There were two reasons for choosing intradermal Botox:
- It was reasoned that more nociceptive pain fibers were likely to be found in skin and, as importantly, to avoid giving the toxin into motor cholinergic fibers.
- In both headache and painful states, it was further reasoned that interference with afferent sensory transmission might contribute to Botox’s analgesic effects.
Method:
- 37 patients with a variety of painful disorders were chosen from a pain and headache practice for treatment with Botox.
- 19 were female and 18 were male.
- Average age was 51.7 years (range = 24-73)
- In all cases; patients were being treated with agents to reduce neuropathic pain or with headache prophylaxis medications, or both. These were tapered in most cases where Botox had reduced pain severity or frequency. Some patients were treated with 25-50 units of Botox; then, it was decided to use a uniform dose of 100 units for each subsequent patient.
- In all cases, Botox was given intradermally.
- In the case of painful cervical spasm (and headaches), the skin overlying the greater and lesser occipital nerve inlets was injected (see Figure 1). A skin wheal was raised in 2-3 areas in both sites.
- In the case of diabetic neuropathy and CRPS, type 1, a digit or digits were injected intradermally proximal to the affected area.
- In the case of TMJ (temperomandibular joint disorder), a fixed site injection (see Figure 2) was utilized, as we are studying this disorder in an ongoing manner. Carpal tunnel patients were injected intradermally in the region of the volar aspect of the wrist crease (Figure 3).
- Trigeminal neuralgia patients were injected intradermally on the affected painful side.
Figure 1
Figure 2
Figure 3
Results:
- In the case of painful cervical spasm, all 14 patients treated with intradermal Botox, had reductions in frequency and severity of pain. Average reductions were 85.2% in severity of painful muscle spasm of cervical origin, with an average response time of 9.5 weeks (range 4-21 weeks).
- In 12 patients with co-existent headaches, there was a 70% reduction in average headache frequency over an average of 8 weeks (range 4-18 weeks). 8 of these patients had prior cervical surgical procedures.
- 2 of 4 patients treated in the lumbar area responded in terms of reduced back pain.
- 5 patients with CRPS, type 1, were treated with intradermal Botox. All 5 responded with reduced burning and allodynia, as well reduced swelling.
- 2 cases of diabetic neuropathy were treated with excellent response, although in 1 case re-treatment did not match prior results. Toe dystonia (prolonged muscular contractions that may cause twisting of body parts, increased muscular tone, and repetitive movements) was markedly improved on both occasions.
- 5 cases of persistent median nerve entrapment pain were treated. 3 had undergone prior nerve release surgery. All 5 responded with reduction in painful symptoms.
- 3 cases of temporomandibular disorder (TMD) were also treated with reductions in jaw pain, popping, bruxism, clenching and muscle pain in all 3 treated subjects.
- Average pain reductions in responders was 8.5 weeks in duration (range 3-20 weeks), with an average reduction of 68% in pain symptoms across all categories of patients.
