A young man with a headache

Abstract

A 28-year-old male presented to hospital with sudden onset of headache associated with vomiting. The patient denied trauma and had no medical history of note apart from having regular headaches, which normally resolved with rest and paracetamol. He had no known drug allergies, was not on any regular medication and had no significant family history. Physical examination revealed a dense right hemiplegia and all initial laboratory investigations were normal. An emergency CT scan of the brain confirmed a left middle cerebral artery (MCA) territory infarct associated with significant cerebral oedema and midline shift towards the right. A subsequent CT cerebral angiogram demonstrated occlusion of the left internal carotid artery. A short time after admission, the patient developed unreactive pupils and decreased GCS (Glasgow coma scale). An emergency left frontoparietal craniotomy was performed and a CT scan of the brain repeated (Figure 1). The scan demonstrated a left frontoparietal craniotomy with a large left MCA infarct with midline shift towards the right. It was noted that the left-sided sulcal effacement and ventricular size was unchanged when compared with the previous CT brain scan. Figure 1 CT brain scan demonstrating a left frontoparietal craniotomy with a left-sided large middle cerebral artery infarct with midline shift to the right. Owing to the young age of the patient, an 18-fluoro-2-deoxyglucose positron emission tomography computed tomography (18F-FDG PET-CT) scan was performed 22 days after the initial presentation to investigate a potential underlying cause (Figure 2). The images obtained raise several questions. What are the radiological abnormalities demonstrated here on the dotted and solid arrows? What is the diagnosis? Figure 2 (a) 18F-FDG PET image of the brain. (b) 18F-FDG PET-CT image of the brain. Images demonstrate hypometabolism in left MCA infarct (solid arrows) and the right cerebellar hemisphere (broken arrows).