Sensorimotor cortical integration remains unchanged after dorsal root ganglion pulsed radiofrequency

Dorsal root ganglion (DRG) pulsed radiofrequency (PRF) is a minimally invasive neuromodulation technique used for the management of chronic radicular pain. While its analgesic effects are well-documented, its impact on sensorimotor integration at the cortical level remains unclear. This study aimed to investigate whether DRG PRF modulates sensorimotor integration via the cholinergic system using the short-latency afferent inhibition (SAI) paradigm.

This prospective, 2-center study included 30 patients with chronic lumbosacral radicular pain who underwent DRG PRF at the L4-5 and L5-S1 levels. SAI was assessed using paired electrical stimulation of the tibial nerve and transcranial magnetic stimulation (TMS) of the motor cortex before and 2 weeks after DRG PRF. SAI measurements were conducted at 3 interstimulus intervals (ISIs: -2 ms, 0 ms, +2 ms of N20 latency). Data were analyzed using repeated measures ANOVA and paired t-tests.

The SAI paradigm confirmed significant sensorimotor inhibition at baseline in all 3 ISIs (P < .001). However, no statistically significant difference was found between pre- and post-DRG PRF SAI values at any ISI (P > .05). These results suggest that DRG PRF did not significantly modulate cholinergic-driven sensorimotor integration in lower limbs.

DRG PRF effectively reduces pain in chronic radicular pain patients, but its effect on cortical cholinergic modulation, as measured by SAI, appears to be limited. This finding suggests that DRG PRF primarily exerts its effects through non-cholinergic mechanisms, such as GABAergic, glutamatergic, or noradrenergic pathways. Further studies are warranted to clarify the broader neurophysiological effects of DRG PRF.