
DaTscan may be used as an adjunct to other diagnostic tests to help differentiate essential tremor from tremor due to PS.
Visualization of striatal dopamine transporter (DaT) distribution within the striatum can aid in the clinical diagnosis of PS, including1,2:
- Differentiation between normal and abnormal scans is assessed by the extent (as indicated by shape) and intensity of the striatal signal following DaTscan administration2,5-6
among readers2
- DaTscan images were evaluated by readers blinded to clinical information2
Reader B, n = 96
Reader C, n = 98
78 (66, 87)
79 (67, 87)
96 (82, 100)
96 (82, 100)
Reader B, n = 185
Reader C, n = 185
Reader D, n = 185
Reader E, n = 185
97 (93, 99)
96 (92, 99)
92 (87, 96)
94 (90, 97)
74 (54, 89)
85 (66, 96)
93 (76, 99)
93 (76, 99)
Study Design: Two multicenter, single-arm studies (Study 1 and Study 2) evaluated 284 adult patients with tremor. DaTscan image outcomes were compared to a reference clinical diagnostic standard of “PS” or “non-PS.” The reference clinical diagnostic standard for “PS” was a diagnosis for PD, MSA, or PSP. The reference clinical diagnostic standard for “non-PS” was an ET diagnosis or other non-PS diagnosis. Study 1 consisted of patients with early features of parkinsonism; patients with features suggestive of MSA or PSP were excluded. Study 2 consisted of patients with clinically established diagnosis of PS (PD, MSA, PSP) or ET.
DaTscan images were evaluated by readers blinded to clinical information. Study 1 readers had no other role in patient assessment; Study 2 readers included site investigators. The reference clinical diagnostic standards were the clinical diagnoses established by a consensus panel of movement disorder specialists that evaluated data inclusive through 36 months of follow-up (Study 1) or the investigator-determined baseline clinical diagnosis (Study 2). Study 1 consisted of patients with early features of parkinsonism; patients with features suggestive of MSA or PSP were excluded. Study 2 consisted of patients with clinically established diagnosis of PS (PD, MSA, PSP) or ET.
Among the 99 patients in Study 1, 44% were female, 42% were aged 65 or over, and all were Caucasian; among the 185 patients in Study 2, 35% were female, 48% were aged 65 or over, and 99% were Caucasian. Among the patients in Study 1, the baseline clinical diagnoses consisted of: probable PD (44%), possible PD (31%), “benign” PD (6%), possible ET (11%), and other diagnoses (7%). Among the patients in Study 2, the baseline clinical diagnoses consisted of: PD (70%), ET (15%), MSA (10%), and PSP (5%).


