Intrathecal Baclofen (ITB) Bolus on Neuropathic Pain (NP). Preliminary Study.
Condition: Neuropathic Pain
MeSH terms: Neuralgia
Study type: Interventional

Summary: 
      Hypothesis:

      ITB bolus can have antinociceptive effect on neuropathic pain in spinal cord injury patients,
      which could depend on the subtype of pain, or on the lesion level, cervical or thoracic
      spinal cord injury.

      Objective:

      To study the effect of intrathecal baclofen bolus on neuropathic pain in patients with spinal
      cord injury at cervico-dorsal level.

      Primary Endpoint:

      Effect of intrathecal baclofen bolus in neuropathic pain (measured using the Neuropathic Pain
      Inventory Scale, the Brief Pain Inventory and the Numerical Rating Scale) in spinal cord
      injury at cervico-dorsal level.

      Secondary Endpoints:

        1. Spasticity and spasms (measured using the Modified Ashworth Scale and the Visual
           Analogue Scale and Penn Spasm Frequency Scale).

        2. Neurophysiological examination (warm perception threshold, heat pain perception
           threshold, evoked pain perception and contact heat evoked potentials).
    

Detailed description: 
      The study will be a randomized, double-blind (patients and who will realize the clinical and
      neurophysiologic evaluation), placebo-controlled trial. We will recruit 10-12 patients with
      SCI with complete or incomplete lesion at cervical or thoracic level to be randomly
      distributed in two study groups: ITB bolus group and a placebo group.

      In 6-8 months, we will administer an intrathecal baclofen bolus of 50 µg (1ml) in 5-6 SCI
      patients or 1ml of physiologic serum subcutaneously in the other 5-6 SCI patients.

      Before the intrathecal baclofen or placebo bolus is administered, patients will be evaluated
      for neuropathic pain, using the Neuropathic Pain Inventory Scale, Brief Pain Inventory and
      Numerical Rating Scale. Spasticity and spasms will also be measured by the Modified Ashworth
      Scale, the Visual Analogue Scale and the Penn Spasm. After that, patients will also undergo,
      early in the morning when the intrathecal baclofen or placebo bolus will be administered, a
      neurophysiology assessment (warm perception threshold, heat pain perception threshold, evoked
      pain perception and contact heat evoked potentials).

      After the neurophysiological evaluation, patients will receive an intrathecal baclofen bolus
      of 50 µg or placebo (randomization). After the intrathecal baclofen or placebo injection, a
      clinical and neurophysiological examination, of neuropathic pain and spasticity and spasms,
      will be repeated at 1, 2 and 4 hours after the bolus administration. Moreover, Kumru et al.
      (2013) reported that the 50 µg intrathecal baclofen bolus reduced the pain perception
      threshold and evoked acute pain perception in patients with SCI.

      During all evaluation period, the patients continue with their analgesic, antispastic and/or
      any other stable medication.
    

Intervention name(s): Intrathecal baclofen bolus; Placebo
Intervention type(s): Drug; Other
Intervention description(s): An intrathecal baclofen bolus injection of 50 µg (1ml) will be injected at L3/L4 level.; 1 ml of physiological saline (isotonic saline) will be injected subcutaneously at L3/L4 level simulating
Other intervention name(s): ITB bolus; physiological saline
Intervention MeSH terms: Baclofen
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Primary purpose: Treatment