Asymptomatic pneumocephalus after head trauma: case report
- Department of Emergency Medicine, Tophanelioglu C, Yurtacan S No 13–15, Altunizade, Istanbul, Turkey
- Ozlem Guneysel,
- Published 5 March 2009
A 66-year-old man was brought in to our emergency department (ED) with head trauma and was diagnosed with frontal located pneumocephalus based on a cranial computed tomography (CT) scan. At the time of arrival, he was alert and his Glasgow Coma Score (GCS) was 15. A neurological examination revealed no deficit and during follow-up in the ED his GCS did not deteriorate. Cranial CT scan demonstrated nasal fracture. On maxillofacial CT examination, we detected a nasal bone fracture, air loss and fluid was seen in the maxillary and ethmoid sinuses. In our case, pneumocephalus is assumed to be the result of ethmoid bone fracture. Despite the large amount of air in the subdural area, our patient had no symptoms. He was admitted to the intensive care unit for close monitoring and was discharged from hospital without neurological deficit on the fifth day of follow-up.
Pneumocephalus is defined as the presence of air within the cranial cavity1 and is usually associated with trauma, neoplasm, infection, surgery and rarely occurs spontaneously.2 Computed tomography (CT) is the study of choice for confirming the diagnosis of pneumocephalus. As little as 0.5 ml of air can be visualised with CT as opposed to 2 ml, which is the minimum that can be seen with plain radiographs.3 We describe a patient with a large, asymptomatic pneumocephalus caused by trauma (with no deterioration in consciousness), which was detected by a CT scan.
A 66-year-old man was brought to our emergency department by ambulance. He said that he fell from stairs (approximately 3 m high) after ingesting alcohol, and relatives confirmed his story. Vital signs on arrival were as follows: blood pressure, 120/80 mmHg; heart rate, 76 beats/min; respiratory rate, 22 breaths/min; body temperature (axillary), 36.5°C; and oxygen saturation, 98% on room air. On physical examination, he was conscious and Glasgow Coma Score (GCS) was 15; he had a dermal laceration on his right eyebrow and a dent, and a deviation to the left on his nose was determined (fig 1). Rhinorrhoea was not detected. No Battle’s sign or raccoon eyes were noted. Cranial CT scan revealed a subdural pneumocephalus in the frontal region and free air starting at the ethmoid sinus level (figs 2 and 3), and no intracranial bleeding. Skull fracture was not noted but multiple nasal fractures and left deviation on the nasal bone were detected. The CT revealed fluid that was considered as a haemorrhage in the maxillary and ethmoid sinuses (fig 1). Pneumocephalus is assumed to be the result of ethmoid bone fracture. Seftriaxone 2 g was administered intravenously as a prophylactic antibiotic. A neurosurgery consultation was made due to a diagnosis of pneumocephalus; he was then admitted to the intensive care unit for close monitoring. No neurosurgical intervention was deemed necessary and conservative treatment was applied. During his hospital stay, he had no neurological compromise and no evidence of cerebrospinal fluid leak. On the fifth day of follow-up he was discharged from hospital with scheduled neurological follow-up.
The incidence of pneumocephalus is reported in 0.5–1.0% of patients with a traumatic brain injury. Studies that measure the incidence of pneumocephalus using CT scans report higher incidence rates because of the enhanced sensitivity of the imaging.4 Post-traumatic pneumocephalus occurs when there is a continuous collection of intracranial air. This type of pneumocephalus may produce mass effect and, as a consequence, neurological signs/symptoms and a deterioration in functional status. Typical symptoms include increased intracranial pressure (eg, vomiting, nausea and headache) and impaired consciousness. Other neurological signs, including seizures, visual field defects and behavioural changes, have been reported.5 The most common presenting complaint of pneumocephalus is headache, which is reported in 38% of cases; however, patients also may experience non-specific signs of meningeal irritation, such as restlessness, confusion or disorientation.6 In our case the patient was completely asymptomatic, which is uncommon in such a situation.
In the presence of craniofacial trauma, the pathophysiological basis of pneumocephalus can be explained by the “ball valve” and the “inverted bottle” mechanisms. In the “inverted bottle” mechanism, air replaces the cerebrospinal fluid that leaks out from the fracture because of the pressure difference. In the “ball valve” mechanism, when cerebrospinal fluid leakage occurs due to actions such as sneezing, swallowing and straining, increased intracranial pressure causes air to enter the intracranial cavity, but not exit.7 Both pathophysiological mechanisms are possible in our patient. The amount of air in the cranium was expected to affect the conscious level of our patient or even result in headache, but, interestingly, he did not complain of anything, including headache. In this asymptomatic case, the patient was managed conservatively, with bed rest and 100% oxygen therapy.
In conclusion, patients with head or maxillofacial trauma may have no complaints or symptoms of trauma. In spite of no symptoms, the emergency medicine physician should be alert for complications of trauma, such as pneumocephalus.
Patients with head or maxillofacial trauma may have no complaints or symptoms of trauma.
In spite of no symptoms, the emergency medicine physician should be alert for complications of trauma, such as pneumocephalus.
Computed tomography is the main diagnostic tool in head trauma even when no symptoms exist.
Competing interests: None.
Patient consent: Patient/guardian consent was obtained for publication.