DOPAMINERGIC DEFICIT IN AMYOTROPHIC-LATERAL-SCLEROSIS ASSESSED WITH [I-123] IPT SINGLE-PHOTON EMISSION COMPUTED-TOMOGRAPHY

Dopamine transporter imaging was performed in 18 patients with sporadi c amyotrophic lateral sclerosis (ALS) and 11 age matched controls with [1-123] IPT (N-(3-iodopropen-2-yl)-2 beta-carbomethoxy-3 beta(4-chlor ophenyl)-tropane), a new cocaine analogue that selectively binds to th e dopamine transporter located on dopaminergic nerve terminals. Image analysis showed that striatal IPT binding was moderately but significa ntly reduced in the ALS group compared with controls (p<0.01). The red uction of IPT binding was similar for patients with bulbar onset compa red with those with limb onset. There was no correlation between value s for uptake of striatal IPT and the age of the patients or the durati on of the disease. These data indicate that nigrostriatal dopaminergic neurons are subclinically affected in a subset of patients with spora dic ALS.