Usefulness of Cardiac MIBG Scintigraphy, Olfactory Testing and Substantia Nigra Hyperechogenicity as Additional Diagnostic Markers for Distinguishing between Parkinson's Disease and Atypical Parkinsonian Syndromes

• Published in: PloS one Vol. 11; no. 11; p. e0165869
• Main Authors: Fujita, Hiroaki, Suzuki, Keisuke, Numao, Ayaka, Watanabe, Yuji, Uchiyama, Tomoyuki, Miyamoto, Tomoyuki, Miyamoto, Masayuki, Hirata, Koichi
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 03.11.2016; Public Library of Science (PLoS)
• Subjects: 3-Iodobenzylguanidine; Accuracy; Aged; Atrophy; Basal ganglia; Batteries; Behavior disorders; Biology and Life Sciences; Central nervous system diseases; Diagnosis, Differential; Diagnostic imaging; Diagnostic systems; Disorders; Female; Heart; Heart - diagnostic imaging; Heart diseases; Humans; Male; Medical diagnosis; Medicine and Health Sciences; Movement disorders; Neurodegenerative diseases; Neurology; Neurosurgery; Odors; Olfactory discrimination; Olfactory discrimination learning; Olfactory Perception; Olfactory testing; Paralysis; Parkinson Disease - diagnosis; Parkinson Disease - diagnostic imaging; Parkinson Disease - physiopathology; Parkinson's disease; Parkinsonian Disorders - diagnosis; Parkinsonian Disorders - diagnostic imaging; Parkinsonian Disorders - physiopathology; Parkinsons disease; Patients; People and Places; Progressive supranuclear palsy; Psychiatry; Radionuclide Imaging; Research and Analysis Methods; Scintigraphy; Sensitivity; Sensitivity analysis; Social Sciences; Substantia nigra; Substantia Nigra - diagnostic imaging; Systematic review; Ultrasonic imaging; Ultrasonography, Doppler, Transcranial; Japan
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0165869

We aimed to evaluate the utility of the combined use of cardiac 123I-metaiodobenzylguanidine (MIBG) scintigraphy, olfactory testing, and substantia nigra (SN) hyperechogenicity on transcranial sonography (TCS) in differentiating Parkinson's disease (PD) from atypical parkinsonian syndromes (APSs), such as multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Cardiac MIBG scintigraphy, card-type odor identification testing (Open Essence (OE), Wako, Japan), and TCS were performed with 101 patients with PD and 38 patients with APSs (MSA and PSP). Receiver operating characteristic (ROC) curve analysis was used to assess the sensitivity and specificity of these batteries for diagnosing PD from APSs. The diagnostic accuracy of the three tests was also assessed among patients at the early disease stage (drug-naïve patients with a disease duration of 3 years or less). In differentiating PD from APSs, the area under the ROC curve was 0.74 (95% CI, 0.65-0.83), 0.8 (95% CI, 0.73-0.87), and 0.75 (95% CI, 0.67-0.82) for TCS, cardiac MIBG scintigraphy, and olfactory testing, respectively. The diagnostic sensitivity and specificity were 53.1% and 91.7%, respectively, for TCS, 70.3% and 86.8%, respectively, for cardiac MIBG scintigraphy, 58.4% and 76.3%, respectively, for OE. Among early-stage patients, sensitivity and specificity were 50.0% and 93.8%, respectively, for TCS, 57.1% and 87.5%, respectively, for cardiac MIBG scintigraphy, and 54.8% and 79.2%, respectively, for OE. At least one positive result from 3 tests improved sensitivity (86.1%) but decreased specificity (63.2%). In contrast, at least 2 positive results from 3 tests had good discrimination for both early-stage patients (50.0% sensitivity and 93.8% specificity) and patients overall (57.8% sensitivity and 95.8% specificity). Positive results for all 3 tests yielded 100% specificity but low sensitivity (25%). At least 2 positive results from among TCS, cardiac MIBG scintigraphy, and olfactory testing can support clinical diagnosis in distinguishing PD from APSs.