Glycerol neurolysis: neurophysiological effects of topical glycerol application on rat saphenous nerve

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✓ The effect of topical glycerol application on normal and previously injured saphenous nerves was tested in 20 Sprague-Dawley rats. Anhydrous glycerol treatment of five normal nerves showed a rapid loss of C-fiber conduction within 5 minutes of application, while after 10 to 30 minutes, a complete conduction blockade in all fiber types was produced. The effect of anhydrous glycerol on both spontaneous firing from the neuroma and impulse propagation within the nerve was examined in 11 rats that had undergone saphenous neurotomy 7 days previously. In these animals, cessation of spontaneous action potential production from the neuroma was the earliest electrophysiological change noted, followed by loss first of C-fiber, then of A-fiber conduction. Graded concentrations of glycerol (25%, 50%, 75%, and 100%) were used in four rats with saphenous neuromas, which allowed selective blockade of spontaneous action potential generation and C-fiber conduction with minimal effect on A-fibers.

The neurophysiological mechanism of glycerol neurolysis appears to be a nonspecific conduction blockade of large and small fibers, which is established within minutes of its application. Spontaneous firing within damaged axons, which may play a role in a variety of cranial and peripheral nerve sensorimotor syndromes, is also exquisitely sensitive to glycerol application.

Article Information

Address reprint requests to: Kim J. Burchiel, M.D., Department of Neurosurgery, Veterans Administration Hospital, 1660 South Columbian Way, Seattle, Washington 98108.

Dr. Burchiel was the recipient of Teacher-Investigator Development Award K07 NS0802 from the National Institute of Neurological and Communicative Disorders and Stroke (PHS/DHHS), and a Veterans Administration Merit Review Research Grant.

© AANS, except where prohibited by US copyright law.

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Figures

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    Microfilament recording in a proximal normal saphenous nerve. a: Two A-alpha fibers recruited by electrical stimulation in this filament at 1-msec latency (10 oscilloscope sweeps are shown). b: Slow oscillographic tracing prior to glycerol application showing no spontaneous discharges. c: Recording 1 to 2 minutes after application of 100% glycerol to the nerve. Occasional single action potential and burst discharges of the previously recruited A-fibers were recorded.

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    Compound action potentials of a subdivided normal saphenous nerve. Baseline evoked potentials show the A-alpha/beta peak, two small A-delta peaks (arrows), and five or six single C-fiber responses. Ten minutes after glycerol application, conduction in all fibers is lost.

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    Recording of a microfilament in a saphenous nerve with a 7-day-old neuroma. a: Two action potentials were recruited in this filament: an A-alpha fiber at 1-msec latency and an A-delta fiber at 4-msec latency. b: The A-delta fiber showed a low level of spontaneous activity while the A-alpha fiber responded only to mechanical stimulation of the neuroma (bracket). c: Firing-rate histogram of the combined low-level spontaneous activity of both fibers. After glycerol application, the A-delta and the A-alpha fibers each showed a brief burst of spontaneous activity. This was followed by cessation of all spontaneous discharge. Calibration pulse is 10 Hz.

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    Firing-rate histogram of a microfilament recording from a saphenous nerve with a 7-day-old neuroma during application of progressively increasing concentrations of glycerol. The initial spontaneous discharge at approximately 10 Hz was inhibited after application of 25% glycerol. Subsequent application of 50% glycerol produced a brief increase in the spontaneous discharge to approximately the baseline firing rate, then all spontaneous activity was eliminated. This latter pattern was repeated after applications of 75% and 100% glycerol. Calibration pulse is 10 Hz.

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    Compound action potentials of a subdivided saphenous nerve with a 7-day-old neuroma. Baseline evoked activity showed A-alpha/beta, A-delta, and C-fiber activity. After application of 25% to 50% glycerol, conduction in two A-delta fibers and one C-fiber was lost. Ten minutes after 75% glycerol application, all C-fiber conduction was absent and an additional A-delta fiber was no longer recruited by stimulation. Ten minutes after 100% glycerol, conduction in two A-alpha fibers remained, but this was lost after 20 minutes. Arrows indicate the onset of stimulation.

References

  • 1.

    Baxter DWSchacherl U: Experimental studies on the morphological changes produced by intrathecal phenol. Can Med Assoc J 86:120012051962Baxter DW Schacherl U: Experimental studies on the morphological changes produced by intrathecal phenol. Can Med Assoc J 86:1200–1205 1962

    • Search Google Scholar
    • Export Citation
  • 2.

    Bennett MHLunsford LD: Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 2. Results and implications of trigeminal evoked potential studies. Neurosurgery 14:4314351984Bennett MH Lunsford LD: Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 2. Results and implications of trigeminal evoked potential studies. Neurosurgery 14:431–435 1984

    • Search Google Scholar
    • Export Citation
  • 3.

    Burchiel KJ: Abnormal impulse generation in focally demyelinated trigeminal roots. J Neurosurg 53:6746831980Burchiel KJ: Abnormal impulse generation in focally demyelinated trigeminal roots. J Neurosurg 53:674–683 1980

    • Search Google Scholar
    • Export Citation
  • 4.

    Burchiel KJ: Effects of electrical and mechanical stimulation on two foci of spontaneous activity which develop in primary afferent neurons after peripheral axotomy. Pain 18:2492651984Burchiel KJ: Effects of electrical and mechanical stimulation on two foci of spontaneous activity which develop in primary afferent neurons after peripheral axotomy. Pain 18:249–265 1984

    • Search Google Scholar
    • Export Citation
  • 5.

    Burchiel KJ: Spontaneous impulse generation in normal and denervated dorsal root ganglia: sensitivity to alpha-adrenergic stimulation and hypoxia. Exp Neurol 85:2572721984Burchiel KJ: Spontaneous impulse generation in normal and denervated dorsal root ganglia: sensitivity to alpha-adrenergic stimulation and hypoxia. Exp Neurol 85:257–272 1984

    • Search Google Scholar
    • Export Citation
  • 6.

    Burchiel KJRussell LC: Effects of potassium channel-blocking agents on spontaneous discharges from neuromas in rats. J Neurosurg 63:2462491985Burchiel KJ Russell LC: Effects of potassium channel-blocking agents on spontaneous discharges from neuromas in rats. J Neurosurg 63:246–249 1985

    • Search Google Scholar
    • Export Citation
  • 7.

    Burchiel KJRussell LC: Spontaneous activity of ventral root axons following peripheral nerve injury. J Neurosurg 62:4084131985Burchiel KJ Russell LC: Spontaneous activity of ventral root axons following peripheral nerve injury. J Neurosurg 62:408–413 1985

    • Search Google Scholar
    • Export Citation
  • 8.

    Håkanson S: Trigeminal neuralgia treated by the injection of glycerol into the trigeminal cistern. Neurosurgery 9:6386461981Håkanson S: Trigeminal neuralgia treated by the injection of glycerol into the trigeminal cistern. Neurosurgery 9:638–646 1981

    • Search Google Scholar
    • Export Citation
  • 9.

    Jannetta PJ: Microsurgical approach to the trigeminal nerve for tic douloureux. Prog Neurol Surg 7:1802001976Jannetta PJ: Microsurgical approach to the trigeminal nerve for tic douloureux. Prog Neurol Surg 7:180–200 1976

    • Search Google Scholar
    • Export Citation
  • 10.

    Kotsuka KNaito H: Comments on Langley's antidromic action on an experimental basis. I. Acta Neuroveg (Wien) 25:1061181962Kotsuka K Naito H: Comments on Langley's antidromic action on an experimental basis. I. Acta Neuroveg (Wien) 25:106–118 1962

    • Search Google Scholar
    • Export Citation
  • 11.

    Lunsford LDBennett MH: Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 1. Technique and results in 112 patients. Neurosurgery 14:4244301984Lunsford LD Bennett MH: Percutaneous retrogasserian glycerol rhizotomy for tic douloureux: Part 1. Technique and results in 112 patients. Neurosurgery 14:424–430 1984

    • Search Google Scholar
    • Export Citation
  • 12.

    Menz LJ: Effect of cryoprotective agents on rat cutaneous nerves. Cryobiology 12:4054161975Menz LJ: Effect of cryoprotective agents on rat cutaneous nerves. Cryobiology 12:405–416 1975

    • Search Google Scholar
    • Export Citation
  • 13.

    Nathan PWSears TA: Effects of phenol on nervous conduction. J Physiol (Lond) 150:5655801960Nathan PW Sears TA: Effects of phenol on nervous conduction. J Physiol (Lond) 150:565–580 1960

    • Search Google Scholar
    • Export Citation
  • 14.

    Pribor DBNara A: Toxicity and cryoprotection by dimethyl sulfoxide and by glycerol in isolated frog sciatic nerves. Cryobiology 5:3553651969Pribor DB Nara A: Toxicity and cryoprotection by dimethyl sulfoxide and by glycerol in isolated frog sciatic nerves. Cryobiology 5:355–365 1969

    • Search Google Scholar
    • Export Citation
  • 15.

    Rengachary SSWatanabe ISSinger Pet al: Effect of glycerol on peripheral nerve: an experimental study. Neurosurgery 13:6816881983Rengachary SS Watanabe IS Singer P et al: Effect of glycerol on peripheral nerve: an experimental study. Neurosurgery 13:681–688 1983

    • Search Google Scholar
    • Export Citation
  • 16.

    Sweet WHPoletti CEMacon JB: Treatment of trigeminal neuralgia and other facial pains by retrogasserian injection of glycerol. Neurosurgery 9:6476531981Sweet WH Poletti CE Macon JB: Treatment of trigeminal neuralgia and other facial pains by retrogasserian injection of glycerol. Neurosurgery 9:647–653 1981

    • Search Google Scholar
    • Export Citation

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