Different Brain Network Connectomic Relationships Subserve Hand Dexterity During Task Versus Resting States in People
Timothy F Boerger1, Leon Taquet1, Kaitlin Goetschel1
1Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, USA.
Purpose:
The purpose of this study was to explore different brain network connectomic relationships subserving hand dexterity in patients with contrast-enhancing brain tumors during task and resting states.
Method:
We measured hand dexterity, resting state functional connectivity, and task-based functional connectivity in 21 participants with newly diagnosed brain tumors. Hand dexterity was measured using the 9-hole peg test (9HPT), and patient-reported outcomes were assessed with the Duroz Hand Index (DHI).
Findings:
We discovered the following: (1) The inability to complete dexterous tasks is most associated with low somatomotor-basal ganglia network connectivity during rest but high somatomotor-basal ganglia network connectivity during tasks; (2) in the subgroup of better dexterous performers, resting somatomotor-salience connectivity is higher in people with poor dexterity-a relationship that holds true in healthy adult subjects from the Human Connectome Project (HCP), suggesting it has fundamental importance; and (3) connectomic measurements were stronger predictors of dexterous performance than classical variables of tumor (i.e., size, grade, or anatomical location).
Conclusions:
These data suggest that connectomic correlates of dexterity are different in resting and task-based states. Additionally, our data suggest a threshold level of somatomotor-to-basal ganglia connectivity is required to accomplish dexterous movements, and, in the cases of appropriately preserved somatomotor-to-basal ganglia connectivity, salience-somatomotor connectivity then becomes the dominant connection facilitating performance in a hierarchical fashion. These findings have fundamental implications for both surgical planning and neuromodulation-based rehabilitation.
