How useful is [123I]β-CIT SPECT in clinical practice?
- 1Department of Neurology, Helsinki University Central Hospital, Helsinki, Finland
- 2HUSLAB, Division of Clinical Physiology and Nuclear Medicine, Helsinki University Central Hospital
- Correspondence to: Dr Johanna Eerola Department of Neurology, HUCH, PO Box 340, FIN-00029 HUS, Helsinki, Finland;
- Received 10 May 2004
- Accepted 18 December 2004
- Revised 16 December 2004
Objective: To assess the accuracy and clinical usefulness of [123I]β-CIT (2β-carbomethoxy-3β-(4-iodophenyl)tropane) SPECT in the differential diagnosis of Parkinson’s disease.
Subjects: 185 consecutive patients with symptoms of movement disorder were studied. The diagnoses were Parkinson’s disease (92), essential tremor (16), vascular parkinsonism (15), various Parkinson plus syndromes (P+) (12), dementia with Lewy bodies (DLB) (5), dystonia (5), drug induced movement disorder (12), and other diagnoses (8). A reference group (psychogenic parkinsonism) comprised 20 subjects with complaints suggesting extrapyramidal disease but with no unequivocal signs on clinical examination and no abnormalities on brain imaging.
Results: β-CIT uptake was significantly lower in the whole striatum as well as separately in the putamen and in the caudate nucleus in Parkinson’s disease than in the reference group or in drug induced movement disorder, essential tremor, or dystonia. The uptake of β-CIT in the vascular parkinsonism group was heterogeneous and mean β-CIT uptake fell between the reference group and the Parkinson’s disease group. In the P+ and DLB groups the striatal uptake ratios overlapped those of the Parkinson’s disease group.
Conclusions: [123I]β-CIT SPECT may not be as useful a tool in the clinical differential diagnosis of Parkinson’s disease as was previously believed, but it was 100% sensitive and specific for the diagnosis in younger patients (age <55 years). In older patients (age >55 years) specificity was substantially lower (68.5%). This differential specificity reflected the different distribution of differential diagnostic disorders (P+, DLB, vascular parkinsonism) in the older and younger age groups.
- CIT, carbomethoxy-3β-(4-iodophenyl)tropane
- DAT, dopamine transporters
- DLB, dementia with Lewy bodies
- MSA, multiple system atrophy
- PSP, progressive supranuclear palsy
- ROC, receiver operating characteristic
- ROI, region of interest
- SPECT, single photon emission computed tomography
Competing interests: none declared