SPAST and hereditary spastic paraplegia: Although increasing research has shown that SPG4-linked HSP is associated with cognitive dysfunction (Orlacchio et al., 2004; Murphy et al., 2009; Chelban et al., 2017; Akaba et al., 2021; Erfanian Omidvar et al., 2021; Giordani et al., 2021), the studies on its mechanism remain few.