Figure 1
Review of Literature and the studies included.
Figure 2
Timeline of the Botulinum toxin in Essential Tremor and Parkinson’s disease tremor.
Table 1
Class of clinical trials and definition of efficacy level endorsed by the Assessment and Guidance Committee of the American Academy of Neurology*.
| Study Class |
| Class I: A randomized clinical trial of the invention of interest with masked or objective outcome assessment, in a representative population. Relevant baseline characteristics are presented substantially equivalent among treatment groups or there is appropriate statistical adjustment for differences. |
| The following are also required: a. concealed allocation. b. primary outcome(s)clearly defined. c. exclusion/inclusion criteria clearly defined. d. adequate accounting for dropouts (with at least 80% of enrolled subjects completing the study) and cross- overs with numbers sufficiently low to have minimal potential for bias. |
| Class II: A randomized controlled clinical trial of the intervention of interest in a representative population with masked or objective outcome assessment that lacks one criteria a-d above or a prospective matched cohort study with masked or objective outcome assessment in a representative population that meets b-d above. |
| Class III: All other controlled trials (including well-defined natural history controls or patients serving as own controls) in a representative population, where outcome is independently assessed, or independently derived by objective outcome measurement. |
| Class IV: Studies not meeting Class I, II or III criteria including consensus or expert opinion. |
| Level of Evidence: |
| Level A (efficacy established, recommended or not recommended), required two class I or one class I and two class II studies. |
| Level B (probably effective or probably not effective), required one class I or two class II studies |
| Level C (possible effective or not effective), requires one class II study |
| Level U (efficacy undetermined): due to contradictory results or lack of quality studies. |
[i] Reproduced from references 16 and 17, excluding the criteria for non-inferiority clinical trials.