|Year : 2019 | Volume
| Issue : 3 | Page : 191-193
Penetrating injury to the maxilla and skull base resulting in the mount fuji sign of tension pneumocephalus and ipsilateral vision loss
Reddy Ravikanth1, Ashwin Chandrasekhar2, Anegh Pavithran3, Sivakumar Kandasamy4, John Joshy5
1 Department of Radiology, Holy Family Hospital, Thodupuzha, Kerala, India
2 Department of Radiology, Malabar Medical College, Kozhikode, Kerala, India
3 Department of Oral and Maxillofacial Surgery, Sree Anjaneya Institute of Dental Sciences, Kozhikode, Kerala, India
4 Department of Neurosurgery, Malabar Medical College, Kozhikode, Kerala, India
5 Department of Emergency Medicine, Malabar Medical College, Kozhikode, Kerala, India
|Date of Submission||11-Jul-2018|
|Date of Decision||16-Dec-2018|
|Date of Acceptance||20-Jan-2019|
|Date of Web Publication||13-Aug-2019|
Department of Radiology, Holy Family Hospital, Thodupuzha . 685 605, Kerala,
Source of Support: None, Conflict of Interest: None
Pneumocephalus is defined as the presence of intracranial air seen most commonly secondary to a traumatic head injury. Tension pneumocephalus is often termed in radiology as the Mount Fuji sign due to a perceived similarity with the iconic mountain peak in Japan. We present the case of a 62-year-old gentleman who presented to the emergency department following a penetrating injury to the right maxilla and skull base which resulted in acute-onset ipsilateral vision loss due to direct traumatic injury to the optic nerve by the fractured bone fragments encountered in the optic canal.
Keywords: Cribriform plate, cerebrospinal fluid leak, intracranial pressure, Mount Fuji, tension pneumocephalus
|How to cite this article:|
Ravikanth R, Chandrasekhar A, Pavithran A, Kandasamy S, Joshy J. Penetrating injury to the maxilla and skull base resulting in the mount fuji sign of tension pneumocephalus and ipsilateral vision loss. CHRISMED J Health Res 2019;6:191-3
|How to cite this URL:|
Ravikanth R, Chandrasekhar A, Pavithran A, Kandasamy S, Joshy J. Penetrating injury to the maxilla and skull base resulting in the mount fuji sign of tension pneumocephalus and ipsilateral vision loss. CHRISMED J Health Res [serial online] 2019 [cited 2019 Dec 7];6:191-3. Available from: http://www.cjhr.org/text.asp?2019/6/3/191/264368
| Introduction|| |
The Mount Fuji sign is seen in bilateral tension pneumocephalus causing compression and separation of the frontal lobes from the skull. The causes of tension pneumocephalus include trauma, previous surgery, tumors of the paranasal sinuses, and infections. In neurosurgical anesthesia, nitrous oxide as an anesthetic agent has been implicated in iatrogenic tension pneumocephalus. Detection of pneumocephalus with evidence of mass effect upon the underlying structures is the key feature in differentiating tension pneumocephalus from benign pneumocephalus. The radiological sign that is most widely reported as specific to tension pneumocephalus is the “Mount Fuji” sign, which is observed when the presence of subdural free air causes the compression and separation of the frontal lobes. Tension pneumocephalus is a neurosurgical emergency that requires prompt surgical intervention. The diagnosis of tension pneumocephalus requires a high index of suspicion and careful clinical correlation. Differentiating normal postneurosurgical benign pneumocephalus from tension pneumocephalus is critical for accurate diagnosis and successful management. Here, we present the case of a 62-year-old gentleman who presented with a penetrating injury to the right maxilla.
| Case Report|| |
A 62-year-old gentleman sustained injury at the workplace following a penetrating injury to the right maxilla with a sickle [Figure 1]. He presented with psychomotor agitation, confusion, dizziness, restlessness, transient loss of consciousness, acute-onset ipsilateral vision loss, and nasal bleed and was complaining of severe headache. Differential considerations at this point were traumatic injury to the optic nerve, ischemic optic neuropathy resulting in sudden-onset vision loss, and traumatic intracranial hemorrhage. Axial computed tomography (CT) scan showed a large collection of air in bilateral frontal subdural space, subarachnoid spaces and ventricles [Figure 2], fractures of the medial wall of right orbit, right maxillary sinus walls, and cribriform plate [Figure 3]. Right maxillary [Figure 4] and ethmoidal hemosinus were noted. Frontal sinuses were intact with no evidence of fractures. Vision in the right eye was lost due to direct injury to the optic nerve by the fractured bone fragments encountered in the optic canal. There was no relation between the pneumocephalus and vision loss. The Glasgow Coma score was low – 8 and the patient was intubated. The patient was admitted to intensive care unit as an emergency case of tension pneumocephalus. He was kept in flat position with 100% oxygen supplement through oxygen mask for 4 days. On the 2nd and 4th days, follow-up head CT scans showed significant decrease in the size of pneumocephalus [Figure 5]. Upon discharge, he was later referred for rehabilitation. Rehabilitation team started training program to improve his motivation, participation, cognitive functions, and ambulation.
|Figure 1: Clinical image demonstrating a linear laceration indicating the site of penetrating injury to the right maxilla|
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|Figure 2: Axial computerized tomography scan image demonstrating frontal accumulation of air (red arrows) causing widening of the interhemispheric fissure, bilateral Sylvian fissures (blue arrows), and intraventricular air (green arrow)|
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|Figure 3: Coronal computerized tomography scan image demonstrating the pathway of penetrating injury causing fracture of the right maxillary sinus wall (red arrow) and fracture of the cribriform plate superiorly (blue arrow)|
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|Figure 4: Coronal computerized tomography scan image showing right maxillary hemosinus (arrow)|
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|Figure 5: Follow-up computed tomography brain image on day 4 demonstrating resolution of pneumocephalus|
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| Discussion|| |
A typical finding after burr holes or craniotomies is frontal air entrapment with a bilateral distribution and has been described as the “Mount Fuji” sign, as it resembles the silhouette of the famous Japanese volcano. The most common location of pneumocephalus is in the subarachnoid and subdural spaces, and the fewer sites for air collection include the intraventricular, intracerebral, and extradural spaces. Early diagnosis of tension pneumocephalus is a crucial step to facilitate early recovery; however, the associated injuries may influence the hospital course. Tension pneumocephalus may develop if the intracranial air creates a mass effect on the brain, resulting in a possibly life-threatening neurosurgical emergency. Two mechanisms have been postulated to account for the entry of air into the cranial vault. The “ball-valve mechanism” was previously described as a causative agent when a fistula allows ambient air at a pressure above the intracranial pressure (ICP) to force itself into the intracranial space. This process continues until the ICP overcomes the ambient pressure, and the brain and dura mater are forced over the fistula. The process may repeat itself multiple times until the higher-pressure ambient air no longer overcomes the ICP. A second mechanism postulates that when a continuous cerebrospinal fluid (CSF) leak from an enclosed space is present such as in our case with fracture to the cribriform plate, the loss of CSF creates a void space and relative negative pressure, allowing air to bubble in and fill the cranial cavity.
The present report is that of a rare case with penetrating injury to the maxillary sinus and cribriform plate with no injury to the frontal sinus. Tension pneumocephalus producing significant symptoms is considered a neurosurgical emergency and must be evacuated similar to an intracranial hematoma. Pneumocephalus usually gets absorbed without any clinical manifestations. The conservative treatment involves placing the patient in the Fowler's position of 30° (angle calculated from the surface), avoiding Valsalva maneuver (coughing and sneezing), administering pain and antipyretic medications to prevent hyperthermia, and osmotic diuretics. When clinical signs such as intracranial hypertension or impaired consciousness appear that endangers the life of the patient, treatment consists of emergent decompression to alleviate pressure on the brain parenchyma which otherwise leads to cerebral edema surrounding the air that evolves into encephalomalacia. Treatment options for TP include the drilling of burr holes, needle aspiration, and closure of the dural defect. In symptomatic postoperative pneumocephalus, treatment with 100% oxygen has been shown to increase the rate of reabsorption of pneumocephalus. Anesthetic implications in patients with tension pneumocephalus include avoidance of nitrous oxide, as the blood–gas partition coefficient of nitrous oxide is 34 times greater than that of nitrogen, allowing nitrous oxide to diffuse into the cranial vault faster than the nitrogen/air can exit; avoidance of hyperventilation, which can lead to decreased cerebral blood flow causing enlargement of the subdural space potentially entraining additional air; and avoidance of high airway pressures during ventilation, because increased intrathoracic pressure impedes cerebral venous return, further increasing ICP.
| Conclusion|| |
Tension pneumocephalus is a neurosurgical emergency that requires prompt surgical intervention. The diagnosis of tension pneumocephalus requires a high index of suspicion and careful clinical correlation. Differentiating normal benign pneumocephalus from tension pneumocephalus is critical for accurate diagnosis and successful management.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]