Cross sectional dopamine transporter imaging and myocardial sympathetic scintigraphy study in patients with dementia with Lewy bodies

Abstract Background Dopamine transporter ( 123 I‐FP‐CIT) single‐photon emission tomography (SPECT) and 123 I‐meta‐iodobenzylguanidine ( 123 I‐MIBG) image play roles as indicative biomarkers in diagnosing patients with dementia with Lewy bodies (DLB). Brain‐ and body‐first subtypes of DLB were hypothesized implying that subset of DLB may have normal 123 I‐FP‐CIT or 123 I‐MIBG results, respectively. The purpose of this study was to explore the diagnostic sensitivity of two combination imaging modalities ( 123 I‐FP‐CIT SPECT and 123 I‐MIBG image) in patients with DLB and examine the clinical difference between brain‐ and body‐first subtype. Method Possible DLB patients, defined by the fourth consensus DLB criteria, who underwent both 123 I‐FP‐CIT SPECT and 123 I‐MIBG image was retrospectively collected. Semi‐automated software and their results were utilized to define abnormality for both scans. Demographic data, cognition, motor, and core features were compared between the brain‐first and body first DLB subgroups. Result Of the 114 patients with DLB, 66 underwent both scans. Mean (SD) age was 74.1 (7.1) years, male was predominant (62.1%), min‐mental state examination total score was 21.7 (4.8) and unified Parkinson’s disease rating scale motort subscore was 14.7 (4.8). Thirty‐six (54.5%) patients showed both abnormal scans and four patients (6.1%) were both normal scans. Seventeen patients (25.8%) showed abnormal 123 I‐FP‐CIT result with normal 123 I‐MIBG result (brain‐first DLB), nine patients (13.6%) showed normal 123 I‐FP‐CIT result with abnormal 123 I‐MIBG result (body‐first DLB). No clinical differences were observed between brain‐first and body‐first DLB subtypes. Conclusion Approximately 40% of DLB patients displayed normal result in either image. Normal results of a single imaging test may not refute the possibility of DLB. No clinical difference was observed between brain‐ and body‐first DLB subtypes.