Infratentorial hemorrhagic cerebral proliferative angiopathy: A rare presentation of a rare disease.

Cerebral proliferative angiopathy (CPA) is a unique and rare vascular malformation with distinct clinico-radiological features. CPA is associated with low risk of hemorrhage as compared to classical cerebral arteriovenous malformations (AVMs). Infratentorial location of diffuse nidus is also an uncommon presentation. Infratentorial hemorrhagic presentation of CPA is a rare co-occurrence. Herein, we report a case of an elderly old male, who presented with acute onset severe headache, recurrent vomiting, vertigo and swaying toward left side while walking. Cerebellar signs in the form of scanning speech, nystagmus, impaired finger-to-nose incoordination test, dysdiadochokinesia, and limb ataxia on the left side were present. Magnetic resonance imaging (MRI) brain revealed diffuse vascular network with intermingled normal brain parenchyma and hemorrhage in the left cerebellum. Digital subtraction angiography (DSA) revealed diffuse, ill-defined, nidus in left posterior fossa involving the left posterior inferior cerebellar, anterior inferior cerebellar and posterior cerebral arterial territories. There were no definite arterial feeders. DSA showed scattered "puddling" appearance of contrast material in the widespread nidus and drained into the multiple ill-defined posterior fossa veins. The MRI brain and DSA findings were consistent with the diagnosis of the CPA. Treatment in our case was limited to supportive medical therapy because selective embolization was not feasible due to nonidentifiable arterial feeders. He was asymptomatic at 1-year follow-up. This case highlights a rare entity called CPAs, which have different clinical presentations, angiographic features, treatment options and patient outcome as compared to classical cerebral AVMs.