A clinical study in elderly patients with Parkinson's disease using MRI and SPECT

Parkinson's disease (PD) is often associated with dementia in elderly patients, and sometimes PD coexists with senile dementia of the Alzheimer type (SDAT) or cerebrovascular disease (CVD) in the elderly. However, since there are few previous clinical studies on the coincidence of, or relationship between PD and CVD, the authors evaluated these aspects in 34 elderly patients with PD using MRI and SPECT. All the patients were over 70 years old. The diagnosis of PD was based on the presence of three symptons (resting tremor, cogwheel rigidity and bradikinesia) which are characteristic of PD, and the effectiveness of L-DOPA therapy. We therefore believe that patients with vascular Parkinsonism were excluded from our study. In 34 cases, 24 (71%) had MRI evidence of CVD (mainly the lacunar state). In the 10 cases who had no CVD, 2 (20%) had severe dementia and the decrease of regional cerebral blood flow (rCBF) in the temporal and parietal lobes bilaterally correlated with the SPECT findings commonly found in SDAT. A comparison of the rCBF and the results of Hasegawa's dementia score (HDS) (verbal intelligence score) was made between the patients with PD associated with CVD and the patients with PD who had no CVD and no SPECT findings which correlated with SDAT. The rCBF in the frontal lobes and the results of the HDS of the former group were significantly lower than those of the latter. As mentioned above, elderly patients with PD often had CVD, leading to dementia. We also pointed out the difficulty in making a differential diagnosis between PD with CVD and vascular Parkinsonism, and the necessity of whether or not the concept of 'mixed type Parkinsonism' should be considered. (author)