Cerebral blood flow increase in striatum by choreoathetosis:N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography findings

A 75-year-old man presented choreoathetosis dominantly on his left side. Diffusion-weighted imaging did not show abnormal intensities, whereas N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography showed a significant cerebral blood flow increase in the right striatum. The patient was treated with a D2-blocker agent, and the choreoathetosis gradually decreased. The cerebral blood flow on the right striatum decreased by the following N-isopropyl-p-[123I]iodoamphetamine single-photon emission computed tomography. We discussed the mechanism of choreoathetosis from the perspective of the direct and indirect pathways in motor control.