TO THE EDITOR: We read with interest the study by Freund et al. 1 (Freund BE, Greco E, Okromelidz e L, et al. Clinical outcome of imaging-based programming for anterior thalamic nucleus deep brain stimulation. J Neurosurg. Published online September 9, 2022. doi: 10.3171/2022.7. JNS221116). The authors found that the proximity of deep brain stimulator contacts to the anterior thalamic nucleus–mammillothalamic tract (ATNMMT) junction determines efficacy of deep brain stimulation (DBS) in drug-resistant epilepsy. 1 The studies of Freund et al. 1 and others in the literature2 are significant as they represent a departure from conventional wisdom that stimulation of the macrostructures alone is sufficient. 3 Building on the findings of Freund et al., if the proximity of the DBS contact to the ATN-MMT junction determines efficacy1 and the MMT is a primary input into the ATN, 1, 4 do the functional integrities of the ATN, MMT, and ATN-MMT junction also determine efficacy (Fig. 1)? If they do, we hypothesize that the functional integrities of the ATN, MMT, and ATN-MMT junction can be used to select patients for ATN-MMT DBS for drug-resistant epilepsy. The functional integrities of the ATN, MMT, and ATN-MMT junction may be investigated using advanced imaging modalities such as functional MRI. 5 The findings of Freund et al. and others1, 2 lay the groundwork for future randomized controlled trials that evaluate the efficacy of DBS across different substructures, so that the precise “sweet spot” to be targeted by DBS can be determined.