Two reports are published that represent important contributions to our understanding of the natural history of cerebrovascular disease, one addressing the haemorrhage and growth risk of small paraclinoid aneurysms and the other addressing arteriovenous malformation (AVM) features associated with seizure presentation.

Jeon and colleagues¹ evaluated a cohort of 524 patients possessing very small, unruptured paraclinoid aneurysms, revealing an exceedingly low rate of rupture (2 cases) and growth (17 cases) over 1675.5 aneurysm-years. Large natural history studies often group internal carotid artery (ICA) or internal carotid artery aneurysms except posterior communicating artery aneurysms (non-PCcomm). This can obscure the haemorrhage risk of paraclinoid aneurysms as a result of mixing them with ICA bifurcation and anterior choroidal artery aneurysms,1 ,2 the latter more akin to posterior communicating artery aneurysms. This more selective study allows for a direct analysis of very small paraclinoid aneurysms and reinforces their generally very low risk …