Optic Ataxia: A Neuropsychological Disorder
Optic ataxia is a clinical syndrome characterized by difficulties in visually guided movements, most notably in reaching and grasping objects. Patients exhibit a combination of ataxia, oculomotor dysfunction, and deficits in spatial cognition. This disorder has been associated with damage to the posterior parietal cortex, a region of the brain responsible for integrating visual and proprioceptive information for the purpose of guiding motor behaviour. In this article, we will discuss the neurological basis of optic ataxia, its clinical presentation, and current research on its treatment.
Neurological Basis of Optic Ataxia
Optic ataxia is believed to result from damage to the posterior parietal cortex (PPC) and related cortical and subcortical structures. The PPC is a region of the brain involved in integrating visual and proprioceptive information for the purpose of guiding motor behaviour. Damage to this region results in deficits in visually guided reaching and grasping, as well as impairments in spatial cognition. It has been proposed that the underlying cause of optic ataxia is a disruption of the normal process of integrating visual and proprioceptive information for the purpose of motor planning and execution.
Clinical Presentation
Patients with optic ataxia present with difficulties in visually guided reaching and grasping movements. These deficits manifest as an inability to accurately reach for objects in space, as well as impaired ability to judge the size and orientation of objects. Additionally, patients may experience difficulties in maintaining posture and balance, as well as deficits in spatial cognition.
Treatment
The treatment of optic ataxia is largely supportive, with physical and occupational therapy being used to reduce the effects of the disorder. Additionally, research has begun to investigate the potential for rehabilitation strategies, such as prism adaptation, to improve visually guided reaching behaviour in patients with optic ataxia.
Conclusion
Optic ataxia is a neuropsychological disorder characterized by deficits in visually guided movements, oculomotor dysfunction, and impairments in spatial cognition. It is believed to result from damage to the posterior parietal cortex, a region of the brain responsible for integrating visual and proprioceptive information for the purpose of guiding motor behaviour. Treatment for optic ataxia is largely supportive, with physical and occupational therapy being used to reduce the effects of the disorder. Additionally, research is beginning to investigate the potential for rehabilitation strategies, such as prism adaptation, to improve visually guided reaching behaviour in patients with optic ataxia.
References
Buxbaum, L. J., Veramonti, T., & Schwartz, M. F. (2011). Optic ataxia: a review of the clinical characteristics, neuroanatomical basis, and treatment implications. Neuropsychology Review, 21(1), 90-108.
Hesse, S., & Rösler, F. (2009). Optic ataxia: clinical features and pathophysiology. Neurocase, 15(6), 392-400.
Rothwell, J. C., & Hallett, M. (2004). Rehabilitation of motor disorders. Oxford University Press.