Uncorrected Tetralogy of Fallot Complicated by Brain Abscess and Postoperative Intracranial Haemorrhage: A Case Report.

Cerebral abscess is a rare but potentially fatal complication of cyanotic congenital heart disease, in which chronic hypoxia, polycythaemia and right-to-left shunting allow bacteraemia to bypass pulmonary filtration. A woman in her 20s with uncorrected tetralogy of Fallot presented with severe headache, right-sided weakness and seizures. Examination showed hemiparesis, hypoaesthesia and hyperreflexia; blood tests revealed secondary polycythaemia and leucocytosis. No dental, sinus, otological or respiratory source was identified. Unenhanced computed tomography demonstrated a left parietal space-occupying lesion with midline shift, and echocardiography confirmed tetralogy of Fallot with pulmonary atresia. She received ceftriaxone, metronidazole and dexamethasone, followed by burr-hole drainage. Recovery was complicated by epidural haemorrhage requiring emergency craniotomy and a later subdural haematoma with focal seizures, both managed successfully. This case illustrates that new focal neurological signs in uncorrected cyanotic heart disease warrant urgent imaging for brain abscess, and that polycythaemia compounds perioperative haemorrhagic risk.