高齢者で認められたすくみ足を主徴とする例の臨床的検討 皮質下白質障害例および純粋アキネジア例のＭＲＩ・ＳＰＥＣＴ所見を中心に

Abstract

The authors have sometimes experienced cases of frozen gait without any other manifestations of parkinsonisms in the elderly, so we examined these cases using MR imaging and SPECT imaging. The group with frozen gait (4 cases, aged 78 to 82 years) which failed to respond to L-dopa therapy, had no limb-kinetic apraxia or frontal signs, but did exhibit "kinésie paradoxale". The clinical symptoms of case 4 were consistent with so-called "pure akinesia". CT findings in this group failed to elucidate the pathogenesis of frozen gait. MR imaging of all of the cases except for the case of pure akinesia (case 4) revealed a high signal intensity areas in subcortical lesions (especially the frontal area). Case 4 had only a few spotty high-signal intensity areas. We then compared 6 cases which have the same lesions (on MRI) as cases 1-3 without frozen gait in cases 1-3 using 123I-IMP SPECT. Relatively low accumulation of radionuclide in the frontal area was observed in these cases. Case 4 had a slightly low perfusion area in the frontal lobe. However in the patient treated with L-threo-DOPS, accumulation of radionuclide in the frontal area increased slightly after L-threo-DOPS therapy. It appears that one of the reasons for frozen gait in the elderly is incomplete infarct of the subcortical white matter with a low perfusion area in the frontal cortex. Furthermore, in some cases of frozen gait it is difficult to distinguish between cases with white matter disorders and cases of pure akinesia on the basis of clinical symptoms and CT alone.