Objective:

Mesenchymal stem cells (MSCs) have been shown in animal models to attenuate
chronic neuropathic pain. This preliminary study investigated if: i) injections of autologous
MSCs can reduce human neuropathic pain and ii) evaluate the safety of the procedure.

Methods:

Ten subjects with symptoms of neuropathic trigeminal pain underwent liposuction.
The lipoaspirate was digested with collagenase and washed with saline three times. Following
centrifugation, the stromal vascular fraction was resuspended in saline, and then transferred to
syringes for local injections into the pain fields. Outcome measures at 6 months assessed reduction in: i) pain intensity measured by standard numerical rating scale from 0–10 and ii) daily
dosage requirements of antineuropathic pain medication.

Results:

Subjects were all female (mean age 55.3 years ± standard deviation [SD] 14.67; range
27–80 years) with pain symptoms lasting from 4 months to 6 years and 5 months. Lipoaspirate
collection ranged from 102–214 g with total cell numbers injected from 33 million to 162 million
cells. Cell viability was 62%–91%. There were no systemic or local tissue side effects from the
stem cell therapy (n=41 oral and facial injection sites). Clinical pain outcomes showed that at 6
months, 5/9 subjects had reduced both pain intensity scores and use of antineuropathic medication. The mean pain score pre-treatment was 7.5 (SD 1.58) and at 6 months had decreased to 4.3
(SD 3.28), P=0.018, Wilcoxon signed-rank test. Antineuropathic pain medication use showed
5/9 subjects reduced their need for medication (gabapentin, P=0.053, Student’s t-test).
Conclusion: This preliminary open-labeled study showed autologous administration of stem
cells for neuropathic trigeminal pain significantly reduced pain intensity at 6 months and is a
safe and well tolerated intervention.

Keywords: adipose, stem cells, neuropathic, orofacial, trigeminal