L5 Root Research Articles

Correlation Between Clinical And Magnetic Resonance Imaging Findings In Patients With Lumbosacral Radiculopathy

Low back pain accounts for a large amount of loss of productivity in the workforce. When the low back pain extends into the lower limb along the distribution of a dermatome then radiculopathy is said to be present. Although most people experience back pain during their lifetime, only a fraction experience lumbosacral radiculopathy as a consequence of nerve root compression or irritation. Almost 5% males and 2.5% females experience lumbosacral radiculopathy at some time in their lifetime. Magnetic resonance imaging (MRI) is the preferred investigation for the diagnosis of lumbosacral radiculopathy. So, in the evaluation of a patient of lumbosacral radiculopathy is essential to correlate clinical symptoms and signs with the finding detected in the MRI to arrive at a correct diagnosis and arrange an appropriate management. So this study was done to see the correlation between clinical and MRI finding of radiculopathy at different nerve root level in patients with lumbosacral radiculopathy. It was a cross sectional descriptive study. All 40 patients of lumbosacral radiculopathy who were presented to Rajshahi Medical College Hospital during the study period from 01/11/2011 to 30/10/2012 were included in the study. There were 30 males and 10 females having an M: F ratio of 3:1. Mean age of total patients 43 + 14.74 years. 67.5% patients were between 20 to 50 years and 60% patients were performing heavy work. 67.5% patients had unilateral involvement while 32.6% patients had bilateral involvement. 72.5% patients had muscle weakness and 27.5% had no muscle weakness. 67.5% patients had sensory impairment and 32.5% had no sensory involvement. Knee jerk changes were present in 60% patients and ankle jerk changes in 66.66% patients. As expected 52.18% had L5 and 32.61% had S1 radiculopathy. The difference in clinical and MRI detection of root involvement was statistically significant (p value < 0.05) in both sides at L4, L5 and S1 root levels but there was no significant difference at the L3 root level (p value 1.00) Intervertebral disc herniation was the commonest cause of lumbosacral radiculopathy (72.32%) and second common cause was spinal canal stenosis (19.44%). Others are intervertebral disc budging (61.52%), disc protrusion (23.08%) and disc extrusion (15.38%). Correlation between clinical severity and MRI grading of lumbosacral radiculopathy which was statistically significant. So, it is concluded that clinical findings correlate well with MRI finding, but all MRI abnormalities need not have a clinical significanceTAJ 2015; 28(1): 32-39

Association between sensory nerve action potential and lumbar dorsal root ganglion area

ObjectiveTo quantify the cross-sectional area (CSA) of lumbar dorsal root ganglion (DRG) by magnetic resonance imaging (MRI) and investigate the relationship between the cross-sectional area (CSA) of DRGs and sensory nerve action potentials (SNAP) amplitude in the lower extremities. MethodsThirty-eight DRGs (20 L5 roots and 18 S1 roots) in 10 adult subjects were reviewed retrospectively. The CSA of the DRG was calculated from MR images of the coronal plane. SNAP amplitudes of the superficial peroneal nerve and sural nerve were corresponded to L5 and S1-DRGs. ResultsThe mean CSA of DRGs was 66.6 ± 13.7 mm2 in L5-DRG and 79.5 ± 14.3 mm2 in S1-DRG. The means of SNAP amplitudes were 19.6 ± 6.2 μV in superficial peroneal nerves and 24.6 ± 9.0 μV in sural nerves. In multivariate regression analysis, the CSA of DRGs had a significant correlation with SNAP amplitude. ConclusionThe area of L5 and S1-DRGs may be positively correlated with SNAP amplitude.

Movements of the lumbo-sacral nerve roots in the spinal canal induced by straight leg raising test: an anatomical study.

The pain involved in the herniated discs could be generated by some mobility of the nerve roots during straight leg raising (SLR). SLR produces some movement of nerves, but the magnitude of this displacement needs to be thorough, that is why we have investigated lumbo-sacral nerve root displacement in the spinal canal during the passive straight leg raise (SLR). Fourteen cadavers underwent laminectomy to mark the nerve roots of L2-S1 with lead balls. X-rays were taken during different movements imposed on the body: bilateral hip extension, left SLR then right and bilateral SLR. By superimposing these images two by two, the displacement of the nerve roots is quantified numerically during the various SLR maneuvers with respect to the reference position corresponding to the bilateral hip extension. The median range of the different nerve root movements ranged from 0.10 to 0.51cm (p < 0.05 except for the L2 root) when the left SLR is applied, from 0.26 to 0.48cm (p < 0.05) with the right SLR and from 0.30 to 0.65cm (p < 0.05) with a bilateral SLR. No statistically significant relationship was found between age and movement value. The lumbo-sacral nerve roots in the spinal canal region move statistically significantly in response to the clinically applied SLR test, except for L2 root during the left SLR. This movement is symmetric and greater when a bilateral SLR is applied. These anatomical results are correlated with those observed empirically in clinical practice.

Anatomic Variations of the Lateral Femoral Cutaneous Nerve: Remnants of Atypical Nerve Growth Pathways Revisited by Intraneural Fascicular Dissection and a Proposed Classification

To trace anatomic variations of the lateral femoral cutaneous nerve (LFCN) in its intrapelvic course. Forty cadavers (80 sides) fixed in 10% formalin solution were dissected. The following parameters were recorded: LFCN diameter and variations in its origin and number. The dissection comprised exposure and excision of the lumbar plexus, together with the roots of LFCN, followed by retrograde intraneural fascicular dissection using microsurgical instruments. Several types of LFCN origin from the lumbar plexus were observed. Typically, the LFCN appears as a single trunk arising from dorsal divisions of the ventral rami of the lumbar plexus. The most prevalent origin of the nerve was from the L2 and L3 roots (47 cases; 58.75%). The LFCN took an origin from the L1-L2 level in 12 cases (15%) and from the L2 nerve in 9 cases (11.25%). The main observed variations were the presence of the accessory LFCN (2 cases; 2.5%) and branching of the LFCN from the femoral nerve (6 cases; 7.5%). Communications between the LFCN and the femoral or genitofemoral nerves also were observed occasionally. An atypical course of the LFCN with respect to the anterior psoas was observed in our material in 3 of the 80 sides (3.75% of the examined LFCN specimens). Considerable variability in the origin and the course of the LFCN was observed, which should be taken into account during clinical assessment of nerve lesions and during surgery via transpsoas approaches to the lumbar spine.

Fixation technique segmental modified with Steinmann pins in a Lumbosacral fracture between L7 and S1: Case Report

Equine tail syndrome occurs due to narrowing of the canal causing ischemia of the nerve roots L6, L7, S1 and S2 origin of the pudendal and sciatic nerve.The objective of this work is to report a case of a bitch, with no defined breed of approximately 9 months of age, attended at the veterinary hospital of Piauí, diagnosed with a lumbosacral fracture between l7 and S1, surgically treated by the segmental fixation technique modified with pins of Steinmann. The technique was effective in the stabilization and immobilization of the fracture, showing a good response in the recovery of the patient.

Transforaminal block of the dorsal ganglion of the root of L5, transfacetary approach: description of an alternative approach

Transforaminal block of the dorsal ganglion of the root of L5, transfacetary approach: description of an alternative approach

Grounding of using treatment-and-rehabilitation complex for patients with occupational lumbosacral radiculopathy

Aim. To ground and estimate the efficiency of using nonmedicamentous methods of treatment in patients with occupational radiculopathy of lumbosacral level.&#x0D; Materials and methods. Sixty seven patients, diagnosed occupational lumbosacral radiculopathy, were examined; patients’ neurological status, manifestation of pain syndrome by 10-score visual analog scale and neuromuscular state by stimulation electroneuromyography data prior to and after treatment were assessed.&#x0D; Results. Treatment-and-rehabilitation complex included magnetic-laser therapy, acupuncture, combined with curative gymnastics. By the completion of treatment, positive dynamics regarding nearly all neurological states, including reduced manifestation of painful sensations, increased volume of active movements in the lumbar spine, decreased hyperesthesia rate and hypoesthesia intensity in the zone of injured roots, decreased occurrence of Lasegue test was observed. Dynamics of electroneuromyographic parameters was expressed by improved conduction of nerve impulses through the peripheral low extremity nerves and roots L4, L5, S1 of cerebrospinal nerves.&#x0D; Conclusions. Application of the offered complex provided positive effect by the end of treatment in 82.3 % of cases.

Inhibitory effects of eugenol on putative nociceptive response in spinal cord preparation isolated from neonatal rats.

Eugenol is contained in several plants including clove and is thought to exert an analgesic effect. It has been suggested that the slow ventral root potential induced by ipsilateral dorsal root stimulation in the isolated (typically lumbar) spinal cord of newborn rats reflects the nociceptive response, and this in vitro experimental model is useful to assess the actions of analgesics. To further elucidate neuronal mechanisms of eugenol-induced analgesia, we examined the effects of extracellularly applied eugenol on the nociceptive spinal reflex response. To evaluate the effects of eugenol on putative nociceptive responses, the ipsilateral fifth lumbar (L5) dorsal root was stimulated using a glass suction electrode, and the induced reflex responses were recorded from the L5 and twelfth thoracic (Th12) ventral roots in spinal cord preparations (Th10-L5) from newborn rats (postnatal day 0-3). We found that eugenol (0.25-1.0mM) caused dose-dependent attenuation of the reflex response and also depressed spontaneous ventral root activity. We also found that the slow ventral root potential was further divided into two components: initial and late components. A lower concentration of eugenol selectively depressed the late component. The inhibitory effects by 1.0mM eugenol were not reversed by 10µM capsazepine (TRPV1 antagonist) or 40µM HC-030031 (TRPA1 antagonist). The depressive effect of eugenol on the reflex response was also confirmed by optical recordings using voltage-sensitive dye. Our report provides additional evidence on the basic neuronal mechanisms of eugenol to support its clinical use as a potential analgesic treatment.

Cisto Ósseo Aneurismático da Coluna Vertebral

Introdução: O cisto ósseo aneurismático é uma patologia óssea rara, benigna, de etiologia desconhecida, localmente agressiva e hipervascularizada. Trata-se de lesão de apresentação solitária e expansiva, com cavidades contendo material hemático em seu interior. Relato de Caso: Paciente do sexo masculino, 16 anos de idade, com quadro de lombalgia e dor irradiada para os membros inferiores de piora progressiva. Exame neurológico evidenciando paresia e parestesia no trajeto da raiz de L2 e hiporreflexia patelar bilateralmente, sendo pior à esquerda. RM da coluna vertebral evidenciou lesão óssea expansiva acometendo o corpo vertebral, pedículos e elementos posteriores da vértebra L3. O paciente foi submetido à ressecção cirúrgica da lesão, descompressão raquidiana, vertebroplastia aberta de L3 com cimento acrílico e fixação dos segmentos L2 a L5. Discussão: A ressecção cirúrgica é o tratamento mais indicado para esse tipo de lesão. Em casos em que há instabilidade da coluna deve-se associar a artrodese, o que promove, além do controle local da lesão, a prevenção de deformidades da coluna.Conclusão: No caso aqui apresentado, a realização da ressecção do cisto ósseo aneurismático associado à vertebroplastiaaberta e artrodese da coluna permitiu adequado tratamento da instabilidade da coluna e efetivo controle da dor relacionada à doença.

A comparative study of three conservative treatments in patients with lumbar spinal stenosis: lumbar spinal stenosis with acupuncture and physical therapy study (LAP study)

BackgroundAlthough the efficiency of conservative management for lumbar spinal stenosis (LSS) has been examined, different conservative management approaches have not been compared. We have performed the first comparative trial of three types of conservative management (medication with acetaminophen, exercise, and acupuncture) in Japanese patients with LSS.MethodsPatients with L5 root radiculopathy associated with LSS who visited our hospital for surgical treatment were enrolled between December 2011 and January 2014. In this open-label study, patients were assigned to three treatment groups (medication, exercise, acupuncture) according to the visit time. The primary outcomes were Zurich claudication questionnaire (ZCQ) scores before and after 4 weeks of treatment. Least square mean analysis was used to assess the following dependent variables in the treatment groups: changes in symptom severity and physical function scores of the ZCQ and the ZCQ score of patient’s satisfaction after treatment.ResultsThirty-eight, 40, and 41 patients were allocated to the medication, exercise, and acupuncture groups, respectively. No patient underwent surgical treatment during the study period. The symptom severity scores of the ZCQ improved significantly after treatment in the medication (p = 0.048), exercise (p = 0.003), and acupuncture (p = 0.04) groups. The physical function score improved significantly in the acupuncture group (p = 0.045) but not in the medication (p = 0.20) and exercise (p = 0.29) groups. The mean reduction in the ZCQ score for physical function was significantly greater for acupuncture than for exercise. The mean ZCQ score for treatment satisfaction was significantly greater for acupuncture than for medication.ConclusionsAcupuncture was significantly more effective than physical exercise according to the physical function score of the ZCQ and than medication according to the satisfaction score. The present study provides new important information that will aid decision making in LSS treatment.Trial registrationThis study was registered with the UMIN Clinical Trials Registry (UMIN000006957).

Novel L5-S1 interbody fusion technique for root anomalies or abnormal root configurations of L5-S1 foramens.

Purpose:We show in this study that if a root anomaly does not permit access to the disc space in the usual way, the technique we define here can be used. If the patient has a root anomaly or an abnormal root configuration at this level, inevitably, an anterior approach is preferred.Materials and Methods:The patient's previous skin incision was used; the L5-S1 space was reached laterally without entering the midline. The dura in the midline and the L5 and S1 roots on both sides were exposed. They were reached through the adjacent points of both S1 pedicles by going around the upper edge of the sacrum, allowing the disc space to be evacuated. An autologous bone graft was placed on both sides of the space. T10-S1 pedicle screws were placed. An L1 pedicle osteotomy was performed and joined using two rods.Results:The patient's back and leg pain disappeared after the surgery. The plain X-rays showed that the sagittal balance was restored. In this case, it is impossible to see the disc space because the nerve root blocks its view.Conclusions:The classic approach in such cases is to perform a fusion by either a transperitoneal or retroperitoneal approach or by performing a posterior intertransverse fusion. However, it is very challenging to execute an anterior L5-S1 fusion on a patient with pelvic retroversion. When the spinopelvic junction is included in the fusion, one common problem observed is pseudarthrosis. The surgical technique defined in this article makes it possible to drill the bone tissue through the disc space and the upper surface of the sacrum, accessing the pedicle bone. Then, a discectomy is performed at the disc space, a bone graft is placed, and a posterior lumbar interbody fusion is performed.

High-resolution nerve ultrasound and magnetic resonance neurography as complementary neuroimaging tools for chronic inflammatory demyelinating polyneuropathy.

Background:We present a clinical, electrophysiological, sonographical and magnetic resonance neurography (MRN) study examining the complementary role of two neuroimaging methods of the peripheral nervous system for patients with chronic inflammatory demyelinating polyneuropathy (CIDP). Furthermore, we explore the significance of cross-sectional area (CSA) increase through correlations with MRN markers of nerve integrity.Methods:A total of 108 nerve segments on the median, ulnar, radial, tibial and fibular nerve, as well as the lumbar and cervical plexus of 18 CIDP patients were examined with high-resonance nerve ultrasound (HRUS) and MRN additionally to the nerve conduction studies.Results:We observed a fair degree of correlation of the CSA values for all nerves/nerve segments between the two methods, with a low random error in Bland–Altman analysis (bias = HRUS-CSA − MRN-CSA, −0.61 to −3.26 mm). CSA in HRUS correlated with the nerve T2-weighted (nT2) signal increase as well as with diffusion tensor imaging parameters such as fractional anisotropy, a marker of microstructural integrity. HRUS-CSA of the interscalene brachial plexus correlated significantly with the MRN-CSA and nT2 signal of the L5 and S1 roots of the lumbar plexus.Conclusions:HRUS allows for reliable CSA imaging of all peripheral nerves and the cervical plexus, and CSA correlates with markers of nerve integrity. Imaging of proximal segments as well as the estimation of nerve integrity require MRN as a complementary method.

Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5-S1 Foraminal Decompression.

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5–S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a 30° arthroscope to enable foraminal decompression at the L5–S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5–S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a 30° arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5–S1 level that preserves facet stability and provides symptomatic relief.

Three-year Follow-Up Results of Lumbar Microendoscopic Discectomy (MED): A Prospective Study in 150 Patients

Background Data: The goal of all described surgical techniques to treat lumbar disc prolapse is removing the offending disc material, decompressing the nerve root, and relieving neurologic symptoms while avoiding complications. The goal of minimum invasiveness is to minimize the added morbidity of a larger exposure; including the creation of perineural scarring. Microendoscopic discectomy (MED) is a minimally invasive technique to treat lumbar disc prolapse. It is unique in that it combines open surgical principles with endoscopic technology. Follow-up will show whether MED will improve upon the long-term results of the “gold standard” procedures.Purpose: To evaluate the efficacy of lumbar MED, regarding results, safety, complications, stability of effectiveness, incidence of recurrence, instability and redo surgeries after 3 years of follow up.Study Design: A prospective clinical case studyPatients and Methods: We report 150 patients with lumbar disc prolapse, admitted at the Neurosurgery Department; Alexandria Main University Hospital and operated with MED technique. Patients were followed for 3 years. Clinical and radiological data were collected preoperatively and postoperativly. The degree of pain and disability were assessed using VAS and ODI. The length of the incision, the duration of surgery, and the average operative blood loss were calculated. Patients were followed at 2 weeks, 3 months, 1 year and 3 years.Results: This study included 150 patients; with 162 levels operated. 138 patients (92 %) had single level and 12 patients (8%) had double level surgery. L4-5 was the most common level. The mean duration of surgery was 55.0 minutes. The mean blood loss was 40.0 cc. The mean duration of hospital stay was 1.3 day. 81.3% of patients returned to their work in less than four weeks. The average length of skin incision was 2.38 cm. Intraoperative complications included four dural tears (2.6%), one (0.6%) pseudomeningocele, one (0.6%) partial nerve root injury (L5 root), and 3 (2%) superficial wound infection. No patient had postoperative instability or recurrences in the follow up period. There was a statistically significant difference between preoperative and postoperative VAS and ODI in the follow up evaluations (at 2 weeks, 3 months, 1 year & 3 years) (P=<0.001).Conclusion: MED technique allowed nerve root decompression; with minimal complications and preserving normal anatomy, with faster recoveries. For surgeons accustomed to performing endoscopic surgery, the use of MED is a safe and reliable alternative to microscopic discectomy. (2017ESJ124)

O99 Muscle velocity recovery cycles in neurogenic muscles

Muscle Velocity Recovery Cycles (MVRC) enable assessment of muscle membrane properties. MVRC has been studied in some myopathies, however, the method has never been tested in neurogenic muscles. We aimed in this study to examine whether MVRC differ in neurogenic and normal muscles and how MVRC variables correlate to the incidence of spontaneous activity (SA) in electromyography (EMG). Twenty-five patients with confirmed peroneal neuropathy (twenty) or L5 root lesion (five) were prospectively included. In addition to EMG, MVRC was done in anterior tibial muscle using Qtrac-software. MVRC parameters comprised muscle relative refractory period (MRRP) and early, late and residual supernormality after 1, 2 or 5 conditioning stimuli. Results were compared to 16 age- and sex-matched healthy subjects (HS). There was significant correlation between the incidence of SA and MRRP (r = 0.54) and early and late supernormality most pronounced in early supernormality after 5 conditioning stimulation (r = 0.64) (p < 0.001). The same MVRC parameters differed between patients and HS (t-test, p < 0.05). In contrast, residual supernormality did not differ between groups and there was no correlation to SA. Significantly prolonged MRRP and pronounced slowing in propagation velocity in early supernormal period suggest lower depolarization threshold in the denervated fibers. This is supported by significant correlation to incidence of SA in EMG. MVRC may be a potential diagnostic tool for electrodiagnosis of neuromuscular disorders and may provide information in understanding muscle pathophysiology. Future studies are required with larger patient groups with comparison of different nerve and muscle disorders.

Morphological anatomy of thoracolumbar nerve roots and dorsal root ganglia.

The aim of this study is to ascertain the anatomic parameters of the spinal roots and dorsal root ganglia and to demonstrate their clinical significance. Samples from 24 adult autopsy subjects were obtained from roots and dorsal root ganglia at levels L1 through L5. The anatomic parameters of epidural nerve roots: the distance between the epidural nerve roots and the proximal edge of the dorsal root ganglia and the average diameter of the nerve root gradually, increased from L1 to L5. The midline nerve root angle gradually decreased from L1 to L5. The anatomic parameters of subarachnoid nerve roots: the length of subarachnoid nerve roots and both the ventral and dorsal roots' diameter, increased from L1 to L5. The number of ventral and dorsal rootlets per nerve root ranged from one to three. The anatomic parameters of dorsal root ganglia: the length and width of the thoracic and lumbar dorsal root ganglia, gradually increased from L1 to L5. The locations of the dorsal root ganglia were recorded as the intraspinal, intraforaminal and extraforaminal using some bony landmarks. Most dorsal root ganglia located intraforaminally, and the extraforaminal type is more common in the L5 root than other thoracic and lumbar roots, regardless of age. This knowledge is a must not only to avoid complications but also for the success, safety and effectiveness of microsurgical operations.

In vivo recording of nerve conduction velocity of spinal CNS fibers in the mouse.

Anesthetic and surgical procedures and an electrophysiological method were developed for recording nerve conduction velocity (NCV) of CNS fibers in the murine spinal cord. Under intravenous anesthesia and artificial ventilation the lumbar spinal cord segments L1 to L4 and dorsal roots L3 to L5 on the left side were exposed by laminectomy. After stimulation of the dorsal root L4, a compound action potential (CAP) was recorded at the ipsilateral left fasciculus gracilis at the spinal cord level L1. The latency from stimulation to the CAP together with the measured distance between the electrodes was used for the determination of the NCV. NCV of the fastest fibers in the fasciculus gracilis was observed to be approximately 28 m/s. Reversible decrease of the NCV was measured, in vivo, under general hypothermia. The technique described serves for in vivo electrophysiological investigations of spinal central fibers in wildtype and mutant mice.

Réduction et fixation à foyer ouvert versus vissage ilio-sacré percutané des lésions postérieures instables de l’anneau pelvien

BackgroundSurgical stabilization of posterior pelvic ring fractures can be achieved by either open or closed methods. They all provide a comparable biomechanical stability. The aim of the present study is to compare the clinical results of both techniques for treating posterior pelvic ring injuries. Material and methodsSeventy patients operated for unstable posterior pelvic ring disruptions were retrospectively reviewed. We compared 35 patients treated by open reduction internal fixation (ORIF group) versus 35 patients stabilized by using closed reduction and percutaneous iliosacral screw fixation (CRIF group) under fluoroscopic guidance. ResultsAccording to pelvic outcome scoring system of Pohlemann et al., 28 patients out of the ORIF group obtained good or excellent results (20 excellent and 8 good), 5 fair and 2 poor. In the CRIF group, 30 patients obtained good or excellent results (25 excellent and 5 good), 4 fair and 1 poor, P=0.64). The average intraoperative blood loss in the ORIF group was 500cc with average blood transfusion of 2 units (1000cc) compared to blood loss 150cc in CRIF group, with average blood transfusion of 1 unit (500cc) (P=0.002). No intraoperative complications were reported in the ORIF group while operative guide wires were broken in two cases in the CRIF group, (P=0.16). There were no neurological complications observed in the ORIF group, but 1 radiculopathy (L5 root palsy) occurred in the CRIF group (P=0.317). In the ORIF group, 3 patients had superficial wound infection and 1 patient had deep infection while in the CRIF group, we noted only 1 case of deep infection, (P=0.083). ConclusionNo difference was noticed between ORIF and CRIF. The technical decision is variable according to time of surgery, fracture types, patient general condition, skin condition, presence of ipsilateral fractures of the acetabulum and feasibility of the closed reduction. More studies are needed to identify prognostic factors related to quality of the reduction that we need for the creation of decisional algorithm for ORIF versus CRIF. Level of evidenceLevel 4.

Reduced laser-evoked potential habituation detects abnormal central pain processing in painful radiculopathy patients.

Repetitive painful laser stimuli lead to physiological laser-evoked potential (LEP) habituation, measurable by a decrement of the N2/P2 amplitude. The time course of LEP-habituation is reduced in the capsaicin model for peripheral and central sensitization and in patients with migraine and fibromyalgia. In the present investigation, we aimed to assess the time course of LEP-habituation in a neuropathic pain syndrome, i.e. painful radiculopathy. At the side of radiating pain, four blocks of 25 painful laser stimuli each were applied to the ventral thigh at the L3 dermatome in 27 patients with painful radiculopathy. Inclusion criteria were (1) at least one neurological finding of radiculopathy, (2) low back pain with radiation into the foot and (3) a positive one-sided compression of the L5 and/or S1 root in the MRI. The time course of LEP-habituation was compared to 20 healthy height and age matched controls. Signs of peripheral (heat hyperalgesia) and central sensitization (dynamic mechanical allodynia and hyperalgesia) at the affected L5 or S1 dermatome were assessed with quantitative sensory testing. Painful radiculopathy patients showed decreased LEP-habituation compared to controls. Patients with signs of central sensitization showed a more prominent LEP-habituation decrease within the radiculopathy patient group. Laser-evoked potential habituation is reduced in painful radiculopathy patients, which indicates an abnormal central pain processing. Central sensitization seems to be a major contributor to abnormal LEP habituation. The LEP habituation paradigm might be useful as a clinical tool to assess central pain processing alterations in nociceptive and neuropathic pain conditions. Abnormal central pain processing in neuropathic pain conditions may be revealed with the laser-evoked potential habituation paradigm. In painful radiculopathy patients, LEP-habituation is reduced compared to healthy controls.

Differentiation of Pre- and Postganglionic Nerve Injury Using MRI of the Spinal Cord

Brachial plexus injury (BPI) is a devastating type of nerve injury, potentially causing loss of motor and sensory function. Principally, BPI is either categorized as preganglionic or postganglionic, with the early establishment of injury level being crucial for choosing the correct treatment strategy. Despite diagnostic advances, the need for a reliable, non-invasive method for establishing the injury level remains. We studied the usefulness of in vivo magnetic resonance imaging (MRI) of the spinal cord for determination of injury level. The findings were related to neuronal and glial changes. Rats underwent unilateral L4 & L5 ventral roots avulsion or sciatic nerve axotomy. The injuries served as models for pre- and postganglionic BPI, respectively. MRI of the L4/L5 spinal cord segments 4 weeks after avulsion showed ventral horn (VH) shrinkage on the injured side compared to the uninjured side. Axotomy induced no change in the VH size on MRI. Following avulsion, histological sections of L4/L5 revealed shrinkage in the VH grey matter area occupied by NeuN-positive neurons, loss of microtubular-associated protein-2 positive dendritic branches (MAP2), pan-neurofilament positive axons (PanNF), synaptophysin-positive synapses (SYN) and increase in immunoreactivity for the microglial OX42 and astroglial GFAP markers. Axotomy induced no changes in NeuN-reactivity, modest decrease of MAP2 immunoreactivity, no changes in SYN and PanNF labelling, and a modest increase in OX42 and SYN labeling. Histological and radiological findings were congruent when assessing changes after axotomy, while MRI somewhat underestimated the shrinkage. This study indicates a potential diagnostic value of structural spinal cord MRI following BPI.