ABSTRACT
BACKGROUND: Impulse control disorders related to alterations in the mesocorticolimbic dopamine network occur in Parkinson's disease (PD). Our objective was to investigate the functional neural substrates of reward processing and inhibitory control in these patients. METHODS: Eighteen PD patients with impulse control disorders, 17 without this complication, and 18 healthy controls performed a version of the Iowa Gambling Task during functional magnetic resonance scanning under 3 conditions: positive, negative, and mixed feedback. Whole-brain contrasts, regions of interest, time courses, functional connectivity analyses, and brain-behavior associations were examined. RESULTS: PD patients with impulse control disorders exhibited hyperactivation in subcortical and cortical regions typically associated with reward processing and inhibitory control compared with their PD and healthy control counterparts. Time-course analyses revealed that only PD patients with impulse control disorders exhibited stronger signal intensity during the initial versus final periods of the negative-feedback condition in bilateral insula, and right ventral striatum. Interestingly, hyperactivation of all the examined right-lateralized frontostriatal areas during negative feedback was positively associated with impulse control disorder severity. Importantly, positive associations between impulse control disorder severity and regional activations in the right insula and right inferior frontal gyrus, but not the right subthalamic nucleus, were mediated by functional connectivity with the right ventral striatum. CONCLUSIONS: During a reward-based task, PD patients with impulse control disorders showed hyperactivation in a right-lateralized network of regions including the subthalamic nucleus that was strongly associated with impulse control disorder severity. In these patients, the right ventral striatum in particular played a critical role in modulating the functional dynamics of right-lateralized inhibitory-control frontal regions when facing penalties. © 2019 International Parkinson and Movement Disorder Society.
Subject(s)
Brain/physiopathology , Disruptive, Impulse Control, and Conduct Disorders/psychology , Neural Inhibition/physiology , Parkinson Disease/psychology , Adult , Aged , Disruptive, Impulse Control, and Conduct Disorders/etiology , Female , Gambling/complications , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Neuropsychological Tests , Parkinson Disease/complications , RewardABSTRACT
The Honduran Ministry of Public Health and Social Welfare, in consultation with the HEALTHCOM Project of the Academy for Educational Development, conducted a national study that examined the characteristic patterns of acute respiratory infections (ARI) in children, as well as the measures being used to control them. Following an ethnographic analysis of the entire population, a pilot intervention program was developed to teach mothers how to recognize ARI symptoms and take appropriate measures in the case of mild, moderate, and severe episodes. The intervention consisted of teaching health workers (HW) in eight rural towns the most important aspects of ARI control and instructing them in a methodology for transmitting these concepts to the community through oral presentations in local health centers. The methodology included behavior modification techniques and incentives. Three observation instruments were used to compare the effectiveness of the health workers' presentations before and after their training, as well as the knowledge acquired by those who attended the presentations and the community at large. The results indicated that the techniques used both to train the HW and by them in their presentations helped the mothers and other members of the community to respond more effectively when children came down with acute respiratory infections of varying degrees of severity.