Abstract
Several studies have found that the uptake of a radioisotope is reduced in the frontal or parietooccipital lobe on SPECT scans of patients with Parkinson's disease accompanied by cognitive impairment. The present study investigated the relationship between the results of SPECT imaging and those of cognitive function tests in patients with Parkinson's disease accompanied by cognitive impairment. Thirty patients with Parkinson's disease served as subjects, including 9 men and 21 women with an average of 66.1 years. Patients underwent 123-IMP SPECT and various cognitive function tests (Japanese alphabet pick-up test, Stroop test, Hasegawa's dementia screening scale, Raven color matrix, and course cube-combination test) . Next, three neurologists with no knowledge of the patient's clinical symptoms were asked to analyze the reduced uptake on SPECT scans as follows: frontal lobe, parietooccipital lobe, frontal and parietooccipital lobes, diffused reduction, and no reduced uptake. The results of SPECT imaging and each cognitive function test were compared. Reduced uptake in the frontal and parietooccipital lobes and diffused reduction correlated with decreases in cognitive function. Cognitive impairment is not notable when cortical blood flow is partially reduced, but is notable when cortical blood flow is widely reduced.
