Distal lenticulostriate artery aneurysm in deep intracerebral haemorrhage.

Aneurysms of the distal lenticulostriate artery (LSA) are rare. Only 16 cases have been reported in the literature. Early detection and treatment of these aneurysms is also difficult because of their deep location, small size and angioarchitecture. We report two additional patients with aneurysms, arising from the distal LSA, who presented with deep intracerebral haemorrhage. The conclusions drawn from our experience and a comprehensive review of the literature include the following. (1) A distal LSA aneurysm should be considered in young (mean 38.5 years) and non-hypertensive (80%) patients with deep intracerebral haemorrhage. (2) These aneurysms are frequently very small (<5 mm). Therefore, they cannot be detected on initial angiograms in some cases. (3) These aneurysms have higher rates of associated vascular lesions. Deep intracerebral haemorrhage, even in those over the age of 50 years, can still be due to underlying, treatable structural abnormalities, and should not be dismissed as being a result of hypertension. In addition, a more comprehensive diagnostic approach seems to be warranted in younger patients and those without known hypertension.