[Identification and lesion of prelemniscal radiation in the surgical treatment of tremor].
In a group of 40 patients operated on for the relief of tremor using stereotaxic techniques, the radiological location and electrophysiological characteristics of the optimum target were studied. The optimum target was defined as the place where the minimal lesion produced by the insertion of a 1.5 mm diameter electrode produced immediate cessation of tremor in the contralateral extremities. It was found that the optimum target is located in the subthalamus. Within this area electrical stimulation did not elicit sensory of pyramidal responses, but increased the amplitude of tremor. The study of somatic evoked potentials produced by stimulation of contralateral median nerve confirmed that the area does not correspond to a specific sensory system (medial lemniscus). By recording multiple unit activity a spontaneous 5 cycle per second rhythmic pattern, similar to that described for the VL thalamic nucleus, was occasionally seen. Finally, through an IBM 1130 computer the radiological location of those electrodes in the target area was approximated to a line, representing a vector whose orientation in space could be compared with that of different anatomical structures, and corresponded to the prelemniscal radiation. We concluded that the target area herein described is part of a reticulothalamic system that conveys tremogrogenic impulses to the pyramidal system and from here to the periphery.
D003201:Computers; D004567:Electrodes, Implanted; D004569:Electroencephalography; D006801:Humans; D011859:Radiography; D012886:Skull / Q000000981:diagnostic imaging; D013238:Stereotaxic Techniques; D013788:Thalamus / Q000601:surgery; D014202:Tremor / Q000601:surgery*
Identificaión y lesión de las radiaciones prelemniscales en el tratamiento quirúrgico del temblor