Objective: To determine the pathologic bases of the abnormal signal intensities detected on magnetic resonance imaging (MRI) in Shy-Drager syndrome (SDS) and striatonigral degeneration (SND).
Methods: The correlation of MRI and pathological findings was prospectively evaluated by postmortem scanning of the brain in a case of SDS and another of SND. MRI was performed by using a 1.0 T superconductive magnetic unit, with spin echo (SE) pulse sequences. The brain sections were prepared parallel to the MRI planes. The gross and microscopic pathological studies were conducted according to the corresponding abnormal signal intensities on MRI.
Results: In SDS, abnormal hypointense signals on T2 weighted MR images were symmetrically demonstrated in bilateral putamen, where a remarkable positive Prussian blue stain reaction was revealed on pathological examinations. In SND, MRI showed isointense signals on T1 weighted images and hyperintense signals on T2 weighted images in bilateral putamen, and the microscopic findings included necrosis, abundant reactive fibrillary astrocytes and prominence of capillary vascular networks, as well as marked lipofuscin. The number of neurons decreased in both cases.
Conclusions: The demonstration of the abnormal signals in the putamen on MRI is of important value in establishing an antemortem diagnosis of SDS and SND.