Original Article

European Journal of Nuclear Medicine and Molecular Imaging

, Volume 39, Issue 11, pp 1767-1777

Posterior parietooccipital hypometabolism may differentiate mild cognitive impairment from dementia in Parkinson’s disease

  • David Garcia-GarciaAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of NavarraCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)
  • , Pedro ClaveroAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of Navarra
  • , Carmen Gasca SalasAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of NavarraCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)
  • , Isabel LametAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of Navarra
  • , Javier ArbizuAffiliated withDepartment of Nuclear Medicine, Clínica, University of Navarra
  • , Rafael Gonzalez-RedondoAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of NavarraCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)
  • , Jose A. ObesoAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of NavarraCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)
  • , Maria C. Rodriguez-OrozAffiliated withNeurosciences Area, CIMA, Department of Neurology and Neurosurgery, Clinica Universidad de Navarra, University of NavarraCentro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED)Department of Neurology and Neuroscience, University Hospital Donostia, BioDonostia Research InstituteIkerbasque, Basque Foundation for Science Email author 

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Purpose

Patients with Parkinson’s disease (PD) may have normal cognition, mild cognitive impairment (MCI) or dementia. We investigated differences in cerebral metabolism associated with these three cognitive states and the relationship between metabolism and cognitive dysfunction.

Methods

FDG PET and a battery of neuropsychological tests were used to study PD patients with dementia (n = 19), MCI (n = 28) and normal cognition (n = 21), and control subjects (n = 20). Regional glucose metabolism in patients and controls was analysed using statistical parametric mapping (SPM8) corrected for age, motor severity and depression. Correlations between the mini-mental state examination score and Z-score values of the different cognitive domains with respect to cerebral FDG uptake were assessed using SPM8.

Results

PD patients with MCI (PD-MCI patients) exhibited decreased FDG uptake in the frontal lobe, and to a lesser extent in parietal areas compared with cognitively normal patients. Patients with dementia showed reduced metabolism in the parietal, occipital and temporal areas and a less extensive reduction in the frontal lobe compared with PD-MCI patients, while widespread hypometabolism was seen in comparison with patients with normal cognition. PD-MCI patients exhibited reduced FDG uptake in the parietal and occipital lobes and in localized areas of the frontal and temporal lobes compared with controls, whereas patients with dementia showed a widespread reduction of cortical metabolism. Mini-mental state examination score correlated positively with metabolism in several lobes, executive function with metabolism in the parietooccipitotemporal junction and frontal lobe, memory with temporoparietal metabolism, visuospatial function with occipitoparietal and temporal metabolism, and language with frontal metabolism.

Conclusion

PD patients with MCI exhibited hypometabolism in several cortical regions compared with controls, and in the frontal and parietal regions compared with cognitively normal patients. Hypometabolism was higher in patients with dementia than in those with MCI, mainly in the posterior cortical areas where it was correlated with visuospatial, memory and executive functions.

Keywords

Parkinson’s disease Mild cognitive impairment PET Cerebral metabolism Dementia