This study evaluates the predictive value of preoperative immunonutritional markers—including the Hemoglobin, Albumin, Lymphocyte, and Platelet (HALP) score, Aggregate Index of Systemic Inflammation (AISI), Lymphocyte-to-Monocyte Ratio (LMR), and systemic inflammatory response syndrome (SIRS)—for the risk of extracranial complications following STN DBS. Here, ALB is linked to systemic inflammatory response syndrome.