[123I]beta-CIT and SPECT in essential tremor and Parkinson's disease

J Neural Transm (Vienna). 1998;105(10-12):1213-28. doi: 10.1007/s007020050124.


Resting and postural tremor may occur in essential tremor (ET) and Parkinson's disease (PD). The aim of the present study was to investigate the cocaine derivative [123I]beta-CIT, which labels striatal dopamine transporters, and SPECT in differentiating these diseases.

Methods: 30 healthy volunteers, 32 patients with ET and 29 patients with idiopathic PD of Hoehn/Yahr stage I were investigated. Specific over nondisplaceable binding ratios (target/cerebellum-1) were calculated for the striatum, the caudate nucleus and the putamen separately as well as a ratio putamen/caudate and the percent deviation of each patient's ratio from age-expected control values.

Results: Striatal [123I]beta-CIT binding ratios in ET were within normal ranges and showed only a discrete elevation to age-expected control values (+14.6%). In PD significantly reduced specific binding was evident not only contralaterally to the clinically affected side (putamen: -62%, caudate nucleus: -35%), but also ipsilaterally (putamen: -45%, caudate nucleus: -22%). All investigated parameters differed significantly between PD and controls and ET respectively.

Conclusion: Imaging striatal dopamine transporters with [123I]beta-CIT and SPECT could clearly distinguish between ET and PD in an early stage of the disease. Findings do not suggest a subclinical involvement of dopaminergic nigrostriatal neurons in ET.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Case-Control Studies
  • Cocaine / analogs & derivatives*
  • Cocaine / metabolism
  • Diagnosis, Differential
  • Female
  • Humans
  • Iodine Radioisotopes
  • Male
  • Middle Aged
  • Parkinson Disease / diagnostic imaging*
  • Parkinson Disease / metabolism
  • Radioligand Assay
  • Reference Values
  • Tomography, Emission-Computed, Single-Photon*
  • Tremor / diagnostic imaging*
  • Tremor / metabolism


  • Iodine Radioisotopes
  • 2beta-carbomethoxy-3beta-(4-iodophenyl)tropane
  • Cocaine