The spinal projection of individual identified A-delta- and C-fibers

1988 ◽  
Vol 59 (1) ◽  
pp. 41-55 ◽  
Author(s):  
R. J. Traub ◽  
L. M. Mendell
Keyword(s):  
Conduction Velocity ◽  
Dorsal Root ◽  
High Threshold ◽  
Entry Zone ◽  
Root Entry Zone ◽  
C Fibers ◽  
Spinal Projection ◽  
Dorsal Columns ◽  
Adequate Stimulus ◽  
Low Threshold

1. Recordings were made from individual sensory neurons with an A-delta peripheral conduction velocity, either intrasomally in the L7 dorsal root ganglion, or extracellularly in Lissauer's Tract or in the dorsal root close to the root entry zone. The spinal projection of these afferents was assessed by their antidromic response to stimulation of the dorsal columns (DC) or Lissauer's Tract (LT) at the L5/L6 border. The adequate stimulus was also ascertained. 2. A-delta-fibers could be divided into two groups: high-threshold mechanoreceptors from either skin or muscle (HTMRs) and low-threshold mechanoreceptors (LTMs), primarily Down Hairs. A third group of cells recorded intrasomally had broad spikes with shoulders on the downstroke characteristic of A-delta-nociceptors and were so classified provisionally, although no adequate stimulus could be identified. HTMRs and broad spike cells projected either in DC or LT, but LTMs projected only in DC, never in LT. About one-quarter of both groups failed to project rostrally as far as L5/L6. 3. Cells with unmyelinated axons recorded intrasomally were found to supply either low-threshold or high-threshold mechanoreceptors. Unlike A-delta-cells, all these cells had broad spikes with shoulders on the downstroke. Proportionally fewer C-fibers than A-delta-fibers projected as far as one segment rostral from their root entry zone. Of those that did, axons supplying low-threshold mechanoreceptors projected only in DC, whereas those innervating high-threshold mechanoreceptors could project either through LT or DC. 4. A-delta-fibers supplying LTMs and HTMRs exhibited a similar reduced conduction velocity was reduced even further in the spinal cord but much more for HTMRs than for LTMs. For C-fibers the conduction velocity decrease was more substantial in the dorsal root for HTMRs than for LTMs. 5. These findings suggest that axons innervating different peripheral receptors exhibit characteristic cellular properties. They confirm that the primary afferent component of Lissauer's Tract is specialized as a “pain pathway” but also indicate that the dorsal columns may play some role in the transmission of nociceptive information.

Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion Pain

2019 ◽  
pp. 71-78
Author(s):  
Daniel R. Cleary ◽  
Sharona Ben-Haim
Keyword(s):  
Brachial Plexus ◽  
Dorsal Horn ◽  
Dorsal Root ◽  
High Speed ◽  
Csf Leak ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Brachial Plexus Avulsion ◽  
Root Entry Zone ◽  
Dorsal Columns

Brachial plexus avulsion is often seen after motorcycle accidents or with high-speed ejection injuries. Rehabilitation focuses on regaining motor and sensory function, but the detrimental effect of pain is often underappreciated. Up to 90% of patients with avulsion injury will experience deafferentation pain, which until relatively recently has been difficult to treat medically or surgically. DREZotomy, the ablation of neurons in the dorsal root entry zone of the spinal cord, was introduced in the 1970s and has since changed how we treat brachial plexus avulsion and other forms of neuropathic pain. The procedure is straightforward: with a standard cervical approach, a hemilamiotomy is used to expose the area of interest. The dura is opened, and areas of root avulsion are identified. Using bipolar cautery, RF ablation, or ultrasound, the 2nd order neurons in dorsal horn are destroyed for the affected dermatomes. Complications include standard cervical spinal approach-related issues, such as infection, hematoma, CSF leak, and kyphosis. Risks specific to the procedure include post-operative motor or sensory deficits, due to the proximity of the corticospinal tracts and the dorsal columns to dorsal horn. As many as 18% of patients report a long-term neurological deficit post-operatively, but despite these complications, 80% of patients say they would repeat the procedure. Multiple outcomes series have been published since the procedure was introduced, and typically 70–80% of patients receive benefit from the procedure.

scholarly journals Dorsal Root Entry Zone Lesioning for Brachial Plexus Avulsion: A Comprehensive Literature Review

2021 ◽  
Author(s):  
Axumawi Mike Hailu Gebreyohanes ◽  
Aminul Islam Ahmed ◽  
David Choi
Keyword(s):  
Brachial Plexus ◽  
Patient Outcomes ◽  
Dorsal Root ◽  
Cervical Spinal Cord ◽  
Entry Zone ◽  
Neurosurgical Procedure ◽  
Dorsal Root Entry Zone ◽  
Brachial Plexus Avulsion ◽  
Root Entry Zone ◽  
Comprehensive Literature Review

Abstract Dorsal root entry zone (DREZ) lesioning is a neurosurgical procedure that aims to relieve severe neuropathic pain in patients with brachial plexus avulsion by selectively destroying nociceptive neural structures in the posterior cervical spinal cord. Since the introduction of the procedure over 4 decades ago, the DREZ lesioning technique has undergone numerous modifications, with a variety of center- and surgeon-dependent technical differences and patient outcomes. We have reviewed the literature to discuss reported methods of DREZ lesioning and outcomes.

Dorsal root entry zone lesions for the treatment of post-herpetic neuralgia

1984 ◽  
Vol 60 (6) ◽  
pp. 1258-1262 ◽  
Author(s):  
Allan H. Friedman ◽  
Blaine S. Nashold ◽  
Janice Ovelmen-Levitt
Keyword(s):  
Pain Relief ◽  
Dorsal Root ◽  
Post Herpetic Neuralgia ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Adequate Pain Relief ◽  
Good Pain Relief ◽  
Transcutaneous Nerve Stimulation

✓ Post-herpetic pain was treated in 12 patients using dorsal root entry zone (DREZ) lesions. All patients had failed to receive adequate pain relief from conservative therapy consisting of transcutaneous nerve stimulation, carbamazepine, and/or amitriptyline. Dorsal root entry zone lesions were made to include the involved dermatomes plus one-half of the dermatomes above and below the painful areas. Eight patients reported good pain relief with follow-up periods ranging from 6 to 21 months. A ninth patient obtained satisfactory pain relief, but the superior 1 cm of the original painful area was not included in the distribution of the DREZ lesions. Patients whose lesions were performed using a thermally controlled lesion probe suffered no significant postoperative neurological deficit. Dorsal root entry zone lesions appeared to be a satisfactory treatment for post-herpetic neuralgia in patients who have failed to respond to more conservative modes of therapy.

Treatment of Refractory Pain after Brachial Plexus Avulsion with Dorsal Root Entry Zone Lesions

Neurosurgery ◽  
2001 ◽  
Vol 48 (6) ◽  
pp. 1269-1277 ◽  
Author(s):  
Madjid Samii ◽  
Steffani Bear-Henney ◽  
Wolf Lüdemann ◽  
Marcos Tatagiba ◽  
Ulrike Blömer
Keyword(s):  
Brachial Plexus ◽  
Dorsal Root ◽  
Intractable Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Root Entry Zone ◽  
Long Term Follow Up ◽  
Cervical Root

Abstract OBJECTIVE Significant numbers of patients experience intractable pain after brachial plexus root avulsions. Medications and surgical procedures such as amputation of the limb are often not successful in pain treatment. METHODS Forty-seven patients with intractable pain after traumatic cervical root avulsions were treated with dorsal root entry zone coagulation between 1980 and 1998. The dorsal root entry zone coagulation procedure was performed 4 months to 12 years after the trauma, and patients were monitored for up to 18 years (average follow-up period, 14 yr). RESULTS Immediately after surgery, 75% of patients experienced significant pain reduction; this value was reduced to 63% during long-term follow-up monitoring. Nine patients experienced major complications, including subdural hematomas (n = 2) and motor weakness of the lower limb (n = 7). Improved coagulation electrodes with thermistors that could produce smaller and more-accurate lesion sizes, which were introduced in 1989, significantly reduced the number of complications. CONCLUSION Central deafferentation pain that persists and becomes intractable among patients with traumatic cervical root avulsions has been difficult to treat in the past. Long-term follow-up monitoring of patients who underwent the dorsal root entry zone coagulation procedure in the cervical cord indicated that long-lasting satisfactory relief is possible for the majority of individuals, with acceptable morbidity rates.

Theoretical Aspects of Radiofrequency Lesions in the Dorsal Root Entry Zone

Neurosurgery ◽  
1984 ◽  
Vol 15 (6) ◽  
pp. 945-950 ◽  
Author(s):  
Eric R. Cosman ◽  
Blaine S. Nashold ◽  
Janice Ovelman-Levitt
Keyword(s):  
Dorsal Root ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Root Entry Zone ◽  
Radiofrequency Lesions

Dorsal root entry zone lesions to control central pain in paraplegics

1981 ◽  
Vol 55 (3) ◽  
pp. 414-419 ◽  
Author(s):  
Blaine S. Nashold ◽  
Elizabeth Bullitt
Keyword(s):  
Dorsal Root ◽  
Central Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Fine Print

✓ Thirteen patients with intractable long-term pain following spinal cord injury and paraplegia were treated with dorsal root entry zone lesions placed at the level just above the transection. Pain relief of 50% or more was achieved in 11 of the 13 patients, with follow-up periods ranging from 5 to 38 months. A previous report showed that central pain from brachial plexus avulsion could be relieved by dorsal root entry zone lesions, and this technique has been extended to the central pain phenomena associated with spinal trauma and paraplegia.

scholarly journals Microsurgical DREZ lesions for the control of cancer-related pain

2020 ◽  
Vol 3 (2) ◽  
pp. V14 ◽  
Author(s):  
Edoardo Mazzucchi ◽  
Andrei Brinzeu ◽  
Patrick Mertens ◽  
Marc Sindou
Keyword(s):  
General Condition ◽  
Dorsal Root ◽  
Lateral Part ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Patients With Cancer ◽  
Root Entry Zone ◽  
Refractory Pain ◽  
Pain Pathways ◽  
Good General Condition

Pain in patients with cancer is a major problem, and sometimes it is necessary to surgically interrupt pain pathways to effectively control refractory pain. Surgical lesion of the dorsal root entry zone (DREZ) was first performed in 1972 for the treatment of pain related to a Pancoast-Tobias tumor. The rationale of DREZotomy is to preferentially interrupt the nociceptive inputs in the lateral part of the DREZ and the ventrolateral (excitatory) part of the dorsal horn. Microsurgical DREZotomy is one technique for DREZ lesioning that is suited for tailored control of pain in patients in good general condition who are experiencing pain in a well-defined territory.The video can be found here: https://youtu.be/JtLQDP7gYSQ

Spinal cord mapping with evoked responses for accurate localization of the dorsal root entry zone

1995 ◽  
Vol 82 (4) ◽  
pp. 587-591 ◽  
Author(s):  
Mahmood Fazl ◽  
David A. Houlden ◽  
Zelma Kiss
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Neurological Deficits ◽  
Intractable Pain ◽  
Specific Stimulus ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Accurate Localization

✓ Direct spinal cord stimulation and recording techniques were used intraoperatively to localize the dorsal root entry zone (DREZ) in four patients with brachial plexus avulsion and severe intractable pain. The spinal cord was stimulated by a cordotomy needle placed on the pia-arachnoid at the DREZ or the dorsal or dorsolateral aspect of the spinal cord. Recordings were obtained from a subdural silver ball electrode placed rostral or caudal to the stimulation site. Spinal cord conduction velocity was significantly faster following dorsolateral stimulation than dorsal stimulation (mean = 66 and 45 m/sec respectively). The spinal cord evoked potential was significantly larger in amplitude following dorsolateral stimulation than dorsal stimulation at a specific stimulus intensity. Stimulation at the DREZ failed to evoke a response. These neurophysiological phenomena helped to accurately localize the DREZ before DREZ lesioning was undertaken. There were no untoward neurological deficits related to the DREZ lesions and all patients had satisfactory pain relief following the procedure. Intraoperative spinal cord mapping facilitates accurate DREZ localization when the DREZ cannot be visually identified.

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