Walsh & Hoyt: Balint's Syndrome and Related Visuospatial Disorders

In 1909, Balint described a triad of visual defects in a man with bilateral hemispheric lesions. Foremost was an inability to perceive together at any one time the several items of a visual scene, which Balint interpreted as a ""spatial disorder of attention."" Holmes used the term ""visual disorientation"" to describe a similar deficit, whereas Wolpert coined the term ""simultanagnosia,"" the ""inability to interpret the totality of a picture scene despite preservation of ability to apprehend individual portions of the whole."" Balints patient was also unable to move the eyes voluntarily to objects of interest despite unrestricted eye rotations. Balint called this ""psychic paralysis of gaze,"" although other authors subsequently used such terms as ""spasm of fixation"" and ""acquired ocular apraxia."" Finally, Balints patient showed ""optic ataxia,"" a defect of hand movements under visual guidance despite normal limb strength and position sense. Among the many reported causes of so-called Balints syndrome are cerebrovascular disease (especially watershed infarctions, as in Balints original case), tumor, trauma, prion diseases such as Jakob-Creutzfeldt disease, infection by human immunodeficiency virus (HIV) type 1, and degenerative conditions such as Alzheimers disease.