This study will evaluate the safety and efficacy of Oxybutynin Chloride 10% Topical Gel in children 3 to less than 17 years old, who have overactive bladder due to a neurogenic condition. Children will be treated with 0.75 g of gel/day for two weeks. Patients will then return to the clinic for a potential dose titration. At this time their dose may be adjusted up to 1g/day, down to 0.5g/day, or remain the same at 0.75g of gel/day depending on the individual response and tolerability. The total treatment time is 14 weeks and total time on the study is 16 weeks.