65 patients were selected to assess variations in third ventricular width. The patients suffered from various extrapyramidal movement disorders, and all had undergone stereotactic VL thalamotomies. Third ventricular width was correlated with age, sex, diagnosis and intercommissural distance. Based upon the analysis of somatosensory response mappings, a medial displacement of the thalamocapsular border was demonstrated for patients with narrow third ventricles.

Age Factors↗

PubMedDate not supplied

Electrophysiologic principles of radiofrequency lesion making.

Understanding of the electrophysiologic principles of radiofrequency lesion making is necessary to ensure reliable results in surgical procedures using this technique. A radiofrequency lesion is produced by tissue electrocoagulation. Its method of formation and factors affecting heat generation and loss are discussed. Guidelines for making radiofrequency lesions, based on electrophysiologic principles are outlined.

Electrocoagulation↗

PubMedDate not supplied

Sensory organization of the human thalamus.

A computerized program has been developed for on-line display and tape-library storage of stimulation-mapping data collected during stereotactic procedures. Using computer-generated displays of pooled clinical physiological data it has been possible to map through the upper midbrain and thalamus the lemniscal, spinoquintothalamic, auditory, vestibular, visual, extrapyramidal, and motor pathways, as well as the location of the pia. Each system is recognizable by a stereotyped, artificial, somatotopically organized stimulation-induced response that is devoid of modality information and independent of the site and parameters of stimulation.

Auditory Pathways↗