This is a Administrative Supplement grant submission requesting supplemental financial support for the fourth year of the ongoing NIH grant, R01-NS 101283. In the originally funded grant application, we had planned for recruitment through a single Hematology clinic with expectations to screen about 250 subjects per year from which an estimated 60 subjects would be fully enrolled in the study. Based on these estimates, we expected to achieve the necessary 240 subjects (120 RLS and 120 control) over the first 4 years of the grant. However, recruitment through a single Hematology clinic has failed to provide adequate subject enrollment. We addressed this problem by developing a wide range of broad-based recruitment endeavors including: increasing the number and types of clinics involved, placement of flyers and posters across local hospitals and colleges, web-based and television advertisement. With the broader range of recruitment endeavors, we have demonstrated that we can increase the rate of recruitments, which we feel will be sufficient to achieve appropriate sample size, though that may require continuation of the recruitment into the fifth year of the grant. The increased recruitment of patients outside the clinical setting has increased the number of screening labs required and therefore the cost. This was not foreseen in the original grant application. The cost of advertising and lab screening has been an unanticipated but necessary expense within the scope of the original project. We are requesting a cost increase in this supplemental grant to preserve the overall impact of the project consistent with its originally approved objectives and purposes.