October 5, 2015: Balint Syndrome
October 5, 2015
In the early twentieth century, a Hungarian physician described the eponymic Balint Syndrome, which in its classic form is characterized clinically by optic apraxia, simultanagnosia, and ocular ataxia. Lesions or disease processes affecting the bilateral dorsal occipitoparietal lobes can cause this triad of signs.
Simultanagnosia describes an inability to attend to more than one stimulus and thereby failure to perceive the visual field as a whole. At bedside this sign can be elicited by showing a complex picture and noting the patient's inability to describe more than one aspect. A subset of simultanagnosia is single-letter reading, wherein entire words cannot be read, constituting a form of alexia. Optic apraxia refers to an inability to initiate and control voluntary eye movements, although the range of movement of the eyes remains full. Ocular ataxia occurs when the visual system fails to coordinate with the motor system to guide complex voluntary movement, and those affected are unable to reach out and grasp objects within their visual field.
- Finney GR. Perceptual-motor dysfunction. Continuum 2015; 21: 678-689.
- Rizzo M, Vecera SP. Psychoanatomical substrates of Bálint's syndrome. J. Neurol. Neurosurg. Psychiatr 2002; 72: 162-178.
Submitted by Sarah Wesley, MD, Mount Sinai Beth Israel Medical Center, Department of Neurology.
Disclosures: Dr. Wesley is a member of the Resident and Fellow Section of Neurology.