KP1 expression of ghost Pick bodies, amyloid P-positive astrocytes and selective nigral degeneration in early onset Picks disease

We present a patient with early-onset Pick's disease in which selective nig ral degeneration, KP1 expression of ghost Pick bodies and amyloid P-positiv e astrocytes were found. We also review the literature on early-onset Pick' s disease. A 34-year-old man showed personality change including stereotypi cal behavior. Muscle rigidity and spasticity developed later, and he died t welve years after the onset of his illness. The brain showed lobar cerebral atrophy prominent in the temporal lobe, and to a lesser degree in the pref rontal and orbitofrontal cortex. The substantia nigra displayed profound de generation whereas the head of the caudate nucleus and the putamen were not so seriously affected because the neurons were preserved and only slight a strocytic proliferation was seen. Many Pick bodies were found in the hippoc ampal formation, and ballooned neurons (Pick cells) were dispersed througho ut the cerebral cortex, subcortical grey matter and hippocampal formation. The affected white matter exhibited severe fibrillary gliosis, and numerous astrocytes positive for glial fibrillary acidic protein and microglial cel ls positive for CR3/43 were found in the atrophied cortical lesions. The in traneuronal Pick bodies expressed ubiquitin, neurofilament and tan, and KP1 distinctly stained ghost Pick bodies. Tau-positive astrocytes were found i n the striatum, hippocampal formation, pontine tegmentum, substantia nigra and affected frontotemporal cortices. These astrocytes were also positive f or amyloid P. Extensive search of the literature on early-onset Pick's dise ase disclosed only a few cases with selective nigral degeneration, and we f ailed to find any differences in duration, progression of the illness and t he extent of subcortical gray matter involvement between cases of early-ons et and presenile onset of Pick's disease. We conclude that the striatopalli dal and nigral system can be affected independently in Pick's disease and r eport new immunohistochemical findings.