Clinical Study to Investigate the Efficacy and Safety of NT 201 Compared to Placebo in the Treatment of Chronic Troublesome Drooling Associated With Neurological Disorders and/or Intellectual Disability

Inclusion Criteria: * Male or female child/adolescent age 2-17 years. * Any neurological disorder (e.g. cerebral palsy or traumatic brain injury) and/or intellectual disability associated with chronic troublesome sialorrhea for at least 3 months up to the screening. In subjects with intellectual disability (ID) without neurological disorders, a diagnosis of ID by a specialist, e.g. pediatrician or by a center for developmental medicine is required for inclusion. * Severe drooling (modified Teacher´s Drooling Scale \[mTDS\] ≥ 6; clothing occasionally becomes damp) as rated by the investigator. * Parental consent and the subject's oral or written assent as the subject is able to provide. Exclusion Criteria: * Chronic troublesome sialorrhea not related to neurological disorders and/or intellectual disability. * Body weight \< 12 kg. * Pharmacological treatment for sialorrhea or concomitant medication known to influence sialorrhea strongly (e.g. anticholinergics with exception of locally applied or short acting drugs used under general anesthesia) within 45 days before baseline and during the entire study period. * Any previous known or suspected hypersensitivity to Botulinum toxin. * Aspiration pneumonia within 6 month before screening. * Any previous treatment with Botulinum toxin for any body region during the year before screening or within the screening period * Prior, concomitant or planned surgery or irradiation to head and neck to control sialorrhea (including salivary gland surgery or salivary gland irradiation) within one year before screening or planned for any part of the entire study period. * Concurrent diseases, including hematological, hepatic, renal, gastrointestinal, endocrine, pulmonary, musculoskeletal, or psychiatric diseases or conditions, which in the judgment of the investigator would put the subject at risk while in the study, could influence the results of the study, or negatively impact the subject's ability to participate in the study. * Extremely poor dental and/or oral condition that might preclude safe study participation by the judgment of the investigator. * Nursing mother or pregnant female subject.