Regional cerebral blood flow measured with N-isopropyl-p-[123I]iodoamphetamine single-photon emission tomography in patients with Joseph disease.

Regional cerebral blood flow (rCBF) was measured in five Japanese patients who were clinically diagnosed as having Joseph disease, also called Machado-Joseph disease or Azorean disease, using N-isopropyl-p-[123I]iodoamphetamine (IMP) and single-photon emission tomography (SPECT). Cerebellar atrophy was evaluated by a five-step rating scale as defined on X-ray computed tomography (X-CT). Compared with ten age-matched normal controls (mean cerebellar CBF +/- SD: 66.9 +/- 6.6 ml/100 g/min), rCBF in patients with Joseph disease was significantly decreased in the cerebellum (mean +/- SD: 50.2 +/- 7.3 ml/100 g/min). No significant relationship, however, was found between the decrease in rCBF in the cerebellum and the degree of cerebellar atrophy on X-CT. rCBF in the cerebellum was minimally decreased in one patient who had severe cerebellar atrophy and in two patients with moderate atrophy. These data may support the findings that Purkinje cells in the cerebellum are almost normal in Joseph disease, and that the granular and molecular layers remain intact in spite of cortical atrophy of the cerebellum. It is concluded that [123I]-IMP SPET is able to identify pathological and metabolic changes in the cerebellum that do not appear on X-CT or magnetic resonance imaging, and thus is useful for the diagnosis of Joseph disease.