The Subthalamic Nucleus, Limbic Function, and Impulse Control

Abstract

It has been well documented that deep brain stimulation (DBS) of the subthalamic nucleus (STN) to address some of the disabling motor symptoms of Parkinson’s disease (PD) can evoke unintended effects, especially on non-motor behavior. This observation has catalyzed more than a decade of research concentrated on establishing trends and identifying potential mechanisms for these non-motor effects. While many issues remain unresolved, the collective result of many research studies and clinical observations has been a general recognition of the role of the STN in mediating limbic function. In particular, the STN has been implicated in impulse control and the related construct of valence processing. A better understanding of STN involvement in these phenomena could have important implications for treating impulse control disorders (ICDs). ICDs affect up to 40% of PD patients on dopamine agonist therapy and approximately 15% of PD patients overall. ICDs have been reported to be associated with STN DBS. In this paper we will focus on impulse control and review pre-clinical, clinical, behavioral, imaging, and electrophysiological studies pertaining to the limbic function of the STN.

GABAA and GABAB receptor subunit localization on neurochemically identified neurons of the human subthalamic nucleus

“…Furthermore, results from STN tracing studies in animal models were often controversial in the number and localization of subdivisions (Keuken et al, ). More recent studies however, supports an overlapping model where merging occurs between functional territories or even coexistence of different territories (Haegelen, Rouaud, Darnault, & Morandi, ; Haynes & Haber, ; Rossi, Gunduz, & Okun, ). Similar to previous cytoarchitectural studies, our results could not discern distinct subregions.…”

Clinical Impact of Deep Brain Stimulation on the Autonomic System in Patients with Parkinson's Disease

“…The STN is commonly associated with both reward and inhibitory control pathways. 45 Indeed, food craving and binge eating have been frequently reported following STN-DBS surgery, 46,47 and patients with other pathology affecting the STN, for example, stroke or tumur, can also experience hyperphagia and increased appetite. 48 Alternatively, the spread of stimulation current beyond the borders of the STN may influence the hypothalamic regulation of energy metabolism or the homeostatic pathway of food intake.…”

The human subthalamic nucleus and globus pallidus internus differentially encode reward during action control

“…Substantial evidence from animal studies over the past decade indicates that the STN plays an important role in processing reward [Rossi et al, ]. Large subsets of STN neurons in the rat have been shown to encode the prospect of reward, reward receipt, and the magnitude of possible reward outcomes.…”

“…Aysegul Gunduz and Michael S. Okun are co-senior authors on this manuscript. *Correspondence to: P. Justin Rossi,3450 Hull Road,Gainesville, Substantial evidence from animal studies over the past decade indicates that the STN plays an important role in processing reward [Rossi et al, 2015]. Large subsets of STN neurons in the rat have been shown to encode the prospect of reward, reward receipt, and the magnitude of possible reward outcomes.…”