Paresthesiae during radiofrequency neurolysis of lumbar sympathetic trunk in CRPS: human evidence of a sympatho-sensory connection?

Pain physician · 2003 · Unclear · Very low evidence

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UnclearVery low evidencePaper 3690

Study snapshot

PublicationPain physician · 2003

Study typecase_report

Reported directionUnclear

Evidence ratingVery low

Abstract

Radiofrequency heat lesioning has been advocated to prolong the duration of therapeutic effect of lumbar sympathetic block in Complex Region Pain Syndrome (CRPS) of the lower extremity. Prior to radiofrequency lesioning of the lumbar sympathetic trunk, sensory and motor stimulation may be used to verify that the active needle tip is not adjacent to a spinal nerve to avoid unwanted neural injury. However, the value of sensory stimulation to aid in precise needle positioning at the desired target remains controversial. In this report we describe our observations using sensory stimulation to aid in needle placement for radiofrequency lesioning. We confirm a novel observation that paresthesiae to the lumbar sympathetic trunk is possible and hypothesize on pathophysiologic meaning. Two representative patients are presented who underwent sensory stimulation of the lumbar sympathetic trunk during needle placement for lumbar sympathetic radiofrequency neurolysis. Sensory stimulation was elicited at the L3 or L4 vertebral level using a 15 cm insulated radiofrequency needle with a 5-mm active tip. During sensory stimulation, patients described paresthesiae to the ipsilateral buttock and lower extremity. Stimulation intensity was less than 0.8 V at 50 Hz at impedance of 300 Ohms or less. Motor stimulation did not occur up to the maximum voltage tested (2.0 V at 2 Hz) Sensory stimulation of the lumbar sympathetic trunk may be used to aid in localization of the active tip of the radiofrequency needle, in preparation for lesioning. A dermatomal sensory pattern was observed, suggesting that afferent sensory fibers travel in the lumbar sympathetic trunk. The implications of this observation for understanding the mechanism of CRPS-related pain are discussed.

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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 typecase_report

Effect directionunclear

PopulationPatients with Complex Regional Pain Syndrome (CRPS) of the lower extremity undergoing lumbar sympathetic radiofrequency neurolysis

Sample size2

ExposureNot supplied

Evidence strengthVery lowConfidence: 74% · Peer reviewed: yes

Main findings

Two patients undergoing needle placement for lumbar sympathetic radiofrequency neurolysis reported paresthesiae in the ipsilateral buttock and lower extremity during sensory stimulation at L3 or L4. Sensory stimulation was elicited at <0.8 V at 50 Hz (impedance ≤300 Ohms), and motor stimulation did not occur up to 2.0 V at 2 Hz. The authors report a dermatomal sensory pattern and discuss this as suggesting afferent sensory fibers may travel in the lumbar sympathetic trunk.

Outcomes measured

Paresthesiae during sensory stimulation of the lumbar sympathetic trunk
Motor response during motor stimulation
Dermatomal sensory pattern (distribution of paresthesiae)

Limitations

Case report with two representative patients
No control/comparator group described
Clinical observations during a procedure; limited generalizability

View raw extracted JSON

{
  "study_type": "case_report",
  "exposure": {
    "band": null,
    "source": "radiofrequency neurolysis (lumbar sympathetic trunk)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": null
  },
  "population": "Patients with Complex Regional Pain Syndrome (CRPS) of the lower extremity undergoing lumbar sympathetic radiofrequency neurolysis",
  "sample_size": 2,
  "outcomes": [
    "Paresthesiae during sensory stimulation of the lumbar sympathetic trunk",
    "Motor response during motor stimulation",
    "Dermatomal sensory pattern (distribution of paresthesiae)"
  ],
  "main_findings": "Two patients undergoing needle placement for lumbar sympathetic radiofrequency neurolysis reported paresthesiae in the ipsilateral buttock and lower extremity during sensory stimulation at L3 or L4. Sensory stimulation was elicited at <0.8 V at 50 Hz (impedance ≤300 Ohms), and motor stimulation did not occur up to 2.0 V at 2 Hz. The authors report a dermatomal sensory pattern and discuss this as suggesting afferent sensory fibers may travel in the lumbar sympathetic trunk.",
  "effect_direction": "unclear",
  "limitations": [
    "Case report with two representative patients",
    "No control/comparator group described",
    "Clinical observations during a procedure; limited generalizability"
  ],
  "evidence_strength": "very_low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "complex regional pain syndrome",
    "CRPS",
    "lumbar sympathetic trunk",
    "radiofrequency neurolysis",
    "radiofrequency lesioning",
    "sensory stimulation",
    "paresthesiae",
    "sympatho-sensory connection"
  ],
  "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: 16871292

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