Functional Outcomes Following Resection of Motor Strip Metastases

Introduction: While there is a clear role of surgery in extending survival and functional independence in patients with brain metastases, the resection of motor strip metastases is often a unique challenge due to concern for post-operative functional decline. We sought to identify factors associated with functional outcome to better inform surgical decision making.

Methods: We conducted a retrospective chart review of all patients who underwent a first-time craniotomy for resection of a Rolandic/peri-Rolandic metastases between 2008 and 2020. All patients underwent resection with at least one motor mapping technique (e.g. grid monitoring, direct cortical and/or subcortical stimulation). Patient demographics, clinical factors and resection techniques were collected. Extent of resection (EOR) was determined by computerized volumetric analysis.

Results: 43 men (50.6%) and 42 women (49.4%) with a median age of 60 years (range 15-77) were included. The most common malignancies were non-small cell lung cancer (n=29, 34.1%), breast (n=14, 16.5%), and melanoma (n=11, 12.9%). 79 patients (92.9%) were symptomatic at presentation, with 23 (27.1%) presenting with seizures and 49 (59.0%) presenting with extremity weakness. Resection was performed in an en bloc fashion in 35 patients (41.2%) and piecemeal in 50 patients (58.8%). Gross total resection was achieved in 82 patients (96.5%). 55 patients (64.7%) had prolonged (>3 days) postoperative length of stay, which was associated with hemorrhagic tumor (OR=4.83, p=0.03), preoperative KPS < 80 (OR=9.47, p=0.001), Rolandic location (OR=4.50, p=0.016), and preoperative weakness (OR=5.68, p=0.008) in multivariate analysis. Postoperative KPS was stable to improved in 65 patients (76.5%) and worsened in 20 (23.5%). Non-home discharge occurred in 27 patients (31.8%) and was associated with age>60 (OR=7.88, p=0.006), preoperative KPS < 70 (OR=4.77, p=0.018), Rolandic tumor location (OR=6.58, p=0.012), and distance from the surface (OR=4.06, p=0.017).

Conclusion : We present the largest cohort of patients with motor region metastases undergoing surgical resection reported in the literature. Metastases in this region can be resected with reasonable post-operative functional outcome, high EOR rate and relatively low risk of permanent worsening of motor function.