To describe the natural history of a condition or disease. To describe the natural history of a condition or disease. To determine effectiveness or cost effectiveness of treatments/services and/or health care products. To measure or monitor safety and harm. To measure quality of care.
According to the NMSS, attacks or flare-ups of symptoms only qualify as exacerbations if: 1  they occur at least 30 days from an earlier flare-up. 2  symptoms last for 24 hours or longer.
How long will the effects of treatment last? The Botox effect continues typically for 4 months. Studies by Carruthers & al (March 2001) show that most practitioners would recommend an initial course of Botox treatments every 4 months for the 1 year.