[Visual-form thinking of patients before and after stereotaxic surgery on the ventrolateral nucleus of the thalamus].

An examination of patients with deformed muscular dystonia before and after stereotaxic surgery on the ventrolateral nucleus of the thalamus showed that prior to the surgery they had a certain difficulty in solving tasks involving mental manipulation with three-dimensional objects and constructive activity. It took them more time to accomplish these tasks and they made different mistakes as compared to normal. Changes in the object and image thinking differed, depending on the side of the destruction of the ventrolateral nucleus of the thalamus. Patients with right-side lesion were prone to overturn both a three-dimensional figure and a two-dimensional image, they showed greater changes in conducting tests on mental manipulation and constructive activity as against the patients who had left-side cryodestruction. It may be assumed that impairment of the complex forms of spatial functions manifested in mental manipulation with objects and in constructive activities is related to the work of the subcortical formations of the right hemisphere.