Morphology of the basal ganglia in Parkinson's disease.

This work consists in part of volume measurements for the caudate nucleus, putamen and pallidum; and in part of a determination of cell-distribution and cell density in the corpus striatum from 9 paralysis agitans patients and 15 control persons from the Institute of Forensic Medicine. All 24 brains were sectioned on a specially constructed apparatus. For each of the individual sections, the size of the basal ganglia was determined by measurements of the section thickness with a capillary tube and area measurements were made by microscopic projection method combined with planimetric methods. For the first six control brains, the area measurements were also taken using point-counting method. The values thus obtained were used in the basic formula for a truncated cone and the volume of the basal ganglia for the individual hemispheres was calculated. The only exception was a single hemisphere where the volume of the basal ganglia was determined after dissecting out and weighing these structures. The results showed that the volume measurements of the corpus striatum and the pallidum in these two groups of brains were quite similar, when differences due to body height, age, and brain weight were taken into account. The volume of the basal ganglia decreased with age in both groups of brains and increased with brain weight. The shrinkage of the tissue as a consequence of the histological procedures was also determined. The shrinkage from fresh to formalin-fixed condition was determined by comparing the distance between the same two marked points in the fresh and formalin-fixed tissue. The shrinkage from the formalin-fixed condition to the completed histological preparation was determined by comparing the distance between known structural characteristics, as measured on photographs showing the formalin-fixed sections, lying beside a millimeter scale, with the same distance on the histologically treated preparations. The accumulated shrinkage in volume was 47.3%.