Treatment of Notalgia Paresthetica With Xeomin
Condition: Notalgia Paresthetica
MeSH terms: Back Pain
Study type: Interventional
Phase: Phase 3

Summary: 
      Patients will be randomized (1:1) to receive either injections of Xeomin in 0.9% NaCl or NaCl
      alone. Xeomin will be reconstituted with 2 mL of NaCl 0.9 which will give a final
      concentration of 5 U of botulinum toxin A per 0.1 mL. The area affected will be injected with
      0.1 mL at each 1-2 cm2 for a maximum total dose of 200 units. Patients will be evaluated at
      Weeks 8, 12, 18 and 24. An unblinded pharmacist or designee will prepare placebo and Xeomin
      injections. Patients will be unblinded at the end of the week 12 visit. After unblinding (at
      week 12) patients who were randomized to placebo will receive Xeomin while patients initially
      randomized to Xeomin will not be injected. All patients will be seen for follow-up visits at
      Weeks 18 and 24. Efficacy in reducing pruritus will be measured with a 10 cm visual analogue
      score. This will be performed at Day 0, Week 8, Week 12, Week 18 and Week 24. Efficacy will
      also be measured by measuring the area of the hyperpigmented zone on the back. Safety will be
      evaluated with adverse events.
    

Detailed description: 
      Notalgia paresthetica is a common sensory neuropathy, affecting mainly the interscapular area
      especially the T2-T6 dermatomes. The characteristic symptom is pruritus on the upper back. It
      is occasionally accompanied by pain, paresthesia, hyperesthesia and a well circumscribed
      hyperpigmentation of the affected area. The correlation of notalgia paresthetica localization
      with corresponding degenerative changes in the spine suggest that spinal nerve impingement
      may be a contributing cause. Topical treatments such as corticosteroids, menthol, capsaicine
      and pramoxine are usually not very effective. Patients are very affected in their daily
      activities by this chronic condition and usually disappointed by the current available
      treatments.

      A recent publication reports success in treating 2 patients with notalgia paresthetica with
      botulinum toxin A. In both cases a complete response for pruritus was noted. The major
      limitations of this publication are the small number of cases (two) and the fact that there
      was no control. The mechanism of action of botulinum toxin A in nostalgia paresthetica has
      not been investigated.

      However the beneficial effects of botulinum toxin A on other diseases causing pruritus and
      pain has previously been reported. Botulinum toxin A has been shown to prevent the release of
      substance P, a well known mediator involved in pain and itch, and this may explain its
      efficacy in pruritic diseases. This proposal plans to study the efficacy and safety of
      botulinum toxin A (Xeomin) for the treatment of notalgia paresthetica in a randomized placebo
      controlled trial. Botulinum toxin A prevents the release of neuromediators such as
      acetylcholine. Botulinum toxin A has been used for many years to treat various disorders
      including blepharospasm, spasmodic torticollis, post stroke spasticity of the upper limbs,
      strabismus, palmar and axillary hyperhidrosis and wrinkles. This study will use Xeomin, a
      purified botulinum clostridium neurotoxin A that has recently been approved by Health Canada.
      Xeomin is currently approved for the treatment of blepharospasm, spasmodic torticollis and
      post stroke spasticity of the upper limbs.

      A recent publication reported success in treating two patients with notalgia paresthetica
      with botulinum toxin A. In both cases a complete response of pruritus was noted. One patient
      was still symptom free after 18 months while the other patient had a mild resurgence of
      pruritus at 18 months. The major limitations of this publication are the small number of
      cases (two) and the fact that there was no control. The current proposal plans to study the
      efficacy and safety of botulinum toxin A for the treatment of notalgia paresthetica in a
      randomized placebo controlled trial. In this study Xeomin will be reconstituted and used
      according to the approved Canadian Product Monograph.
    

Intervention name(s): Xeomin; Placebo / Xeomin
Intervention type(s): Drug; Drug
Intervention description(s): Patients will receive Xeomin only at Day 0.; Patients will receive 0.9% mL NaCl alone at Day 0. After unblinding (at week 12) patients who were randomized to placebo will receive Xeomin.
Other intervention name(s): Botulinum Toxin A; Sodium Chloride; Saline
Intervention MeSH terms: Botulinum Toxins; Botulinum Toxins, Type A; incobotulinumtoxinA
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Notalgia paresthetica; Xeomin; Botulinum Toxin A; Pruritus; Upper Back; Hyperpigmentation