[An autopsy case of corticobasal degeneration with predominant involvement of the prefrontal lobe, limbic system, and especially of the medial temporal base].

We report a case of corticobasal degeneration (CBD) with prominent degenerative changes in the temporal base. The patient developed parkinsonism with a marked tendency to fall and dementia at the age of 69. His symptoms progressively worsened. Finally, he was akinetic and mute and died by infection at 71 years of age, 32-months after the onset of his neurological symptoms. At autopsy, symmetrical atrophy of the prefrontal lobe was seen, yet the regions around the central sulci were preserved. Neuronal depletion and numerous achromatic ballooned neurons were found in the prefrontal lobe, cingulate and rectal gyri, insula, and the medial temporal base. In these regions astrocytic plaque-like structures and argyrophilic threads were demonstrated with Gallyas' silver stain. These findings were compatible with CBD and were most pronounced in the prefrontal lobe and the medial temporal base, more predominantly on the right side. In contrast, the regions around the central sulci, which were the most severely involved in usual cases of CBD, had only mild changes. The substantia nigra was atrophic and showed marked neuronal loss and occasional argyrophilic inclusions in the remaining neurons. No Pick body was seen. In addition, findings of mild Alzheimer's disease and degenerative changes in the middle portions of the crus cerebri were observed. Our case of CBD is notable for this atypical topography of degeneration.