of the gas collection into the nasal cavity, sphenoid sinuses and/or ethmoid air cells. Magnetic resonance imaging (MRI) of the brain was thus performed, and demonstrated air—fluid levels in the intraparenchymal and intraventricular pneumocephalus (Fig. 3). The patient was initially treated with bed rest and oxygen therapy, and returned 10 days later for definitive surgical repair. The
Figure 1 Non-contrast axial head CT of a 25-year-old man with tension pneumocephalus shows a large right frontal intraparenchymal gas collection and a small amount of bifrontal subdural pneumocephalus. Midline shift and effacement of the interhemispheric fissure are also evident.
patient subsequently followed an uneventful postoperative course.
Discussion Tension pneumocephalus is defined as the entrapment of intracranial air under pressure, which can result in brain compression, thereby potentially leading to brain herniation and death [1,2]. Two primary mechanisms of the development of tension pneumocephalus are known: the ball-valve effect; and inverted soda-bottle effect. The ball-valve effect occurs when air is forced out of an air-containing extracranial space (such as a paranasal sinus) through a fistulous connection into an intracranial cavity. The inverted soda-bottle effect occurs when negative intracranial pressure is induced by a loss of CSF through a leak. As a result, air is drawn into the intracranial cavity through a bony or dural defect in the skull base and replaces the CSF until the pressure in the two cavities is equalized [3]. The present patient had both a CSF leak and a defect in the ethmoid air cells. Two CT findings of increased tension of intracranial gas were noted: the ‘‘Mount Fuji sign’’, in which subdural air with increased tension separates and compresses the frontal lobes [4]; and the ‘air-bubble sign’, wherein small air bubbles are diffusely spread throughout a variety of cisterns rather than clustered together in the subarachnoid space [5]. Our patient’s CT demonstrated the latter sign. It is unusual for tension pneumocephalus to spontaneously decompress and, in this case, decompression via the ventricular system afforded the patient extra time during which definitive surgery could be planned to repair the CSF leak. It is important for radiologists to recognize the diagnosis of tension pneumocephalus because, if left untreated, it can lead to rapid clinical deterioration and even death.
Correspondences
147
Figure 2 a: non-contrast axial maxillofacial CT shows a right frontal intraparenchymal pneumocephalus with partial decompression of the lateral ventricles; b: another non-contrast axial maxillofacial CT reveals small bubbles of gas, which were also visible throughout the subarachnoid space.
Figure 3 a: axial T2-weighted (1.5-T magnet) MRI scan shows air-fluid levels in the intraparenchymal and intraventricular pneumocephalus. Right-to-left midline shift is again present. There is also a small left frontal subdural fluid collection; b: sagittal T2-weighted (1.5-T magnet) MRI scan shows air-fluid levels in the intraparenchymal and intraventricular pneumocephalus.
Disclosure of interest The authors have not supplied their declaration of conflict of interest.
References [1] Öge K, Akpinar G, Bertan V. Traumatic subdural pneumocephalus causing rise in intracranial pressure in the early phase of head trauma: report of two cases. Acta Neurochir 1998;140:655—8. [2] Gönül E, Yetis¸er S, ¸ Sirin S, et al. Intraventricular traumatic tension pneumocephalus: a case report. Kulak Burun Bogaz Ihtis Derg 2007;17(4):231—4. [3] Lunsford LD, Maroon JC, Sheptak PE, et al. Subdural tension pneumocephalus. Report of two cases. J Neurosurg 1979;50(4):525—7. [4] Ishiwata Y, Fujitsu K, Sekino T, et al. Subdural tension pneumocephalus following surgery for chronic subdural hematoma. J Neurosurg 1988;68:58—61.
[5] Dandy WE. Pneumocephalus (Intracranial pneumatocele or aerocele). Arch Surg 1926;132(5):949—82.
J.N. Kucera a,∗ N. Dragicevic b F.R. Murtagh c a University of South Florida College of Medicine, Tampa, Florida, USA b Mount Sinai School of Medicine, Department of medicine, New York, USA c Moffitt Cancer Center and Research Institute, Tampa, Florida, USA ∗
Corresponding author. E-mail address: [email protected] (J.N. Kucera) doi:10.1016/j.neurad.2012.05.001