Abstract 2493: Enrollment In Early Brain Stimulation Arm Motor Recovery Studies Is Limited Primarily By Stimulation-unrelated Exclusions Including Ethnic And Racial Characteristics

Introduction: The high incidence of disability related to upper extremity (UE) motor impairments in stroke has led to an increasing number of clinical trials of UE motor interventions. These now include transcranial magnetic stimulation (TMS) and direct current stimulation (TDCS). Trial enrollment criteria typically depend on isolated unilateral motor impairments, a single acute stroke, with limited co-morbidities, and criteria specific to the intervention. Objectives: To determine the frequency of stimulation trial candidates in an acute stroke population, evaluate the impact of stimulation-specific exclusion criteria in trial recruitment, and examine how potential participants differ from the broader stroke population. Methods: 1701 patients evaluated at an urban academic acute stroke service over a 3 year-period were screened for a TDCS trial. Demographics, stroke characteristics were recorded prospectively. Results: This was a young (mean 58.8 +14.8 yr), predominantly male (60.6%), and racially and ethnically mixed population (non-Hispanic white 38.1%, Hispanic 21.4%, AA 32.8%, Asian 2.6%, others 5.0%). Only 29 subjects met eligibility criteria (1.7%). The five most common causes for exclusion were in descending order: 1) UE motor impairment normal or complete, 2) old strokes causing weakness, 3) stroke mimics, 4) hemorrhagic strokes, 5) severe medical conditions. African American (AA) patients trended towards less likelihood of eligibility for participation (1.09%) then the other ethnic/racial groups (p=0.2). AA patients were more likely to have had old strokes causing weakness than other patients (p < 0.001), and this was the most common cause of their exclusion. 2.88% were excluded for stimulation related reasons. 8 individuals refused participation (1 non-hispanic white, 2 females). Minority men were more likely to refuse participation than minority women and non-Hispanic white patients (p=0.008). Demographics of the 21 enrolled participants were not significantly different (age 62.0+12.0 yr, 57.1% women, non-Hispanic white 52.4%, Hispanic 23.8%, AA 14.3%, Asian 9.5%). Conclusion: In this urban multiracial sample, potential participants for brain stimulation trials are rare, and the main reasons for exclusion are suitable motor impairments and stroke lesion characteristics. Exclusions specific to the stimulation intervention were few. African Americans had old strokes causing hemiparesis limiting their eligibility. Techniques to recruit minority men to stroke recovery studies require improvement. When recruiting for highly refined study populations, racial and ethnic differences in stroke characteristics and research participation are important.