Rinsho Shinkeigaku (Clinical Neurology)

Brief Clinical Note

Increase in regional cerebral blood flow of striatum induced by low dose levodopa in a patient with hemiparkinsonism

Yoshiharu Taguchi, M.D., Shutaro Takashima, M.D., Etsuko Asaoka, M.D., Nobuhiro Dohgu, M.D. and Hiroshi Inoue, M.D.

The Second Department of Internal Medicine, Toyama Medical and Pharmaceutical University

A 54-year-old woman was admitted to our hospital because of left-sided rigidity. Neurological examination revealed cogwheel-type rigidity in the left upper and lower limbs without tremor. A brain MRI showed no abnormal findings. She was diagnosed as having left-sided hemiparkinsonism. A 99mTc-ECD SPECT detected a decrease in regional cerebral blood flow (rCBF) in the right corpus striatum. Administration of levodopa/DCI (100 mg/day) improved not only her left-sided rigidity but also the rCBF in the right corpus striatum. The ratio of rCBF in the right corpus striatum to that in the left corpus striatum increased from 96.03% to 99.26% on the three-dimensional stereotactic ROI template. These findings suggest that L-dopa may directly activate the metabolism in the bilateral corpus striatum, and that rCBF in the corpus striatum may be increased indirectly according to the increase of movement in the legs. And also it is suggested that denervation supersensitivity to dopamine may exist in the corpus striatum on the contralateral side of the signs and symptoms in this patient with hemiparkinsonism.

(CLINICA NEUROL, 44: 443|445, 2004)
key words: hemiparkinsonism, cerebral blood flow, supersensitivity, levodopa, SPECT

(Received: 27-May-03)