Chronic subdural haematoma and arachnoid cyst in autosomal dominant polycystic kidney disease (ADPKD).

We present the unusual association between chronic subdural haematoma (CSDH), intracranial arachnoid cyst and autosomal dominant polycystic kidney disease (ADPKD) in a 27-year-old man. CSDH is a documented complication of intracranial arachnoid cyst, the incidence of which is increased in patients with ADPKD. Awareness of this association may lead to earlier diagnosis of ADPKD and treatment of its systemic complications, including renal insufficiency, systemic hypertension and previously unsuspected intracranial saccular aneurysm. Surgery for CSDH associated with intracranial arachnoid cyst may be complicated by over-drainage of cerebrospinal fluid due to communication between the cyst and the cisternal subarachnoid space, as illustrated in the present case, and the development of epidural haemorrhage.