“…These investigations began in the 1960s with selective ablation (Bertrand, Hardy, Molina‐Negro, & Martínez, 1969; Mundinger, 1965; Spiegel et al, 1962, 1964; Spiegel & Wycis, 1954; Velasco, Velasco, & Machado, 1975; Wertheimer, Lapras, & Levy, 1960), but as technologies improved, various groups (Blomstedt, Sandvik, & Tisch, 2010; Mohadjer, Goerke, Milios, Etou, & Mundinger, 1990; Nowacki et al, 2018; Plaha, Ben‐Shlomo, Patel, & Gill, 2006; Velasco et al, 2001) demonstrated that electrical stimulation to these regions was also effective. Yet because of poor direct visualization, controversy has remained as to whether the therapeutic effect is derived from modulation of the cell bodies in the cZI, wayward connections such as the fasciculus cerebellothalamicus (fct; also known as the prelemniscal radiations or raprl) (Castro et al, 2015; Velasco, Molina‐Negro, Bertrand, & Hardy, 1972), or some combination of both (Blomstedt et al, 2010). Given the ambiguity and high functional density of the region, the stereotactic target is often considered more broadly as the posterior subthalamic area (PSA; Blomstedt et al, 2018; Hariz & Blomstedt, 2017; Nowacki, Debove, et al, 2018).…”