title: Dopamine transporter imaging in clinically unclear cases of parkinsonism and the importance of scans without evidence of dopaminergic deficit (SWEDDs).
abstract: The clinical diagnosis of Parkinson's disease (PD) is susceptible to misdiagnosis, especially in the earlier stages of the disease. Recently, in vivo imaging techniques assessing the presynaptic dopamine transporter (DAT) have emerged as a useful tool in PD diagnosis, improving its accuracy.
  
  
  OBJECTIVE
  It was to illustrate the clinical usefulness of a brain single-photon emission computed tomography (SPECT) DAT ligand, and highlight relevant aspects of scans without evidence of dopaminergic deficit (SWEDDs) in this context.
  
  
  METHODS
  We described four representative patients with clinically unclear parkinsonian syndromes who underwent [(99m)Tc]-TRODAT-1 SPECT and reviewed the clinical implications.
  
  
  CONCLUSIONS
  DAT-SPECT is an important, cost-effective, technique for the differential diagnosis of parkinsonian syndromes. Additionally, SWEDD cases present clinical and paraclinical peculiarities that may retrospectively identify them as essential/dystonic tremor. The lack of histopathological data limits further conclusions.
authors.affiliation: Movement Disorders Unit, Neurology Service, Internal Medicine Department, Hospital de Clínicas, Universidade Federal do Paraná (UFPR), Curitiba PR, Brazil.
authors.forename: Marco A T
authors.initials: MA
authors.lastname: Utiumi
authors.forename: André C
authors.initials: AC
authors.lastname: Felício
authors.forename: Conrado R
authors.initials: CR
authors.lastname: Borges
authors.forename: Vera L
authors.initials: VL
authors.lastname: Braatz
authors.forename: Sheyla A S
authors.initials: SA
authors.lastname: Rezende
authors.forename: Renato P
authors.initials: RP
authors.lastname: Munhoz
authors.forename: Rodrigo A
authors.initials: RA
authors.lastname: Bressan
authors.forename: Henrique B
authors.initials: HB
authors.lastname: Ferraz
authors.forename: Hélio A G
authors.initials: HA
authors.lastname: Teive
mesh_terms: D000328:Adult; D003937:Diagnosis, Differential; D050483:Dopamine Plasma Membrane Transport Proteins / Q000378:metabolism*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D015609:Organotechnetium Compounds; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon / Q000191:economics; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D014326:Tropanes; C104196:technetium Tc 99m TRODAT-1