Neurological Deficits in Stroke Patients that May Impede the Capacity to Provide Informed Consent for Endovascular Treatment Trials

Background: We assessed the occurrence of neurological deficits that may impede the capacity to provide consent for trial participation in patients with an acute stroke, who are eligible for endovascular treatment (EVT). Methods: We used data from the Multicenter Randomized Controlled Trial of Endovascular Treatment for Acute Ischemic Stroke in the Netherlands Registry, a prospective observational cohort study. We included 1526 patients with an anterior large vessel occlusion, undergoing EVT between March 2014 and June 2016. We based our assessment of decision-making capacity for trial participation on neurological symptoms influencing conditions concerning informed consent as stated in the declaration of Helsinki. We formulated a strict and a mild capacity assessment rule, using 2 different cut points in item scores on the National Institutes of Health Stroke Scale (NIHSS). Results: Applying the strict and mild rule, respectively 1469 (96%) and 1220 (80%) patients deemed not capable of decision-making for trial participation on admission, and 1077 (79%) and 825 (60%) patients at 24-48 hours after admission. Highest frequencies of predefined scores suggesting incapacity based on the strict rule were on the NIHSS items "Level of Consciousness Questions" (59%), "Best Gaze" (68%), and "Best Language" (58%). Patients who were considered incapable were older (median 71 versus 66 years, P = .043), had higher NIHSS scores (median 16 versus 8, P < .001), and had more often left hemisphere strokes (55% versus 28%, P < .001) than patients who were presumably capable. Conclusions: In the majority of patients with an anterior circulation stroke who are eligible for EVT, neurological deficits are present that may impede the capacity to provide informed consent for trial participation.