[Dissecting aneurysm of the posterior inferior cerebellar artery--a case report].

Abstract

The authors present a case of dissecting aneurysm of the right posterior inferior cerebellar artery (PICA) in a 47-year-old female, who suffered from mild subarachnoid hemorrhage. Right vertebral angiogram showed typical "pearl and string" sign of the PICA, but we could not fully understand the condition until a surgical exposure revealed a purple sausage-like dissecting aneurysm of the PICA. The aneurysm was wrapped with muscle pieces. Postoperatively she developed Wallenberg's syndrome, but it subsided gradually. No specific disorder concerning the mural dissection was found in this patient, except for a history of mild hypertension. This case is unusual because it affected not an arterial trunk but a small branch and we could find only one other case reported in the literature. Other formerly reported cases were of arterial trunks. The intracranial dissecting aneurysm has been known as a rare cause of cerebral infarct in children and adolescents. Infants are also affected and referred to as "infantile hemiplegia". It mainly affects one of the trunk arteries and cause a severe ischemic stroke, and surgically treatable case is rare. But as the typical angiographic findings are commonly known the number of the reported cases is increasing at an accelerating rate, and some of them are being noted to need surgical treatment because they cause subarachnoid hemorrhage. We here emphasize that not only trunk arteries but also small branch arteries can develop mural dissection, leading to subarachnoid hemorrhage. Dissecting aneurysm of a smaller artery would be milder in symptom, and would give more chance for surgical intervention.(ABSTRACT TRUNCATED AT 250 WORDS)