Lucia Ricciardi1,2, Petra Fischer2, Abteen Mostofi1, Gerd Tinkhauser3, Flavie Torrecillos2, Fahd Baig1,2, Mark J Edwards1, Erlick A C Pereira1, Francesca Morgante1,4, Peter Brown2. 1. Neurosciences Research Centre, Molecular and Clinical Sciences Research Institute, St George's University of London, London, United Kingdom. 2. Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, Oxford, United Kingdom. 3. Department of Neurology, Bern University Hospital and University of Bern, Bern, Switzerland. 4. Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy.
Abstract
BACKGROUND: Impulsivity is common in people with Parkinson's disease (PD), with many developing impulsive compulsive behavior disorders (ICB). Its pathophysiological basis remains unclear. OBJECTIVES: We aimed to investigate local field potential (LFP) markers of trait impulsivity in PD and their relationship to ICB. METHODS: We recorded subthalamic nucleus (STN) LFPs in 23 PD patients undergoing deep brain stimulation implantation. Presence and severity of ICB were assessed by clinical interview and the Questionnaire for Impulsive-Compulsive Disorders in PD-Rating Scale (QUIP-RS), whereas trait impulsivity was estimated with the Barratt Impulsivity Scale (BIS-11). Recordings were obtained during the off dopaminergic states and the power spectrum of the subthalamic activity was analyzed using Fourier transform-based techniques. Assessment of each electrode contact localization was done to determine the topography of the oscillatory activity recorded. RESULTS: Patients with (n = 6) and without (n = 17) ICB had similar LFP spectra. A multiple regression model including QUIP-RS, BIS-11, and Unified PD Rating Scale-III scores as regressors showed a significant positive correlation between 8-13 Hz power and BIS-11 score. The correlation was mainly driven by the motor factor of the BIS-11, and was irrespective of the presence or absence of active ICB. Electrode contact pairs with the highest α power, which also correlated most strongly with BIS-11, tended to be more ventral than contact pairs with the highest beta power, which localize to the dorsolateral motor STN. CONCLUSIONS: Our data suggest a link between α power and trait impulsivity in PD, irrespective of the presence and severity of ICB.
BACKGROUND:Impulsivity is common in people with Parkinson's disease (PD), with many developing impulsive compulsive behavior disorders (ICB). Its pathophysiological basis remains unclear. OBJECTIVES: We aimed to investigate local field potential (LFP) markers of trait impulsivity in PD and their relationship to ICB. METHODS: We recorded subthalamic nucleus (STN) LFPs in 23 PDpatients undergoing deep brain stimulation implantation. Presence and severity of ICB were assessed by clinical interview and the Questionnaire for Impulsive-Compulsive Disorders in PD-Rating Scale (QUIP-RS), whereas trait impulsivity was estimated with the Barratt Impulsivity Scale (BIS-11). Recordings were obtained during the off dopaminergic states and the power spectrum of the subthalamic activity was analyzed using Fourier transform-based techniques. Assessment of each electrode contact localization was done to determine the topography of the oscillatory activity recorded. RESULTS:Patients with (n = 6) and without (n = 17) ICB had similar LFP spectra. A multiple regression model including QUIP-RS, BIS-11, and Unified PD Rating Scale-III scores as regressors showed a significant positive correlation between 8-13 Hz power and BIS-11 score. The correlation was mainly driven by the motor factor of the BIS-11, and was irrespective of the presence or absence of active ICB. Electrode contact pairs with the highest α power, which also correlated most strongly with BIS-11, tended to be more ventral than contact pairs with the highest beta power, which localize to the dorsolateral motor STN. CONCLUSIONS: Our data suggest a link between α power and trait impulsivity in PD, irrespective of the presence and severity of ICB.