Changes in Somatomotor Network Connectivity Differentiate Better Versus Worse Recovery of Hand Dexterity After Brain Tumor Surgery: A Cohort Study.

INTRODUCTION: Hand dexterity is critical for everyday function and involves the coordinated integration of multiple brain networks. However, we know very little about how changes in connectivity across networks facilitate recovery after removal of a pathological brain lesion, like a tumor. METHODS: Resting-state functional connectivity and 9-hole peg test (9HPT) times were collected before and after surgical resection in 16 patients with brain tumors. All patients had contrast-enhancing brain lesions (12 glioblastomas, 2 metastases, and 2 radionecrosis). Patients were retrospectively grouped into better or worse recovery based on change in 9HPT scores. Connectivity was assessed between the ipsilesional dorsomedial somatomotor network A (SMN A) with 39 other networks in the brain using partial correlations. RESULTS: Patients with worse recovery of hand function had a decrease in somatomotor connectivity to the rest of the brain (p  < 0.05) and a decrease in interhemispheric connectivity to the contralesional SMN A (p  < 0.05). Conversely, patients with better recovery had higher ipsilesional SMN A to ventrolateral SMN B connectivity preresection (p  < 0.05) and higher ipsilesional SMN A-to-contralesional dorsal attention network B (DAN B) connectivity postresection (p  < 0.05). CONCLUSIONS: Recovery of hand dexterity from presentation to postoperative follow-up in patients with brain tumors most strongly correlated with ipsilesional SMN A connectivity to the contralesional SMN A, contralesional DAN B, and ipsilesional SMN B. This finding suggests promising neuromodulation targets for postoperative therapies aiming to improve hand dexterity.