Evaluation of the effect of botulinum toxin injection in the treatment of neuropathy in ESRD patients

Effect of botulinum toxin on lower limb neuropathy in ESRD patients

Phase III randomized, double-blind, placebo-controlled, parallel-group trial in 60 patients, with 1:1 computer-generated block randomization to Botox or placebo.

This is a randomized, double-blind clinical trial in patients with ESRD and lower limb neuropathy. Patients are assigned by blocked randomization to the intervention group (botulinum toxin) or control group (placebo). The study is conducted at Sina Hospital, Tehran University of Medical Sciences, with all procedures, interventions, follow-up, and outcome assessments performed at this center. patients and outcome assessors are unaware of group assignments. Botulinum toxin and placebo injections are identical in appearance, volume, and administration to minimize bias.

Inclusion: ESRD with lower limb neuropathy, ≥18 years, both genders, no botulinum toxin or invasive pain treatment in last 6 months, ≥3 months since RRT start, informed consent. Exclusion: Botulinum toxin allergy, neuromuscular disorder, uncontrolled systemic disease, pregnant/breastfeeding, non-compliance or new treatments, spinal injury/spinal stenosis/stroke, serious botulinum toxin adverse events.

Intervention group: ESRD patients with lower limb neuropathy receiving a single Dysport botulinum toxin injection (100 units, 50 per limb). Control group: ESRD patients with lower limb neuropathy receiving a placebo (normal saline) injection at the same sites.

1.Change in mean pain intensity score based on the Visual Analog Scale (VAS) before and after the intervention 2.Change in mean pain score measured by the McGill Pain Questionnaire (MPQ) before and after the intervention 3.Change in quality of life score measured by the EQ-5D questionnaire before and after the intervention

The unit of randomization in this study is the individual participant. Participants will be allocated to the study groups using block randomization with a 1:1 allocation ratio. The randomization sequence will be generated by computer using statistical software. The randomization sequence will be prepared by an independent researcher who is not involved in participant recruitment, intervention administration, or outcome assessment, in order to minimize selection bias. To ensure allocation concealment, allocation codes will be kept in sequentially numbered, opaque, sealed envelopes and will be opened only after a participant has been definitively enrolled in the study and according to the predetermined sequence.

In this trial, blinding will be implemented for participants, outcome assessors, and data analysts. Participants will not be informed whether they receive botulinum toxin or placebo. In addition, the clinician/researcher responsible for clinical assessments and data collection will remain unaware of group allocation. Preparation of syringes containing botulinum toxin or placebo will be performed by an independent researcher who is not involved in outcome assessment or data analysis. Each syringe will be labeled with a unique code and will be identical in appearance and volume to prevent identification of the assigned intervention. The allocation code list will be kept by the independent researcher and will not be disclosed to the study team until completion of data collection. Statistical analyses will be conducted using group codes, and the codes will be unblinded only after the final analysis is completed.