2.6. Randomization
An independent statistic centre assigned BoNT-A or placebo administration according to a computer generated simple
randomization (Suresh, 2011). The allocation sequence was concealed from the researchers enrolling participants in
sequentially numbered, opaque, sealed envelopes. The appropriate numbered envelope was opened at the hospital by the
nurse; the card inside indicated if the patient was to be inoculated with BoNT-A or placebo.