Pitfalls in the determination of intracranial spread of complicated suppurative sinusitis

We present two cases of suppurative sinusitis that presented to our casualty department over a one-week period. Both patients suffered complications of the disease secondary to extension of the inflammatory process beyond the bony confines of the sinus. Neither of the patients had a previous history of sinus disease. The first patient deteriorated suddenly 24 hours after admission. The initial computed tomography (CT) scan failed to demonstrate a developing subdural empyema. This complication was confirmed following repeat scanning 24 hours later and the patient required urgent neurosurgical intervention and drainage. The second patient presented with periorbital cellulitis secondary to sinusitis and suffered a grand mal seizure on admission. Once again initial CT scan changes were subtle and significant intracranial extension was not noted until the subsequent magnetic resonance imaging (MRI) scan was performed. The purpose of this paper is to highlight the potential dangers over reliance on CT scanning in diagnosing early intracranial spread of sinus disease and we emphasise that the clinician must interpret any radiological investigations in light of the associated clinical findings.