Substantia nigra echogenicity and imaging of striatal dopamine transporters in Parkinson's disease: A cross-sectional study

• Published in: Parkinsonism & related disorders 2014-05, Vol.20 (5), p.477-481
• Main Authors: Bor-Seng-Shu, Edson, Pedroso, Jose Luiz, Felicio, Andre C, Ciampi de Andrade, Daniel, Teixeira, Manoel Jacobsen, Braga-Neto, Pedro, Batista, Ilza Rosa, Barsottini, Orlando Graziani Povoas, Borges, Vanderci, Ferraz, Henrique Ballalai, Shih, Ming Chi, Bressan, Rodrigo A, de Andrade, Luiz Augusto Franco, Walter, Uwe
• Format: Article
• Language: English
• Subjects: Adult; Aged; Corpus Striatum - diagnostic imaging; Corpus Striatum - metabolism; Cross-Sectional Studies; Dopamine Plasma Membrane Transport Proteins - metabolism; Dopamine transporter; Female; Humans; Male; Middle Aged; Neurology; Organotechnetium Compounds; Parkinson Disease - diagnostic imaging; Parkinson Disease - pathology; Parkinson's disease; Radiopharmaceuticals; Sensitivity and Specificity; SPECT; Substantia Nigra - diagnostic imaging; Substantia Nigra - metabolism; Substantia nigra echogenicity; Tomography, Emission-Computed, Single-Photon; Transcranial sonography; Tropanes; Ultrasonography, Doppler, Transcranial
• ISSN: 1353-8020; 1873-5126
• DOI: 10.1016/j.parkreldis.2014.01.015

Abstract Approximately 10% of patients with a presumed diagnosis of Parkinson's disease (PD) remain misdiagnosed despite recent advances in neuroimaging. The current study addresses the use of transcranial sonography and single-photon emission computed tomography (SPECT) using99m Tc-TRODAT-1 to evaluate the echogenicity of the substantia nigra (SN) and the density of striatal presynaptic dopamine transporters, respectively, in a sample of 20 PD patients (13 males and 7 females) and 9 healthy subjects. The median age of the PD patients was 62 years. The median age at disease onset was 56 years, and the median disease duration was 5 years. The SN echogenic area was larger in PD patients than healthy subjects. The cut-off value of 0.22 cm2 for the SN echogenic area was associated with 100% sensitivity and 78% specificity for the diagnosis of PD. Striatal and putaminal99m Tc-TRODAT-1 binding was lower in PD patients than healthy subjects. The cut-off value of 0.90 for the striatal99m Tc-TRODAT-1 binding was associated with 100% sensitivity and an 89% specificity for the diagnosis of PD, and the cut-off value of 0.76 for putaminal99m Tc-TRODAT-1 binding was associated with an 85% sensitivity and an 89% specificity. The size of the SN echogenic area did not correlate with the degree of striatal99m Tc-TRODAT-1 binding in PD patients. In conclusion, both SN hyperechogenicity and decreased striatal or putaminal99m Tc-TRODAT-1 binding constitute surrogate markers for differentiating PD patients from healthy individuals with a slightly higher diagnostic specificity of99m Tc-TRODAT-1 SPECT.