Third ventricular width and the thalamocapsular border.

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.