['chronic troublesome sialorrhea', "parkinson's disease", 'post-stroke', 'traumatic brain injury']
['incobotulinumtoxina (100 units)', 'incobotulinumtoxina (75 units)', 'placebo']

        Inclusion Criteria:

          -  Documented diagnosis of the basic neurological condition associated with sialorrhea
             (as above, (i), (ii) or (iii); with onset at least 6 months before screening).

          -  Chronic troublesome sialorrhea related to parkinsonism or stroke or traumatic brain
             injury (for at least 3 months) at screening, defined as the presence of all of the
             following, at screening and at baseline and for at least the 3 months before screening
             (where retrospective response to questionnaires is impossible, a statement of
             equivalent severity will suffice):

               1. A Drooling Severity and Frequency Scale [DSFS] sum score of at least 6 points and

               2. A score of at least 2 points for each item of the DSFS and

               3. A score of at least 3 points on the modified Radboud Oral Motor Inventory for
                  Parkinson's Disease [mROMP], Section 'III Drooling', Item A).

          -  A score of at most 2 points on the mROMP Section 'II Swallowing Symptoms' Item A) and
             a score of at most 3 points on Item C), at screening and at baseline.

        Exclusion Criteria:

          -  Non-neurological secondary causes of sialorrhea.

          -  Unstable concomitant medication influencing sialorrhea (such as anticholinergics for
             the treatment of parkinsonism; dosages of these medications must have been stable for
             at least 4 weeks before study entry, i.e. screening, and must be planned to remain
             stable during the course of the study.

          -  Recent (i.e., four weeks) drug treatment for sialorrhea.

          -  History of recurrent aspiration pneumonia.

          -  Extremely poor dental/oral condition as assessed by a qualified dentist.

          -  Recent (i.e., one year for sialorrhea, 14 weeks for other indications) treatment with
             - or known hypersensitivity to - Botulinum toxin, or known hypersensitivity to any
             ingredient of the study preparation.

          -  Recent (i.e., four weeks) changes in anti-parkinsonian medication.

          -  Previous or planned surgery or irradiation to control sialorrhea.
      