Electric and Thermal Field Effects in Tissue Around Radiofrequency Electrodes

Abstract

Continuous RF lesioning causes heat destruction of neurons. Pulsed RF lesioning (PRFL) produces heat bursts with temperatures in the range associated with destructive heat lesions. PRFL also produces very high electric fields that may be capable of disrupting neuronal membranes and function. Finite-element calculations agree substantially with the measured data, giving confidence to their predictions of fields around the RF electrode.

Whiplash Patients with Cervicogenic Headache After Lateral Atlanto- Axial Joint Pulsed Radiofrequency Treatment

“…Fini et al (27) suggest that the delivery of pulsed electromagnetic fields combines an anabolic effect on chondrocytes, a catabolic cytokine blockage, a stimulatory effect on anabolic cytokine production, and a counteraction of the inflammatory process in osteoarthritis. Cosman et al (35) assert that magnetic fields generated in PRF are negligible and any therapeutic effects are due to the electric fields. More research will therefore be required to verify in-vitro effects, if this hypothesized chondro-protective mechanism is indeed true.…”

Radiofrequency Treatments for Neuropathic Pain: Review and New Approaches

“…Cosman and Cosman (Cosman & Cosman, 2005) calculated that the rapid oscillation in transmembrane potential in response to a 500-kHz current would induce transmembrane rectification of neuronal currents, which might also cause LTD as well as depolarizing pulses at 1-2 Hz. In this case, both temporal phases of current oscillation might induce LTD and thereby decrease afferent pain transmission.…”

“…The calculated and measured heat spikes during PRF should be proportional to V(peak) 2 /2R (resistance), where V (peak) is the peak RF voltage on the electrode (Cosman & Cosman, 2005). Therefore heat spikes in this study were about 1/16-81 in comparison with that at 20-45 V. Although the actual tissue temperature around the electrode could not be measured, it was assumed that the heat spikes by L-PRF treatment were suppressed enough.…”

“…One is that pain relief depends on the rapidly changing electric fields (Sluijter, 1998); the other is that PRF produces brief heat bursts at temperatures in the range associated with destructive heat lesions (Cosman & Cosman, 2005). It is not known, however, if these transient heat bursts do have an ablative effect (Chua et al, 2011).…”

“…However, rapid temperature spikes above 42 °C were observed during PRF bursts of 45 V, occasionally reaching the lethal temperature range of 45-50 °C or more (Cosman & Cosman, 2005). These rapid temperature spikes might induce microscopic tissue damage, leading to a period of discomfort after PRF, and induce antinociceptive action.…”