Trouillas 1995.
| Methods | Randomised, double‐blind, placebo‐controlled trial | |
| Participants | 26 participants with Friedreich ataxia (diagnosed by clinical symptoms) were recruited from 12 centres in France. Only 19 participants (mean age 25.9 years, SD 8.1) from 8 centres completed the study. 11 participants with a mean age of 28.5 years (SD 9.4) received the levorotatory form of 5‐hydroxytryptophan (L‐5HT) and 8 participants with a mean age of 22.3 years (SD 4.1) received placebo | |
| Interventions | Participants received L‐5HT or placebo for 6 months. Dose was progressively increased in the treatment arm based on participant weight as follows: weight < 50 kg, 200 mg/day for the 1st month, 600 mg/day for the remaining 5 months; weight > 50 kg, 300 mg/day for the 1st month, then 900 mg/day for the remaining 5 months Participants in the control arm received gelules of the same size and number as their counterparts in the treatment arm |
|
| Outcomes | Post treatment assessments versus baseline were made every 2 months for 6 months Clinical symptoms were evaluated with a modified ataxia rating scale involving kinetic and static tasks, which did not include speech tasks. Quantitative values were obtained including: mean time for writing a standard sentence, mean time for pronouncing a standard sentence. 3 tests measured the time of standing in a natural position |
|
| Notes | Dose was not consistent for all participants randomised in the treatment arm The provider of L‐5HT is not stated. Panmedica Laboratories, Carros, France funded the study |
|
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | The method of random allocation is not described |
| Allocation concealment (selection bias) | Unclear risk | The method of allocation concealment is not described |
| Blinding of participants and personnel (performance bias) All outcomes | Low risk | Participants in the control arm received gelules of same size and number as the treatment group |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | The method of blinding of investigators is not outlined. Experience of adverse effects in the treatment arm may have weakened the blinding process |
| Selective reporting (reporting bias) | Low risk | All planned outcomes reported |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Only 19/26 participants completed the study. 4 did not complete from the placebo group (due to "secondary refusal of consent", "no respect of regimen", "cardiac flutter" and "general discomfort") and 3 from the treatment group (2 due to "vomiting and gastralgia" and 1 to "no respect of regimen") |
| Other bias | Low risk | None identified |