title: Cognitive-nigrostriatal relationships in de novo, drug-naïve Parkinson's disease patients: a [I-123]FP-CIT SPECT study.
abstract: To unveil cognitive-nigrostriatal correlations in Parkinson's disease (PD), 30 de novo, drug-naïve PD patients and 15 patients with essential tremor (Controls, CTR) underwent a neuropsychological (NPS) battery and brain SPECT with [I-123]Ioflupane, as a biomarker of nigrostriatal function. Automatic extraction of uptake at caudate and putamen level was conducted through the BasGan software, also allowing partial volume effect correction. Because of the multicollinearity among neuropsychological tests and among SPECT variables, factor analysis was applied to 16 neuropsychological scores; moreover, the four SPECT variables were merged into a mean SPECT value (mSPECT). Factor analysis identified four NPS factors: a dys-executive (NPS-EX), a visuospatial (NPS-VS), a verbal memory (NPS-VM), and a "mixed" (NPD-MIX) factor. In PD group, there were inverse correlations between UPDRS-III score and both NPS-VS (P < 0.01) and mSPECT (P < 0.05), and a direct correlation between mSPECT and NPS-EX (P < 0.05). Post hoc analysis showed a direct correlation between NPS-EX and caudate uptake in both hemispheres (P < 0.05). Moreover, inverse correlations were found between UPDRS-III and, respectively, putamen uptake in the less affected hemisphere (P < 0.01), and putamen and caudate uptake in the more affected hemisphere (P < 0.05). In CTR, no correlation was found between mSPECT and either NPS or GDS values. Nigro-caudate function affects executive capabilities in PD but not in CTR, which appears to be unrelated to the disease motor severity at its onset. Instead, PD motor severity is related to nigro-putaminal impairment and visuospatial dysfunction. The role of these data as predictive features of cognitive decline and eventually dementia remains to be established in longitudinal studies.
authors.affiliation: Department of Neurosciences, Ophthalmology and Genetics, Clinical Neurophysiology Unit, University of Genoa, Genoa 516132, Italy. flaviomariano.nobili@hsanmartino.it
authors.forename: Flavio
authors.initials: F
authors.lastname: Nobili
authors.forename: Claudio
authors.initials: C
authors.lastname: Campus
authors.forename: Dario
authors.initials: D
authors.lastname: Arnaldi
authors.forename: Fabrizio
authors.initials: F
authors.lastname: De Carli
authors.forename: Gaia
authors.initials: G
authors.lastname: Cabassi
authors.forename: Andrea
authors.initials: A
authors.lastname: Brugnolo
authors.forename: Barbara
authors.initials: B
authors.lastname: Dessi
authors.forename: Silvia
authors.initials: S
authors.lastname: Morbelli
authors.forename: Gianmario
authors.initials: G
authors.lastname: Sambuceti
authors.forename: Giovanni
authors.initials: G
authors.lastname: Abbruzzese
authors.forename: Guido
authors.initials: G
authors.lastname: Rodriguez
mesh_terms: D000368:Aged; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D003342:Corpus Striatum / Q000000981:diagnostic imaging*; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000473:pathology; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D013378:Substantia Nigra / Q000000981:diagnostic imaging*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D014326:Tropanes
chemical_list: D014326:Tropanes; C087552:2-carbomethoxy-8-(3-fluoropropyl)-3-(4-iodophenyl)tropane