title: Striatal dopamine transporter function in dementia with Lewy bodies and Parkinson's disease.
abstract: The aim of this study was to compare parkinsonian features and loss of striatal dopamine transporter (DAT) function in patients with dementia with Lewy bodies (DLB) and Parkinson's disease (PD), matched for age and disease duration. Twenty patients with DLB. 24 PD patients and 10 matched controls were examined with SPET using a dual-head camera and the dopamine-transporter ligand 123I-beta-CIT (148 MBq). Moreover, in a subgroup of patients (16 DLB and 20 PD patients), subscores of the Unified Parkinson's Disease Rating Scale (UPDRS)-motor examination (ME) subscale were obtained during "practical off", i.e. 12 h following withdrawal of antiparkinsonian therapy. Compared with controls, striatal/cerebellar (S/C) ratios of DAT binding were significantly reduced in both DLB and PD, deficits being more marked in DLB patients (controls 7.2 +/- 1.2, DLB 3.3 +/- 1, PD 4.2 +/- 1.4; means +/- SD). The side-to-side differences in the S/C ratios were lower in the DLB group and the controls than in PD patients (0.4 +/- 0.4. 0.2 +/- 0.2 and 0.6 +/- 0.3, respectively, P<0.05). The total UPDRS-ME scores during practical-off were significantly higher in the DLB than in the PD group (41.2 +/- 12.7 vs 26.6 +/- 15.3, P<0.01). The side-to-side differences of the summed UPDRS extremity subscores were smaller in the DLB than in the PD group (2.2 +/- 2.3 vs 7.4 +/- 3.9, P<0.0001). Our findings suggest that parkinsonism evolves largely symmetrically and progresses more rapidly with more severe loss of striatal dopamine transporter function in DLB compared to PD. Whether these findings are helpful in the differential diagnosis of DLB and PD needs to be examined in further studies.
authors.affiliation: Department of Neurology, University Hospital Innsbruck, Austria. gerhard.ransmayr@uibk.ac.at
authors.forename: G
authors.initials: G
authors.lastname: Ransmayr
authors.forename: K
authors.initials: K
authors.lastname: Seppi
authors.forename: E
authors.initials: E
authors.lastname: Donnemiller
authors.forename: E
authors.initials: E
authors.lastname: Luginger
authors.forename: J
authors.initials: J
authors.lastname: Marksteiner
authors.forename: G
authors.initials: G
authors.lastname: Riccabona
authors.forename: W
authors.initials: W
authors.lastname: Poewe
authors.forename: G K
authors.initials: GK
authors.lastname: Wenning
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000503:physiopathology; D050483:Dopamine Plasma Membrane Transport Proteins; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins / Q000502:physiology*; D008875:Middle Aged; D009419:Nerve Tissue Proteins; D010300:Parkinson Disease / Q000000981:diagnostic imaging / Q000503:physiopathology*; D020955:Striatonigral Degeneration / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D050483:Dopamine Plasma Membrane Transport Proteins; D008562:Membrane Glycoproteins; D026901:Membrane Transport Proteins; D009419:Nerve Tissue Proteins; C493214:SLC6A3 protein, human