(+)-alpha-[C-11]dihydro-tetrabenazine PET imaging in familial paroxysmal dystonic choreoathetosis

Clinical observations suggest a disturbance of striatal dopaminergic functi on in familial paroxysmal dystonic choreoathetosis (PDC). The authors used PET with [C-11]dihydrotetrabenazine (DTBZ) to study striatal dopaminergic i nnervation in PDC. The results did not reveal abnormal DTBZ binding potenti al in PDC striatum. This suggests that dopaminergic abnormalities, if prese nt, may be due to altered regulation of dopamine release or to postsynaptic mechanisms, rather than to an altered density of nigrostriatal innervation .