Lateral coordinate of the thalamic Vim neurons in the cases with dilated third ventricle
Maeda, T.; Yokochi, F.; Narabayashi, H.
No Shinkei Geka. Neurological Surgery 16(9): 1045-1052
1988
ISSN/ISBN: 0301-2603 PMID: 3205365 Document Number: 322770
Precise radiographical measurement of the third ventricle is the first and essential procedure in stereotaxic surgery in order to determine the target point. This is done while referring to an available standard brain atlas such as Schaltenbrand and Bailey. However there have been no criteria established for determining the deviation of the coordinates of the thalamic nuclei, especially in their lateral coordinates when the third ventricles is highly dilated. Therefore, in 109 cases encountered recently (81 parkinsonism, 11 essential tremor, 10 cerebral palsy, 3 thalamic pain, 1 Benedikt's syndrome, 1 torticollis, 1 oral dyskinesia, 1 striato-nigral degeneration), we studied the correlation between the width of the third ventricle and the lateral coordinate of the thalamic point where kinesthetic neurons of the thalamic point where kinesthetic neurons or tremor-synchronously discharging neurons were detected. These neurons were especially related to the arm. According to the width of the third ventricle, we classified the cases into three types : 18 cases with large ventricles (more than 10 mm), 37 cases with medium-sized ventricles (4-10 mm) and 16 cases with small ventricles (less than 4mm). By plotting the lateral coordinate of the thalamic point where kinesthetic neuron of the upper extremity was recorded in reference of the upper extremity was recorded in reference to the radiogram of anteroposterior view, we found that the lateral coordinates of large ventricular cases generally tended to show more lateral displacement than cases where the ventricles were narrower. Their mean lateral coordinate was 16.9mm from the midline in contrast to 14.0mm in cases with small ventricular width. There was a linear correlation between the width of the third ventricle and the lateral coordinate of the kinesthetic neuron of the Vim nucleus. If a regression line was fitted, the slope of this line was about one third.