Positron emission tomography in cases of chorea with different underlying diseases.

Local cerebral metabolic rate for glucose (LCMRglc) was measured with positron emission tomography using the 18F-fluorodeoxy-glucose method in five patients with chorea due to different underlying diseases. Hypometabolism was observed in the striatum bilaterally in patients with Huntington's disease, choreoacanthocytosis, sporadic progressive chorea and dementia, and pseudo-Huntington form of dentato-rubro-pallido-luysian atrophy (DRPLA). The patient with hemichorea showed hypometabolism in the striatum on the contralateral side to the chorea. The patient with pseudo-Huntington form of DRPLA showed a diffusely decreased LCMRglc in other structures including the cerebral cortex, thalamus and cerebellum. These findings indicated that dysfunction of the striatum is relevant to the genesis of chorea in all these patients, even though the extent of dysfunction in other structures is different in each case.