Incidence and management of idiopathic peri-lead edema (IPLE) following deep brain stimulation (DBS) surgery: Case series and review of the literature.

OBJECTIVE: Idiopathic peri-lead edema (IPLE) is being increasingly described as a potential complication occurring after DBS surgery. Its incidence and relationship to post-operative symptoms, though, are still poorly defined and its understanding and management yet limited. METHODS: We reviewed delayed (≥ 72 h) post-operative CT imaging of patients who underwent DBS surgery at our Institution. A comparison of clinical and laboratory findings was carried out between patients with IPLE and controls. RESULTS: 61 patients, accounting for 115 electrodes, were included. Incidence of IPLE was 37.7 % per patient and 29.5 % per electrode. Patients with IPLE were significantly older than controls (52.82 ± 15.65 years vs 44.73 ± 18.82 years, p = 0.04). There was no difference in incidence of new-onset neurological symptoms between patients with IPLE and controls. Longer operative time (180.65 ± 34.30 min vs 158.34 ± 49.28 min, p = 0.06) and a greater number of MERs per electrode were associated with IPLE (3.37 ± 1.21 vs 3.00 ± 1.63, p = 0.089), though these comparisons did not meet the statistical significance. None of the patients with IPLE underwent hardware removal, with IPLE vanishing spontaneously over months. CONCLUSIONS: IPLE is an underestimated, benign event that may occur after DBS surgery. Age, longer operative time and MER use may represent risk factors for IPLE formation, but further studies are needed. The presence of post-operative neurological symptoms and fever was not associated with IPLE presence, highlighting its benign nature and suggesting that empiric treatment may not be always justified.