(123I) beta-CIT and single-photon emission computed tomographic imaging vs clinical evaluation in Parkinsonian syndrome: unmasking an early diagnosis.
BACKGROUND
The diagnosis of Parkinson disease is currently based on clinical evaluation. Functional neuroimaging using (123I) beta-carboxymethyoxy-3-beta-(4-iodophenyl) tropane (CIT) and single-photon emission computed tomography (SPECT) provides information on the integrity of the dopaminergic system in vivo and is a promising diagnostic tool in early Parkinson disease.


OBJECTIVE
To evaluate the diagnostic accuracy of dopamine transporter imaging using (123I)beta-CIT in patients with suspected parkinsonian syndrome (PS).


METHODS
Community neurologists referred patients with suspected PS for imaging evaluation. Clinical diagnoses (positive PS or negative PS) were provided by the community neurologists and 2 movement disorder experts. We performed (123I)beta-CIT and SPECT imaging, and imaging diagnoses of positive PS or negative PS were assigned. A 6-month follow-up clinical diagnosis was assigned by a movement disorder expert blind to the imaging data, which represented the "gold standard" diagnosis for the study.


RESULTS
Thirty-five patients with suspected PS were referred. Diagnoses in question included essential tremor, psychogenic parkinsonism, drug-induced parkinsonism, primary dystonia, and unspecified gait disorder. Comparing the community neurologist's diagnoses at referral with the gold standard diagnosis, there was dis agreement in 25.7% (sensitivity, 0.92; specificity, 0.30). Comparing the quantitative imaging diagnoses with the gold standard, there was disagreement in 8.6% (sensitivity, 0.92; specificity, 1.00).


CONCLUSIONS
Performing (123I)beta-CIT and SPECT imaging at baseline appears to be a useful diagnostic tool to detect patients thought to have PS at baseline but who, after follow-up, do not have PS.
Institute for Neurodegenerative Disorders, New Haven, Conn 06510, USA. djennings@indd.org
Danna L
DL
Jennings
John P
JP
Seibyl
David
D
Oakes
Shirley
S
Eberly
John
J
Murphy
Ken
K
Marek
D000368:Aged; D000369:Aged, 80 and over; D019540:Area Under Curve; D003042:Cocaine / Q000031:analogs & derivatives; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000175:diagnosis* / Q000378:metabolism*; D015203:Reproducibility of Results; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods
D007457:Iodine Radioisotopes; C069723:2beta-carbomethoxy-3beta-(4-iodophenyl)tropane; D003042:Cocaine