Diabetic striatal disease: clinical presentation, neuroimaging, and pathology.

Unilateral movement disorders and contralateral neuroimaging abnormalities of the striatum have been sporadically reported as a rare syndrome associated with diabetes mellitus. Despite characteristic imaging findings and clinical manifestations, the mechanism underlying this syndrome is still unclear. Six patients with this syndrome were studied clinically and subjected to MRI neuroimaging; one underwent biopsy of the striatum, and another underwent additional MR spectroscopy at 3.0T and FDG-PET. Neuroimaging findings were characterized by a T1-hyperintense unilateral lesion restricted to the striatum, contralateral to the symptomatic limbs. The biopsied striatum contained patchy necrotic tissue, severe thickening of all layers of arterioles, and marked narrowing of vessel lumens. Hyaline degeneration of the arteriolar walls, extravasation of erythrocytes, and prominent capillary proliferation were also notable, together with lymphocytic infiltration and macrophage invasion. In one patient, PET examination revealed decreased accumulation of FDG in the lesion. The MR spectrum for the diseased striatum revealed a decrease in the NAA/Cr ratio (1.35), normal Cho/Cr ratio (1.22), and a peak for myoinositol, while the spectrum on the contralateral site revealed a decrease in the NAA/Cr ratio (1.48), increase in Cho/Cr (1.32), but no peak for myoinositol. The constellation of signs and symptoms and neuroimaging characteristics in previous reports and the six additional cases described here with neuropathological data and findings of MR spectroscopy appears unique enough to be termed "diabetic striatopathy." This syndrome appears in poorly controlled diabetics due to obliterative vasculopathy with prominent vascular proliferation, vulnerability to which is restricted to the striatum.