Decreased interhemispheric functional connectivity in subtypes of Parkinson's disease

J Neurol. 2015 Mar;262(3):760-7. doi: 10.1007/s00415-014-7627-x. Epub 2015 Jan 11.

Abstract

Parkinson's disease (PD) can be classified into tremor-dominant (TD) subtype and akinetic-rigid (AR) subtype, which exhibit different clinical courses and prognoses. However, the neural mechanisms underlying different subtypes of PD are not well understood. Using voxel-mirrored homotopic connectivity (VMHC), we examined the homotopic resting-state functional connectivity patterns in akinetic-rigid PD (AR-PD) and tremor-dominant PD (TD-PD) to study the neural basis for these disparate manifestations of PD. Twenty-one TD-PD patients, 29 AR-PD patients and 26 normal control subjects participated in this study. Resting-state fMRI data were analyzed using VMHC. Correlations between VMHC values and each clinical characteristic were also calculated. Compared with normal control subjects and subjects with AR-PD, subjects with TD-PD exhibited significantly lower VMHC values in the posterior lobe of the cerebellum. Moreover, tremor scores and VMHC values for the cerebellum were found to be significantly negatively correlated in TD-PD patients. By contrast, subjects with AR-PD exhibited lower VMHC values in the precentral gyrus compared with normal control subjects. These findings suggest that functional coordination between homotopic brain regions is impaired in AR-PD and TD-PD patients. This study provides evidence of both cerebellum-related connectivity deficits in TD-PD. The finding that VMHC values and tremor scores were significantly correlated suggests that VMHC measurements may be of potential clinical relevance in TD-PD.

MeSH terms

  • Adult
  • Aged
  • Analysis of Variance
  • Brain / blood supply
  • Brain / pathology*
  • Brain Mapping*
  • Corpus Callosum / blood supply
  • Corpus Callosum / pathology*
  • Female
  • Humans
  • Image Processing, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Oxygen / blood
  • Parkinson Disease / classification*
  • Parkinson Disease / complications
  • Parkinson Disease / pathology*
  • Rest / physiology
  • Tremor / complications

Substances

  • Oxygen