title: Relative preservation of thalamic centromedian nucleus in parkinsonian patients with dystonia.
abstract: To determine whether variable thalamic degeneration in Parkinson's disease (PD) contributes to less drug responsive clinical features. Formalin-fixed thalami from longitudinally followed patients with PD and early dystonia (N = 6), early falls (N = 5) or no dystonia or falls (N = 6) and age-matched controls without neuropathology (N = 10) were serially sectioned, stained, and analyzed. Neurons in the centromedian parafascicular (CM-Pf) nucleus were quantified using the optical disector method and analysis of variance with post hoc testing used to determine variability in neurodegeneration between groups. Patients with PD were confirmed to have significant neurodegeneration in the CM-Pf complex, with no difference in the degree of neurodegeneration between patients with PD with early falls compared with patients with no history of falls or dystonia. In contrast, patients with PD with early dystonia had significantly less neurodegeneration of the CM but not the Pf than patients without this feature. Preservation of the CM in patients with PD with early dystonia would result in a relative increase in CM activity through the direct basal ganglia pathway and increased primary motor cortex activity. Overall this data provides evidence for pathway-specific neurodegeneration as an underlying feature of the clinical variability observed in patients with PD.
authors.affiliation: Prince of Wales Medical Research Institute, University of New South Wales, Randwick, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Truong
authors.forename: Daniel
authors.initials: D
authors.lastname: Brooks
authors.forename: Fabricio
authors.initials: F
authors.lastname: Amaral
authors.forename: Jasmine M
authors.initials: JM
authors.lastname: Henderson
authors.forename: Glenda M
authors.initials: GM
authors.lastname: Halliday
mesh_terms: D000368:Aged; D000978:Antiparkinson Agents / Q000627:therapeutic use; D001284:Atrophy; D002452:Cell Count; D018450:Disease Progression; D004421:Dystonia / Q000209:etiology / Q000473:pathology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D020646:Intralaminar Thalamic Nuclei / Q000473:pathology*; D016631:Lewy Bodies / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009410:Nerve Degeneration / Q000473:pathology; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy / Q000473:pathology*; D051844:alpha-Synuclein / Q000378:metabolism
chemical_list: D000978:Antiparkinson Agents; D051844:alpha-Synuclein