RF Safe

Evaluation of laser and radiofrequency induced dorsal root entry zone lesion for pain control in rats.

Zhonghua yi xue za zhi = Chinese medical journal; Free China ed · 1996 · Benefit · Low evidence

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BenefitLow evidencePaper 4198

In groups of eight rats, RF thermocoagulation, CO2 laser, and KTP laser DREZ lesions were each associated with significantly increased forepaw withdrawal latency on a hot-plate test at 3 weeks compared with baseline (p<0.05). Reported mean latencies increased…

Study snapshot

PublicationZhonghua yi xue za zhi = Chinese medical journal; Free China ed · 1996
Study typeanimal
Reported directionBenefit
Evidence ratingLow

Abstract

BACKGROUND: Dorsal root entry zone (DREZ) lesions have been believed to be effective for control of intractable pain. These lesions are usually made using radiofrequency (RF) technique. Theoretically, laser can provide very fast, precise, reproducible and easy control of photothermal effect, possibly achieving better pain control than RF. The objective here was to learn more about the effect of pain control among the RF, carbon dioxide (CO2) laser and potassium titanyl phosphate (KTP) laser in rats. METHODS: The adult rat was anesthetized and the dorsal spinal cord from C5 to T1 was exposed under a microscope. The DREZ lesions were created in each group of eight including sham, RF thermocoagulation, CO2 laser and KTP laser. The latency of pain withdrawal in the fore-paw by a hot-plate test was recorded before the DREZ lesions and three weeks afterward. RESULTS: The data showed that RF, CO2 and KTP laser could significantly reduce pain in rats (p < 0.05, one-way ANOVA and Dunnett's test). Latencies of pain withdrawal in the fore-paw by the hot-plate test before, and three weeks after, DREZ lesions were 13.9 +/- 1.4 sec and 65.2 +/- 4.9 sec in the RF group, 15.9 +/- 1.4 sec and 59.0 +/- 5.9 sec in the CO2 laser group, and 14.1 +/- 0.9 sec and 64.8 +/- 5.7 sec in the KTP group, respectively. CONCLUSIONS: The density of opioid receptor in DREZ lesions cord showed no significant change three weeks after operation in the sham and CO2 laser groups. It was concluded that DREZ lesions caused by RF, CO2 laser and KTP laser can achieve pain control significantly in the rats. The effect of KTP laser was close to RF, followed by CO2 laser.

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AI evidence extraction

Structured fields below were generated from the paper’s abstract and metadata to make the evidence easier to inspect. Automated extraction may be incomplete or incorrect; verify important details against the original paper.

Study typeanimal
Effect directionbenefit
PopulationAdult rats
Sample size32
ExposureNot supplied
Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

In groups of eight rats, RF thermocoagulation, CO2 laser, and KTP laser DREZ lesions were each associated with significantly increased forepaw withdrawal latency on a hot-plate test at 3 weeks compared with baseline (p<0.05). Reported mean latencies increased from 13.9 to 65.2 s (RF), 15.9 to 59.0 s (CO2 laser), and 14.1 to 64.8 s (KTP). Opioid receptor density showed no significant change at 3 weeks in the sham and CO2 laser groups.

Outcomes measured

  • Pain withdrawal latency (hot-plate test)
  • Opioid receptor density in DREZ lesion cord (3 weeks post-op)

Limitations

  • No RF exposure parameters (e.g., frequency, power, lesion temperature) reported in abstract
  • Short follow-up (3 weeks)
  • Small group sizes (n=8 per group)
  • Outcome limited to hot-plate latency; generalizability to other pain models/behaviors unclear from abstract
View raw extracted JSON
{
  "study_type": "animal",
  "exposure": {
    "band": null,
    "source": "radiofrequency lesioning (thermocoagulation)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Adult rats",
  "sample_size": 32,
  "outcomes": [
    "Pain withdrawal latency (hot-plate test)",
    "Opioid receptor density in DREZ lesion cord (3 weeks post-op)"
  ],
  "main_findings": "In groups of eight rats, RF thermocoagulation, CO2 laser, and KTP laser DREZ lesions were each associated with significantly increased forepaw withdrawal latency on a hot-plate test at 3 weeks compared with baseline (p<0.05). Reported mean latencies increased from 13.9 to 65.2 s (RF), 15.9 to 59.0 s (CO2 laser), and 14.1 to 64.8 s (KTP). Opioid receptor density showed no significant change at 3 weeks in the sham and CO2 laser groups.",
  "effect_direction": "benefit",
  "limitations": [
    "No RF exposure parameters (e.g., frequency, power, lesion temperature) reported in abstract",
    "Short follow-up (3 weeks)",
    "Small group sizes (n=8 per group)",
    "Outcome limited to hot-plate latency; generalizability to other pain models/behaviors unclear from abstract"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "dorsal root entry zone",
    "DREZ",
    "radiofrequency",
    "thermocoagulation",
    "laser",
    "CO2 laser",
    "KTP laser",
    "rat",
    "pain control",
    "hot-plate test"
  ],
  "suggested_hubs": []
}
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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: Not supplied
PubMed: 9068209

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