Grey matter changes in cognitively impaired Parkinson's disease patients.
BACKGROUND
Cortical changes associated with cognitive decline in Parkinson's disease (PD) are not fully explored and require investigations with established diagnostic classification criteria.


OBJECTIVE
We used MRI source-based morphometry to evaluate specific differences in grey matter volume patterns across 4 groups of subjects: healthy controls (HC), PD with normal cognition (PD-NC), PD with mild cognitive impairment (MCI-PD) and PD with dementia (PDD).


METHODS
We examined 151 consecutive subjects: 25 HC, 75 PD-NC, 29 MCI-PD, and 22 PDD at an Italian and Czech movement disorder centre. Operational diagnostic criteria were applied to classify MCI-PD and PDD. All structural MRI images were processed together in the Czech centre. The spatial independent component analysis was used to assess group differences of local grey matter volume.


RESULTS
We identified two independent patterns of grey matter volume deviations: a) Reductions in the hippocampus and temporal lobes; b) Decreases in fronto-parietal regions and increases in the midbrain/cerebellum. Both patterns differentiated PDD from all other groups and correlated with visuospatial deficits and letter verbal fluency, respectively. Only the second pattern additionally differentiated PD-NC from HC.


CONCLUSIONS
Grey matter changes in PDD involve areas associated with Alzheimer-like pathology while fronto-parietal abnormalities are possibly an early marker of PD cognitive decline. These findings are consistent with a non-linear cognitive progression in PD.
Brain and Mind Research Program, Central European Institute of Technology, Central European Institute of Technology Masaryk University, Masaryk University, Brno, Czech Republic ; First Department of Neurology, School of Medicine, Masaryk University and St. Anne's University Hospital, Brno, Czech Republic.
Irena
I
Rektorova
Center for Parkinson's disease and Movement Disorder "Fondazione Ospedale San Camillo" - Istituto di Ricovero e Cura a Carattere Scientifico, Venice-Lido, Italy.
Roberta
R
Biundo
Brain and Mind Research Program, Central European Institute of Technology, Central European Institute of Technology Masaryk University, Masaryk University, Brno, Czech Republic ; First Department of Neurology, School of Medicine, Masaryk University and St. Anne's University Hospital, Brno, Czech Republic.
Radek
R
Marecek
Center for Parkinson's disease and Movement Disorder "Fondazione Ospedale San Camillo" - Istituto di Ricovero e Cura a Carattere Scientifico, Venice-Lido, Italy.
Luca
L
Weis
Department of Neurology and Clinical Neuroscience, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden ; Centre for Age-Related Diseases, Stavanger University Hospital, Stavanger, Norway.
Dag
D
Aarsland
Center for Parkinson's disease and Movement Disorder "Fondazione Ospedale San Camillo" - Istituto di Ricovero e Cura a Carattere Scientifico, Venice-Lido, Italy.
Angelo
A
Antonini
D000368:Aged; D002531:Cerebellum / Q000473:pathology / Q000503:physiopathology; D060825:Cognitive Dysfunction / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D003704:Dementia / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D005260:Female; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008636:Mesencephalon / Q000473:pathology / Q000503:physiopathology; D008875:Middle Aged; D009483:Neuropsychological Tests; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology; D010300:Parkinson Disease / Q000150:complications / Q000473:pathology* / Q000503:physiopathology; D013702:Temporal Lobe / Q000473:pathology / Q000503:physiopathology