interpretation of command and fixation saccades
Last reviewed 01/2018
- amplitude - is the gaze excursion full?
- induced nystagmus in the presence of a reduced gaze excursion (usually gaze-paretic nystagmus). It is slow (1-2 cps). The fast phase is in the direction of attempted gaze - signifies an incomplete or recovering gaze palsy.
- speed - slow saccades may signify different pathologies, for example, be the only sign in a child of infantile kernicterus - the fronto-mesencephalic fibres having been affected near the basal ganglia. Slow saccades occur also in parkinsonism.
- smoothness. Hypermetric saccades - small jerks towards the final goal - this may occur in saccadic paresis as well as in the extrapyramidal system disorders and cerebellar cortical atrophy, or diffuse cerebellar disease which causes saccadic pursuit.
Other abnormalities may be noted e.g. flutter, eyeball retraction.