optic ataxia
Pronunciation: OP-tik ah-TAX-ee-ah
A visuomotor disorder characterized by misreaching for visually presented objects despite intact visual perception and motor function.
Full Definition
Optic ataxia is a specific visuomotor deficit characterized by inaccurate reaching and grasping movements toward visually guided targets, particularly in peripheral visual fields. This condition typically results from lesions in the superior parietal cortex, particularly the parietal reach region, which is crucial for transforming visual information into motor coordinates for reaching movements. Patients with optic ataxia show normal visual perception, can accurately describe object locations, and have intact motor function for non-visually guided movements, but demonstrate significant errors when attempting to reach for objects, especially those presented in their contralesional visual field. Optic ataxia is often one component of Balint syndrome, along with simultanagnosia and oculomotor apraxia. Assessment involves systematic testing of reaching accuracy across different visual field locations.
Usage
Usage note: Distinguish from other forms of ataxia in clinical documentation.
In Context
- "Optic ataxia was evident in the patient's inability to accurately reach for objects in her left visual field." — Visuospatial assessment
- "The patient's optic ataxia improved significantly with prism adaptation training." — Rehabilitation progress note