Branch Atheromatous Disease: A Clinically Meaningful, Yet Unproven Concept

In 1989, Louis Caplan first used the term branch atheromatous disease (BAD) to describe an occlusion or stenosis at the origin of a deep penetrating artery of the brain, associated with a microatheroma or a junctional plaque, and leading to an internal capsule or pontine small infarct. BAD remained an understudied concept for decades. In recent years, the increasing diffusion of high-resolution magnetic resonance imaging (HRMRI) techniques brought new attention to the BAD debate. We have reviewed clinical studies dealing with BAD-related stroke checking whether a univocal definition of BAD existed, as well as to what extent were consistently associated clinical and imaging features reported.