Long-term inhibition of soleus H-reflex with epidural adhesiolysis and pulsed radiofrequency in lumbosacral neuropathic pain.
Scientific data about neurophysiological changes subsequent to pulsed radiofrequency (PRF) are still lacking. Goal of this study was to evaluate sural nerve conduction and Hoffmann reflex in soleus muscle following adhesiolysis and PRF in patients with unilateral chronic lumbosacral L5-S1 neuropathic radiating pain.Seventeen patients received two cycles of 240 seconds high-voltage PRF and epidural adhesiolysis. SNAP and H/M ratio as well as pain scores were collected in both lower limbs before, immediately following and one month after the treatment.At follow up, a significant reduction in NRS and DN4 scores was observed in 53% of patients reporting pain improvement of ≥ 30% over baseline. The ratio of maximum H-reflex to maximum M response (H/M ratio) was decreased in the affected limb following PRF (p=0.01) and one month after the treatment (p=0.04). A direct correlation was observed between H/M ratio variation and NRS score at follow up in the treated limb (p=0.04). No significant difference in sural nerve latency, amplitude and velocity was detected between affected and normal side after treatment and at follow up.Epidural adhesiolysis and PRF of the dorsal root ganglion seem to significantly affect spinal reflexes in patients with lumbosacral neuropathic radiating pain.