Saccadic movement present in all except:

Saccades Rapid, ballistic movement of eyes that abruptly change the point of fixation. Can be elicited voluntarily, but occur reflexly whenever the eyes are open, even when fixated on a target. Rapid eye movement that occur during sleep are also saccades. Site -Basal ganglia or cerebellum. Option B- Huntington's chorea - damage to caudate nucleus Option C- Progressive supranuclear palsy - damage to Basal ganglia Option D- Spinocerebellar ataxia- damage to cerebellum falls backwards But in Alzheimer's - coical dementia