The Role of Peripheral Afferents in Modulating Post-stroke Central Pain — APEDOC  

Stroke Clinical Trial

Official title: The Role of Peripheral Afferents in Modulating Post-stroke Central Pain

Status Recruiting

Clinical Trial Summary

Central post-stroke pain (CPP) is extremely difficult to relieve and responds very poorly to analgesics targeting neuropathic pain, probably because the mechanisms underlying this pain remain poorly understood.

Stroke pain is traditionally considered to be of central origin and related to changes in the spinal cord and/or brain nociceptive systems. However, a recent study in a small cohort of patients has suggested that the peripheral nervous system (PNS) may have a role in the initiation and persistence of APD.

The main objective of this prospective randomised controlled bicentric study (Raymond Poincaré and Ambroise Paré) in double blind and parallel groups against placebo (3 arms) will be to evaluate the efficacy of two peripheral nerve blocks performed 14 days apart on spontaneous neuropathic pain after stroke. The active treatments used for the blocks will be either lidocaine 20 mg/ml or levobupivacaine 1.25 mg/ml or placebo (saline)

Clinical Trial Description

The primary endpoint will be the change in neuropathic pain intensity (assessed on an 11-point pain intensity scale), expressed as a difference in pain intensity between the value obtained before each block and that obtained 45 minutes after, corresponding to the maximum expected effect. Secondary endpoints will include exertional pain, pain quality, % relief, clinical global impression, pain assessment on a patient diary for a fortnight after each block and adverse events.

Patients will be randomised to receive one of 3 study treatments (lidocaine 2%, levobupivacaine 1.25 mg/ml or placebo). The treatment protocol will involve 2 perineural blocks performed 14 days apart. Assessment will continue for up to 2 weeks after each block, i.e. up to one month after the start of treatment. An evaluation of pain will be carried out before the block and after each block, at 45 minutes and at 5 hours, and then daily by the patient on a self-evaluation booklet for the 14 days following each block.

Randomisation will be centralised on a server from a list drawn up in advance by computer rogramme, balanced by blocks of variable size. Allocation between the 3 arms will be done according to a balanced 1:1:1 distribution. Treatments will be numbered from 1 to n, and allocated to patients in the chronological order of their inclusion in the trial.

Patients will be randomised on the day of treatment using a centralised computerised randomisation procedure to receive one of the 3 study treatments (lidocaine 20 mg/ml levobupivacaine 1.25 mg/ml or saline). No matching by age or duration of pain is planned, as randomisation usually results in groups matched at baseline on these criteria. The treatment will be administered over two visits performed 14 days apart by a qualified anaesthetist using the peri-nervous route according to current ecommendations (see above). Only one randomisation will be performed at baseline, so that a patient on active treatment cannot receive placebo at a later date and vice versa (see figure 1).

The investigators plan to randomise 10 patients per group and a total of 30 patients to achieve 90% power with a two sided α risk=0.05,. Given the estimated premature discontinuation rate, the investigators consider it necessary to include 12 patients per group for a total of 36 patients.

This study opens the way to new therapeutic avenues for these patients who often fail all treatments ;

Related Conditions & MeSH terms

• Stroke

• NCT number: NCT06446960
• Study type: Interventional
• Source: Institut National de la Santé Et de la Recherche Médicale, France
• Contact: VALERIA MARTINEZ, MD
• Phone: 01 47 10 76 22
• Email: valeria.martinez@aphp.fr
• Status: Recruiting
• Phase: Phase 3
• Start date: February 12, 2024
• Completion date: February 12, 2027