title: Brain perfusion correlates of cognitive and nigrostriatal functions in de novo Parkinson's disease.
abstract: OBJECTIVE
  Subtle cognitive impairment is recognized in the first stages of Parkinson's disease (PD), including executive, memory and visuospatial dysfunction, but its pathophysiological basis is still debated.
  
  
  METHODS
  Twenty-six consecutive, drug-naïve, de novo PD patients underwent an extended neuropsychological battery, dopamine transporter (DAT) and brain perfusion single photon emission computed tomography (SPECT). We previously reported that nigrocaudate impairment correlates with executive functions, and nigroputaminal impairment with visuospatial abilities. Here perfusion SPECT was first compared between the PD group and age-matched controls (CTR). Then, perfusion SPECT was correlated with both DAT SPECT and four neuropsychological factors by means of voxel-based analysis (SPM8) with a height threshold of p < 0.005 at peak level and p < 0.05 false discovery rate-corrected at cluster level. Both perfusion and DAT SPECT images were flipped in order to have the more affected hemisphere (MAH), defined clinically, on the same side.
  
  
  RESULTS
  Significant hypoperfusion was found in an occipital area of the MAH in PD patients as compared to CTR. Executive functions directly correlated with brain perfusion in bilateral posterior cingulate cortex and precuneus in the less affected hemisphere (LAH), while verbal memory directly correlated with perfusion in the precuneus, inferior parietal lobule and superior temporal gyrus in the LAH. Furthermore, positive correlation was highlighted between nigrocaudate and nigroputaminal impairment and brain perfusion in the precuneus, posterior cingulate and parahippocampal gyri of the LAH.
  
  
  CONCLUSIONS
  These data support the evidence showing an early involvement of the cholinergic system in the early cognitive dysfunction and point to a more relevant role of parietal lobes and posterior cingulate in executive functions in PD.
authors: Clinical Neurophysiology, Department of Neurosciences, Ophthalmology and Genetics, University of Genoa, Via De Toni, 5, 16132 Genoa, Italy. flaviomariano.nobili@hsanmartino.it
authors: Flavio
authors: F
authors: Nobili
authors: Dario
authors: D
authors: Arnaldi
authors: Claudio
authors: C
authors: Campus
authors: Michela
authors: M
authors: Ferrara
authors: Fabrizio
authors: F
authors: De Carli
authors: Andrea
authors: A
authors: Brugnolo
authors: Barbara
authors: B
authors: Dessi
authors: Nicola
authors: N
authors: Girtler
authors: Silvia
authors: S
authors: Morbelli
authors: Giovanni
authors: G
authors: Abruzzese
authors: Gianmario
authors: G
authors: Sambuceti
authors: Guido
authors: G
authors: Rodriguez
mesh_terms: D000368:Aged; D001783:Blood Flow Velocity; D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology*; D002560:Cerebrovascular Circulation; D003071:Cognition; D003072:Cognition Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology*; D003342:Corpus Striatum / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055420:Perfusion Imaging; D013223:Statistics as Topic; D013378:Substantia Nigra / Q000000981:diagnostic imaging / Q000503:physiopathology*; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods; D016896:Treatment Outcome