While the oculomotor features of PSP and IgLON5 disease show great overlap, a lack of saccadic intrusions and square wave jerks has been found to be more common in anti-IgLON5 than in PSP, which may be a result of the involvement of the cerebellum in PSP but not in IgLON5 disease [7]. Here, IGLON5 is linked to supranuclear palsy, progressive, 1.