Cortico-basal ganglia and cortico-cerebellar circuits in Parkinson's disease: Pathophysiology or compensation?

Abstract

The basal ganglia and the cerebellum are anatomically and functionally linked to the cerebral cortex through a series of well-established circuits. The disruption of dopaminergic projections in Parkinson's disease (PD) leads to an imbalance within these circuits, leading to motor and cognitive symptoms. The cortico-cerebellar (CC) network has often been viewed as a compensatory network, helping the dysfunction of the cortico-basal ganglia (CBG) circuits in PD. However, evidence for this compensatory role is scarce; most changes in cerebellar activity could equally be attributed to pathophysiological changes underlying PD. This paper will review the anatomy, interaction and function of the CBG and CC circuits, the pathophysiological, metabolic, and functional changes observed in PD, as well as the effect of levodopa and deep brain stimulation on these changes. We will use this framework to discuss the pathophysiological and compensatory mechanisms behind CBG and CC circuit activity in PD.

Patterns of Longitudinal Neural Activity Linked to Different Cognitive Profiles in Parkinson's Disease

“…It has been reported in non-demented PD patients that lowered regional cerebral metabolic rates in the occipital area correlate with the motor dysfunction (Bohnen et al, 1999) We also previously reported lower regional cerebral metabolic rates for glucose in the occipital area accompanied by dopaminergic availability in the striatum, along with motor dysfunction in non-demented PD patients (Nagano-Saito et al, 2004) Simultaneously, cerebellar activity is likely to contribute to pathophysiological change underlying PD (Martinu and Monchi, 2013) Thus, the reduced activation in the occipital area and cerebellum may reflect remote effects of the progress of the disease on dopamine projections in the striatum. However, they might also reflect a learning effect with reduction of visual attention and motor effort at Time 2.…”

Differential Functional Connectivity Alterations of Two Subdivisions within the Right dlPFC in Parkinson's Disease

“…This can be interpreted as a seed specific PD-related FC decrease, i.e., that the FC between the anterior right dlPFC seed and the left lateral cerebellum shows a significantly stronger decrease in PD than between the posterior right dlPFC cluster and this cerebellar region. In PD, several alterations in the functional activation and connectivity of the cerebellum have been reported related to various motor and cognitive symptoms of the disease (see Martinu and Monchi, 2013; Wu and Hallett, 2013 for reviews). The cerebellum is reciprocally connected to the prefrontal cortex via the cerebello-thalamo-cortical circuit.…”

Brain activity during walking: A systematic review

“…However, while our review does not especially addresses a neurological disease (e.g. Parkinson disease), we would like to refer to other reviews which deal with cognitive dysfunctions and the resulting motor limitations (Grabli et al, 2012;Heremans et al, 2013;Hirano et al, 2012;Iansek et al, 2013;Lindenbach and Bishop, 2013;Martinu and Monchi, 2013;Ricciardi et al, 2014;Silbert and Kaye, 2010;Vercruysse et al, 2014). Interestingly, exercise treatments are helpful to improve cognitive and motor symptoms in Parkinson disease (Ahlskog, 2011;Murray et al, 2014;Petzinger et al, 2013).…”