COVID-19 nasopharyngeal swab and cribriform fracture

Abstract

Since the start of the pandemic, over 400 million COVID-19 swab tests have been conducted in the UK with a non-trivial number associated with skull base injury. Given the continuing use of nasopharyngeal swabs, further cases of swab-associated skull base injury are anticipated. We describe a 54-year-old woman presenting with persistent colourless nasal discharge for 2 weeks following a traumatic COVID-19 nasopharyngeal swab. A β2-transferrin test confirmed cerebrospinal fluid (CSF) rhinorrhoea and a high-resolution sinus computed tomography (CT) scan demonstrated a cribriform plate defect. Magnetic resonance imaging showed radiological features of idiopathic intracranial hypertension (IIH): a Yuh grade V empty sella and thinned anterior skull base. Twenty-four hour intracranial pressure (ICP) monitoring confirmed raised pressures, prompting insertion of a ventriculoperitoneal shunt. The patient underwent CT cisternography and endoscopic transnasal repair of the skull base defect using a fluorescein adjuvant, without complications. A systematic search was performed to identify cases of COVID-19 swab-related injury. Eight cases were obtained, of which three presented with a history of IIH. Two cases were complicated by meningitis and were managed conservatively, whereas six required endoscopic skull base repair and one had a ventriculoperitoneal shunt inserted. A low threshold for high-resolution CT scanning is suggested for patients presenting with rhinorrhoea following a nasopharyngeal swab. The literature review suggests an underlying association between IIH, CSF rhinorrhoea and swab-related skull base injury. We highlight a comprehensive management pathway for these patients, including high-resolution CT with cisternography, ICP monitoring, shunt and fluorescein-based endoscopic repair to achieve the best standard of care.

Keywords: COVID-19 nasopharyngeal swab; Cribriform fracture; Endoscopic transnasal surgery; Idiopathic intracranial hypertension; Skull base repair.

Figure 1

Images obtained at presentation at the local hospital (a,b) and neurosciences centre (c,d). (a) Computed tomography (CT) head scan (2.5mm slice thickness) with arrow indicating loss of integrity of the right anterior skull base with opacification of the right intranasal olfactory recess. (b) High-resolution CT sinuses (0.63mm slice thickness) with arrowheads indicating thinning of the anterior skull base and sella turcica. (c) T1-weighted magnetic resonance imaging sequence (5.0mm slice thickness) and (d) magnified view framing the pituitary fossa showing evidence of an empty sella. A = anterior; L = left; P = posterior; R = right

Figure 2

Twenty-four hour intracranial pressure (ICP) monitoring results. The ICP was consistently positive, despite the profusely leaking cerebrospinal fluid, even during daytime in the upright position.

Figure 3

Timeline of patient hospital events

Figure 4

Computed tomography (CT) and shunt X-ray (XR) series following shunt insertion. (a) CT head, indicating the proximal catheter inside the foramen of Monro. (b) XR skull, showing: (a) Miethke telesensor reservoir, (b) ProGav2 valve and (c) MBlue valve. (c) XR abdomen, with superimposed red dotted lines indicating the outline and trajectory of the distal catheter. A = anterior; L = left; P = posterior; R = right

Figure 5

Neuro-navigation computed tomography (CT) cisternogram (a–c) and intraoperative endoscopic image (d). (a) Coronal non-enhanced CT cisternogram. (b) Coronal CT cisternogram with Omnipaque iodinated contrast, red arrowhead indicating contrast pool below the skull base defect below the cribriform plate and within the nasal cavity. (c) Parasagittal CT cisternogram with iodinated contrast, with red arrowheads indicating the pooled iodine tracking in the nasal cavity and nostril. Also shown is the arachnoid herniation into the sella (open arrowhead). (d) Intraoperative endoscopic image displaying the anterior cribriform plate defect via a right-sided transnasal approach, with fluorescein leakage. L = left; R = right

Figure 6

Safe and unsafe trajectories for nasopharyngeal swabs (produced using BioRender software)