title: Dopaminergic dysfunction and psychiatric symptoms in movement disorders: a 123I-FP-CIT SPECT study.
abstract: OBJECTIVE
  Psychiatric symptoms frequently occur in patients with movement disorders. They are not a mere reaction to chronic disability, but most likely due to a combination of psychosocial factors and biochemical dysfunction underlying the movement disorder. We assessed dopamine transporter (DAT) availability by means of (123)I-FP-CIT SPECT, and motor and psychiatric features in patients with Parkinson's disease, primary dystonia and essential tremor, exploring the association between SPECT findings and symptom severity.
  
  
  METHODS
  Enrolled in the study were 21 patients with Parkinson's disease, 14 patients with primary dystonia and 15 patients with essential tremor. The severity of depression symptoms was assessed using the Hamilton depression rating scale, anxiety levels using the Hamilton anxiety rating scale and hedonic tone impairment using the Snaith-Hamilton pleasure scale. Specific (123)I-FP-CIT binding in the caudate and putamen was calculated based on ROI analysis. The control group included 17 healthy subjects.
  
  
  RESULTS
  As expected, DAT availability was significantly decreased in patients with Parkinson's disease, whereas in essential tremor and dystonia patients it did not differ from that observed in the control group. In Parkinson's disease patients, an inverse correlation between severity of depression symptoms and DAT availability in the left caudate was found (r = -0.63, p = 0.002). In essential tremor patients, levels of anxiety symptoms were inversely correlated with DAT availability in the left caudate (r = -0.69, p = 0.004). In dystonia patients, the severities of both anxiety and depression symptoms were inversely associated with DAT availability in the left putamen (r = -0.71, p = 0.004, and r = -0.75, p = 0.002, respectively). There were no correlations between psychometric scores and (123)I-FP-CIT uptake ratios in healthy subjects.
  
  
  CONCLUSIONS
  We found association between presynaptic dopaminergic function and affective symptoms in different movement disorders. Interestingly, the inverse correlation was present in each group of patients, supporting the fascinating perspective that common subcortical substrates may be involved in both anxiety and depression dimensions and movement disorders.
authors.affiliation: Istituto di Medicina Nucleare, Università Cattolica del Sacro Cuore, Rome, Italy. danieladigiuda@rm.unicatt.it
authors.forename: Daniela
authors.initials: D
authors.lastname: Di Giuda
authors.forename: Giovanni
authors.initials: G
authors.lastname: Camardese
authors.forename: Anna Rita
authors.initials: AR
authors.lastname: Bentivoglio
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Cocciolillo
authors.forename: Arianna
authors.initials: A
authors.lastname: Guidubaldi
authors.forename: Lorella
authors.initials: L
authors.lastname: Pucci
authors.forename: Isabella
authors.initials: I
authors.lastname: Bruno
authors.forename: Luigi
authors.initials: L
authors.lastname: Janiri
authors.forename: Alessandro
authors.initials: A
authors.lastname: Giordano
authors.forename: Alfonso
authors.initials: A
authors.lastname: Fasano
mesh_terms: D000328:Adult; D000368:Aged; D001526:Behavioral Symptoms / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D050483:Dopamine Plasma Membrane Transport Proteins / Q000032:analysis*; D004421:Dystonia / Q000000981:diagnostic imaging; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000000981:diagnostic imaging*; D019275:Radiopharmaceuticals; D015899:Tomography, Emission-Computed, Single-Photon; D014202:Tremor / Q000000981:diagnostic imaging; D014326:Tropanes
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D019275:Radiopharmaceuticals; D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane