A Parsimonious Nomogram for Individualized Prediction of 1-Year Functional Outcome After STN-DBS in Parkinson's Disease: A Single-Center Retrospective Study

Yiming ZhangQiushi Zhu^*Baojun FangFengyang Geng

• Liaocheng People's Hospital, Liaocheng, China

Background: In Parkinson's disease (PD), subthalamic nucleus deep brain stimulation (STN-DBS) alleviates motor symptoms; however, functional outcomes at follow-up remain heterogeneous. Identifying patients at higher risk of unsatisfactory functional recovery using a personalized risk stratification tool may help guide perioperative management. Methods: We retrospectively reviewed consecutive PD patients who underwent STN-DBS at the Department of Functional Neurosurgery, Liaocheng People's Hospital, between January 1, 2015 and August 1, 2024, with a 1-year follow-up. Functional outcome was defined by the medication-off Schwab and England Activities of Daily Living Scale (S&E) at 1 year as good (S&E >70) or poor (S&E ≤70). Candidate predictors were prespecified and collected from general clinical characteristics, perioperative indicators, and preoperative specialist assessments. Independent predictors of poor outcomes were identified using multivariable logistic regression, and a nomogram was constructed. Internal validation was performed using bootstrap resampling. Model discrimination was quantified by the area under the receiver operating characteristic curve [AUC (C-index)], calibration was assessed using calibration plots and the Hosmer–Lemeshow test, and clinical utility was evaluated using decision curve analysis (DCA). Results: A total of 184 patients were included, of whom 109 had a good outcome and 75 had a poor outcome; 11 of 195 eligible patients were lost to follow-up. Poor functional outcome was independently associated with older age (odds ratio [OR] 1.08, 95% confidence interval [CI] 1.03–1.14), lower Mini-Mental State Examination (MMSE) scores (OR 0.66, 95% CI 0.56–0.79), and postoperative electrolyte disorder (OR 2.97, 95% CI 1.28–6.91). The nomogram demonstrated good discrimination (AUC 0.846; bootstrap 95% CI 0.781–0.905) with low optimism on internal validation (optimism-corrected C-index 0.841). Calibration analysis showed good agreement between predicted and observed risks. DCA indicated a positive net benefit across a wide range of threshold probabilities (0.20–0.99). Conclusion: We developed a parsimonious nomogram incorporating age, MMSE, and postoperative electrolyte imbalance to predict 1-year functional prognosis after STN-DBS in PD patients. With external validation, this model may support individualized perioperative risk assessment and shared decision-making.