Are there any new procedures or medications to help with cerebral palsy after age 18?

By symptom, not age: Treatment for cerebral palsy (CP) depends on symptoms. Medication to control seizures, as well as meds and/or surgery to relieve GI problems and muscle spasticity, are options that can be used at various ages. Each CP patient has a different set of issues so it is important to consult a doctor familiar with the patient's history & progress. For adults, jobs, mobility, & independence are important.

It depends: Are you referring to musculoskeletal issues? If so, there has been a lot of great research on helping children and young adults in this regard with both operative and non-operative treatments. Consult a pediatric orthopaedist (many still see adult patients), or an adult orthopaedist who treats cp.