Baclofen‐enhanced spinal cord stimulation and intrathecal baclofen alone for neuropathic pain: Long‐term outcome of a pilot study

Abstract

In a previously published pilot study, we addressed the possibility to increase the effectiveness of spinal cord stimulation (SCS) applied for neuropathic pain by using adjunct pharmacological therapy. This combined treatment approach was a direct spin-off from animal experiments aiming at the exploration of transmitter and receptor mechanisms involved in the pain relieving effect of SCS. Out of 48 patients with neuropathic pain of peripheral origin responding poorly to SCS, seven received pumps for intrathecal baclofen (GABA-B receptor agonist) delivery together with SCS, and four had pumps alone. In order to assess the long-term effect a follow-up has been performed, with an average, total treatment time of 67 months. At the follow-up the remaining nine patients still enjoy about the same pain relief as initially, but with a mean, further dose increase of about 30%. This study demonstrates that a deficient SCS effect in neuropathic pain may be considerably improved by intrathecal baclofen administration, and that this enhanced effect persists for a long-time. On-going and future animal studies may provide new and even more efficient pharmaceutical candidates for such combined therapy.

Mechanisms of Spinal Cord Stimulation in Neuropathic Pain

“…Lind et al illustrated the administration of intrathecal baclofen in patients increasing the effects of SCS in neuropathic pain of peripheral origin. These patients initially responded poorly to SCS however they experienced a satisfactory relief during SCS (Lind et al, 2004, Lind et al, 2008. A promising observation was that follow-up obviously demonstrated a sustained pain relieving effect.…”

Spinal Cord Stimulation and Intrathecal Baclofen Therapy: Combined Neuromodulation for Treatment of Advanced Complex Regional Pain Syndrome

“…Basic research has revealed the role of GABA-B receptors in the central nervous system in the regulation of pain [16]. Some clinical studies have also demonstrated the analgesic effect of ITB in treating intractable pain syndromes after spinal cord injury or cerebral infarction [13,14,15]. ITB may reduce neuropathic pain by modulating spinal GABA mechanisms, and thus, ITB can be an important option for patients with CRPS whose conditions are refractory to other methods of pain control [11,16,17].…”

“…However, intrathecal baclofen (ITB) therapy alone did not appear to be sufficient for providing dramatic pain relief in patients with CRPS. Recently, some reports have suggested that ITB therapy can enhance the effect of SCS [11,12,13]. Furthermore, ITB therapy has been reported to be an effective modality for treating fixed dystonia related to CRPS [14,15].…”

Spinal Stimulation for Pain: Future Applications

“…After an average follow-up of 6 years, they continued to enjoy >50 % improvement in pain scores. Although the dose of baclofen had to be gradually increased over the years, the range of daily doses was 140-270 μg at the last follow-up [39].…”

“…Intrathecal adenosine turned out to be "technically problematic" [38], but intrathecal baclofen, the GABA-B receptor agonist that is commonly used both orally and intrathecally for the treatment of spasticity, has been evaluated in a prospective fashion [38,39]. Out of 48 patients who received an intrathecal baclofen bolus during SCS trial, 20 obtained a pain relief reduction of >50 %; of these, 7 were implanted with an intrathecal baclofen pump and SCS system [39]. After an average follow-up of 6 years, they continued to enjoy >50 % improvement in pain scores.…”