Manuela Fumagalli1, Sara Marceglia1, Filippo Cogiamanian2, Gianluca Ardolino2, Marta Picascia3, Sergio Barbieri2, Gabriella Pravettoni4, Claudio Pacchetti2, Alberto Priori5. 1. Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Via Francesco Sforza 35, Milan, Italy. 2. U.O. Neurofisiopatologia, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Via Francesco Sforza 35, Milan, Italy. 3. Unità Operativa Parkinson e Disordini del Movimento, IRCCS Istituto Neurologico Mondino, Via Mondino 2, Pavia, Italy. 4. Dipartimento di Economia, Management e Metodi Quantitativi, Università degli Studi di Milano, Via Festa del Perdono 7, Milan, Italy; Applied Research Unit for Cognitive and Psychological Science, Istituto Europeo di Oncologia, Via Giuseppe Ripamonti 435, Milan, Italy. 5. Centro Clinico per la Neurostimolazione, le Neurotecnologie ed i Disordini del Movimento, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Via Francesco Sforza 35, Milan, Italy; Dipartimento di Fisiopatologia Medico-Chirurgica e dei Trapianti, Università degli Studi di Milano, Via Francesco Sforza 35, Milan, Italy. Electronic address: alberto.priori@unimi.it.
Abstract
INTRODUCTION: The possibility that deep brain stimulation (DBS) in Parkinson's disease (PD) alters patients' decisions and actions, even temporarily, raises important clinical, ethical and legal questions. Abnormal moral decision-making can lead to ethical rules violations. Previous experiments demonstrated the subthalamic (STN) activation during moral decision-making. Here we aim to study whether STN DBS can affect moral decision-making in PD patients. METHODS: Eleven patients with PD and bilateral STN DBS implant performed a computerized moral task in ON and OFF stimulation conditions. A control group of PD patients without DBS implant performed the same experimental protocol. All patients underwent motor, cognitive and psychological assessments. RESULTS: STN stimulation was not able to modify neither reaction times nor responses to moral task both when we compared the ON and the OFF state in the same patient (reaction times, p = .416) and when we compared DBS patients with those treated only with the best medical treatment (reaction times: p = .408, responses: p = .776). CONCLUSIONS: Moral judgment is the result of a complex process, requiring cognitive executive functions, problem-solving, anticipations of consequences of an action, conflict processing, emotional evaluation of context and of possible outcomes, and involving different brain areas and neural circuits. Our data show that STN DBS leaves unaffected moral decisions thus implying relevant clinical and ethical implications for DBS consequences on patients' behavior, on decision-making and on judgment ability. In conclusion, the technique can be considered safe on moral behavior.
INTRODUCTION: The possibility that deep brain stimulation (DBS) in Parkinson's disease (PD) alters patients' decisions and actions, even temporarily, raises important clinical, ethical and legal questions. Abnormal moral decision-making can lead to ethical rules violations. Previous experiments demonstrated the subthalamic (STN) activation during moral decision-making. Here we aim to study whether STN DBS can affect moral decision-making in PDpatients. METHODS: Eleven patients with PD and bilateral STN DBS implant performed a computerized moral task in ON and OFF stimulation conditions. A control group of PDpatients without DBS implant performed the same experimental protocol. All patients underwent motor, cognitive and psychological assessments. RESULTS:STN stimulation was not able to modify neither reaction times nor responses to moral task both when we compared the ON and the OFF state in the same patient (reaction times, p = .416) and when we compared DBS patients with those treated only with the best medical treatment (reaction times: p = .408, responses: p = .776). CONCLUSIONS: Moral judgment is the result of a complex process, requiring cognitive executive functions, problem-solving, anticipations of consequences of an action, conflict processing, emotional evaluation of context and of possible outcomes, and involving different brain areas and neural circuits. Our data show that STN DBS leaves unaffected moral decisions thus implying relevant clinical and ethical implications for DBS consequences on patients' behavior, on decision-making and on judgment ability. In conclusion, the technique can be considered safe on moral behavior.