Fronto-striatal deficit in Parkinson's disease during semantic event sequencing

Abstract

Studies of Parkinson's disease (PD) suggest that cognitive deficits accompany the classically recognized motor symptoms, and that these cognitive deficits may result from damage to frontalbasal ganglia circuits. PD patients are impaired on ordering events and action components into coherent sequences. In this study, we examined early-stage, nondemented, medicated PD subjects and matched control subjects during a semantic event sequencing task using functional MRI (fMRI). The task required subjects to examine four pictures of meaningful events, determine the correct temporal relationship between each picture, and re-order the pictures into a coherent sequence. There were two main findings. First, we found abnormal activation within the prefrontal cortex (PFC) and the "default" network in the PD group. Distinct areas of the PFC showed both hypoactivation and hyperactivation, whereas the "default" network showed reduced levels of resting activation in PD. Secondly, we observed left caudate hyperactivation in the PD group. The findings are discussed in relationship to how more activation may be compensatory, but does not necessarily mean efficient and correlated brain function.

Functional Neuroimaging in Parkinson's Disease

“…Using fMRI and a semantic event sequencing task, Tinaz et al found that in contrast to controls, patients with PD did not show decreased activation of the DMN during task performance (Tinaz et al 2008). Similarly, during a Montreal card sorting task, PD patients did not only show less deactivation of the parietal DMN nodes, but even showed decreased activation of these same areas during the control task (van Eimeren et al 2009).…”

A Case Report of Drug-Induced Parkinsonism Treated with Jodeung-san and Electro-acupuncture at GB34

“…Because acupuncture in our study was conducted on the right leg, brain activation can be expected to be greater in opposite brain areas. Moreover, note that the prefrontal cortex and precentral gyrus are known to be affected by PD [37,38]. Our neuroimaging results seem to indicate that the effects of acupuncture treatment are visible in these areas in patients with PD, but not in healthy participants.…”

“…Moreover, the putamen was activated in both groups. The prefrontal cortex [37], precentral gyrus [38], and putamen [38] are all known to be affected by PD. In a simple finger-tapping task, acupuncture at GB34 showed a significant improvement of motor function on the affected hand before and after ACUP on GB34 (13.6%; P < 0.05) [47], and led to increased activation of the putamen and the primary motor cortex in patients with PD [47].…”

“…Based on the literature, we hypothesize that acupuncture stimulation on GB 34 has an effect on brain areas that are known to show dysfunction due to nigral dopamine depletion: the prefrontal cortex [37], precentral gyrus [38], thalamus [39], globus pallidus [40], caudate [41], and putamen [38]. Moreover, our second hypothesis is that a significant difference in brain activity in patients with PD compared with healthy participants will be found.…”

Current Role of Functional MRI in the Diagnosis of Movement Disorders

“…The findings of these early studies have identified dysfunction in numerous cognitive domains including working memory [17], set-shifting or the ability to alter behavior to dynamically changing circumstances [18], reward processing [19], and semantic sequencing [20]. Such cognitive impairments also have the potential to impact motor performance.…”