Anin VitroModel of the Rat Dorsal Root Entry Zone Reveals Developmental Changes in the Extent of Sensory Axon Growth into the Spinal Cord

1996 ◽  
Vol 7 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Jon P. Golding ◽  
Derryck Shewan ◽  
Martin Berry ◽  
James Cohen
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Axon Growth ◽  
Developmental Changes ◽  
Sensory Axon ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Root Entry Zone

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.

scholarly journals Neurosurgical treatment of pain

2006 ◽  
Vol 59 (9-10) ◽  
pp. 450-455
Author(s):  
Eugen Slavik
Keyword(s):  
Spinal Cord ◽  
Chronic Pain ◽  
Surgical Treatment ◽  
Spinal Cord Stimulation ◽  
Dorsal Root ◽  
Neurosurgical Procedures ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Root Entry Zone ◽  
Deep Brain

Introduction. Surgical treatment of chronic pain includes destructive procedures (neurectomy, rhizotomy, sympathectomy), often referred to as ablative, and accompanied by high morbidity and mortality rates. Surgical treatment of pain. During the past three decades, thanks to current knowledge on chronic pain mechanisms and technological developments, such as improved microsurgical and stereotactic techniques, guided by computerized tomography, magnetic resonance imaging and neural tissue impedance monitoring, the majority of ablative procedures have been replaced by new methods. Among them, a few can be considered as selectively and minimally ablative (microsurgical spinothalamic cordotomy, dorsal root entry zone lesions, limited midline myelotomy) and others as neuroaugumentative procedures for neuromodulatory processes (deep brain structures and spinal cord stimulation, drug-delivery systems). Neurosurgical procedures. Cordotomy is very effective in pain treatment and it may produce complete abolishment of pain, especially in patients suffering from neoplastic invasion of the brachial plexus (Pancoast?s syndrome) or lumbosacral plexus. Dorsal root entry zone operation is generally the only treatment option for pain due to root avulsion and segmental pain in spinal cord injury. Spinal cord stimulation is useful in management of pain following peripheral nerve injury. Deep brain stimulation is a promising treatment of central pain. Conclusion. The purpose of this review is to draw attention to neurosurgical approaches to treatment of chronic and opioid-resistant pain. .

scholarly journals Spinal cord injury below-level neuropathic pain relief with dorsal root entry zone microcoagulation performed caudal to level of complete spinal cord transection

2018 ◽  
Vol 28 (6) ◽  
pp. 612-620 ◽  
Author(s):  
Scott Falci ◽  
Charlotte Indeck ◽  
Dave Barnkow
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Spinal Cord Transection ◽  
Central Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Somatotopic Map ◽  
Neuronal Transmission

OBJECTIVESurgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically been performed at and cephalad to, but not below, the level of SCI. This study was initiated to investigate the validity of 3 proposed concepts regarding the DREZ in SCI central pain: 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through sympathetic nervous system (SNS) pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain-generators.METHODSThree unique patients with both intractable SCI below-level central pain and complete spinal cord transection at the level of SCI were identified. All 3 patients had previously undergone surgical intervention to their spinal cords—only cephalad to the level of spinal cord transection—with either DREZ microcoagulation or cyst shunting, in failed attempts to relieve their SCI below-level central pain. Subsequent to these surgeries, DREZ lesioning of the spinal cord solely caudal to the level of complete spinal cord transection was performed using electrical intramedullary guidance. The follow-up period ranged from 1 1/2 to 11 years.RESULTSAll 3 patients in this study had complete or near-complete relief of all below-level neuropathic pain. The analyzed electrical data confirmed and enhanced a previously proposed somatotopic map of SCI below-level DREZ pain generators.CONCLUSIONSThe results of this study support the following hypotheses. 1) The spinal cord DREZ caudal to the level of SCI can be a primary generator of SCI below-level central pain. 2) Neuronal transmission from a DREZ that generates SCI below-level central pain to brain pain centers can be primarily through SNS pathways. 3) Perceived SCI below-level central pain follows a unique somatotopic map of DREZ pain generators.

Somatosensory function following dorsal root entry zone lesions in patients with neurogenic pain or spasticity

1991 ◽  
Vol 74 (6) ◽  
pp. 916-932 ◽  
Author(s):  
Daniel Jeanmonod ◽  
Marc Sindou
Keyword(s):  
Spinal Cord ◽  
Dorsal Horn ◽  
Dorsal Root ◽  
Neurogenic Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Somatosensory Function ◽  
Fine Print

✓ The goal of this study was to assess the effects of the dorsal root entry zone (DREZ) lesioning procedure, microsurgical DREZ-otomy (MDT), on spinal cord somatosensory function based on peri- and intraoperative clinical and electrophysiological data. The study was performed prospectively on a series of 20 patients suffering from either chronic neurogenic pain or spasticity. Physiological observations were made of the intraoperative evoked electrospinographic recordings as collected from the surface of the spinal cord. The MDT procedure produced analgesia or severe hypalgesia, moderate hypesthesia, and only slight deficits in proprioception and cutaneous spatial discrimination on the body segments operated on. These clinical data correlated well with evoked electrospinographic recordings, which showed a moderate effect of MDT on presynaptic compound action potentials recorded from the spinal cord (N11 and N21), a partial or even reversible effect on the cortical postcentral N20 wave, a more marked effect on the postsynaptic dorsal horn waves N13 and N24 related to large primary afferent fibers, and a disappearance of dorsal horn waves related to finer afferents (N2 and possibly N3). These data provide evidence for an acceptably selective action of MDT on spinal cord nociceptive mechanisms, and for a partial, often slight, involvement of the other somatosensory domains. The presence of abnormal evoked electrospinographic waves is discussed in relation to the mechanisms of neurogenic pain and spasticity. The hypothesis of a “retuning” of the dorsal horn as the mode of action of MDT is presented.

Dorsal Root Entry Zone Lesioning Used to Treat Central Neuropathic Pain in Patients With Traumatic Spinal Cord Injury

Spine ◽  
2002 ◽  
Vol 27 (7) ◽  
pp. E177-E184 ◽  
Author(s):  
Matthew R. Denkers ◽  
Heather L. Biagi ◽  
Mary Ann O’Brien ◽  
Alejandro R. Jadad ◽  
Mary E. Gauld
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Neuropathic Pain ◽  
Dorsal Root ◽  
Traumatic Spinal Cord Injury ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Central Neuropathic Pain ◽  
Root Entry Zone ◽  
Cord Injury

Dorsal root entry zone microcoagulation for spinal cord injury—related central pain: operative intramedullary electrophysiological guidance and clinical outcome

2002 ◽  
Vol 97 (2) ◽  
pp. 193-200 ◽  
Author(s):  
Scott Falci ◽  
Lavar Best ◽  
Rick Bayles ◽  
Dan Lammertse ◽  
Charlotte Starnes
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Central Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Electrical Data ◽  
Fine Print

Object. Surgically created lesions of the spinal cord dorsal root entry zone (DREZ) to relieve central pain after spinal cord injury (SCI) have historically resulted in modest outcomes. A review of the literature indicates that fair to good relief of pain is achieved in approximately 50% of patients when an empirical procedure is performed. This study was undertaken to determine if intramedullary electrical guidance in DREZ lesioning could improve outcomes in patients with SCI-induced central pain. Additionally, electrical data were used to determine if the spinal cord could be somatotopically mapped with regard to this pain of central origin. Methods. Forty-one patients with traumatic SCI and intractable central pain underwent DREZ lesioning in which intramedullary electrical guidance was conducted. In nine patients, recording of DREZ-related spontaneous electrical hyperactivity guided the lesioning process. In 32 patients, recording of DREZ-induced evoked electrical hyperactivity during transcutaneous C-fiber stimulation (TCS) additionally guided lesioning. The follow-up period ranged from 1 to 7 years. The analyzed electrical data allowed for somatotopic mapping of the spinal cord. Conclusions. Intramedullary electrical guidance of DREZ lesioning substantially improves pain outcomes in patients with traumatic SCI—induced central pain, compared with an empiric technique. The best outcome occurs when DREZ-related spontaneous electrical hyperactivity and evoked hyperactivity during TCS are both used to guide the DREZ lesioning procedure. With such guidance, 100% relief of pain was achieved in 84% of patients and 50 to 100% relief of pain in 88%. Somatotopic mapping of the electrical data led to a proposed pain mechanism for below-level pain, implicating the sympathetic nervous system.

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