Relationship of cervical spinal rootlets and the inferior vertebral notch

The anatomic features of cervical spinal rootlets from C5 to T1 and their relationships to the inferior vertebral notches were studied. Fifteen fresh cadavers were dissected and the cervical spinal cord and spinal rootlets were exposed by posterior total laminectomy. The dorsal rootlet entry zone of each spinal root was located proximal to the inferior vertebral notch, with an increasing distance from 15 mm at C5 to 28 mm at T1. The angle sustained by the rootlets to the cord decreased from 45 degrees to 89 degrees at C5 and to 23 degrees to 41 degrees at T1. Ventral rootlet exit zones shared similar arrangements and orientations, but they could not be exposed with posterior laminectomy only. Spinal rootlets of a particular cervical spinal segment may be found medial to the pedicles or through the intervertebral foramen one level above. They may be exposed by foraminotomy or partial excision of the pedicles. The inferior vertebral notch, which is the inferior border of the pedicle, is a reliable landmark for location of the rootlets. The information is useful for safe surgical manipulation and instrumentation around the pedicles, and when reimplantation of spinal nerve roots is considered for total brachial palsy.     

Subpial spinal evoked potentials in patients undergoing junctional dorsal root entry zone coagulation for pain relief

Summary Seven patients with complete avulsion of the brachial plexus underwent junctional coagulation lesions of the dorsal root entry zone (DREZ) for relief of intractable pain in the paralyzed arm. Intra-operative monitoring by recording spinal cord somatosensory evoked potentials (SEP) resulting from tibial nerve stimulation was done using subpial recording electrodes situated dorsal to the posterior median sulcus at the C4 and T2 segment. SEP on the normal side showed an initial positive wave and two negative waves followed by a group of high frequency waves of relatively high amplitude which continued into high frequency, low amplitude potentials. The conduction velocity of the fastest spinal evoked potential components were, on average, 86 m/s. Recordings from the side of avulsion revealed a steep positive potential of high amplitude which appeared in five patients prior to the creation of the DREZ lesion. This effect was assumed to be secondary to spinal cord damage caused by avulsion. During the DREZ coagulation the SEP from the unaffected side did not change. On the side of DREZ coagulation the velocity of the fastest fibres decreased. Four patients reported sensory deficits after the operation, which were transient in three. In one of these patients, the first two negative potentials disappeared. In the fourth patient, who had permanent sensory deficits, the positive steep potential appeared after generation of the lesion. Our results point to the usefulness of the subpial SEPs monitoring during microneurosurgical procedures on the spinal cord to provide further insight into evoked electrical activity of the normal and injured spinal cord, and to minimize post-operative neurological morbidity.     

Contributions of the fourth spinal nerve to the brachial plexus without prefixation

OBJECT: The intradural contributions of the C-4 nerve rootlets have not been previously evaluated for their connections to the brachial plexus. The authors undertook a cadaveric study to evaluate the C-4 contributions to the upper trunk of the brachial plexus. METHODS: The posterior cervical triangles from 60 adult cadavers were dissected. All specimens that were found to have extradural C-4 contributions to the upper trunk of the brachial plexus were excluded from further study. In specimens found to have no extradural C-4 contributions to the brachial plexus a C1-T1 laminectomy was performed. Observations were made of any neural communications between adjacent spinal rootlets, specifically between C-4 and C-5. RESULTS: Nine (15%) of the 60 sides were found to have extradural C-4 contributions to the upper trunk of the brachial plexus. These sides were excluded from further study. No specimen was found to have a postfixed brachial plexus. Of the remaining 51 sides, 11 (21.6%) were found to have intradural neural connections between C-4 and C-5 dorsal rootlets and 1 (1.96%) had a connection between the ventral roots of C-4 and C-5. Communications between these 2 adjacent dorsal cervical cord levels were of 3 types. Type I was a vertical communication between the more horizontally traveling dorsal roots. Type II was a forked communication between adjacent C-4 and C-5 dorsal rootlets. The Type III designation was applied to connections between ventral rootlets. Although communications were slightly more frequent on left sides, this did not reach statistical significance. CONCLUSIONS: In approximately 20% of normally composed brachial plexuses (those with extradural contributions from only C5-T1) we found intradural C4-5 neural connections. Such variations may lead to misinterpretation of spinal levels in pathological conditions of the spinal axis and should be considered in surgical procedures of this region, such as rhizotomy.     

Clinical and electrophysiological expression of deafferentation pain alleviated by dorsal root entry zone lesions in rats

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.     

Selective posterior rhizotomy in the dorsal root entry zone for treatment of hyperspasticity and pain in the hemiplegic upper limb

The authors report a series of 16 hemiplegic patients suffering from harmful spasticity in the upper limb and treated with selective posterior rhizotomy (SPR) in the dorsal root entry zone (DREZ). This severe spasticity was associated with irreducible abnormal postures in flexion in 11 cases and painful manifestations in 12. The method was introduced in 1972 on the basis of anatomical studies of the DREZ in humans, in which a topographical segregation of the root afferents, according to their anatomicofunctional destinations, has been shown. It consists of a DREZ microsurgical lesion 1 to 2 mm in depth and directed at a 45 degree angle, performed ventrolaterally in the posterolateral sulcus of the spinal cord and into the internal part of the Lissauer's tract. The procedure is carried out in each rootlet of the posterior roots considered to be responsible for the harmful spasticity. SPR interrupts selectively the (lateral) nociceptive and (central) myotactic afferent fibers connecting the motor neurons, while sparing most of the (medial) lemniscal fibers and the inhibitory circuitry of Lissauer's tract and the dorsal horn. The results were evaluated after a 1- to 12-year follow-up. There were no deaths and no general complications; in 1 case a loss of motility in the leg ipsilateral to the procedure occurred. The excess of spasticity was slightly diminished (2 cases), markedly reduced (9 cases), or totally abolished (5 cases), making possible an improvement in voluntary movements in 8 patients and at least a good passive mobilization in 7 further cases. In 1 case only, a marked tendency for spasticity to return was observed. Of the 12 patients with painful manifestations, 9 were completely relieved and 3 improved. These beneficial effects on both spasticity and pain led to a gain in functional status in 93% of cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Conus medullaris nerve root avulsions

The association of avulsive lesions and pain has been well established in avulsions of the brachial plexus from the cervical spinal cord, but avulsive lesions of the conus medullaris have not previously been recognized or documented by direct observation. Six patients with intractable lower-extremity pain due to avulsion of nerve roots from the conus medullaris were treated by thoracolumbar laminectomy and dorsal root entry zone (DREZ) lesions. Patients with avulsion of lumbosacral roots from the conus medullaris have a characteristic clinical presentation. They are usually young men who, as a result of a motorcycle accident, have suffered multiple pelvic or long-bone fractures or traumatic amputation of part of the lower extremity. Early in their course there is pain not directly attributable to the injured part. The pain is described as intense and burning, with episodic radiation and electric shock-like sensations in the injured or phantom limb. If the leg is intact, there is usually a dermatomal pattern to the distribution of the pain and neurological deficit. A myelogram often reveals a traumatic pseudomeningocele similar to those seen in the cervical region after avulsion of the brachial plexus. Surgical exploration of the conus medullaris usually reveals the extent of nerve root avulsion, and an appropriate DREZ operation can be performed.     

Microsurgical anatomy of the dorsal cervical rootlets and dorsal root entry zones

Summary Background. Detailed anatomical knowledge of the dorsal cervical rootlets and dorsal root entry zones (DREZ) is important for the diagnosis and treatment of cervical myeloradiculopathy and surgical management of pain. There are far fewer micro-anatomical studies of this area than gross anatomical studies. This study presents several anatomical points regarding the dorsal cervical rootlets and dorsal root entry zones.Method. Fifteen adult formalin-fixed cadaveric spines from C1 to T1 were used to observe the posterior structures. They were studied under the surgical microscope following en bloc laminectomy and foraminotomy. The morphological features of the dorsal root entry zones and dorsal rootlets were determined. The distance from the midline to the DREZ, the longitudinal length of the DREZ in the spinal canal, the length of the dorsal rootlets, the number of dorsal rootlets and the intersegmental anastomoses between the dorsal rootlets were measured.Findings. The distance from the midline to the DREZ ranged from 1.1 to 4.7mm. Longitudinal length of the dorsal rootlets ranged 4.3–17.7mm. The shortest length of the dorsal rootlets ranged between 5–28mm, and longest lengths of the dorsal rootlets ranged 6.8–30.3mm. The number of dorsal rootlets ranged from 2–13. Between the C2–T1 dorsal rootlets, 142 connections out of 30 intersegments were noted.Conclusions. The distance from the midline to the DREZ decreased in the lower cervical spine. The longest longitudinal length of the DREZ was at the C5 level. The length of the dorsal rootlets was increased in the lower cervical spine. The average number of dorsal rootlets tended to increase in the lower cervical spine. Anastomoses were most often found between C6–7 and C5–6 dorsal rootlets. Knowledge of the anatomical features of dorsal cervical rootlets and dorsal root entry zones is essential for a surgeon to avoid injuring the neural structures. This knowledge is a must not only to avoid complications but also for the success, safety and effectiveness of microsurgical operations of the pathological conditions like posterior myeloradiculopathy and pain treatment such as DREZ operations.     

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

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.     

神经干细胞对脊髓前角运动神经元保护作用的实验研究

目的观察臂丛根性撕脱伤后神经干细胞脊髓内移植对前角运动神经元的保护作用。方法取孕龄15～18d胎鼠脑组织，分离获得神经干细胞，在体外培养、扩增，并用5溴-2脱氧尿苷(BrdU)标记。取Wistar大鼠72只，随机分成实验组与对照组。先将C5～T1神经根撕脱，实验组把体外培养的神经干细胞移植于C5～T1脊髓节段前角附近，而对照组则用缓冲液替代神经干细胞。术后1、2、4、6、8、12周取脊髓标本进行组织学与免疫组化染色观察。结果臂丛根性撕脱伤后脊髓前角运动神经元数目明显减少，到术后12周时，对照组运动神经元减少达80．3％，实验组达63．7％。并且，各时间点实验组运动神经元的存活率均高于对照组。实验组脊髓前角内可见散在但仍保持未分化特征的神经干细胞。结论神经干细胞在植入臂丛根性撕脱伤的脊髓后能存活，并能明显减少前角运动神经元的继发性死亡。     

Biomechanical characteristics of spinal cord tissue--basis for the development of modifications of the DREZ (dorsal root entry zone) operation

Mechanical properties of the spinal cord tissue--biological basis for the development of the modality of the DREZ surgery lesioning technique Succesful treatment of the chronic neurogenic pain of spinal cord and cauda equina injury origin remains a significant management problem. The mechanism of this pain phenomenon has been shown to be related to neurochemical changes that lead to the state of hypereactivity of the second order dorsal horn neurons. The DREZ surgery (Dorsal Root Entry Zone lesion), designed to destroy anatomy structures involved in pain generating thus interrupting the neurogenic pain mechanism, as a causative procedure in treating this chronic pain, has been performed by using different technical modalities: Radiofrequency (RF) coagulation technic, Laser, Ultrasound and Microsurgical DREZotomy technic. The purpose of the study was to assess the possibility for the establishment of the lesioning technic based on the natural difference in the mechanical properties between the white and gray cord substance. We experimentally deteminated mechanical properties of the human cadaveric cord white versus gray tissue for the purpose of testing possibility of selective suction of the dorsal horn gray substance as a DREZ lesioning procedure. Based on the fact of the difference in tissue elasticity between white and gray cord substance we established a new and simple DREZ surgical lesioning technique that was tested on cadaver cord. For the purpose of testing and comparing the size and shape of the DREZ lesion axchieved the DREZ surgery has been performed on cadaver cord by employing selective dorsal horn suction as a lesioning method. After the procedure cadaver cord underwent histological fixation and analysis of the DREZ lesions achieved. Our result revealed that the white cord substance with longitudinal fiber structure had four time higher dynamical viscosity than gray substance of local neuronal network structure (150 PaS versus 37.5 PaS) that provided possibility for the safe and selective suction of the gray substance of the dorsal horn. Technic includes incision of the dorsolateral sulcus according to Sindous Microsurgical DREZotomy technic than suction under visual control of the dorsal horn gray matter using succer adopted from the lumbar puncture nidle. Operative experimental testing and hystological analysis confirmed expected size and shape of the DREZ lesion performed by dorsal horn suction as DREZ lesioning technique. The utility, selectivity and safety of this technic has been provided by the natural mechanical properties of the cord tissue itself. Application of the Dorsal horn suction as a DREZ lesioning in humans confirmed this technic as a safe and reliable DREZ lesioning method.     

Surgery in the dorsal root entry zone for treatment of chronic pain

Microsurgical drezotomy (MDT) consists of an incision and bipolar coagulations performed ventro-laterally in the Dorsal Root Entry Zone (DREZ) at the entrance of the rootlets into the dorso-lateral sulcus. The lesion is directed at 35 ventro-medially, and to 2-3 mm deep according to the pre-operative neurological status and the desired effects. MDT i) interrupts the small (nociceptive) fibres regrouped laterally and the large (myotatic) afferents which runs centrally, whilst sparing part of the large medial (lemniscal) fibres, ii) destroys the (excitatory) medial part of the Lissauer's tract, iii) and the cells of the dorsalmost layers of the dorsal horn, which can be the site of hyperactivity, as we were able to record in patients with deafferentation pain. Best indications are: i) well-localized cancer pain, such as Pancoast syndrome; ii) neuropathic pain due to: brachial plexus injuries; cauda equina and/or spinal cord lesions (especially for pain corresponding to segmental lesions); peripheral nerve injuries, amputation, herpes zoster - especially when the predominant component of pain is of the paroxysmal type and/or corresponds to provoked hyperalgesia/allodynia); iii) excess of spasticity, especially when associated with severe pain.     

The DREZ procedure: an update on technique

The DREZ operation was first done in 1975 on a patient with arm pain following a brachial plexus avulsion. Since then approximately 500 patients have undergone the DREZ procedure under our care for treatment of various pain syndromes including deafferentation pain, post-herpetic neuralgia, and post-paraplegia pain. We report several modifications in instrumentation and technique. Currently, we use two types of electrodes for lesion production. The first is the standard 0.25 mm diameter, thermocouple, temperature monitoring electrode which has a 2 mm long tip for introduction into the spinal cord. A second type, recently modified from the original, is used only for lesioning the nucleus caudalis in patients with trigeminal post-herpetic neuralgia. Its tip is 3 mm long with insulation along the first 1 mm. This allows lesioning of the caudalis nucleus while sparing the more superficial spinocerebellar tracts. We no longer lesion only the dorsal root entry zones at each root level but include all the contiguous substantia gelatinosa between roots. With lesions only 1 mm apart this greatly increases the number of lesions and decreases the incidence of incomplete postoperative pain relief. In patients undergoing caudalis lesioning, we make two rows of lesions, one above the other, from C2 to slightly above the obex. This prevents sparing of the facial midline with resultant residual pain. Finally, lesions are made by heating the electrode tip to 75 degrees C for exactly 15 sec, thus allowing for a more uniform lesion. With these modifications, we have a decreased incidence of incomplete pain relief as well as a decreased incidence of complications, especially in patients undergoing caudalis lesioning.     

Microsurgical DREZ-lesion in the treatment of deafferentation pain

The lesion of the dorsal root entry zone (DREZL) of the spinal cord, recently introduced by Nashold and performed with radiofrequency or with laser, may be carried out with a microsurgical technique. Since 1978 up 1982 we have treated a series of 12 patients suffering from Pancoast's syndrome with a C8-T2 selective posterior rhizotomy (SPR). It has been observed that every deafferentative aspect of the pain was completely relieved. Such effect on the deafferentative aspect of the pain was most probably due to a lesion on the perforating vessels feeding the posterior grey horn. The lesion of this structure was therefore ischemic and this operation had to be indicate for the treatment of such pain. A series of 8 patients, suffering from cancer pain projected to anaesthetic areas, and 2 patients with benign post-thoracotomy pain, underwent to microsurgical DREZ lesion. The relief from pain was complete and no complications concerning pyramidal or posterior pathways involvement was observed. Preliminary good results suggest that a more selective lesion is possible with the microsurgical DREZ. It should be interesting a comparison between more large series of microsurgical DREZL and the more tested radiofrequency lesion.     

Selective posterior rhizotomy at the posterior radiculomedullary junction in the treatment of hyperspasticity and pain in the lower limbs

The authors report a series of 53 bedridden patients having harmful spasticity in one (6) or both (47) lower limb(s) and treated with selective posterior rhizotomy (SPR) in the dorsal root entry zone (DREZ). This severe spasticity was associated with irreducible flexion contracture in 49 cases and hyperextension in 3 others. 37 of these patients also had painful manifestations. The method was introduced in 1972 on the basis of anatomical studies of the DREZ in humans which showed a topographical segregation of the afferent roots according to their anatomico-functional destinations. The technique consists of a 2 mm deep DREZ microsurgical cut directed at a 45 degree angle into the posterior lateral sulcus just ventral to DREZ and Lissauer's tract of the spinal cord. The procedure was carried out at each sensory rootlet considered to be responsible for the harmful spasticity and pain. SPR interrupts selectively the lateral nociceptive and central myotactic afferent fibers curving toward Lissauer's tract and the anterior spinal cord, while sparing most of the medial lemniscal fibers curving toward the dorsal columns, as well as the fibers of the inhibitory circuitry of Lissauer's tract and dorsal horn. The results were evaluated after a 1 to 14 year follow-up. Mild to severe complications occurred in 25 patients (47.1%) and were responsible for death in 5 (9.4%). Both spasticity and spasm were significantly decreased or completely eliminated in 75% and 88.2% respectively; when present, pain was relieved without a total suppression of sensation in 91.6%. These benefits-combined with complementary orthopedic surgery in 23 patients--resulted in either a complete resolution or marked reduction of the abnormal postures and articular limitations (85.2% complete and 96.75 marked reduction). Because of the extreme severity of the pre-operative neurological deficits in almost all the patients in this series, surgery improved voluntary movements with a significant functional benefit in only 5 cases and vesico-sphincter function in none. Thanks to its valuable effects on hyperspasticity and pain, SPR in the DREZ made it possible for these very disable patients to be more comfortable in bed and wheel-chair and it allowed effective nursing and kinesitherapy to be resumed.     

Microsurgical junctional DREZ coagulation for treatment of deafferentation pain syndromes

BACKGROUND: In the treatment of intractable deafferentation pain, different procedures in the DREZ have proved most effective. For most of the spot-like techniques special equipment is mandatory. In this study the technique and the results of junctional DREZ coagulation for treatment of different pain syndromes with the help of bipolar forceps is presented. METHODS: In 40 patients with intractable deafferentation pain syndromes a junctional DREZ coagulation lesion along the entire dorsolateral fissure of the involved spinal cord segments was made using bipolar forceps. Etiologies of the pain included avulsion of the brachial plexus (21 cases), postherpetic pain (4 cases), phantom pain (3 cases), peripheral nerve injury (3 cases), reflex sympathetic dystrophy (2 cases), spinal cord transsection (1 case), and syringomyelia (6 cases). RESULTS: Of 21 patients who underwent junctional DREZ surgery for pain because of brachial plexus avulsion 10 (47.6%) had complete, 7 (33.3%) excellent, 3 (14.3%) good, and 1 (4.7%) fair pain relief (follow-up 20 to 120 months). In the group of 19 patients (follow-up 6 to 84 months) with pain syndromes other than postavulsion pain we achieved excellent results in 10 cases (52.6%), good in 8 (42.1%) and no pain relief in 1 case (5.3%). Transient sensory neurological disturbances lasting up to 8 weeks were observed in 6 (15%) cases; permanent sensory and motor deficit in 1 (2.5%) case. CONCLUSIONS: Clinical results of junctional coagulation DREZ lesion for the treatment of deafferentation pain syndromes are promising. There is no need for special equipment for creating DREZ lesions. The lesions are precisely placed with only a bipolar electrode. Postoperative complications are rare and transient. We believe that the junctional coagulation includes the entire dorsolateral sulcus and DREZ structures important for deafferentation pain.     

椎管内修复臂丛神经损伤的解剖及临床应用研究

目的观察通过打开椎管找到残存的臂丛神经根并进行神经修复的可行性。方法甲醛溶液固定的成人尸体标本15具30侧，测量C5-T1，神经前根椎间孔段的直径、长度和有髓神经纤维计数。选择5例臂丛神经损伤患者，2例为椎孔处刀刺伤，3例为闭合性创伤。自受伤到椎管内探查的时间为3-6个月，平均4个月。CTM显示部分已损伤的神经根其椎管内神经前后根仍存在，而锁骨上臂丛神经探查在椎间孔外找不到相应的具有正常结构的神经根近端，通过打开椎管将椎管内残存的神经根用腓肠神经桥接进行神经修复。结果C5-T1，神经前根的有髓神经纤维数目为4000-6000根，椎间孔段的长度为11～14mm，外径为1．2～1．5mm。5例患者的椎管内均找到了具有正常结构的神经根近端，其中C5神经根3例，C5、C6神经根1例，C7神经根1例。C5修复肩胛上神经和C5神经远端各1例，C5修复正中神经内侧头1例，C7修复内侧束1例，C5、C6分别修复上干后股、肌皮神经1例。术后随访38--46个月，平均42个月。5例患者其修复神经所支配肌肉的肌力分别达3-4级。结论对于神经根在椎间孔处断裂的臂丛神经损伤，可通过打开椎管找到损伤神经根的近端，为臂丛神经根性损伤的修复提供理想的动力神经源，有利于臂丛神经治疗效果的提高。     

臂丛损伤神经干细胞脊髓前角移植后分化情况及对运动神经元的保护作用

目的观察臂丛根性撕脱伤后将脊髓源性神经干细胞(neuralstemcell,NSC)移植于脊髓前角后的存活、分化情况及对脊髓前角受损运动神经元的保护作用。方法取新生鼠脊髓,分离获得脊髓源性神经干细胞,体外培养、扩增、鉴定、5溴2-脱氧尿苷(BrdU)标记。取SD大鼠60只,随机分成实验组、对照组和单纯组。从后路制备C5~C7臂丛神经根性撕脱伤动物模型。实验组移植神经干细胞于C6脊髓前角,对照组移植灭活神经干细胞,单纯组不作移植。术后1、2、4、8、12周取脊髓标本进行组织学与免疫组化染色观察。结果神经干细胞移植入脊髓后能存活、分化;臂丛根性撕脱伤后脊髓前角运动神经元数目明显减少;实验组神经干细胞移植后2、4、8、12周各个时间点运动神经元的存活率均高于对照组和单纯组。结论臂丛根性撕脱伤脊髓前角神经干细胞移植后能存活并分化为神经元及星型胶质细胞,脊髓源性神经干细胞移植能明显减少前角运动神经元的继发性死亡,对脊髓前角受损运动神经元有保护作用。     

Spinal repair of ventral root avulsions after brachial plexus injuries: Towards new surgical strategies?

BACKGROUND AND PURPOSE: Avulsion of nerve roots associated with the brachial plexus results in dramatic lesions with a prognosis which remains poor to this day. These lesions are considered as involving the central nervous system and therefore not amenable to surgical repair. However, the results of many experiments in animals have shown that if continuity can be re-established between the cervical cord and a denervated muscle or the distal end of its nerve, spinal motor neurons can regrow into a peripheral nerve graft, ultimately leading to the restoration of functional contraction. A preliminary experiment was attempted in humans but the outcomes were modest. In light of all the controversy raised by these preliminary results, we sought to demonstrate that axons can indeed regrow after intra-spinal re-implantation of an avulsed nerve root, that such re-growth can lead to the recovery of function, and that the phenomenon should be focused upon for the development of new surgical modalities to correct this serious condition. METHODS: We first studied the anatomy of the intradural compartment and developed a posterior approach to the brachial plexus for implantation in the ventrolateral aspect of the spinal cord. The fact that the white matter of the central nervous system is not propitious for axon re-growth led us to investigate the advantages of directly implanting the graft in the ventrolateral sulcus of the spinal cord in order that it might reach the anterior horn of the gray matter. In order to do this, we developed in the laboratory a direct surgical approach to the anterior horn, an approach which we subsequently used in patients with avulsion of multiple nerve roots at different levels. RESULTS AND CONCLUSIONS: Intraspinal re-implantation did not induce any neurological complications and co-contraction of different muscles was not observed in any of the patients. Partial re-innervation was obtained of the triceps, biceps and deltoid muscles, the exact pattern depending on the type of lesion and the type of graft. Treatment with neurotrophic factors represents a parallel line of research which might well help improve outcomes in spinal surgery to repair nerve root avulsion.     

Effects of dorsal root entry zone lesion on spinal cord potentials evoked by segmental,ascending and descending volleys

Summary The spinal cord potentials (SCPs) were recorded from the dorsal root entry zone (DREZ) and posterior epidural space in patients before and after dorsal root entry zone lesion (DREZL) during general anaesthesia. The SCPs from the DREZ activated by segmental, ascending and descending volleys were basically the same in fundamental waveform as those recorded from the posterior epidural space. Segmentally activated slow negative (N₁) wave, reflecting synchronized activities of dorsal horn neurones, and positive (P₂) wave, thought to indicate primary afferent depolarization, were affected by DREZL in all 4 subjects tested, even by contralateral stimulation, suggesting that these components of the segmental SCPs in man partly reflect the activities of the contralateral dorsal horn. The spike-like potentials activated by ascending volleys were not affected by DREZL, while the subsequent slow components were decreased in the lesioned level. This may indicate that ascending spinal cord tracts are not affected by the operation, and suggests that the origin of the slow components by ascending volleys lies at least in part in the segmental dorsal horn. The slow negative and positive components, recorded at a remote segment from DREZL, in response to the descending volleys, were augmented after DREZL, suggesting that activation of ascending or descending inhibition through a feedback loop via the supraspinal structures might occur at least transiently following DREZL. All components of the SCPs activated by descending volleys were decreased or disappeared in recording from the lesioned level, as expected. Thus, intra-operative recording of the SCPs during DREZL might be beneficial for monitoring and studying human spinal cord function.     

Microsurgical DREZotomy (MDT) for pain,spasticity, and hyperactive bladder: A 20-year experience

Summary Since 1972, micro-DREZ-tomy has been performed in 367 patients: with cancer pain in 81, neurogenic pain in 139, hyperspasticity in 135, and hyperactive neurogenic bladder in 12.MDT consists of an incision and bipolar coagulations performed ventro-laterally in the Dorsal Root Entry Zone (DREZ) at the entrance of the rootlets into the dorso-lateral sulcus. The lesion is directed at 45 ° ventro-medially, and 2–3 mm deep according to the pre-operative neurological status and the desired effects. MDT 1 ° interrupts the small (nociceptive) fibres regrouped laterally and the large (myotatic) afferents which runs centrally, whilst sparing part of the large medial (lemniscal) fibres, 2 ° destroys the (excitatory) medial part of the Lissauer's tract, 3 ° and the cells of the dorsalmost layers of the dorsal horn, which can be the site of hyperactivity, as we were able to record in patients with deafferentation pain.Best indications are: 1) well localized cancer pain, such as Pancoast syndrome; 2) neuropathic pain due to: brachial plexus injuries, cauda equina and/or spinal cord lesions especially for pain corresponding to segmental lesions, peripheral nerve injuries — amputation — herpes zoster — (especially when the predominant component of pain is of the paroxysmal type and/or corresponds to provoked hyperalgesia/allodynia); 3) excess of spasticity and 4) neurogenic hyperactive bladder.