title: Evidence of delayed nigrostriatal dysfunction in corticobasal syndrome: a SPECT follow-up study.
abstract: OBJECTIVE
  To demonstrate that degeneration of substantia nigra neurons may occur at later stages of disease in some patients with corticobasal syndrome (CBS) who evidenced preserved nigrostriatal pathway at a baseline FP-CIT SPECT study.
  
  
  BACKGROUND
  Current pathological criteria for the definite diagnosis of corticobasal degeneration consider substantia nigra cell loss as a mandatory finding. However, dopamine transporter SPECT imaging performed in a large cohort of CBS patients showed about 10% of normal scans.
  
  
  METHODS
  We describe 4 patients with clinical diagnosis of CBS and normal FP-CIT SPECT at baseline whose tracer uptake resulted pathological at 1-year follow-up scan. Clinical assessment has been performed at the time of SPECT scan. A semi-quantitative approach was performed for striatal FP-CIT binding values.
  
  
  RESULTS
  Baseline SPECT scans have been performed after 2.3 ± 1.5 years from onset. All CBS patients presented asymmetric rigid-akinetic parkinsonism (mean Hoehn-Yahr stage 2.5; UPDRS motor score 18) with poor levodopa response and ideo-motor limb apraxia. At follow-up, neurological examination revealed some additional features, including limb dystonia, language impairment, postural instability, ocular gaze impairment, alien limb. All patients showed pathological FP-CIT uptake at the SPECT performed 10-15 months apart from the baseline scan.
  
  
  CONCLUSIONS
  Our longitudinal FP-CIT SPECT findings support in vivo the hypothesis that substantia nigra neuronal loss may occur at later stages in some patients with CBS, despite early extrapyramidal symptoms.
authors: Department of Neuroscience, University of Pisa, Via Roma, 67, 56126 Pisa, Italy. r.ceravolo@med.unipi.it
authors: Roberto
authors: R
authors: Ceravolo
authors: Carlo
authors: C
authors: Rossi
authors: Roberto
authors: R
authors: Cilia
authors: Gloria
authors: G
authors: Tognoni
authors: Angelo
authors: A
authors: Antonini
authors: Duccio
authors: D
authors: Volterrani
authors: Ubaldo
authors: U
authors: Bonuccelli
mesh_terms: D000368:Aged; D015331:Cohort Studies; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020734:Parkinsonian Disorders / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*