All of the seven SPG11 probands had a complicated form of HSP and showed cognitive impairment: dysarthria 5/7; dysphagia 2/7; nystagmus 3/7; ophthalmoparesis (horizontal gaze) 2/7; cervical dystonia 1/7 and mild ataxia 3/7. Here, SPG11 is linked to Nystagmus.