Deep Brain Stimulation of the subthalamic nucleus does not negatively affect social cognitive abilities of patients with Parkinson’s disease

Abstract

Bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) is a treatment option for patients with advanced idiopathic PD successful at alleviating disabling motor symptoms. Nevertheless, the effects of STN-DBS on cognitive functions remain controversial and few studies have investigated modification of social cognitive abilities in patients with PD treated with STN-DBS. Here we expanded the typically-investigated spectrum of these abilities by simultaneously examining emotion recognition, and both affective and cognitive Theory of Mind (ToM). By means of a cross-sectional study, 20 patients with PD under dopaminergic replacement therapy, 18 patients with PD treated with STN-DBS, and 20 healthy controls performed the Ekman 60-Faces test, the full version of the Reading the Mind in the Eyes test, and the Protocol for the Attribution of Communicative Intentions. There were no differences between the PD groups (treated and not treated with STN-DBS) on any of the social cognitive tests. Our results suggest that patients with PD who are treated with STN-DBS do not experience detrimental effects on their social cognitive abilities. The present study, the first one examining a wide spectrum of social cognitive abilities after DBS of the STN, suggests that this surgical procedure can be considered safe from this standpoint.

Effects of Subthalamic Nucleus Deep Brain Stimulation on Facial Emotion Recognition in Parkinson’s Disease: A Critical Literature Review

“…Regarding the methodology of studies conducted so far, patients were tested in alternating experimental settings with stimulation ON or OFF and medication on or off, i.e., DBS ON/med on, DBS ON/med off, DBS OFF/med on, and DBS OFF/med off. Studies have either compared the pre- to postoperative condition after STN DBS within the same PD group [ 40 – 42 , 63 , 64 ], matched PD groups [ 44 , 48 , 49 ], or PD patients with matched HC [ 46 , 48 , 62 , 65 ]. Most studies reported impaired FER after STN DBS compared to before surgery [ 40 – 44 ].…”

“…Regarding the recognition of specific emotions (i.e., the seven basic emotions: happiness, surprise, fear, anger, sadness, disgust, and neutral), few studies showed a significant reduction of decoding accuracy for sadness [ 40 , 41 , 63 ], fear [ 41 , 42 , 44 , 63 ], anger [ 40 ], and a trend for disgust [ 40 ] after DBS compared to before, although there was not always a comparison with a HC group before surgery. Moreover, Enrici et al [ 48 ] showed a significant impairment of FER for surprise in the STN-DBS-PD group compared to the HC group. With regard to specific emotion performances in different stimulation conditions, Schroeder et al [ 43 ] showed impaired anger recognition in PD patients in the ON STN condition compared to the OFF condition, while Mondillon et al [ 62 ] found a significant decrease in the recognition of disgust ON STN stimulation and a tendency toward impaired recognition of fear OFF stimulation compared to HC (both off medication).…”

“…Vice versa, the studies that found no significant FER differences should have had small LED reduction, which was again not the case (ranging from 19 to 63%) [ 63 , 64 ]. Peron et al [ 41 ] showed a postoperative FER deficit of fear and sadness irrespective of dopaminergic medication modification, and Enrici et al [ 48 ] found no correlation of FER with LED in the two PD groups (PD group on dopaminergic therapy and PD group under STN DBS and dopaminergic therapy). On the other hand, Mondillon et al [ 62 ] showed a greater benefit in FER performance when the two therapies (DBS and L-Dopa) were combined.…”

“…In fact, the identification of emotions can be seen as a complex cognitive process, relying on many cognitive domains such as working memory, language, and visuospatial perception [ 78 ]. Most of the studies assessing FER after DBS measured neuropsychological function as well [ 40 – 42 , 44 , 46 – 48 , 63 ]. Regarding the contribution of cognitive changes to FER worsening after DBS, while some studies, which showed a total or specific emotion FER worsening after DBS also showed worsening of cognitive measures such as verbal fluency [ 40 , 41 ] or correlation between the two functions [ 46 ], others did not [ 41 , 42 , 63 ].…”

“…Moreover, Drapier et al [ 63 ] found no correlation between the postoperative worsening of apathy and emotion recognition and suggested that each of these functions has separate functional networks, probably passing through the STN. On the other hand, Enrici et al [ 48 ] found a significant negative correlation between apathy and FER performance in both PD groups (receiving dopaminergic therapy or both dopaminergic therapy and STN DBS).…”