Intractable pain of spinal cord origin: clinical features and implications for surgery

1992 ◽  
Vol 77 (3) ◽  
pp. 373-378 ◽  
Author(s):  
Ronald R. Tasker ◽  
Gervasio T. C. DeCarvalho ◽  
Eugen J. Dolan
Keyword(s):  
Spinal Cord ◽  
Clinical Features ◽  
Surgical Procedures ◽  
Brain Stimulation ◽  
Dorsal Root ◽  
Intractable Pain ◽  
Vertebral Level ◽  
Entry Zone ◽  
Content Type ◽  
Root Entry Zone

✓ The clinical features and types of pain affecting 127 patients with central pain caused by lesions in the spinal cord were studied and correlated with the results of surgical procedures performed on 103 of them. The surgical procedures consisted of percutaneous cordotomy in 39 cases, cordectomy in 12, dorsal root entry zone (DREZ) surgery in four, dorsal cord stimulation in 35, and brain stimulation in 13. The three most common types of pain in the 127 patients were characterized as: steady in 95% of cases, intermittent (usually shooting) in 31%, and evoked (allodynia, hyperpathia, or hyperesthesia) in 45%. Steady pain was usually causalgic (74.8%) or dysesthetic (27.6%). The only obvious clinical correlation with pain type was the association of intermittent pain with lesions at the T10-L2 vertebral level. Destructive surgery (cordotomy, DREZ surgery, or cordectomy) affected the three chief types of pain differently from treatment with cord or brain stimulation. Destructive surgery resulted in reduction of steady pain in 26% of affected cases, of intermittent pain in 89%, and of evoked pain in 84%, while stimulation resulted in pain reductions in 36%, 0%, and 16% of cases, respectively. The differential effect of destructive surgery on steady and intermittent pain is consistent with published experience. These observations suggest differing mechanisms for the three types of pain.

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.

Laser-induced dorsal root entry zone lesions for pain control

1983 ◽  
Vol 59 (5) ◽  
pp. 884-886 ◽  
Author(s):  
Walter J. Levy ◽  
Alan Nutkiewicz ◽  
Q. Michael Ditmore ◽  
Clark Watts
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Scar Tissue ◽  
Intractable Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Cord Injury ◽  
Alternative Means

✓ Dorsal root entry zone lesions have been documented as effective for control of intractable pain in patients with brachial plexus avulsion or severe spinal cord injury. These lesions are usually made with the radiofrequency technique. The authors report three cases in which the CO2 laser was used as an alternative means of making the lesions. This latter technique provided effective pain relief in two of the patients and was efficient to use. It was noted that the presence of overlying scar tissue can be deceptive in judging the depth of the lesion made with the laser. The CO2 laser provided a means of producing controlled spinal cord lesions which may be more precise than the radiofrequency method.

Intraoperative evoked potentials recorded in man directly from dorsal roots and spinal cord

1985 ◽  
Vol 62 (5) ◽  
pp. 680-693 ◽  
Author(s):  
Blaine S. Nashold ◽  
Janice Ovelmen-Levitt ◽  
Robbin Sharpe ◽  
Alfred C. Higgins
Keyword(s):  
Spinal Cord ◽  
Dorsal Root ◽  
Mean Amplitude ◽  
Dorsal Column ◽  
Intractable Pain ◽  
Neurosurgical Procedures ◽  
Negative Wave ◽  
Content Type ◽  
Root Entry Zone ◽  
Dorsal Columns

✓ Direct spinal cord surface recordings of evoked spinal cord potentials have been made in 26 patients during neurosurgical procedures for intractable pain. Monopolar recordings at the dorsal root entry zone after peripheral nerve stimulation have been made at multiple levels for segmental localization and to monitor the state of the afferent path and dorsal horn. Dorsal root and dorsal column conduction has been tested on diseased and intact sides. Normal afferent conduction velocity was found to have an overall mean of 61.33 m/sec for cervicothoracic and lumbosacral peripheral nerves, and 50 m/sec for the dorsal columns. The normal mean amplitude for the slow negative wave (N1) recorded at the root entry was 52.54 µV, while that for the dorsal column conducted response recorded within 4 cm of the stimulus point on the dorsal columns was 347.5 µV. Several different placements of stimulating and recording electrodes are described, as well as their application. An interpretation of the resulting data is proposed.

Dorsal root entry zone lesions for intractable pain after trauma to the conus medullaris and cauda equina

1995 ◽  
Vol 82 (1) ◽  
pp. 28-34 ◽  
Author(s):  
John H. Sampson ◽  
Robert E. Cashman ◽  
Blaine S. Nashold ◽  
Allan H. Friedman
Keyword(s):  
Dorsal Root ◽  
Cauda Equina ◽  
Conus Medullaris ◽  
Intractable Pain ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Relieve Pain ◽  
Fine Print

✓ This review was undertaken to determine the efficacy of using dorsal root entry zone (DREZ) lesions to treat intractable pain caused by trauma to the conus medullaris and cauda equina. Traumatic lesions of this area are unique in that both the spinal cord and the peripheral nerve roots are injured. Although DREZ lesions have been shown to relieve pain of spinal cord origin in many patients, they have been shown not to relieve pain of peripheral nerve origin. Therefore, 39 patients with trauma to the conus medullaris and cauda equina who underwent DREZ lesioning for intractable pain were reviewed retrospectively. The results of this review demonstrate the efficacy of DREZ lesions in these patients. At a mean follow-up period of 3.0 years, 54% of patients were pain-free without medications, and 20% required only nonnarcotic analgesic drugs for pain that no longer interfered with their daily activities. Better outcomes were noted in patients with an incomplete neurological deficit, with pain having an “electrical” character, and with injuries due to blunt trauma. Operative complications included weakness (four patients), bladder or sexual dysfunction (three), cerebrospinal fluid leak (two), and wound infection (two), but overall, 79.5% of patients (31 of 39) were without serious complications. Complications were limited to patients with prior tissue damage at the surgical exploration site and were most prevalent in patients who underwent bilateral DREZ lesions. In conclusion, this preliminary report suggests that DREZ lesions may be useful in combating intractable pain from traumatic injuries to the conus medullaris and cauda equina, with some risk to neurological function that may be acceptable in this group of patients.

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 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.

Bilateral cortical stimulation for deafferentation pain after spinal cord injury

2004 ◽  
Vol 101 (4) ◽  
pp. 687-689 ◽  
Author(s):  
Naoki Tani ◽  
Youichi Saitoh ◽  
Masayuki Hirata ◽  
Amami Kato ◽  
Toshiki Yoshimine
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Intractable Pain ◽  
Entry Zone ◽  
Content Type ◽  
Deafferentation Pain ◽  
Root Entry Zone ◽  
Thalamic Stimulation ◽  
Cord Injury ◽  
New Treatment

✓ The relief of intractable pain after spinal cord injury (SCI) is very difficult to obtain, even with dorsal root entry zone lesioning, spinal cord stimulation, and thalamic stimulation. Using bilateral motor cortex stimulation (MCS) the authors successfully treated a woman who experienced deafferentation pain 4 years after sustaining an SCI. To the authors' knowledge, this is the first report of bilateral MCS for pain relief after SCI. The success they achieved using this method indicates that MCS could be a new treatment option for deafferentation pain following SCI.

Dorsal root entry zone lesions for pain relief

1979 ◽  
Vol 51 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Blaine S. Nashold ◽  
Roger H. Ostdahl
Keyword(s):  
Spinal Cord ◽  
Pain Relief ◽  
Brachial Plexus ◽  
Dorsal Root ◽  
Dorsal Column ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Arm Pain ◽  
Root Entry Zone

✓ Arm pain due to avulsion of the cervical dorsal roots of the brachial plexus may become intractable, ameliorated little, if at all, by contemporary medical or surgical treatment. Severe and sudden trauma to the neck, shoulder, or arm is the usual cause of avulsion of the cervical rootlets. The injury may result in complete sensorimotor paralysis of the involved extremity, or a partial deficit if only a few rootlets are involved. Previous therapies have included stellate block, sympathectomy, high cervical cordotomy, rhizotomy, transcutaneous stimulation, dorsal column stimulation, mesencephalic tractotomy, cingulotomy, and the use of narcotics. The extent of the pathological change in the spinal cord following root avulsion is not completely known; at the time of operation, abnormalities frequently noted included ipsilateral atrophy of the dorsal aspect of the cord, dense arachnoid scarring, microcyst formation, and loss of both dorsal and ventral roots. The cervical myelogram is abnormal, although not necessarily pathognomonic of the extent of injury. The surgical technique of coagulation of the dorsal root entry zone is discussed, and the results and morbidity in 21 patients are reviewed. Thirteen patients (67%) continue to have good pain relief, with follow-up periods ranging from 6 months to 3½ years. Three patients with extremity pain from other causes are included in the series. Clinical observations suggest the possibility that pain resulting from brachial plexus avulsion originates from pathophysiological changes in the injured dorsal horn of the spinal cord. This report is a discussion of a new technique aimed at destruction of the dorsal root entry zone for relief of chronic extremity pain.

Dorsal root entry zone localization using direct spinal cord stimulation: an experimental study

1995 ◽  
Vol 82 (4) ◽  
pp. 592-594 ◽  
Author(s):  
Mahmood Fazl ◽  
David A. Houlden
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Stimulation ◽  
Dorsal Root ◽  
Dorsal Spinal Cord ◽  
Specific Stimulus ◽  
Entry Zone ◽  
Dorsal Root Entry Zone ◽  
Content Type ◽  
Root Entry Zone ◽  
Dorsal Spinal

✓ Direct spinal cord stimulation and recording was performed in five dogs to identify the dorsal root entry zone (DREZ) and long tracts within the dorsal and dorsolateral spinal cord using electrophysiological mapping techniques. Intrathecal recordings were obtained from sites distal to the site of stimulation. Conduction velocity in the fastest conducting fibers was higher following low-intensity stimulation of the dorsolateral spinal cord than after dorsal spinal cord stimulation. The evoked response was larger following dorsolateral than dorsal spinal cord stimulation at a specific stimulus intensity. This technique is useful in identifying the DREZ using electrophysiological criteria alone.

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