What causes for this haemorrhage would you consider?
Hypertension and amyloid angiopathy could be considered as they are common but the pattern of parenchymal, subdural and subarachnoid haemorrhage is atypical. An underlying cause such as vascular malformation or aneurysm should be considered.
What would you do next?
CT angiography is the first line test because of it is noninvasive and readily available but DSA is the gold standard for investigation of cerebral vascular abnormalities.
Large posterior fossa haematoma centred within the right cerebellar hemisphere with spread into the subarachnoid and subdural spaces, and further intraventricular spread with haematoma in the trigones of both lateral ventricles.
Significant mass effect with ascending transtentorial herniation and cerebellar tonsil herniation.
Hydrocephalus secondary to complete effacement of the fourth ventricle. Normal aortic arch anatomy.