Microsurgical lesioning in the dorsal root entry zone for pain due to brachial plexus avulsion: a prospective series of 55 patients

2005 ◽  
Vol 102 (6) ◽  
pp. 1018-1028 ◽  
Author(s):  
Marc P. Sindou ◽  
Eric Blondet ◽  
Evelyne Emery ◽  
Patrick Mertens

Object. Most patients with preganglionic lesions after brachial plexus injuries suffer pain that is hard to control through medication or neuromodulation. Lesioning in the dorsal root entry zone (DREZ) is undeniably effective. Fifty-five patients who had undergone the so-called microsurgical DREZotomy (MDT) procedure were studied with the two following objectives: 1) to describe the anatomical lesions observed during MDT in correlation with sensory deficits and pain features; and 2) to analyze the results in the 44 patients who were followed for more than 1 year (mean 6 years). Methods. The observed lesions were severe: 79.6% of ventral and 78.2% of dorsal roots from C5—T1 were impaired. Damage extended to all five roots in 42% of patients. Strong arachnoiditis was present in 38.2%, pseudomeningoceles in 31%, spinal cord distortion and/or atrophy in 49%, and abundant gliotic tissue and/or microcavitations within the dorsal horn at the avulsed segments in 36.4% of cases. Sensory deficit corresponded to the entire territory of the dorsal root lesions in 52% of patients, but was larger in 30% most certainly due to the associated extrarachidian lesions. At the last evaluation after MDT, 66% of patients showed excellent (total relief without medication) or good (total relief with medication) pain relief and 71% experienced an improvement in activity level. Conclusions. Apart from other indications not addressed in this article, MDT can be performed to treat refractory pain due to brachial plexus avulsions. The long-term efficacy of this procedure strongly indicates that pain after brachial plexus avulsion originates from the deafferented (and gliotic) dorsal horn.

2002 ◽  
Vol 97 (6) ◽  
pp. 1402-1409 ◽  
Author(s):  
Marc Guenot ◽  
Jean Bullier ◽  
Marc Sindou

Object. The aims of this study were to construct an animal model of deafferentation of the spinal cord by brachial plexus avulsion and to analyze the effects of subsequent dorsal root entry zone (DREZ) lesions in this model. To this end, the authors measured the clinical and electrophysiological effects of total deafferentation of the cervical dorsal horn in rats and evaluated the clinical efficacy of cervical DREZ lesioning. Methods. Forty-three Sprague—Dawley rats were subjected to total deafferentation of the right cervical dorsal horn by performing a posterior rhizotomy from C-5 to T-1. The clinical effects of this deafferentation, namely self-directed mutilations consisting of scraping and/or ulceration of the forelimb skin or even autotomy of some forelimb digits, were then evaluated. As soon as some of these clinical signs of pain appeared, the authors performed a microsurgical DREZ rhizotomy ([MDR], microincision along the deafferented DREZ and dorsal horn). Before and after MDR, single-unit recordings were obtained in the deafferented dorsal horn and in the contralateral (healthy) side. The mean frequency of spontaneous discharge from the deafferented dorsal horn neurons was significantly higher than that from the healthy side (36.4 Hz compared with 17.9 Hz, p = 0.03). After deafferentation, 81.4% of the rats developed clinical signs corresponding to pain following posterior rhizotomy. Among these animals, scraping was observed in 85.7% of cases, ulceration (associated with edema) in 37.1%, and autotomy in 8.5%. These signs appeared a mean 5.7 weeks (range 1–12 weeks) after deafferentation. Thirteen rats benefited from an MDR; nine (69%) experienced a complete cure, that is, a total resolution of scraping or ulceration (a mean 4.6 weeks after MDR). In contrast, only one of 11 sham-operated animals showed signs of spontaneous recovery (p = 0.01). Conclusions. These results emphasize the role of the spinal dorsal horn in the genesis of deafferentation pain and suggest that dorsal horn deafferentation by cervical posterior rhizotomy in the rat provides a reliable model of chronic pain due to brachial plexus avulsion and its suppression by MDR.


2019 ◽  
pp. 71-78
Author(s):  
Daniel R. Cleary ◽  
Sharona Ben-Haim

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.


1991 ◽  
Vol 74 (6) ◽  
pp. 916-932 ◽  
Author(s):  
Daniel Jeanmonod ◽  
Marc Sindou

✓ 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.


1993 ◽  
Vol 78 (4) ◽  
pp. 598-602 ◽  
Author(s):  
Eugene Rossitch ◽  
M. Abdulhak ◽  
Janice Ovelmen-Levitt ◽  
M. Levitt ◽  
Blaine S. Nashold

✓ Extensive longitudinal lesions of the dorsal root entry zone (DREZ) are effective in relieving some chronic deafferentation pain in humans. A deafferentation syndrome follows C5—T2 dorsal root ganglionectomies in rats. The syndrome consists of biting and scratching the completely and partially denervated limb areas, respectively. This study examines the effect of DREZ lesions on the deafferentation syndrome in the rat. Of 37 rats, 24 underwent C5—T2 ganglionectomies only, five received C4—T3 micromechanical DREZ lesions only, and eight underwent ganglionectomies plus simultaneous DREZ lesions. The animals were observed for 45 days postoperatively. Histological analysis of the spinal cord lesions was performed. All rats with ganglionectomies alone exhibited the deafferentation syndrome; however, no rats with DREZ lesions alone showed this feature. Only 25% of rats with combined ganglionectomies and DREZ lesions exhibited the deafferentation syndrome in the first 30 days, whereas 80% of the animals with ganglionectomies only did so. Although 75% of the animals with combined lesions eventually bit the insensitive forepaw, this behavior was significantly attenuated: the day of onset was delayed and the extent of self-mutilation was reduced. Postmortem histological examination of the DREZ lesions indicated a close association between the completeness of the dorsal horn destruction and the reduction or prevention of self-mutilation. These data support the validity of the animal model and also the hypothesis stating that the deafferentation syndrome results from abnormal spontaneous neural activity in the dorsal horn. Moreover, the variability of the histological findings in these experiments stresses the importance of making contiguous and complete dorsal horn lesions in human DREZ surgery.


2001 ◽  
Vol 94 (1) ◽  
pp. 165-173 ◽  
Author(s):  
Patrick Mertens ◽  
Chantal Ghaemmaghami ◽  
Lionel Bert ◽  
Armand Perret-Liaudet ◽  
Marc Guenot ◽  
...  

✓ The aim of this study was to develop, for the first time in the human spinal dorsal horn (DH), an in vivo method for the study of amino acids (AAs). A microdialysis technique was used to sample AAs in the extracellular fluid of the DH apex in eight patients in whom surgery in the dorsal root entry zone (DREZ) was performed. Before making microsurgical lesions, specific concentric-type microdialysis probes were implanted over a 60-minute period in the DREZ and directed to the DH apex (10 implantations). The AA concentrations in the dialysates were determined using high-performance liquid chromatography with fluorescence detection. The concentrations of excitatory AAs (glutamate and aspartate) and inhibitory AAs (γ-aminobutyric acid and glycine) decreased and were stabilized by 45 minutes after probe implantation, whereas the levels of nonneurotransmitter AAs (alanine and threonine) were not stabilized at 60 minutes. The ability of the probe to track the changes of extracellular AAs was demonstrated. Neither intra- nor postoperative microdialysis-related complications were observed (with a follow up of 18 months). The present study demonstrates that microdialysis can be performed safely in the human DH during DREZ lesioning. Despite technical and analytical limitations related to the intraoperative conditions, this technique offers new possibilities for clinical research on neurotransmitters involved in some relevant pathological states, especially in chronic pain and spasticity.


2021 ◽  
Author(s):  
Axumawi Mike Hailu Gebreyohanes ◽  
Aminul Islam Ahmed ◽  
David Choi

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.


1981 ◽  
Vol 55 (3) ◽  
pp. 414-419 ◽  
Author(s):  
Blaine S. Nashold ◽  
Elizabeth Bullitt

✓ 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.


2011 ◽  
Vol 114 (1) ◽  
pp. 196-199 ◽  
Author(s):  
Nestor D. Tomycz ◽  
John J. Moossy

Brachial plexus avulsion and limb amputation are often associated with intractable chronic pain. Dorsal root entry zone (DREZ) thermocoagulation is an effective surgical treatment for upper-extremity deafferentation pain. The authors describe the clinical follow-up and imaging in a patient who underwent DREZ thermocoagulation 26 years ago for postamputation phantom limb syndrome with associated brachial plexus avulsion. This patient continues to have successful pain control without phantom limb sensation and has never experienced a recurrence of his left upper-extremity pain syndrome. This report lends credibility to the notion that, among ablative neurosurgical pain operations, DREZ thermocoagulation may provide the greatest durability of pain control.


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