An immunohistochemical study was carried out to investigate the topographic distribution of calbindin-D28k in the human basal ganglia and substantia nigra and its alterations in patients with idiopathic Parkinson's disease (PD), parkinsonism-dementia complex on Guam, progressive supranuclear palsy, and striatonigral degeneration. In normal control subjects, calbindin-D28k immunoreactivity was identified in the medium-sized neurons and neuropil of the matrix compartment of the striatum, the woolly fiber arrangements of the globus pallidus, and the fiber structures of the pars reticulata of the substantia nigra. Calbindin-D28k expression in the basal ganglia of patients with PD and parkinsonism-dementia on Guam was not different from that of control subjects, suggesting that the matrical output pathway is spared in these disorders. In contrast, its disruption is inferred from the observed disorganization of woolly fibers in the globus pallidus of patients with progressive supranuclear palsy and the reduced calbindin-D28k reactivity in the putaminal matrix and the pars reticulata of the substantia nigra of subjects with striatal degeneration. Thus, our results indicate that calbindin-D28k is a useful marker for the projection system from the matrix compartment and that its expression is modified in patients with progressive supranuclear palsy and striatal degeneration.

Abstract

This study was designed to estimate cerebral dysfunction in senile dementia of the Alzheimer's type (SDAT). Regional cerebral blood flow (rCBF), oxygen extraction fraction (rOEF) and cerebral oxygen consumption (rCMR02) were studied in 16 patients with SDAT and 5 age-matched normal elderly people by positron emission tomography (PET), using the 150 labeled CO2 and 02 inhalation technique.This technique was also applied to the evaluation of PET in diagnosing the dementing illnesses.In this study, a total of 19 pairs of bilateral cerebral regions were analyzed and the reductions of rCBF and rCMR02 in each region were compared with those of the primary sensorimotor cortex to demonstrate any significant localized difference between each clinical stage of the SDAT and normal controls.In the mild SDAT group, CMR02 of the temporal cortex was significantly reduced, as compared with that of controls. In the moderate SDAT group, CBF of the temporal cortex and CMR02 of the temporal and parietal cortices were significantly reduced. In the severe SDAT group, CBF and CMR02 of the frontal cortex were also reduced and those of the occipital cortex were relatively unchanged. This suggested that mildly demented patients showed a metabolic reduction in the temporal cortex and as the dementia progressed, metabolic reductions were extended to the parietal and frontal cortices. Reductions in blood flow were followed by further metabolic reductions. More detailed investigation of the PET images of SDAT revealed that relative oxygen hypometabolism of the posterior temporal and posterior parietal association cortices occurred in the mildly demented patients earlier than that of the other association cortices. These findings are consistent with neuropathological studies of SDAT.The right/left ratio of rCMR02 was also analyzed in each region. The right/left oxygen metabolic asymmetry in the temporal and parietal cortices was correlated with the difference between speech and visuospatial functions. Namely, the patients with a lower metabolism in the left hemisphere had more disturbances in speech than visuospatial functions.In addition, the PET images of SDAT were compared with those of multi-infarct dementia (MID) and Pick disease. In patients with MID, there were reductions of CBF and CMR02 unhomogeneously all over association cortices, but the reductions were most remarkable in the frontal cortex. Patients with Pick disease showed diffuse lobar reductions of CBF and CMR02 in the frontal and temporal cortices. These findings of MID and Pick disease were clearly different from those of SDAT, so PET will provide a sensitive means to differentiate among the dementing illnesses.These results suggest that PET using the 150 steady state technique is sensitive in detecting abnormalities of rCBF and rCMRO, of SDAT and useful for estimating cerebral dysfunction in SDAT, Key words: senile dementia of the Alzheimer's type, positron emission tomography, cerebral blood flow, cerebral oxygen metabolism, dementing illnessCorrespondence to Shizuki Sakam...

Measurement of myocardial blood flow with 13N-ammonia, a technique previously employed successfully in animal experiments, was introduced into clinical use to study patients with coronary artery disease. This advance has become possible by the development of a high resolution gated scan positron emission tomographic (PET) scanner equipped with a real time decay correction mechanism, HEADTOME-IV. The information obtainable includes myocardial size and wall motion as well as the absolute quantity of blood flow in various myocardial regions. The technique is simple but requires continuous arterial blood withdrawal for calculation of the arterial input function time integral. The alternative to this technique, i.e. the computation of intra left ventricular blood pool activity by PET is also discussed.