ablative brain surgery ablative brain surgery ablative brain surgery (also known as brain lesioning) is the surgical ablation by various methods of brain tissue to treat neurological or psychological disorders. the word "ablation" stems from the latin word ablatus meaning "carried away". in most cases, however, ablative brain surgery does not involve removing brain tissue, but rather destroying tissue and leaving it in place. the lesions it causes are irreversible. there are some target nuclei for ablative surgery and deep brain stimulation. those nuclei are the motor thalamus, the globus pallidus, and the subthalamic nucleus.