Up to 15% of patients with Parkinson's Disease (PD) experience impulse control and related behaviours (ICRBs), though it is not fully understood why ( [1] Maloney E.M. Djamshidian A. O'Sullivan S.S. Phenomenology and epidemiology of impulsive-compulsive behaviours in Parkinson's disease, atypical parkinsonian disorders and non-parkinsonian populations.

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). Dopamine agonists (DA) and high total dose of levodopa have been associated with development of ICRBs, with the reduction or withdrawal of a DA often improving these symptoms. Subthalamic nucleus deep brain stimulation (STN-DBS) can be used as a tertiary therapy for PD in order to reduce DA dosage ( [2] Rossi P.J. Shute J.B. Opri E. Molina R. Peden C. Castellanos O. et al. Impulsivity in Parkinson's disease is associated with altered subthalamic but not globus pallidus internus activity.

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, [3] Rossi P.J. De Jesus S. Hess C.W. Martinez-Ramirez D. Foote K.D. Gunduz A. et al. Measures of impulsivity in Parkinson's disease decrease after DBS in the setting of stable dopamine therapy.

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), however, the effect of STN-DBS on ICRBs is unclear ( 4 Merola A. Romagnolo A. Rizzi L. et al. Impulse control behaviors and subthalamic deep brain stimulation in Parkinson disease. , 5 Santin Voullemnot Vrillon et al. Impact of subthalamic DBS on ICD in PD patients: a prospective study. , 6 Kasemsuk C. Oyama G. Hattori N. Management of impulse control disorders with deep brain stimulation: a double-edged sword.

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).