The Width of the Third Ventricle in Neurosurgical Patients with Extrapyramidal Movement Disorders

Abstract

The width of the posterior part of the third ventricle was measured at peroperative encephalography in 105 patients with extrapyramidal movement disorders, undergoing thalamotomy. The average width was found to be 8.9 mm (true dimensions), which means that it was found to be wider than earlier published average widths of the third ventricle in ‘normal’ brains. The width was found to be larger in men than in women. The immediate result of the operation was better in patients with small than in those with wide third ventricles. A normal variation in the width of the third ventricle from day to day of up to 2 mm in the same individual was found.

Third Ventricular Width and the Thalamocapsular Border

“…From this ta ble, it can be readily seen that there is little agreement amongst authors as to what constitutes a normal third ventricle. A likely explanation is the varying degree of cerebral atrophy in extrapyramidal movement disor ders, which is reflected in third ventricular enlargement [1,5,9]. The mean ventricular widths for the various disorders are presented in table II.…”

Position of the Medial Internal Capsular Border in Relation to Third-Ventricular Width

“…These authors also point out that males have slightly but significantly larger ventricles than females. Furthermore, Bogren et al [7] have found, by comparison measurements of preoperative and peroperative encephalograms, a normal variation in the width of the third ventricle from 'day to day' of up to 2 mm in the same patient. During this study, an additional factor has been considered as a cause for the present confusing results reported for the 'normal range' of thirdventricular width.…”

“…Although several authors have used the same contrast encéphalogra phie method (pneumoencephalography), there is little agreement between them as to the normal upper limit of third-ventricular width [7,20], pos sibly due to the patient population used in the sampling. Studies by Nel son et al [16] and Borgen et al [7] indicate that the average width of the third ventricle is significantly larger in patients with extrapyramidal movement disorders than in patients without.…”

“…Studies by Nel son et al [16] and Borgen et al [7] indicate that the average width of the third ventricle is significantly larger in patients with extrapyramidal movement disorders than in patients without. Selby [20] concluded, how ever, that there is no significant difference in the ventricular size of par kinsonian patients, but he stated that there is an increased incidence of associated cortical atrophy.…”

Displacements of Brain Due to Positional Changes during Stereotactic Operations

“…Comparison of X-ray films from studies so separated in time may contain sources of error, e.g. the effects of postencephalographic oedema [1],…”