The search for a physiologic marker of Machado‐Joseph disease

Abstract

Machado-Joseph disease is a dominantly inherited, multisystem, degenerative disorder that lacks a proven genetic marker. Peripheral nerve conduction-refractory period, sensory evoked potentials, and quantified oculomotor recordings were studied in nine patients affected with this disease to look for a potential physiologic marker. Only the oculomotor measurements of saccade and smooth pursuit gain were consistently abnormal in all patients. Identical eye movement recordings in 12 asymptomatic individuals at risk for Machado-Joseph disease revealed findings typical of affected patients in only 1 individual. Quantified oculomotor studies may contribute to the early confirmation of the disease, primarily in individuals at risk with minor or equivocal neurologic signs.

Basic and translational neuro-ophthalmology of visually guided saccades: disorders of velocity

“…Eye movement abnormalities such as impaired smooth pursuit, optokinetic nystagmus, gaze evoked nystagmus, saccadic dysmetria and horizontal vestibulo-ocular reflex dysfunction are well known deficits of spinocerebellar ataxia type 3 [221, 222, 223, 224, 225, 226]. The saccades in some spinocerebellar ataxia type 3 patients may have dynamic overshoot of the target, however, those without dynamic overshoot have saccades with low peak velocity [228].…”