In this retrospective, monocentric, observational study, cross-sectional and longitudinal data of 1351 patients documented at our BONT outpatient clinic between 1989 and 2014 were retrospectively analyzed. All patients had been treated with BONT at our outpatient clinic for neurological conditions, including cervical dystonia (CD), blepharospasm (BSP), other dystonias (ODT), facial hemispasm (FHS), and spasticity (SPAS). The parameters longitudinally analyzed for the entire cohort were therapy duration, mean and cumulative BoNT/A dose, and cross sectionally for subgroups of >721 patients global self perceived quality of health and life, global self perceived reduction of symptoms with BoNT/A treatment as well as clinical global impression evaluated by the treating physician.  Furthermore, we attempted to contact all patients not longer at follow up at our clinic (n=694) by telephone to assess their current treatment and self perceived health status and reached 143 of these patients.

The mean treatment duration was 4.58±4.89 years, and the majority of therapy drop outs occurred within the first 8 years of therapy for all indications. Treatment adherence at 16 years was >50% for the 173 BSP and 184 FHS patients, > 40% for the 527 CD and >20% for the 283 ODT and 184 SPAS patients.

Adherence to therapy and self perceived symptom reduction by long-term BoNT/A treatment over the years was significantly longer in BSP, FHS and CD compared to ODT and SPAS.

The treatment indication determines long-term adherence and self perceived symptom reduction in BoNT/A therapy and is better in BSP, FHS, and CD patients compared to ODT and SPAS.