A common complaint ... a rare disease!

A 2-year-old previously well child presented to the emergency department with temperatures and lethargy. He was pale and looked unwell. He received a fluid bolus and was commenced on intravenous ceftriaxone. Pus was discharging from his left ear with postauricular swelling and erythema. Given clinical concerns, urgent neuroimaging was arranged. QUESTION 1: What does the CT scan of head show (figure 1)?edpract;107/4/268/F1F1F1Figure 1Enhanced CT showing external and middle ear infection with skull base osteomyelitis.Acute subdural collectionAcute mastoiditis secondary to sinusitisEnhanced cerebral lesionsMeningitis with abscess formationMiddle ear infection with skull base osteomyelitisA subsequent MRI scan was performed (figure 2).edpract;107/4/268/F2F2F2Figure 2MRI shows thrombus in left jugular vein, and MRA demonstrates occlusion of left internal carotid artery secondary to carotid sheath infection. QUESTION 2: What do these two images show?Left jugular vein dissection with subdural haematomaLeft jugular vein thrombus and carotid artery occlusionPosterior fossa tumourRight sided posterior communicating artery aneurysmSkull base abscess QUESTION 3: What is the most likely diagnosis?Acute mastoiditis secondary to chronic sinusitisCerebral tuberculosis (TB)Hereditary thrombophilia (protein S deficiency)Lemierre's syndromeNon-accidental head trauma (NAI) QUESTION 4: What is the most commonly identified organism in this syndrome?