Dopamine transporter binding study in differentiating carbon disulfide induced parkinsonism from idiopathic parkinsonism

Long-term exposure to carbon disulfide (CS₂) may induce parkinsonian features. There may be confusion in distinguishing between CS ₂ parkinsonism and idiopathic parkinsonism, especially for workers who developed parkinsonian features in viscose rayon plants. We performed clinical examinations, and laboratory studies including magnetic resonance imaging (MRI) and dopamine transporter (DAT) studies with ^99mTc- TRODAT-1 brain single photon emission computed tomography (SPECT) in three workers who had long-term exposure to CS₂. Patient 1 had polyneuropathy, and encephalopathy with tremor; patient 2 had polyneuropathy, and encephalopathy with parkinsonian features; and patient 3 had pure parkinsonian features without polyneuropathy or cerebellar signs. The treatment with L-dopa was effective in patient 3, but non-effective in patient 2. Brain MRI revealed multiple high signal intensities over the subcortical white matter, basal ganglia, and/or even the brainstem in patients 1 and 2, but normal in patient 3. In DAT studies, the bindings were normal in patients 1 and 2 and was decreased in patient 3. We conclude that CS₂ exposure may induce polyneuropathy, and cerebellar dysfunction in addition to parkinsonian features and that brain MRI may show multiple lesions in the cerebral white matter and basal ganglia. In addition, DAT with ^99mTc-TRODAT-1 brain SPECT may provide a useful information in differential diagnosis between CS₂ parkinsonism and idiopathic parkinsonism.