Skin and not dorsal root stimulation reduces hypertonus in thoracic motor complete spinal cord injury: a single case report

On demand and localized treatment for excessive muscle tone after spinal cord injury (SCI) is currently not available. Here, we examine the reduction in leg hypertonus in a person with mid-thoracic, motor complete SCI using a commercial transcutaneous electrical stimulator (TES) applied at 50 or 150 Hz to the lower back and the possible mechanisms producing this bilateral reduction in leg tone. Hypertonus of knee extensors without and during TES, with both cathode (T11-L2) and anode (L3-L5) placed over the spinal column (midline, MID) or 10 cm to the left of midline (lateral, LAT) to only active underlying skin and muscle afferents, was simultaneously measured in both legs with the pendulum test. Spinal reflexes mediated by proprioceptive (H-reflex) and cutaneomuscular reflex (CMR) afferents were examined in the right leg opposite to the applied LAT TES. Hypertonus disappeared in both legs but only during thoracolumbar TES, and even during LAT TES. The marked reduction in tone was reflected in the greater distance both lower legs first dropped to after being released from a fully extended position, increasing by 172.8% and 94.2% during MID and LAT TES, respectively, compared with without TES. Both MID and LAT (left) TES increased H-reflexes but decreased the first burst, and lengthened the onset of subsequent bursts, in the cutaneomuscular reflex of the right leg. Thoracolumbar TES is a promising method to decrease leg hypertonus in chronic, motor complete SCI without activating spinal cord structures and may work by facilitating proprioceptive inputs that activate excitatory interneurons with bilateral projections that in turn recruit recurrent inhibitory neurons.NEW & NOTEWORTHY We present proof of concept that surface stimulation of the lower back can reduce severe leg hypertonus in a participant with motor complete, thoracic spinal cord injury (SCI) but only during the applied stimulation. We propose that activation of skin and muscle afferents from thoracolumbar transcutaneous electrical stimulation (TES) may recruit excitatory spinal interneurons with bilateral projections that in turn recruit recurrent inhibitory networks to provide on demand suppression of ongoing involuntary motoneuron activity.

Long-Term Suppression of c-Jun and nNOS Preserves Ultrastructural Features of Lower Motor Neurons and Forelimb Function after Brachial Plexus Roots Avulsion

Brachial plexus root avulsions cause debilitating upper limb paralysis. Short-term neuroprotective treatments have reported preservation of motor neurons and function in model animals while reports of long-term benefits of such treatments are scarce, especially the morphological sequelae. This morphological study investigated the long-term suppression of c-Jun- and neuronal nitric oxide synthase (nNOS) (neuroprotective treatments for one month) on the motor neuron survival, ultrastructural features of lower motor neurons, and forelimb function at six months after brachial plexus roots avulsion. Neuroprotective treatments reduced oxidative stress and preserved ventral horn motor neurons at the end of the 28-day treatment period relative to vehicle treated ones. Motor neuron sparing was associated with suppression of c-Jun, nNOS, and pro-apoptotic proteins Bim and caspases at this time point. Following 6 months of survival, neutral red staining revealed a significant loss of most of the motor neurons and ventral horn atrophy in the avulsed C6, 7, and 8 cervical segments among the vehicle-treated rats (n = 4). However, rats that received neuroprotective treatments c-Jun JNK inhibitor, SP600125 (n = 4) and a selective inhibitor of nNOS, 7-nitroindazole (n = 4), retained over half of their motor neurons in the ipsilateral avulsed side compared. Myelinated axons in the avulsed ventral horns of vehicle-treated rats were smaller but numerous compared to the intact contralateral ventral horns or neuroprotective-treated groups. In the neuroprotective treatment groups, there was the preservation of myelin thickness around large-caliber axons. Ultrastructural evaluation also confirmed the preservation of organelles including mitochondria and synapses in the two groups that received neuroprotective treatments compared with vehicle controls. Also, forelimb functional evaluation demonstrated that neuroprotective treatments improved functional abilities in the rats. In conclusion, neuroprotective treatments aimed at suppressing degenerative c-Jun and nNOS attenuated apoptosis, provided long-term preservation of motor neurons, their organelles, ventral horn size, and forelimb function.

The eight cervical nerve and its role in tinnitus

INTRODUCTION

The eight cervical nerve might be a source of input to the auditory system.

OBJECTIVES

The object was to assess the efficacy of infiltration of the eight cervical nerve root for treating tinnitus patients and to find indicators for a successful result.

DESIGN

Retrospective cohort study. Subjects were 79 tinnitus patients visiting our clinic in a three-year period and who were treated with infiltration of the eight cervical nerve root.

RESULTS

Twenty-six percent of the tinnitus patients had a reduction of their tinnitus following an infiltration of the eight cervical nerve root. Most of the successfully treated patients rated the effect of therapy as a moderate reduction of 25% to 50%. Fifty percent of the successful treated patients still had benefit at 6.6 months. In 5% of the patients, their tinnitus was aggravated after the infiltration of the eight cervical nerve roots. Patients with a hearing loss at 500 Hz that exceed the hearing loss at 2 kHZ responded the most to infiltration of the eight cervical nerve.

CONCLUSION

Infiltration of the eight cervical nerve root reduced the intensity of tinnitus in 26% of the cohort of 79 tinnitus patients with a moderate to good effect. This therapy for tinnitus patients' needs to be considered, especially in those with a hearing loss at 500 Hz that exceed the hearing loss at 2 kHZ.

Upper Cervical Nerves Can Induce Tinnitus

INTRODUCTION

Treating cervical spine disorders can result in a reduction of tinnitus.

OBJECTIVES

The object of the study was to ascertain the benefit of therapy of the third and fourth cervical nerves in reducing tinnitus and to assess parameters indicating a long-term relief.

DESIGN

Subjects were 37 tinnitus patients who were treated with infiltration of the third and fourth cervical nerves. Clinical data form these patients were reviewed retrospectively. An independent perceiver evaluated the long-term effect of the therapy by telephone interview.

RESULTS

In a group of tinnitus patients, 19% of the patients reported less tinnitus after therapy of the third and fourth cervical nerves. Most of the patients had a moderate reduction of 25% to 50%. At 3.8 months, 50% of the successful treated patients still had a positive effect. No adverse events of the procedure were observed. The combination of an evident anterior spur at the third cervical vertebrae together with less hearing at 2 kHz indicate patients who responded the best to therapy of the third and fourth cervical nerves.

CONCLUSIONS

Treating cervical spine disorders can reduce tinnitus. In a group of tinnitus patients, 19% of the patients had less tinnitus after therapy of the C3 and C4. Screening of tinnitus patients is needed for the proper selection of the ones who could benefit from a somatic approach. In our study, the combination of an evident anterior spur at the third cervical vertebrae together with less hearing at 2 kHz indicate patients who responded the best following therapy of the C3 and C4.

Multimodal intraoperative monitoring during surgical correction of scoliosis to avoid neurologic damage

The purpose of this study was to evaluate the application of multimodal intraoperative monitoring (MIOM) system in patients with congenital scoliosis (CS) and adolescent idiopathic scoliosis (AIS).Twelve patients who underwent posterior surgical correction of scoliosis for CS and AIS from June 2014 to July 2018 were enrolled in this study. During the operation, we monitored the functional status of the spinal cord by MIOM. An abnormal somatosensory evoked potential was defined as a prolonged latency of more than 10% or a peak-to-peak amplitude decline of more than 50% when compared to baseline. An abnormal transcranial motor evoked potential (TcMEP) was defined as a TcMEP amplitude decrease of more than 50%. A normal triggered electromyography response, which presented with the absence of an electrical response on stimulation at 8.2 mA, indicated that the pedicle screw was not in contact with the spinal cord or nerve root.A total of 12 patients underwent MIOM surgery, of which 9 patients with negative MIOM had no significant deterioration of neurological function postoperatively, and exhibited satisfactory surgical correction of scoliosis during follow-ups. However, the remaining 3 patients suffered from MIOM events, 2 patients had normal neurological function, and 1 patient had deteriorated neurological function postoperatively.Using MIOM in CS and AIS surgery could promptly detect iatrogenic neurological injury at the early stage. Therefore, rapid response by appropriate intraoperative interventions can be taken to minimize the injury. Besides, stable MIOM recordings encourage surgeons to correct scoliosis even when the Cobb angle of scoliosis was extremely large.

Theory of Bowstring Disease: Diagnosis and Treatment Bowstring Disease

Bowstring disease (BSD) is a new classification of spine disease caused by axial stretched lesion on nerve roots and the spinal cord, which is differentiated from disc herniation and canal stenosis in that it is caused by nerve compression lesions. BSD could be caused by mismatched growth rates between the spine and nerve roots (the juvenile type), or by imbalanced degenerative rates between the spine column and nerve roots (degenerative type). Here, we propose that there are several self-adjust mechanisms to relieve axial nerve tension: (i) nerve growth; (ii) posture adjustment and low back pain; (iii) autogenous degeneration of intervertebral disc; and (iv) idiopathic and degenerative scoliosis. Iatrogenic lesions could also result in BSD, which could be presented as adjacent segment degeneration, leading to adding-on effects and other neurological symptoms. The diagnosis criteria are proposed based on symptoms, physical examination, and radiological presentations. To remove axial tension on nerve roots, lumbar surgery should aim to restore the coordination of spine and cord units. Capsule surgery, shortening the spine column, could decompress cord and nerve roots 3-dimensionally.

Electroacupuncture Direct to Spinal Nerves as an Alternative to Selective Spinal Nerve Block in Patients with Radicular Sciatica – a Cohort Study

We applied electroacupuncture to the spinal nerve root by inserting needles under x ray imaging in three cases with radicular sciatica, as a non-pharmacological substitute for lumbar spinal nerve block. In all three cases, symptoms were markedly reduced immediately after electroacupuncture to the spinal nerve root. The sustained effect was noticeably longer than that of spinal nerve blocks previously performed, in two out of the three cases. We suggest that descending inhibitory control, inhibitory control at the spinal level, inhibition of potential activity by hyperpolarisation of nerve endings, or changes in nerve blood flow may be involved in the mechanism of the effect of electroacupuncture to the spinal nerve root. These results suggest that electroacupuncture to the spinal nerve root may be superior to lumbar spinal nerve block when it is applied appropriately in certain cases of radicular sciatica, taking into consideration patient age, severity of symptoms and duration of the disorder.

EMG characteristics of the external anal sphincter guarding reflex and effects of a unilateral ventral root avulsion injury in rhesus macaques ( Macaca mulatta)

The external anal sphincter (EAS) is important for the maintenance of bowel continence and may be compromised by a variety of neuropathic conditions. However, large animal models for the study of EAS functions have been sparse. The EAS guarding reflex was examined by electromyography (EMG) in neurologically intact rhesus macaques ( n = 6) and at 4-6 wk after a unilateral EAS denervation from an L6-S3 ventral root avulsion (VRA) injury ( n = 6). Baseline EAS EMG recordings were quiescent in all subjects, and evoked responses showed an initial large-amplitude EMG activity, which gradually returned to baseline within 1-2 min. At 4-6 wk postoperatively, the EAS guarding reflex showed a significantly reduced EMG response duration of 47 ± 15 s and area under the curve (AUC) of 0.198 ± 0.097 mV·s compared with the corresponding evoked EAS EMG duration of 102 ± 19 s and AUC of 0.803 ± 0.225 mV·s ( P < 0.05) in the control group. Detailed time- and frequency-domain analysis of the evoked EAS EMG responses for the first 40 s showed no difference between groups for the maximum amplitude but a significant decrease for the mean amplitude across the study period and an early AUC reduction for the first 10 s in the VRA injury group. Time-frequency analysis and power spectrum plots indicated decreased intensity and a narrower midrange of frequencies in the VRA injury group. We conclude that the EAS guarding reflex in rhesus macaques shows characteristic EMG features in control subjects and signs of partial target denervation after a unilateral L6-S3 VRA injury. NEW & NOTEWORTHY The external anal sphincter guarding reflex showed initial large-amplitude peaks and a gradual return to a quiescent baseline after a rectal probe stimulus in rhesus macaques. At 4-6 wk after a unilateral ventral root avulsion (VRA) injury, the electromyography duration, mean amplitude, and area under the curve measurements were decreased. Time-frequency analysis and power spectrum plots indicated decreased intensity and a narrowed midrange of frequencies in the VRA injury cohort.

Origins of antidromic activity in sensory afferent fibers and neurogenic inflammation

Neurogenic inflammation results from the release of biologically active agents from the peripheral primary afferent terminal. This release reflects the presence of releasable pools of active product and depolarization-exocytotic coupling mechanisms in the distal afferent terminal and serves to alter the physiologic function of innervated organ systems ranging from the skin and meninges to muscle, bone, and viscera. Aside from direct stimulation, this biologically important release from the peripheral afferent terminal can be initiated by antidromic activity arising from five anatomically distinct points of origin: (i) afferent collaterals at the peripheral-target organ level, (ii) afferent collaterals arising proximal to the target organ, (iii) from mid-axon where afferents lacking myelin sheaths (C fibers and others following demyelinating injuries) may display crosstalk and respond to local irritation, (iv) the dorsal root ganglion itself, and (v) the central terminals of the afferent in the dorsal horn where local circuits and bulbospinal projections can initiate the so-called dorsal root reflexes, i.e., antidromic traffic in the sensory afferent.

Neuroinflammation of the spinal cord and nerve roots in chronic radicular pain patients

Numerous preclinical studies support the role of spinal neuroimmune activation in the pathogenesis of chronic pain, and targeting glia (eg, microglia/astrocyte)- or macrophage-mediated neuroinflammatory responses effectively prevents or reverses the establishment of persistent nocifensive behaviors in laboratory animals. However, thus far, the translation of those findings into novel treatments for clinical use has been hindered by the scarcity of data supporting the role of neuroinflammation in human pain. Here, we show that patients suffering from a common chronic pain disorder (lumbar radiculopathy), compared with healthy volunteers, exhibit elevated levels of the neuroinflammation marker 18 kDa translocator protein, in both the neuroforamina (containing dorsal root ganglion and nerve roots) and spinal cord. These elevations demonstrated a pattern of spatial specificity correlating with the patients' clinical presentation, as they were observed in the neuroforamen ipsilateral to the symptomatic leg (compared with both contralateral neuroforamen in the same patients as well as to healthy controls) and in the most caudal spinal cord segments, which are known to process sensory information from the lumbosacral nerve roots affected in these patients (compared with more superior segments). Furthermore, the neuroforaminal translocator protein signal was associated with responses to fluoroscopy-guided epidural steroid injections, supporting its role as an imaging marker of neuroinflammation, and highlighting the clinical significance of these observations. These results implicate immunoactivation at multiple levels of the nervous system as a potentially important and clinically relevant mechanism in human radicular pain, and suggest that therapies targeting immune cell activation may be beneficial for chronic pain patients.

Posterior Branches of Lumbar Spinal Nerves - Part III: Spinal Dorsal Ramus Mediated Back Pain - Pathomechanism, Symptomatology and Diagnostic Work-up

Spinal Dorsal Ramus Mediated Back Pain is the second most frequently described condition (the first one being Lumbar Facet Syndrome) originating from pathology involving posterior branches of lumbar spinal nerves. Spinal Dorsal Ramus Mediated Back Pain was described as "thoracolumbar junction syndrome" by Maigne in 1989. As a rule, Spinal Dorsal Ramus Mediated Back Pain presents unilaterally within posterior branches at the levels Th11-12 and L1-2. The pain is triggered by extension and/or rotation. Typical symptoms include pain that may radiate towards the gluteal area and posterior iliac crest and does not cross the body midline. Clinical symptoms may correlate with the area supplied by the whole spinal nerve of the given segment, including both the posterior and anterior branch. For this reason, patients may report not only low back pain, but also pseudovisceral pain in the hypogastric area, false sciatic neuralgia, tenderness of the pubic symphysis and hypersensitivity of the intestines. The above symptoms may lead to diagnostic difficulties. Diagnostic work-up may benefit from performance of the Kibler Fold Test to determine sensitivity of the tissues surrounding the iliac crest. Patients with Spinal Dorsal Ramus Mediated Back Pain respond well to manual manipulative techniques if these are delivered in a technically correct manner and address the appropriate segment. A recommended approach for patients with absolute contraindications to manipulation, i.e. advanced osteoporosis or osteogenesis imperfecta, is a block of the po-sterior branch of the spinal nerve involved.

Clinically relevant concentration of pregabalin has no acute inhibitory effect on excitation of dorsal horn neurons under normal or neuropathic pain conditions: An intracellular calcium-imaging study in spinal cord slices from adult rats

Pregabalin is thought to exert its therapeutic effect in neuropathic pain via binding to α2δ-1 subunits of voltage-gated calcium (Ca(2+)) channels. However, the exact analgesic mechanism after its binding to α2δ-1 subunits remains largely unknown. Whether a clinical concentration of pregabalin (≈10μM) can cause acute inhibition of dorsal horn neurons in the spinal cord is controversial. To address this issue, we undertook intracellular Ca(2+)-imaging studies using spinal cord slices with an intact attached L5 dorsal root, and examined if pregabalin acutely inhibits the primary afferent stimulation-evoked excitation of dorsal horn neurons in normal rats and in rats with streptozotocin-induced painful diabetic neuropathy. Under normal conditions, stimulation of a dorsal root evoked Ca(2+) signals predominantly in the superficial dorsal horn. Clinically relevant (10μM) and a very high concentration of pregabalin (100μM) did not affect the intensity or spread of dorsal root stimulation-evoked Ca(2+) signals, whereas an extremely high dose of pregabalin (300μM) slightly but significantly attenuated Ca(2+) signals in normal rats and in diabetic neuropathic (DN) rats. There was no difference between normal rats and DN rats with regard to the extent of signal attenuation at all concentrations tested. These results suggest that the activity of dorsal horn neurons in the spinal cord is not inhibited acutely by clinical doses of pregabalin under normal or DN conditions. It is very unlikely that an acute inhibitory action in the dorsal horn is the main analgesic mechanism of pregabalin in neuropathic pain states.

[Acupuncture combined with moxibustion plaster for nerve-root type cervical spondylosis]

OBJECTIVE

To compare the clinical efficacy differences between acupuncture combined with moxi-bustion plaster and electroacupuncture (EA) for nerve-root type cervical spondylosis.

METHODS

A total of 60 casesof nerve-root type cervical spondylosis were randomly divided into a plaster group and an EA group, 30 cases ineach one. Patients in the plaster group were treated with regular acupuncture at Jiaji(EX-B 2) points and ashipoints, combined with moxibustion plaster at Gaohuang (BL 43); patients in the EA group were treated with EAat identical acupoints as plaster group. The treatment was given once a day, and 5 days were taken as one course;there was an interval of 2 days between courses and totally 2 courses were performed. The pain questionnaires andquantitative score of signs and symptoms were observed before and after treatment in the two groups. The clinicalefficacy of the two groups was compared.

RESULTS

The total effective rate was 96. 7% (29/30) in the plastergroup, which was not significantly different from 93. 3% (28/30) in the EA group (P>0. 05). After treatment,PRI, VAS and PPI were all reduced in the two groups (all P<C. 01), which were also significantly different be-tween the two groups (all P<0. 05). The quantitative score of each sign and symptom was increased after treat-ment in the two groups (all P<0. 01). Compared with the EA group, the work and life ability, function, feelingand strength of hand were increased in the plaster groups (all P<. 05). Pain score of neck and shoulder aftertreatment in the EA group was higher than the plaster group (all P<0. 05).

CONCLUSION

Acupuncture combinedwith moxibustion plaster and EA both have superior clinical efficacy for nerve-root type cervical spondylosis; EA issuperior to acupuncture combined with moxibustion plaster on relieving pain, while acupuncture combined withmoxibustion plaster is superior to EA on improving life quality, muscle strength and feeling.

[Pathology of the Peripheral Nervous System in Guillain-Barré Syndrome]

Guillain-Barré syndrome is composed of two distinct clinicopathological entities: acute inflammatory demyelinating polyradiculoneuropathy (AIDP), and acute motor or motor and sensory axonal neuropathy (AMAN and AMSAN). AIDP is characterized by the patchily distributed demyelinative foci throughout the peripheral nervous system (PNS), whereas in AMAN/AMSAN primary axonal degeneration is observed in the PNS, particularly accentuated at the spinal nerve roots. The aim of this article is to provide an overview of previous findings regarding GBS pathology and thus, to elucidate the pathomechanisms of this life-threatening disorder. The most critical cause for AIDP may be the autoimmune attack on the Schwann cell membrane wrapping the myelinated nerve fibers, and that in AMAN/AMSAN may be an antibody-mediated attack on the axolemma at the nodes of Ranvier.

Intraoperative Spinal Cord and Nerve Root Monitoring: A Hospital Survey and Review

Intraoperative monitoring (IOM) of spinal cord and nerve root injury through somatosensory evoked potentials (SSEP), transcranial motor evoked potentials (TcMEP), spontaneous electromyography (sEMG), and triggered electromyography (tEMG) modalities is vital during spinal surgery. However, there are currently no practice guidelines or practice patterns for the utilization of unimodal and multimodal IOM for specific surgeries. This study reviews IOM modalities and documents practice patterns of spine surgeons at our single-center tertiary hospital about their use of various IOM modalities on 23 spinal procedures. As different intraoperative monitoring modalities have shown to have different sensitivities and specificities, devising practice guidelines for IOM utilization in specific spinal procedures should be considered.

[Incidences of C5 nerve palsy after multi-segmental cervical decompression through different approaches]

OBJECTIVE

To investigate the incidence of C5 nerve root palsy after multi-segmental cervical decompression through different approaches.

METHODS

This study was conducted among 375 patients undergoing multi-segmental cervical decompression in anterior corpectomy and fusion fixation, anterior cervical corpectomy and fusion fixation + posterior decompression and fusion fixation, posterior cervical laminectomy decompression, fusion and internal fixation, and posterior laminoplasty and fusion groups. The exclusion criteria included lack of follow-up data, spinal cord injury preventing preoperative or postoperative motor testing, or surgery not involving the C5 level. The incidence of C5 palsy was determined and the potential risk factors C5 palsy were analyzed including age, sex, revision surgery, preoperative weakness, diabetes, smoking, number of levels decompressed, and a history of previous upper extremity surgery.

RESULTS

Of the 375 patients, 60 patients were excluded and the data of 315 patients were analyzed, including 146 women and 169 men with a mean age of 57.7 years (range 39-72 years). The overall incidence of C5 nerve palsy was 6.03% (19/315) in these patients; in the subgroups receiving different surgeries, the incidence was 8.62% in the cervical road laminectomy and fusion fixation group, 7.79% in the anterior cervical corpectomy and fusion fixation + posterior decompression and fusion and internal fixation, 4.68% in the anterior corpectomy and fusion fixation group, and 3.85% in the posterior laminoplasty and fusion group. No significant difference was found in the incidences among the subgroups, but men were more likely than women to develop cervical nerve root palsy (8.28% vs 3.42%, P<0.05).

CONCLUSION

The overall incidence of C5 nerve palsy following postoperative cervical spinal decompression was 6.03% in our cohort. The incidence of C5 nerve palsy did not differ significantly following different cervical decompression surgeries, but the incidence was the highest in the posterior cervical laminectomy and fusion and internal fixation group.

Characterization of the discrepancies between four-dimensional phase-contrast magnetic resonance imaging and in-silico simulations of cerebrospinal fluid dynamics

The purpose of the present study was to compare subject-specific magnetic resonance imaging (MRI)-based computational fluid dynamics (CFD) simulations with time-resolved three-directional (3D) velocity-encoded phase-contrast MRI (4D PCMRI) measurements of the cerebrospinal fluid (CSF) velocity field in the cervical spinal subarachnoid space (SSS). Three-dimensional models of the cervical SSS were constructed based on MRI image segmentation and anatomical measurements for a healthy subject and patient with Chiari I malformation. CFD was used to simulate the CSF motion and compared to the 4D PCMRI measurements. Four-dimensional PCMRI measurements had much greater CSF velocities compared to CFD simulations (1.4 to 5.6× greater). Four-dimensional PCMRI and CFD both showed anterior and anterolateral dominance of CSF velocities, although this flow feature was more pronounced in 4D PCMRI measurements compared to CFD. CSF flow jets were present near the nerve rootlets and denticulate ligaments (NRDL) in the CFD simulation. Flow jets were visible in the 4D PCMRI measurements, although they were not clearly attributable to nerve rootlets. Inclusion of spinal cord NRDL in the cervical SSS does not fully explain the differences between velocities obtained from 4D PCMRI measurements and CFD simulations.

Ultrasound of the peripheral nerves in systemic vasculitic neuropathies

INTRODUCTION

Ultrasound of the peripheral nerves (PNUS) can be used to visualize nerve pathologies in polyneuropathies (PNP). The aim of this study was to investigate, whether PNUS provides additional information in patients with proven systemic vasculitic neuropathies (VN).

MATERIAL AND METHODS

Systematic ultrasound measurements of several peripheral nerves, the vagal nerve and the 6th cervical nerve root were performed in 14 patients and 22 healthy controls. Nerve conduction studies of the corresponding nerves were undertaken. Finally, the measured results were compared to a study population of demyelinating immune-mediated and axonal neuropathies.

RESULTS

Patients with VN displayed significant smaller amplitudes of compound muscle action potentials (CMAP) (p<0.05) and sensory nerve action potentials (SNAP) compared to healthy controls, while conduction velocity did not differ between groups. The mean nerve cross-sectional areas (CSA) were increased in several peripheral nerves compared to the controls, most prominent in tibial and fibular nerve (p<0.01). PNUS revealed nerve enlargement in most of the clinically and electrophysiologically affected nerves (22 out of 31) in VN. Nerve enlargement was more often seen in vasculitic neuropathies than in other axonal neuropathies, but significantly rarer than in demyelinating neuropathies.

CONCLUSION

Focal CSA enlargement in one or more nerves in electrophysiologically axonal neuropathies can be a hint for VN and thus facilitate diagnostic and therapeutic procedures.

Vascular endothelial growth factor gene therapy improves nerve regeneration in a model of obstetric brachial plexus palsy

The treatment of obstetric brachial plexus palsy has been limited to conservative therapies and surgical reconstruction of peripheral nerves. In addition to the damage of the brachial plexus itself, it also leads to a loss of the corresponding motoneurons in the spinal cord, which raises the need for supportive strategies that take the participation of the central nervous system into account. Based on the protective and regenerative effects of VEGF on neural tissue, our aim was to analyse the effect on nerve regeneration by adenoviral gene transfer of vascular endothelial growth factor (VEGF) in postpartum nerve injury of the brachial plexus in rats. In the present study, we induced a selective crush injury to the left spinal roots C5 and C6 in 18 rats within 24 hours after birth and examined the effect of VEGF-gene therapy on nerve regeneration. For gene transduction an adenoviral vector encoding for VEGF165 (AdCMV.VEGF165) was used. In a period of 11 weeks, starting 3 weeks post-operatively, functional regeneration was assessed weekly by behavioural analysis and force measurement of the upper limb. Morphometric evaluation was carried out 8 months post-operatively and consisted of a histological examination of the deltoid muscle and the brachial plexus according to defined criteria of degeneration. In addition, atrophy of the deltoid muscle was evaluated by weight determination comparing the left with the right side. VEGF expression in the brachial plexus was quantified by an enzyme-linked immunosorbent assay (ELISA). Furthermore the motoneurons of the spinal cord segment C5 were counted comparing the left with the right side. On the functional level, VEGF-treated animals showed faster nerve regeneration. It was found less degeneration and smaller mass reduction of the deltoid muscle in VEGF-treated animals. We observed significantly less degeneration of the brachial plexus and a greater number of surviving motoneurons (P < 0·05) in the VEGF group. The results of this study confirmed the positive effect of VEGF-gene therapy on regeneration and survival of nerve cells. We could demonstrate a significant improvement on the motor-functional as well as on the histomorphological level. However, increased vascularization of the nerve tissue caused by VEGF does not seem to be the major reason for these effects. The clinical use of adenoviral VEGF-gene therapy in the newborn cannot be justified so far.

Symptomatic vertebral artery loop: a case report and review of literature

Vertebral artery loop formation is a rare anatomical variant capable of causing bony erosion, encroachment on cervical neural foramen, neurovascular compression, or vertebrobasilar insufficiency. Health professionals should keep the diagnosis of vertebral artery loop formation in mind, especially when the plain radiograph of the cervical spine shows enlargement of the intervertebral foramen. If overlooked, serious complications like vertebral artery injury may occur during surgery or vertebrobasilar angiography, as well as cerebrovascular stroke during transforaminal cervical epidural steroid injections. This case report aims at increasing the awareness of both clinicians and radiologists of this entity as a known rare cause of cervical radiculopathy. In suspected cases, Magnetic resonance imaging & Magnetic resonance angiography should always be the first choice in this regard.

The impact of spinal cord nerve roots and denticulate ligaments on cerebrospinal fluid dynamics in the cervical spine

Cerebrospinal fluid (CSF) dynamics in the spinal subarachnoid space (SSS) have been thought to play an important pathophysiological role in syringomyelia, Chiari I malformation (CM), and a role in intrathecal drug delivery. Yet, the impact that fine anatomical structures, including nerve roots and denticulate ligaments (NRDL), have on SSS CSF dynamics is not clear. In the present study we assessed the impact of NRDL on CSF dynamics in the cervical SSS. The 3D geometry of the cervical SSS was reconstructed based on manual segmentation of MRI images of a healthy volunteer and a patient with CM. Idealized NRDL were designed and added to each of the geometries based on in vivo measurments in the literature and confirmation by a neuroanatomist. CFD simulations were performed for the healthy and patient case with and without NRDL included. Our results showed that the NRDL had an important impact on CSF dynamics in terms of velocity field and flow patterns. However, pressure distribution was not altered greatly although the NRDL cases required a larger pressure gradient to maintain the same flow. Also, the NRDL did not alter CSF dynamics to a great degree in the SSS from the foramen magnum to the C1 level for the healthy subject and CM patient with mild tonsillar herniation (∼6 mm). Overall, the NRDL increased fluid mixing phenomena and resulted in a more complex flow field. Comparison of the streamlines of CSF flow revealed that the presence of NRDL lead to the formation of vortical structures and remarkably increased the local mixing of the CSF throughout the SSS.

Monitoring superficial peroneal nerve somatosensory evoked potential during L4-5 lumbar root decompression

BACKGROUND CONTEXT

Posttibial nerve somatosensory evoked potential (PTN-SSEP) often fails to detect individual nerve root dysfunction, whereas dermatomal somatosensory evoked potential (DSSEP) can be difficult to obtain in anesthetized patients.

PURPOSE

The main aim of this study is to investigate whether the superficial peroneal nerve SSEP (SPN-SSEP), a cutaneous nerve SSEP derived from L4-5 roots, can be relied on as an intraoperative neurophysiological assessment for L4-5 roots.

STUDY DESIGN/SETTING

Retrospective review of consecutive case series.

PATIENT SAMPLE

Thirty-five consecutive patients who underwent lumbar root microdecompression were reviewed. The control group consisted of 11 patients who underwent anterior cervical discectomy and fusion (ACDF).

OUTCOME MEASURES

Intraoperative SSEP measures defined outcome measures.

METHODS

Data from 35 patients undergoing SPN-SSEP, PTN-SSEP, and sural nerve SSEP (SN-SSEP) monitoring during lumbar surgeries were analyzed and compared with the control group of patients underwent ACDF surgery.

RESULTS

Cortical SPN-SSEP could be readily recorded in more than 90% patients from both groups. The waveforms of SPN-SSEP were about 30% smaller than PTN-SSEP, but very similar to SN-SSEP. Importantly, SPN-SSEP was capable of detecting intraoperative L4-5 root dysfunction without the corresponding PTN-SSEP or SN-SSEP alterations. Overall, SPN-SSEP displayed twofold greater sensitivity over PTN-SSEP or SN-SSEP.

CONCLUSIONS

SPN-SSEP was a more sensitive measure for intraoperative L4-5 nerve root dysfunction in comparison with PTN-SSEP and SN-SSEP.

Conservative and surgical treatment improves pain and ankle-brachial index in patients with lumbar spinal stenosis

PURPOSE

The pathological mechanism of lumbar spinal stenosis is reduced blood flow in nerve roots and degeneration of nerve roots. Exercise and prostaglandin E1 is used for patients with peripheral arterial disease to increase capillary flow around the main artery and improve symptoms; however, the ankle-brachial index (ABI), an estimation of blood flow in the main artery in the leg, does not change after treatment. Lumbar spinal nerve roots contain somatosensory, somatomotor, and unmyelinated autonomic nerves. Improved blood flow by medication with prostaglandin E1 and decompression surgery in these spinal nerve roots may improve the function of nerve fibers innervating muscle, capillary, and main vessels in the lower leg, resulting in an increased ABI. The purpose of the study was to examine whether these treatments can improve ABI.

MATERIALS AND METHODS

One hundred and seven patients who received conservative treatment such as exercise and medication (n=56) or surgical treatment (n=51) were included. Low back pain and leg pain scores, walking distance, and ABI were measured before treatment and after 3 months of conservative treatment alone or surgical treatment followed by conservative treatment.

RESULTS

Low back pain, leg pain, and walking distance significantly improved after both treatments (p<0.05). ABI significantly increased in each group (p<0.05).

CONCLUSION

This is the first investigation of changes in ABI after treatment in patients with lumbar spinal stenosis. Improvement of the spinal nerve roots by medication and decompression surgery may improve the supply of blood flow to the lower leg in patients with lumbar spinal stenosis.

Motor recovery and synaptic preservation after ventral root avulsion and repair with a fibrin sealant derived from snake venom

BACKGROUND

Ventral root avulsion is an experimental model of proximal axonal injury at the central/peripheral nervous system interface that results in paralysis and poor clinical outcome after restorative surgery. Root reimplantation may decrease neuronal degeneration in such cases. We describe the use of a snake venom-derived fibrin sealant during surgical reconnection of avulsed roots at the spinal cord surface. The present work investigates the effects of this fibrin sealant on functional recovery, neuronal survival, synaptic plasticity, and glial reaction in the spinal motoneuron microenvironment after ventral root reimplantation.

METHODOLOGY/PRINCIPAL FINDINGS

Female Lewis rats (7 weeks old) were subjected to VRA and root replantation. The animals were divided into two groups: 1) avulsion only and 2) replanted roots with fibrin sealant derived from snake venom. Post-surgical motor performance was evaluated using the CatWalk system twice a week for 12 weeks. The rats were sacrificed 12 weeks after surgery, and their lumbar intumescences were processed for motoneuron counting and immunohistochemistry (GFAP, Iba-1 and synaptophysin antisera). Array based qRT-PCR was used to evaluate gene regulation of several neurotrophic factors and receptors as well as inflammatory related molecules. The results indicated that the root reimplantation with fibrin sealant enhanced motor recovery, preserved the synaptic covering of the motoneurons and improved neuronal survival. The replanted group did not show significant changes in microglial response compared to VRA-only. However, the astroglial reaction was significantly reduced in this group.

CONCLUSIONS/SIGNIFICANCE

In conclusion, the present data suggest that the repair of avulsed roots with snake venom fibrin glue at the exact point of detachment results in neuroprotection and preservation of the synaptic network at the microenvironment of the lesioned motoneurons. Also such procedure reduced the astroglial reaction and increased mRNA levels to neurotrophins and anti-inflammatory cytokines that may in turn, contribute to improving recovery of motor function.

[Pseudoexfoliation syndrome: pathogenesis of impairment of vegetative sympathetic innervation associated with cervical spine disorder]

The results of magnetic resonance imaging of the cervical spine in 33 patients with mono- and bilateral pseudoexfoliation syndrome (PES) and cervical osteochondrosis are presented. The protrusion of intervertebral discs localized in the site of ciliospinal center and rarer in the site of superior cervical sympathetic ganglion is found. The protrusion of intervertebral discs in patients with PES was associated with compression of spinal roots significantly more often than in patients with cataract and osteochondrosis but without PES (control group). The side of protrusion and compression of spinal roots corresponded to the side of PES in more than 50% of cases. Compressive disorders of cervical spinal structures may be of considerable importance in pathogenesis of PES.

Cervical radiculopathy: study protocol of a randomised clinical trial evaluating the effect of mobilisations and exercises targeting the opening of intervertebral foramen [NCT01500044]

BACKGROUND

Cervical radiculopathy is a common form of neck pain and has been shown to lead to severe disability. Clinical rehabilitation approaches for cervical radiculopathies commonly include exercise and manual therapy interventions targeting the opening of intervertebral foramen, but evidence regarding their effectiveness is scarce. The primary objective of this randomised clinical trial is to compare, in terms of pain and disability, a rehabilitation program targeting the opening of intervertebral foramen to a conventional rehabilitation program, for patients presenting acute or subacute cervical radiculopathies. The hypothesis is that the rehabilitation program targeting the opening of intervertebral foramen will be significantly more effective in reducing pain and disability than the conventional rehabilitation program.

METHODS/DESIGN

This study is a double-blind (participants and evaluators blinded) randomised clinical trial that will allow the comparison of patients with a cervical radiculopathy randomly assigned to one of two groups: one group will receive a 4-week rehabilitation program targeting the opening of intervertebral foramen, and the second group will receive a 4-week conventional rehabilitation program. Thirty-six subjects with cervical radiculopathy will be recruited from participating medical and physiotherapy clinics and will be evaluated at baseline, at the end of the 4-week program and four weeks following the end of the program. The primary outcome measure will be the validated Neck Disability Index questionnaire. Secondary outcome measures will include the short version of the Disabilities of the Arm, Shoulder and Hand questionnaire, a numerical pain rating scale, cervicothoracic mobility and patients' perceived global rating of change. During the 4-week rehabilitation program, each participant will take part in eight physiotherapy treatment sessions (2 session/week) and will perform a home exercise program. A mixed-model, 2-way ANOVA will be used to analyze the effects of the rehabilitation programs.

DISCUSSION

Control trials are needed to define ideal intervention approaches in rehabilitation for this population. This randomised clinical trial will be the first study that directly compares a rehabilitation program targeting the opening of intervertebral foramen to a conventional rehabilitation program for patients with cervical radiculopathy. The results of this study may help to establish best clinical practice guidelines for this patient population.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT01500044.

Unilateral T13 and L1 dorsal root avulsion: methods for a novel model of central neuropathic pain

Central neuropathic pain is associated with many disease states including multiple sclerosis, stroke, and spinal cord injury, and is poorly managed. One type of central neuropathic pain that is particularly debilitating and challenging to treat is pain that occurs below the level of injury (below-level pain). The study of central neuropathic pain is commonly performed using animal models of stroke and spinal cord injury. Most of the spinal cord injury models currently being used were originally developed to model the gross physiological impact of clinical spinal cord injury. In contrast, the T13/L1 dorsal root avulsion model of spinal cord injury described here was developed specifically for the study of central pain, and as such, was developed to minimize confounding complications, such as paralysis, urinary tract infections, and autotomy. As such, this model induces robust and reliable hindpaw mechanical allodynia. Two versions of the model are described. The first is optimal for testing systemically administered pharmacological manipulations. The second was developed to accommodate intrathecal application of pharmacological manipulations. This model provides an additional means by which to investigate central pain states associated with spinal cord injury, including below-level pain. Finally, a brief discussion of at-level pain measurement is described as it has been suggested in the literature that the mechanisms underlying below- and at-level pain are different.

Rectal ulcer in a patient with VZV sacral meningoradiculitis (Elsberg syndrome)

This report describes the case of a 55-year-old woman with varicella-zoster virus (VZV) sacral meningoradiculitis (Elsberg syndrome) who presented with herpes zoster in the left S2 dermatome area, urinary retention, and constipation. Lumbar magnetic resonance imaging showed the left sacral nerve root swelling with enhancement. Thereafter, she suddenly showed massive hematochezia and hemorrhagic shock because of a rectal ulcer. To elucidate the relation between Elsberg syndrome and rectal ulcer, accumulation of similar cases is necessary. To avoid severe complications, attention must be devoted to the possibility of rectal bleeding in the early stage of Elsberg syndrome.

Vertebral artery loop--a cause of cervical radiculopathy

OBJECTIVE

To report a case of cervical radiculopathy caused by an anomalous vertebral artery (VA) and illustrate the efficacy of microvascular decompression by the anterolateral approach.

METHODS

A 50-year-old woman was referred because of an 8-year history of progressive left C6 radiculopathy refractory to other forms of treatment, including C5-6 anterior cervical discectomy. Clinical and radiologic evaluation showed an abnormally tortuous loop of V2 causing direct neurovascular compression.

RESULTS

A left cervical anterolateral approach was used to expose the anomalous loop. After a generous bony decompression, the loop was identified, and the artery was mobilized and ultimately separated from the C6 nerve root removing the direct pulsatile compression.

CONCLUSIONS

Cervical root compression by an aberrant or anomalous extracranial VA is a rare cause of radiculopathy. The best management of such lesions is the anterolateral approach with bony and direct microvascular decompression.

[Long term depression of the recurrent inhibition of monosynaptic spinal reflexes after sciatic nerve crush in adult rats]

Sciatic nerve injury is a common disease of peripheral nerve in clinic. After nerve injury, there are many dysfunctions in motoneurons and muscles following regeneration. Previous studies mostly investigated the aspects related to the injured nerve, and the effect on the recurrent inhibition (RI) pathway of spine following regeneration was not fully understood. Following reinnervation after temporary sciatic nerve crush, the functional alteration of RI was studied. In adult rats, RI between lateral gastrocnemius-soleus (LG-S) and medial gastrocnemius (MG) motor pools was assessed by conditioning monosynaptic reflexes (MSRs) elicited from the cut dorsal roots and recorded from either the LG-S or MG nerves by antidromic stimulation of the synergist muscle nerve. The following results were obtained. (1) The RI of MSRs in rats was almost lost (<5 weeks) after sciatic nerve crush. Although the RI partially recovered following reinnervation (6 weeks), it remained permanently depressed (up to 14 weeks). (2) Sciatic nerve crush on one side did not affect the contralateral RI. (3) Sciatic nerve crush did not induce any motoneuron loss revealed by immunohistochemistry. Peripheral nerve temporary disconnection causes long term alterations in RI pathway which make up motoneuron's function enhance for the alteration of muscle power and suggests that peripheral nerve injury induces long term plastic changes in the spinal motoneuron circuitry.

[Therapy-refractory overactive bladder: alternative treatment approaches]

The treatment of patients with overactive bladder (OAB) refractory to conventional treatment is gaining clinical significance. This article intends to review alternative therapy options for patients with OAB refractory to conventional treatment. A search of the PubMed database as well as the abstracts presented at the European Association of Urology and the American Urological Association annual meetings was conducted. Keywords used during this search included overactive bladder (OAB) refractory to conventional treatment, electromotive drug administration (EMDA), sacral neuromodulation, augmentation cystoplasty and cystectomy. Eighteen articles with an adequate number of patients were identified. All articles published before 2001 were not included in this analysis. Because of first-line treatment failure, 30% of the patients required alternative treatment. This included EMDA, botulinum toxin injections into the detrusor, sacral neuromodulation, augmentation cystoplasty or cystectomy. Based on this review it appears that a significant improvement in micturition parameters, continence and in quality of life was achieved. Overall EMDA, intradetrusor injections of botulinum toxin and sacral neuromodulation seem to be highly effective and safe. Augmentation cystoplasty or cystectomy remains the last choice of treatment in refractory cases.Overall EMDA, intradetrusor injections of botulinum toxin and sacral neuromodulation seem to be highly effective and safe. Augmentation cystoplasty or cystectomy remains to be the last choice of treatment in refractory cases.

Meralgia paresthetica-like syndrome may be caused by transient lumbar nerve root injury without definite compression: a case report

Meralgia paresthetica is a well-known sensory syndrome describing paresthesia and/or anesthesia in the anterolateral aspect of the thigh that is supplied by the lateral femoral cutaneous nerve. Compression of the nerve usually occurs at the point where it passes between the anterior superior iliac spine and the inguinal ligament. Proximal lesions such as lumbar radiculopathy, lumbar disc herniation, and spinal stenosis have been reported to cause meralgia paresthetica-like syndrome. These proximal lesions directly injure L2 and L3 spinal nerve roots and cause a constant compression of the nerve roots. The presented paper introduces a hypothesis that this syndrome can be caused by transient injury to the L2 and L3 nerve roots by the upper adjacent disc bulge without definite compression. This hypothesis is supported by lumbar spine magnetic resonance imaging of a patient presenting with a meralgia paresthetica-like symptom during bending forward and twisting of the body, showing no L2/L3 herniated disc but mildly posterior bulging of T12/L1 disc. This hypothesis emphasizes an importance of appropriate postures in patients with meralgia paresthetica-like symptoms in order to prevent long-term morbidity.

Evaluation of the effectiveness of lumbar interlaminar epidural injections in managing chronic pain of lumbar disc herniation or radiculitis: a randomized, double-blind, controlled trial

BACKGROUND

The pathophysiology of lumbar radicular pain is the subject of ongoing research, with a reported prevalence of sciatica or radiculitis ranging from 1.2% to 43%. Among the numerous non-surgical interventions available, epidural injections are the most commonly performed interventions in the United States in managing chronic low back and lower extremity pain.

STUDY DESIGN

A randomized, double-blind, controlled trial.

SETTING

An interventional pain management practice, a specialty referral center, a private practice setting in the United States.

OBJECTIVE

To evaluate the effectiveness of lumbar interlaminar epidural injections with local anesthetic, with or without steroids, in managing chronic low back and lower extremity pain secondary to disc herniation or radiculitis in providing effective and long-lasting pain relief.

METHODS

Patients were assigned to one of 2 groups with local anesthetic only or with local anesthetic mixed with non-particulate betamethasone. Randomization was performed by computer-generated random allocations sequence by simple randomization. Seventy patients were included in this analysis.

OUTCOMES ASSESSMENT

Patient outcomes were measured at baseline, 3, 6, and 12 months post-treatment with the Numeric Rating Scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake. Decrease of > or = 50% of NRS scores and Oswestry scores were considered significant.

RESULTS

Significant pain relief (> or = 50%) was seen at 12 months in 74% of patients in Group I and 86% in Group II, and 69% and 83% in ODI scores respectively. Significant differences were noted in pain relief characteristics at 6 months between Group I and Group II (p = 0.001) and functional status improvement was significantly better in Group II at 6 months and 12 months (p = 0.019 and 0.045). The overall average procedures per year were 4.3 in Group I and 4.2 in Group II with an average total relief per year of 42.2 +/- 10.5 weeks in Group I and 41.4 +/- 11.0 weeks in Group II over a period of 52 weeks in the successful group.

LIMITATIONS

The study limitations include the lack of a placebo group and the fact that this is a preliminary report of 35 patients in each group.

CONCLUSION

Overall, 74% of patients in Group I without steroids and 86% in Group II with steroids with lumbar disc herniation or radiculitis might benefit from lumbar interlaminar epidural injections.

[Segmental root palsy (SRP) after cervical decompression surgery]

OBJECTIVE

To explore the occurrence, prevention and cure prognosis of segment root polsy (especially in C5 palsy) after cervical decompression surgery.

METHODS

From February 2006 and December 2008,162 patients were operated with cervical decompression through approach for anterior or posterior in our hospital. Among them, 10 cases occurred SRP after operation included 6 males and 4 females aged from 40 to 68 with an average of 53 years old. These cases were treated with dehydration, trophic nerve, hyperbaric oxygenation. The clinical data were retrospective analzed.

RESULTS

Ten patients were followed up from 8 months to 3 years with an average of 2.4 years. It was observed that all the patients recovered during a period of 4.4 months on average (ranging from 3 weeks to 8 months).

CONCLUSION

SRP(especially in C5 palsy) is one of the common complications of anterior or posterior cervical decompression surgery. SRP is usually the result of various nosogenesis. As there was no effective treatment, conservative treatment is usually adopted with optimistic prognosis.

Protocol for evaluation of the comparative effectiveness of percutaneous adhesiolysis and caudal epidural steroid injections in low back and/or lower extremity pain without post surgery syndrome or spinal stenosis

BACKGROUND

Treatment of chronic low back pain with or without lower extremity pain continues to be a challenge. Epidural steroids are commonly utilized in patients after the failure of conservative treatment. The results of epidural steroid injections have been variable based on the pathophysiology, the route of administration, injected drugs, and utilization of fluoroscopy. In patients resistant to fluoroscopically directed epidural injections, percutaneous epidural adhesiolysis and percutaneous targeted delivery of injections with or without adhesiolysis has been recommended. Percutaneous adhesiolysis has been studied in chronic pain syndromes related to post laminectomy syndrome and spinal stenosis with encouraging results. There is a paucity of literature regarding the effectiveness of the targeted delivery of medications with or without epidural adhesiolysis in patients recalcitrant to epidural steroid injections without a history of surgery and spinal stenosis.

STUDY DESIGN

A randomized, equivalence trial of percutaneous lumbar adhesiolysis and caudal epidural steroid injections in patients with low back and/or lower extremity pain without post surgery syndrome or spinal stenosis.

SETTING

An interventional pain management practice setting in the United States.

OBJECTIVE

The study is designed to evaluate the effectiveness of percutaneous epidural adhesiolysis in managing chronic low back and/or lower extremity pain in patients without post lumbar surgery syndrome or spinal stenosis and compare it with fluoroscopically directed caudal epidural steroid injections

METHODS

The study design includes 120 patients randomly assigned into 2 groups. Group I (60 patients), the control group, will receive caudal epidural injections with catheterization up to S3 with local anesthetic, steroids, and 0.9% sodium chloride solution; Group II (60 patients), the intervention group, will receive percutaneous adhesiolysis with target delivery of lidocaine, 10% hypertonic sodium chloride solution, and non-participate betamethasone. Randomization will be performed by computer-generated random allocation sequence by simple randomization.

OUTCOME MEASURES

Multiple outcome measures will be utilized including numeric rating scale (NRS), the Oswestry Disability Index 2.0 (ODI), employment status, and opioid intake with assessment at 3, 6, 12, 18 and 24 months post treatment. Significant pain relief is considered as 50% or more, whereas significant improvement in the disability score is defined as a reduction of 40% or more.

RESULTS

The results will be analyzed to show significant relief as well as improvement in functional status.

LIMITATIONS

This study is limited by potentially inadequate double blinding and the lack of a placebo group.

A complementary approach for evaluating S1-root in diabetic neuropathic patients

Diabetic neuropathy is one of the most common causes of peripheral neuropathy. Conventional electrodiagnostic evaluation or even magnetic resonance imaging (MRI) of lumbosacral vertebrae cannot confirm radiculopathy (e.g S1-root irritation) in diabetic neuropathic patients definitely. The purpose of the present study was to evaluate spinal nerve pathway of H-reflex in diabetic neuropathic patients by the central loop of H-reflex when its conventional pathway was impaired. No similar study, however, has been done on this subject. Forty two diabetic neuropathic patients with impaired conventional H-reflex were studied by the central loop of H-reflex bilaterally. The central loop of H-reflex was elicited by monopolar needle stimulation of S1 nerve root at the level of S1 foramen and recorded in the half way of the line from popliteal crease to the medial malleolus. In 82 out of 84 (97.6%) limbs with impaired conventional H-reflex, the central loop of H-reflex was measurable with latency less than 8 ms. Therefore the central loop of H-reflex was a more reliable approach for investigating S1-root in these patients with significant statistical difference (P < 0.001). The central loop of H-reflex latency in this study was 6.34 +/- 0.96 ms with the range of 4.3-7.85 ms. In conclusion the presence of central loop of H-reflex with latency less than 8 ms can be used as a complementary approach for assessment of S1-root sparing in diabetics.

Distribution of inducible nitric oxide synthase and tumor necrosis factor-alpha in the peripheral nervous system of Lewis rats during ascending paresis and spontaneous recovery from experimental autoimmune neuritis

BACKGROUND

Inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-alpha) are pleiotropic molecules with widespread action in autoimmune diseases.

OBJECTIVE

This study characterizes the distribution of iNOS and TNF-alpha in the spinal nerve roots, dorsal root ganglia and sciatic nerve of Lewis rats during experimental autoimmune neuritis (EAN).

METHODS

Macrophages and neutrophils were identified by immunofluorescence as cellular sources of iNOS and TNF-alpha at various stages of EAN induced by synthetic peptide 26.

RESULTS

As the disease progressed, iNOS- and TNF-alpha-bearing cells gradually infiltrated the cauda equina, dorsal root ganglia, Th12-L3 spinal roots, and the sciatic nerve. A severer EAN profile developed when more iNOS- and TNF-alpha-bearing cells were present, and the recovery from EAN was related to the disappearance of these cells and the regeneration of nerve fibers.

CONCLUSIONS

This is the first report to show iNOS- and TNF-alpha-immunoreactive cells in dorsal root ganglia during EAN, suggesting an underlying pathology for the neuropathic pain behavior in EAN. Our results suggest that the cells bearing iNOS and TNF-alpha in the different parts of the peripheral nervous system are involved in the development of the clinical signs observed at each stage of EAN.

Peripheral Primitive Neuroectodermal Tumour (pPNET) in the cervical spine

Primary spinal primitive neuroectodermal tumours are rare. We present a 45-year-old man with a peripheral primitive neuroectodermal tumour arising in the cervical spine. We believe this to be the first report of this type of tumour in the cervical spine.

Behavioral models of pain states evoked by physical injury to the peripheral nerve

Physical injury or compression of the root, dorsal root ganglion, or peripheral sensory axon leads to well-defined changes in biology and function. Behaviorally, humans report ongoing painful dysesthesias and aberrations in function, such that an otherwise innocuous stimulus will yield a pain report. These behavioral reports are believed to reflect the underlying changes in nerve function after injury, wherein increased spontaneous activity arises from the neuroma and dorsal root ganglion and spinal changes increase the response of spinal projection neurons. These pain states are distinct from those associated with tissue injury and pose particular problems in management. To provide for developing an understanding of the underlying mechanisms of these pain states and to promote development of therapeutic agents, preclinical models involving section, compression, and constriction of the peripheral nerve or compression of the dorsal root ganglion have been developed. These models give rise to behaviors, which parallel those observed in the human after nerve injury. The present review considers these models and their application.

The classification and identification of human somatic and parasympathetic nerve fibres including urinary bladder afferents and efferents is preserved following spinal cord injury

Single-fibre extracellular action potentials were recorded with 2 pairs of wire electrodes from lower human sacral nerve roots during surgery. The roots from which was recorded from were used for morphometry. Nerve fibre groups were identified by conduction velocity distribution histograms of single afferent and efferent fibres and partly by nerve fibre diameter distribution histograms. The values of group conduction velocity and group nerve fibre diameter measured in the paraplegics were very similar to those obtained from brain-dead humans and patients with no spinal cord injury. Thus the classification and identification of nerve fibre groups remained preserved following spinal cord injury. Upon retrograde bladder filling the urinary bladder stretch and tension receptor afferent activities were increased; on two occasions they even fired when the bladder was empty. Two reasons are brought forward for a too small storage volume of the urinary bladder in paraplegics: too high afferent activity of the bladder due to changed receptor field transduction mechanisms and too low compliance.

SUMMARY

1. Single nerve fibre action potentials (APs) of lower sacral nerve roots were recorded extracellularly with 2 pairs of wire electrodes during an operation for implanting an anterior root stimulator for bladder control in 9 humans with a spinal cord injury and a dyssynergia of the urinary bladder. Roots that were not saved and that were used to record from were later used for morphometry. 2. Nerve fibre groups were identified by conduction velocity distribution histograms of single afferent and efferent fibres and partly by nerve fibre diameter distribution histograms, and correlation analysis was performed. Group conduction velocity values were obtained additionally from compound action potentials (CAPs) evoked by electrical stimulation of nerve roots and the urinary bladder. 3. The group conduction velocities and group nerve fibre diameters had the following pair-values at 35.5 degrees C: Spindle afferents: SP1 (65 m/s / 13.1 microm), SP2 (51/12.1); touch afferents: T1 (47/11.1), T2 (39/10.1), T3 (27/9.1), T4 (19/8.1); urinary bladder afferents: S1 (41 m/s / -), ST (35/-); alpha-motoneurons: alpha 13 (-/14.4), alpha 12 (65 m/s /13.1 microm), alpha 11 (60?/12.1)[FF], alpha 2 (51/10.3)[FR], alpha 3 (41/8.2)[S]; gamma-motoneurons: gamma(beta) (27/7.1), gamma 1 (21/6.6), gamma 21 (16/5.8), gamma 22 (14/5.1); preganglionic parasympathetic motoneurons: (10 m/s / 3.7 microm). 4. The values of group conduction velocity and group nerve fibre diameter measured in the paraplegics were very similar to those obtained earlier from brain-dead humans and patients with no spinal cord injury. Also, the axon number and the axon density of myelinated fibres of lower sacral nerve roots remain unchanged following spinal cord injury. Thus the classification and identification of nerve fibre groups remained preservedfollowing spinal cord injury. A direct comparison can thus be made of natural impulse patterns of afferent and efferent nerve fibres between paraplegics (pathologic) and brain-dead humans (supraspinal destroyed CNS, in many respects physiologic). 5. When changing the root temperature from 32 degrees C to 35.5 degrees C, the group conduction velocities changed in the following way in one case: SP2: 40 m/s (32 degrees C) to 50 m/s (35.5%), S1: 31.3 to 40, ST: 25 to 33.8, M: 12.5 to 13.8; alpha 2: 40 to 50, alpha 3: 33 to 40. The group conduction velocities showed different temperature dependence apart from SP2 fibres and alpha 2-motoneurons. 6. Upon retrograde bladder filling the urinary bladder stretch (S1) and tension receptor afferent (ST) activity levels were undulating and increased. As compared to activity levels detected in a brain-dead human, S1 (designates afferents, not cord segment) and ST afferents fired even when the bladder was empty, with an activity level similar to those observed in a brain-dead human with the bladder half filled. Two reasons are brought forward for an too small storage volume of the urinary bladder in paraplegics: too high afferent activity of the bladder due to changed receptor field signal transduction mechanisms and too low compliance. 7. With the newly developed 'coordination dynamics therapy', applied early after spinal cord injury, such complications of bladder functioning can be avoided; the bladder can causally be cured in severe spinal cord injury.

Herpes zoster radiculopathy treated with fluoroscopically-guided selective nerve root injection

BACKGROUND

Varicella-zoster virus, a member of the herpes virus family, is a neurotrophic virus that primarily affects afferent sensory neurons. Reactivation of latent virus within the dorsal root ganglion and axoplasmic transport to epithelial nerve terminals causes the segmental cutaneous rash and neuralgic pain characteristic of herpes zoster.

SETTING

Outpatient orthopedic practice.

CASE DESCRIPTION

A 75-year-old male developed a herpetic rash followed by burning pain in the right L5 distribution. The pain was exacerbated by standing or walking. Six weeks later, the rash had improved, but the patient developed a right foot drop requiring use of a molded ankle-foot orthosis. MRI of the lumbar spine revealed mild degenerative changes without evidence of significant spinal stenosis or disc disease. Electrodiagnostic studies confirmed the diagnosis of right L5 radiculopathy.

RESULTS

The patient had dramatic improvement of pain and weakness after undergoing a fluoroscopically guided right L5 selective nerve root block with Depo-Medrol and Lidocaine. He then began a course of physical therapy and, 6 weeks later, had only trace weakness of the ankle dorsiflexor group on the right side. The patient has continued without significant weakness or pain since the procedure and has returned to normal functioning.

DISCUSSION

This case demonstrates apparent treatment of a relatively uncommon phenomenon, herpes zoster radiculopathy, using selective nerve root block.

LIMITATIONS

There is a limited amount of data regarding this disorder presently available regarding Herpes Zoster Radiculopathy. A second limitation would be an inability to exclude spinal pathology as an alternative etiology of this patient's condition.

CONCLUSION

Cases of herpes zoster-induced radiculopathy may become more frequent, as evidenced by the increasing number of cases of herpes zoster in the United States noted epidemiologically.

Comparison of neuropathic pain and neuronal apoptosis following nerve root or spinal nerve compression

Altered dorsal root ganglion (DRG) function is associated with neuropathic pain following spinal nerve injury. However, compression of the cauda equina and dorsal rhizotomy proximal to the DRG do not induce significant pain, whereas in the spinal nerve and peripheral nerve, injury distal to the DRG does induce neuropathic pain. Caspase signaling induces apoptosis, and caspase inhibitors prevent pain-related behavior. The degree of DRG neuronal apoptosis is thought to play a role in pain behavior. We suggest that differences in pain behavior according to the injury sites within the DRG may be related to imbalances in apoptotic injuries. The aim of this study was to determine which compression injury was more painful and to compare behavior with expression of tumor necrosis factor (TNF)-alpha in DRG and apoptosis in the DRG following crush injury to the L5 nerve root or L5 spinal nerve. Sprague–Dawley rats received a crush injury to the L5 spinal nerve (distal to the DRG), crush injury to the L5 nerve root (proximal to the DRG), or no crush injury (sham). Mechanical allodynia was determined by the von Frey test. Expression of TNF-alpha was compared among three groups using immunoblot findings. Furthermore, we compared the percentage of neurons injured in the DRG using immunostaining for apoptotic cells and localization of activated caspase 3. Mechanical allodynia was observed in both crush injury groups. The duration of mechanical allodynia in the distal crush group was significantly longer than in the proximal crush group (P < 0.05). TNF-alpha expression was increased in DRG neurons following injury. DRG apoptosis in the distal crush group was significantly higher than in the proximal group at each time point (P < 0.05). This study suggests that spinal nerve crush injuries produce a greater degree of DRG apoptosis than do corresponding nerve root crush injuries, and that the former injuries are associated with longer lasting mechanical allodynia. Thus, differences in the time course of mechanical allodynia might be associated with an imbalance in DRG apoptosis.