Blog

The disruption of radial neuronal migration during brain development results in malformations composed of heterotopic grey matter (Barkovich et al., 2012). These may form continuous bands (laminar heterotopia) or discrete nodules, either in subcortical or periventricular locations (periventricular nodular heterotopia, PVNH). PVNH typically resides along the walls of the ventricular trigone, either unilaterally or bilaterally (Tassi et al., 2005). Nodular heterotopia is often associated with other types of cortical malformation, including polymicrogyria (PMG) (Wieck et al., 2005) and focal cortical dysplasia (Meroni et al., 2009), and is a common cause of refractory focal epilepsy (Dubeau et al., 1995; Battaglia et al., 2006).