A 49-year-old man had acute-onset dizziness, vomiting and diplopia. He had taken treatment for HIV infection since 2017, with a CD4 count over 300x106/L (430–1690) and suppressed HIV viral load. His blood pressure was 170/110 mm Hg on presentation though without history of hypertension. On examination, there were cerebellar signs, including bilateral horizontal gaze-evoked nystagmus, dysdiadochokinesia, dysmetria and an ataxic gait. An uncontrasted CT scan of the head identified bilateral cerebellar and brainstem (midbrain, pontine and medullary) haemorrhages, but CT angiogram of the cerebral and neck vessels was normal. We initially diagnosed a hypertensive-related intracranial haemorrhage and admitted him to optimise vascular risk factors and for rehabilitation.
Over the next 48 hours, he had a persistent low-grade temperature. Blood culture grew Listeria monocytogenes, and cerebrospinal fluid (CSF) showed a lymphocyte-predominant pleocytosis, a mildly elevated CSF protein concentration and CSF PCR positive for Listeria. His platelet count and partial thromboplastin time were normal….