Dementia with Lewy bodies: a comparison of clinical diagnosis, FP-CIT single photon emission computed tomography imaging and autopsy

Abstract

Background: Dementia with Lewy bodies (DLB) is a common form of dementia. The presence of Alzheimer's disease (AD) pathology modifies the clinical features of DLB, making it harder to distinguish DLB from AD clinically during life. Clinical diagnostic criteria for DLB applied at presentation can fail to identify up to 50% of cases. Our aim was to determine, in a series of patients with dementia in whom autopsy confirmation of diagnosis was available, whether functional imaging of the nigrostriatal pathway improves the accuracy of diagnosis compared with diagnosis by means of clinical criteria alone. Methods: A single photon emission computed tomography (SPECT) scan was carried out with a dopaminergic presynaptic ligand [123 I]-2beta-carbometoxy-3beta-(4-iodophenyl)-N-(3-fluoropropyl) nortropane (FP-CIT; ioflupane) on a group of patients with a clinical diagnosis of DLB or other dementia. An abnormal scan was defined as one in which right and left posterior putamen binding, measured semiquantitatively, was more than 2 SDs below the mean of the controls. Results: Over a 10 year period it was possible to collect 20 patients who had been followed from the time of first assessment and time of scan through to death and subsequent detailed neuropathological autopsy. Eight patients fulfilled neuropathological diagnostic criteria for DLB. Nine patients had AD, mostly with coexisting cerebrovascular disease. Three patients had other diagnoses. The sensitivity of an initial clinical diagnosis of DLB was 75% and specificity was 42%. The sensitivity of the FP-CIT scan for the diagnosis of DLB was 88% and specificity was 100%. Conclusion: FP-CIT SPECT scans substantially enhanced the accuracy of diagnosis of DLB by comparison with clinical criteria alone.

Clinicopathological and 123I‐FP‐CIT SPECT correlations in patients with dementia

“…However, autopsy validation of 123 I‐FP‐CIT SPECT for predicting LBD strengthens the study findings. In addition, the results of the study were consistent with the findings of larger European studies, including ~10% of cases with LBD pathology with normal findings on 123 I‐FP‐CIT SPECT 6, 7, 8. One would also predict neurodegenerative disorders associated with dementia plus striatonigral pathology such as progressive supranuclear palsy and corticobasal degeneration would have reduced uptake on 123 I‐FP‐CIT SPECT, but since none of our patients had such pathologies, the generalizability to the full spectrum of patients with dementia cannot be addressed in this series.…”

“…Decreased 123 I‐FP‐CIT binding in putamen measured semiquantitatively showed 88% sensitivity and 100% specificity for predicting LBD pathology at autopsy 6. Abnormal 123 I‐FP‐CIT SPECT on visual rating was associated with LBD pathology with 80% sensitivity and 92% specificity 8.…”

“…Limited studies have validated 123 I‐FP‐CIT SPECT findings in DLB with neuropathologic confirmation 6, 7, 8. Decreased 123 I‐FP‐CIT binding in putamen measured semiquantitatively showed 88% sensitivity and 100% specificity for predicting LBD pathology at autopsy 6.…”

Efficacy of Single Photon Emission Computed Tomography in Differentiating Dementia with Lewy Bodies - A Review of Neurotransmitter and Perfusion Imaging

“…4 The sensitivity of an initial clinical diagnosis of DLB was 75% and the specificity was 42%. The sensitivity for the diagnosis of DLB of an abnormal FP-CIT scan, defined as total (bilateral) posterior putamen binding less than two standard deviations below the mean of controls, was 88%, and the specificity was 100%.…”

Nuclear Medicine Applications in Movement Disorders

“…Presinaptik dopaminerjik görüntülemenin kullanıldığı bir diğer alan da LCD ve AH ayırıcı tanısıdır. Post-mortem doğrulamanın da yapıldığı bir çalışmada SPECT ile DAT görüntülemesinin LCD tanısında %88 duyarlılığa ve %100 özgüllüğe sahip olduğu bildirilmiştir (47).…”