[Electrophysiological atlas of human thalamus and adjacent structures.--Microcomputer assisted mapping of neurophysiological data and its application to stereotaxic surgery].
During stereotaxic surgery anatomical structures and their extent on trajectories were identified by neural noise (field potential) obtained by semi-microelectrode technique. Locations of anatomical structures (the white mater, caudate nucleus, thalamus, subthalamic field and nuclei in the subthalamic field) were fed into microcomputer (NEC PC-8001) as 3 dimensional correlates and stored in minifloppy disc system (NEC PC-8031). Data with satisfactory recordings from 48 trajectories from 30 patients (18 parkinsonism, 5 central pain, 7 others) entered this study. Microcomputer was so programmed that locations of the trajectories and electrophysiologically identified anatomical structures at that location in various coronal, sagittal and horizontal planes were displayed. Accumulation of this display from various groups of patients automatically created electrophysiological atlas. For comparison of thus created electrophysiological atlas with anatomical atlas display was made on various sections of the Schaltenbrand and Bailey's Atlas which were also stored in the mimifloppy disc system. Electrophysiological topography of the thalamus and adjacent structures was reasonably similar to anatomical topography with minor, but significant individual variations. In most cases the ventral border of the thalamus was located in the close vicinity of CA-CP line, however, in some cases the thalamus was located deep into the subthalamic field. This was thought to be due to the difficulty in identifying the ventral border of the thalamus by this technique and in such occasions other neurophysiological method for identifying the ventral border of the thalamus, i.e., thalamocortical evoked potential and other stimulation technique, were necessary. Medial aspect of the V. im. nucleus emitted neural noise of different characteristics which in current program was recognized as the subthalamic field. This implies that the medial and lateral aspects of the V. im. nucleus are cytoarchitecturally different and that it is possible to differentiate the medial and lateral aspects of the V. im. nucleus by this technique. The lateral thalamic border, i.e., thalamocapsular border, also showed relatively wide range of individual variations. When various parameters including age, sex, diagnosis and width of the 3rd ventricles were examined for possible cause of these variations, a tendency was noted that the thalamocapsular border was medially placed when the width of the 3rd ventricle was small. In this system it is possible to display sequentially electrophysiologically identified structures along any trajectory. This display method, which was called "tract study," was very usefull for comprehensive understanding of location of trajectory in relation to individually varying anatomical structures...
D000293:Adolescent; D000328:Adult; D001931:Brain Mapping / Q000379:methods; D003201:Computers; D004027:Diencephalon / Q000033:anatomy & histology* / Q000502:physiology / Q000601:surgery; D004558:Electric Stimulation; D004594:Electrophysiology; D005260:Female; D006801:Humans; D008297:Male; D008838:Microcomputers; D008875:Middle Aged; D010148:Intractable Pain / Q000601:surgery*; D010300:Parkinson Disease / Q000601:surgery*; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000033:anatomy & histology / Q000502:physiology