Brain Pathology Case of the Month - July 2000


The fixed brain weighed 1270 grams without evidence of cortical atrophy. Macroscopic examination revealed symmetrical atrophy of the midbrain and pontine tegmentum. The substantia nigra was slightly depigmented. The globus pallidus and subthalamic nuclei also appeared symmetrically small. Hematoxylin and eosin stained sections revealed many distended neurons containing globose tangles with a fibrillary and whorled texture (Figure 1). These tangles were highlighted by Bodian stain (Figure 2). The globose tangles, frequently accompanied by neuronal loss, were noted in several structures of the brain. The oculomotor complex contained the highest density of globose tangles (Figure 3) with approximately two thirds of the neurons affected. The subthalamic nuclei and pontine tegmentum also contained a high density of globose tangles, followed by the nucleus basalis of Meynert, globus pallidus, putamen, basis pontis, and inferior olive. The substantia nigra contained a moderate number of globose tangles accompanied by a moderate loss of pigmented neurons and gliosis. By immunohistochemistry, the globose tangles were positive for tau protein (Figure 4). In addition, a small number of Bodian stain negative glial cells also demonstrated positive staining for the tau protein (Figure 5). Immunostaining for synuclein or ubiquitin were negative but amyloid deposition was demonstrated by thioflavin S staining. The number of senile (neuritic) plaques or typical neurofibrillary tangles in the hippocampus or neocortex was not increased. Pick's bodies, cortical ballooned neurons or glial inclusion bodies were not identified.


International Society of Neuropathology