Degeneration of pyramidal tract of MRI (magnetic resonance imaging)

MRI (magnetic resonance imaging) examinaion was performed on cases of hemiplegia and hemiparesis. These included seven cases of intracerebral hemorrhage, four cases of subarachnoid hemorrhage, one case of cerebral infarct, and two cases of head trauma. The pyramidal tract in the brain stem was studied in five patients with complete hemiplegia and in nine with incomplete hemiparesis. The scanner of the MRI was a resistive type operating at a field of 0.2 Tesla. The inversion recovery (IR) and saturation recovery (SR) techniques were utilized. The pyramidal tract at the level of the midbrain and the pons was recognized as a low intensity area on the T1 image (IR 1500/43) in the cases of complete hemiplegia. However, it was recognized as a high intensity area on the SR image (SR 1000/60) and the T2 image (SR 2000/100). No abnormal signal intensity was found in the cases of incomplete hemiparesis. A low intensity area on the T1 image and a high intensity area on the T2 image were recognized in the ventral portion of the midbrain and the pons on the affected side. These findings indicate a degeneration of the pyramidal tract at the level of the brain stem in patients with complete hemiplegia. (author)