Comparaison des performances de l’imagerie des transporteurs dopaminergiques et de la tomoscintigraphie de perfusion cérébrale à l’HMPAO- 99mTc dans le diagnostic de maladie à corps de Lewy diffus

Abstract

Dementia with Lewy bodies is the second cause of degenerative dementia. Differential diagnosis may be difficult, in spite of the emergence of standardized diagnostic criteria. Tomoscintigraphy using iodine 123-labelled FP-CIT (DaTSCAN ®) could play a role in this process. Cerebral perfusion SPECT imaging is an important step of demented patient evaluation. We compared the diagnostic performance of both of these procedures in the diagnosis of dementia with Lewy bodies. We studied 15 patients; ten DaTSCAN ® and 14 cerebral perfusion studies were performed. Clinical diagnosis at the end of follow-up was established as the diagnostic reference. Cerebral perfusion SPECT showed a very low sensitivity (20%) and a good specificity (89%); considering a prevalence of dementia with Lewy bodies of 20%, positive predictive value (PPV) was 31% and negative predictive value (NPV) 82%. Performances of DaTSCAN ® tomoscintigraphy were more encouraging, (sensitivity and specificity of 100%); predictive values are both of 100%. As a conclusion, DaTSCAN ® tomoscintigraphy performs better than cerebral perfusion SPECT in the diagnosis of dementia with Lewy bodies and no conjoint or sequential use of those tests can be recommended.