Case report

A 19-year-old man presented to the emergency department following a witnessed fall from 1 m onto concrete. He sustained a head injury with loss of consciousness lasting 3 minutes. On arrival in the emergency department, the patient's Glasgow Coma Score was 13/15 (Eye(E)3 Verbal(V)4 Motor response (M)6), his pupils were equal and reactive, and a neurological examination showed no sensorimotor deficit. The patient was reported to have lost approximately 200 ml of clear fluid from the left ear.

Otoscopy showed haemoserous fluid within the left ear canal but no visible canal wall or tympanic membrane defect. The head and neck examination was otherwise unremarkable, with normal facial nerve function and no other signs of skull base fracture.

The patient's serum ethanol level on admission was 252 mg/dl.

Computed tomography (CT) showed indirect evidence of temporal bone fracture, with fluid in the left mastoid air cells and emphysema within the left temporomandibular joint (TMJ) and parapharyngeal tissues (Figure 1). There were no other intracranial or cervical spinal injuries identified, and no evidence of pneumocephalus.

Fig. 1 Sagittal, non-contrast computed tomography scan on initial admission, showing air locules (arrow) within the parapharyngeal tissues.

Notably, the patient had undergone previous surgery at the age of eight years for drainage of a left retropharyngeal abscess, via an external approach.

The patient was admitted for observation, and his level of consciousness improved over several hours. Repeated otoscopy after 24 hours showed an intact canal wall and tympanic membrane with a middle-ear effusion. Audiometry showed a moderate conductive hearing loss across all frequencies.

The patient was observed for 48 hours. There was no further otorrhoea, and he was discharged home without antimicrobial prophylaxis.

Shortly after leaving hospital, the patient developed a sudden, painful swelling in the left side of the neck after blowing his nose.

He returned to the emergency department with stridor. Flexible nasendoscopy showed extrinsic compression of the left supraglottic structures, with partial airway obstruction.

Repeated CT imaging showed extensive fluid stranding within the soft tissues of the left parapharyngeal space, with displacement of the oropharynx towards the right (Figure 2). The fluid extended inferiorly within the left parapharyngeal space, causing a mass effect displacing the carotid sheath. Inferiorly, the fluid did not conform to normal fascial planes, extending both superficial and deep to the strap muscles.

Fig. 2 Axial computed tomography scans taken during second admission, after the patient presented with stridor, showing a parapharyngeal fluid collection causing extrinsic compression of pharyngeal structures.

Based on the degree of upper airway compromise, the patient was electively intubated and admitted to the intensive care unit.

Over the next 12 hours, he developed a fever of 39°C with leukocytosis. Lumbar puncture showed 272 × 10⁶ white cells, while polymerase chain reaction analysis confirmed Neisseria meningitidis infection.

Antimicrobial treatment with intravenous ceftriaxone was commenced, with a good clinical response. The patient was successfully extubated the following day, and his neck swelling resolved over 24 hours.

A literature search showed only one previously documented case of parapharyngeal emphysema associated with temporal bone fracture, following a bicycle crash.Reference Plaza, Martinez-San Millan, Navas and Martinez-Vidal² In this case, a 36-year-old woman presented with dysphagia two days post-injury, and CT scanning showed emphysema below the tympanic bone and spreading along the parapharyngeal space.

Guidelines for the management of CSF fistula include bedrest and stool softeners to avoid elevating the intracranial pressure.Reference Brodie and Thompson¹ In our patient, we propose that a sudden rise in intracranial pressure associated with nose-blowing precipitated a CSF leak into the neck via a flap-valve mechanism. A similar phenomenon has been described with the development of tension pneumocephalus following temporal bone fracture.Reference Ommaya, Wilkins and Rengachary³

The differential diagnosis for a parapharyngeal fluid collection includes haematoma and infection. Rapid resolution of swelling and the absence of clinical signs of infection make these diagnoses less likely. In our patient, percutaneous aspiration of a fluid sample for β-2 transferrin assay may have confirmed CSF leakage; however, this was contraindicated given the risk of iatrogenic infection.

A further literature review returned several case reports of parapharyngeal CSF collection following cervical discectomy.Reference Spennato, Rapana, Sannino, Iaccarino, Tedeschi and Massarelli⁴ In one such case, a tiny dural defect associated with raised intracranial pressure led to a retropharyngeal CSF collection causing severe dysphagia. A similar phenomenon has been described in patients following excision of skull base tumours.Reference Cheng, Maronian and Futran⁵

This case illustrates a previously unreported complication of temporal bone fracture. A CSF fistula following temporal bone fracture can lead to a parapharyngeal CSF collection causing airway obstruction.