[en] We reported three cases of neuro-Behcet's syndrome which showed brainstem lesions on MRI compatible with the clinical symptoms. In Case 1, MRI showed a large, abnormal signal-intensity area in the pons and small, abnormal signal-intensity areas at the right cerebral peduncle, the bilateral basal ganglia, and the left thalamus. These lesions disappeared on MRI, in accordance with the remission of clinical symptoms. On the other hand, CT showed no positive findings. In Case 2, an abnormal signal-intensity area was disclosed at the left cerebral peduncle on MRI. This lesion was also identified on the CT scan. In Case 3, an abnormal signal-intensity area was present in the pons on MRI. In this case, CT showed no positive findings. In Cases 2 and 3, these lesions seemed to represent inflammatory or necrotic areas attributable to vasculitis; however, the extensive brainstem lesion seen on the MRI of Case 1 was a quite unique finding, for which no exact pathophysiological explanation is possible at the present time. (author)

[en] A case of progressive multifocal leukoencephalopathy (PML), diagnosed at an early stage of the disease, was documented with sequential MRI and CT findings. A 45-year-old woman was doing well until April, 1985, when she developed mild left hemiparesis. The low-density area on a CT scan, which was present equivocally in the right frontal lobe on retrospective observation, became apparent in June, so she underwent an operation under the presumptive diagnosis of glioma. The pathological diagnosis of PML was confirmed and several therapeutic regimens were tried, but she went into an apallic state in 8 months. The abnormal-density area in the right frontal lobe became not only enlarged, but came to have a multifocal distribution without any mass effect or contrast enhancement on the CT scan. These lesions were detected more apparently and definitely on MRI, which revealed such abnormalities as a low-signal-intensity area in the IR imaging and a high-signal-intensity area in the long SE imaging. On MRI, the long SE imaging seemed to be more sensitive than the IR in detecting lesions. The superiority of the MRI in detectability and the usefulness of the clinical evaluation of PML were stressed. (author)