Severe Obstructive Sleep Apnoea Leading to Raised Intracranial Pressure Hydrocephalus in a Patient with Aqueduct Stenosis.

We present the case of a patient with severe obstructive sleep apnoea (OSA) and hypoventilation syndrome who had hydrocephalus and acquired aqueduct stenosis. A link between these conditions in our patient is postulated. We discuss the mechanisms through which this might have occurred and the potential problems which might arise in applying non-invasive ventilation to a patient with hydrocephalus. LEARNING POINTS: Patients with severe obstructive sleep apnoea (OSA) and hypoventilation require AVAPS-AE ventilation to deal with obstructive and central events which may occur.Arterial blood gas analysis and MRI of the brain are indicated in the assessment of patients with severe OSA.Hydrocephalus may develop in patients with severe OSA if there is a structural brain abnormality but may resolve with OSA treatment. © EFIM 2021.