Abstract
We described a patient who exhibited action disorganization syndrome(ADS)with callosal disconnection syndrome. We studied the mechanism and the region concerned with ADS. ADS's characteristic action errors are object substitution, sequential errors, omissions, quality errors and place substitutions. These errors appear in activities of daily living which involve many steps. The concepts of the target action are preserved in ADS patients, but the action schema in the contention scheduling system is incorrectly represented. For example, an action schema is omitted or an inappropriate schema is represented. Moreover, the function of the supervisory attention system gets out of order. As a result, the disordered action schema in CSS is accepted and output in the state prescribed, and action disorders are exhibited.
An MRI scan of our patient revealed damages in the left superior, middle frontal gyri and genu of the corpus callosum. The records of other ADS patients showed they were all damaged in the lateral or bilateral superior, middle frontal gyri. One was damaged in the corpus callosum as well. Due to the damage to the wide frontal lobe area which contains commissural fibers connected to the bilateral frontal lobes, especially the superior, middle frontal gyri, neural information is not integrated. Disorders of attention and inhibition are thought to relate to this disorder.
