Figure 1.
Spatial localisation of peak Vop and Vim voxels as defined by probabilistic tractography.
Individual images were realigned to standard space with a 6 DOF transformation in a way to match the location of the AC and align the AC-PC line and the midsagittal plane. The registered peak connectivity voxels for the primary motor (Vim - in red) and for the premotor cortex (Vop – in blue) are shown on three orthogonal slices.
Figure 2.
Preoperative FLAIR images show the right perirubral mesencephalic traumatic haemorrhage.
Images are presented in radiological convention.
Figure 3.
Connectivity-based segmentation of the right thalamus of the patient operated on for tremor caused by traumatic mesencephalic bleeding.
Results are overlaid on the postoperative FLAIR images. The bright area represents the Stereotactic thalamotomy. The key to the colour coding of the thalamic segmentation is shown in the inset. The colour in each thalamic voxel represents the colour of the cortical area that has the highest connection probability to that voxel.
Figure 4.
Connectivity of the thalamic lesion, evaluated using multi-fiber probabilistic tractography.
The tracts reach the premotor cortex, on one hand, and the nucleus ruber and the perirubral mesencephalon, on the other hand, with some travelling further to the cerebellum. The image is thresholded at 500 particles (10%).
Figure 5.
Connectivity-based segmentation of the left thalamus of the patient having essential tremor.
Results are overlaid on the postoperative T1-weighted image. White voxels represent the location of the Stereotactic lesion. The colour coding of the thalamic segmentation is the same as that using in Figure 3. The lesion is in the area of the thalamus connected most strongly to the primary motor cortex: the putative Vim.
Figure 6.
Connectivity of the thalamic lesion of the essential tremor patient, evaluated using multi-fiber probabilistic tractography.
The tracts reach the primary motor cortex, on one hand, and travelling to the cerebellum on the other hand. The image is thresholded at 250 particles (5%).