The next step for imaging the subthalamic nucleus.

Sir, We read with interest the recently published study by Accolla and colleagues (2016) on brain networks modulated by subthalamic nucleus deep brain stimulation (DBS; Accolla et al. , 2016). In their study, the authors combined neurophysiological recordings with MRI to obtain much needed, more detailed information on the functional organization of the subthalamic nucleus (STN) in patients suffering from Parkinson’s disease. More concretely, the authors set out to answer the question whether the STN consist of three distinct subdivisions or gradients including a motor, cognitive, and limbic part (Temel et al. , 2005; Mallet et al. , 2007; Keuken et al. , 2012). Answering this question is of crucial importance for understanding DBS and optimizing its clinical outcome. As a major determinant of clinical outcome is the precise location of the stimulation electrode (Castrioto et al. , 2014), a detailed knowledge of STN anatomy is essential to determine the optimal …