Electrophysiology of radiculopathies

Neurologic Approach to Radiculopathy, Back Pain, and Neck Pain

Back pain and neck pain are common in clinical practice, but significant challenges and pitfalls exist in their diagnosis, treatment, and management. From the neurologic standpoint, cervical radiculopathy and lumbosacral radiculopathy are characterized by neck pain or back pain accompanied by sensory and motor symptoms in an arm or leg. The basic neurologic examination is vital, but testing like electromyography and MRI is often needed especially in cases that fail conservative management. Oral medications, injection-based therapies, physical therapy, and surgical evaluation all have a place in the comprehensive neurologic management of back and neck pain and associated radiculopathy.

Non-invasive central nervous system assessment of a porcine model of neuropathic pain demonstrates increased latency of somatosensory-evoked potentials

BACKGROUND

The study of chronic pain and its treatments requires a robust animal model with objective and quantifiable metrics. Porcine neuropathic pain models have been assessed with peripheral pain recordings and behavioral responses, but thus far central nervous system electrophysiology has not been investigated. This work aimed to record non-invasive, somatosensory-evoked potentials (SEPs) via electroencephalography in order to quantitatively assess chronic neuropathic pain induced in a porcine model.

NEW METHOD

Peripheral neuritis trauma (PNT) was induced unilaterally in the common peroneal nerve of domestic farm pigs, with the contralateral leg serving as the control for each animal. SEPs were generated by stimulation of the peripheral nerves distal to the PNT and were recorded non-invasively using transcranial electroencephalography (EEG). The P30 wave of the SEP was analyzed for latency changes.

RESULTS

P30 SEPs were successfully recorded with non-invasive EEG. PNT resulted in significantly longer P30 SEP latencies (p < 0.01 [n = 8]) with a median latency increase of 14.3 [IQR 5.0 - 17.5] ms. Histological results confirmed perineural inflammatory response and nerve damage around the PNT nerves.

COMPARISON WITH EXISTING METHOD(S)

Control P30 SEPs were similar in latency and amplitude to those previously recorded invasively in healthy pigs. Non-invasive recordings have numerous advantages over invasive measures.

CONCLUSIONS

P30 SEP latency can serve as a quantifiable neurological measure that reflects central nervous system processing in a porcine model of chronic pain. Advancing the development of a porcine chronic pain model will facilitate the translation of experimental therapies into human clinical trials.

Differential Screening of Herniated Lumbar Discs Based on Bag of Visual Words Image Classification Using Digital Infrared Thermographic Images

Doctors in primary hospitals can obtain the impression of lumbosacral radiculopathy with a physical exam and need to acquire medical images, such as an expensive MRI, for diagnosis. Then, doctors will perform a foraminal root block to the target root for pain control. However, there was insufficient screening medical image examination for precise L5 and S1 lumbosacral radiculopathy, which is most prevalent in the clinical field. Therefore, to perform differential screening of L5 and S1 lumbosacral radiculopathy, the authors applied digital infrared thermographic images (DITI) to the machine learning (ML) algorithm, which is the bag of visual words method. DITI dataset included data from the healthy population and radiculopathy patients with herniated lumbar discs (HLDs) L4/5 and L5/S1. A total of 842 patients were enrolled and the dataset was split into a 7:3 ratio as the training algorithm and test dataset to evaluate model performance. The average accuracy was 0.72 and 0.67, the average precision was 0.71 and 0.77, the average recall was 0.69 and 0.74, and the F1 score was 0.70 and 0.75 for the training and test datasets. Application of the bag of visual words algorithm to DITI classification will aid in the differential screening of lumbosacral radiculopathy and increase the therapeutic effect of primary pain interventions with economical cost.

Ultrasound-guided caudal epidural steroid injection in chronic radicular low back pain: short-term electrophysiologic benefits

OBJECTIVE

To assess the short-term efficacy of ultrasound-guided caudal epidural steroid injections (ESIs) in improving pain, and nerve function as measured by electrophysiological testing in chronic radicular low back pain.

METHODS

Patients diagnosed with chronic radicular low back pain were randomized into one of two groups. The injection group (n = 20) underwent a single ultrasound-guided Caudal ESI of 1 ml of 40 mg ml-1 Triamcinolone Acetonide (Kenacort-A), with local anesthetic. The control group (n = 20) underwent a 12-session physiotherapy program. Both groups were evaluated before and 2 weeks after the intervention using visual analog scale for pain and electrophysiological testing comprising peroneal and tibial terminal motor latencies and F-response latencies and chronodispersion.

RESULTS

Both groups showed significant pain reduction on the visual analog scale after the intervention. The injection group showed a significant reduction in F wave chronodispersion post-treatment (<0.01). In the control group, there were no significant differences in F wave parameters pre- and post-treatment (p > 0.05).

CONCLUSION

Caudal ESIs were shown to provide short-term improvement of nerve function as evident by improvement in the electrophysiological parameters sensitive to radiculopathy. It was found to be superior to standard physical therapy in this regard.

ADVANCES IN KNOWLEDGE

This work shows a novel electrophysiologic evidence of the short-term efficacy ultrasound-guided caudal ESI.

Electrodiagnosis of radiculopathy

While nerve conduction studies are an important part of the electrodiagnostic examination (EDX), the diagnosis of a radiculopathy rests mainly on the needle electrode examination (NEE) findings. Myotomal spontaneous activity and neurogenic motor unit potential (MUP) changes are the key abnormalities seen. To optimize the rate of identifying a radiculopathy, selection of appropriate muscles for the NEE is paramount. Myotomal charts derived from anatomic, radiographic, and EDX studies may help guide development of the NEE protocol for radiculopathy and increase the diagnostic yield. As recommended by a number of studies, the suggested minimum NEE protocol should consist of at least five proximal and distal limb muscles. NEE of paraspinal muscles should also be included routinely, but several limitations preclude reliance on isolated findings for establishing a diagnosis of radiculopathy. In addition to the NEE, the preservation of sensory nerve action potentials is also important in localizing the lesion to the nerve root. In some cases, they may be absent due to age or technical factors, confounding the diagnosis. Finally, various patterns of EDX findings may be seen in specific nerve root disorders that can help expedite diagnosis and clinical management.

Motor amplitudes may predict electromyography-confirmed radiculopathy in patients referred for radiating limb pain

INTRODUCTION

Radiculopathy is diagnosed by needle electromyography, with nerve conduction studies excluding alternative diagnoses.

METHODS

In patients referred for electrodiagnostic evaluation of radiating limb pain, we compared ulnar motor amplitudes between those with and without electromyographically confirmed C8 radiculopathy, as well as fibular motor amplitudes between those with and without electromyographically confirmed L5 radiculopathy.

RESULTS

Patients with electromyographically confirmed C8 or L5 radiculopathy demonstrated decreased ulnar or fibular motor amplitudes, respectively, as compared to patients without radiculopathy. Receiver operating characteristic curves demonstrated good diagnostic accuracy, with areas under the curve of 0.85 and 0.82, respectively. Optimal cut-offs for electromyographically confirmed C8 and L5 radiculopathies were 10.2 mV and 3.6 mV, respectively, with associated sensitivities/specificities of 0.86/0.74 and 0.92/0.60.

DISCUSSION

Ulnar and fibular motor amplitudes may have clinical utility in assessing the likelihood of patients demonstrating electromyographically confirmed C8 and L5 radiculopathies with active denervation. The findings may be particularly useful in patients intolerant of needle electromyography. Muscle Nerve 59:561-561, 2019.

Neurologic Injury After Sacral Neuromodulation

OBJECTIVE

Neurologic injury after sacral nerve stimulation (SNS) is rare, but the incidence is unknown. Infection is a potential mechanism for neurologic damage. This report illustrates the presentation, pathophysiology, diagnostic considerations, and treatment of epidural infection causing neurologic deficits after SNS.

CASE REPORT

We present a case of a woman with severe fecal incontinence due to Crohn's disease who underwent SNS implantation and subsequently developed a wound infection requiring complete device explantation. A few days later, she presented with leg pain and weakness. Urgent evaluation and treatment of epidural infection were performed. She had persistent neurologic deficits 6 months later.

CONCLUSIONS

Neurologic sequelae from an infection after SNS are a rare event and should be considered in patients with fevers, leg pain, and neurologic deficits.

Electrodiagnosis-based management of patients with radiculopathy: The concept and application involving a patient with a large lumbosacral disc herniation

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Postural H-reflex evaluates the degree/direction of neural compression/decompression.

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Direction sensitive exercise protocol based on H-reflex rehabilitates disc hernia.

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In this case report, 19 mm disc hernia reduced to 4 mm by the end of the treatment.

Objectives

The evaluation of patients with lower back pain (LBP) is based mainly on clinical examinations and imaging procedures that are subjective or anatomic in nature. The treatments, either physical therapy or osteopathy, lack evidence-based protocol and may be disruptive to the spine. Therefore, a neurophysiologic-based approach to managing such patients is necessary.

Methods

A 40-year-old female complained of LBP and radiculopathy for more than 12 years, a condition that was accompanied by numbness, tingling and weakness in the left leg. This study examined the effectiveness of using an innovative concept and method on a patient with a 19-mm disc herniation. An electro diagnosis-based evaluation and treatment approach testing tool, Soleus H-reflexes, was applied during unloading (with the patient lying down), loading (with the patient standing or sitting), and various trunk position protocols. A structured treatment was based on the results of H-reflex, including direction-sensitive exercises and manipulation, progressing from unloading to full loading. A custom-based home program was developed for sleeping and sitting positions, with all being directed at non-invasively decompressing the compromised nerve root. Data was analyzed using descriptive statistics.

Intervention and results

Stepwise application of the developed procedures resulted in complete resolution of the radicular and spinal symptoms, with a reduction in the size of the herniated disc from 19 mm to 4 mm and recovery of the H-amplitude by the end of the treatment. Functional recovery was also complete by the end of the program. A follow-up after 12 months showed maintained results.

Conclusions

The discussed concept and method exhibited their effectiveness in this case study, and the results obtained are due to the consistency and maintenance of the neural decompression using a direction sensitive therapy protocol.

Significance

Direction sensitive exercise therapy based on H-reflex testing is effective in treating large herniated lumbar discs.

Electromyographic Findings After Epidural Steroid Injections in Patients with Radicular Low Back Pain: A Prospective Open-Label Study

Epidural steroid injections (ESIs) are commonly used in the management of chronic lower back and leg pain. The aim of this study was to investigate the short- and long-term electromyographic and clinical outcome of patients with chronic radicular pain after ESIs. This prospective, open-label study, included patients with chronic radicular pain due to disc herniation or spinal stenosis, who underwent interlaminar, fluoroscopy-guided ESIs. Patients were assessed before ESIs, as well as after 6 and 12 months, clinically (VAS 0-10, BPI, DN4, Rolland Morris, DASS, STAI) and electromyographically for the improvement of spontaneous activity (SA) and of motor unit recruitment/interference pattern (IP/MUR). A total of 39 patients were studied, 20 (51.3%) who had a significant improvement in VAS, RM, DN4 and BPI were revealed, mainly during the first 6 months (P < 0.05). Statistically significant improvement was revealed in MUR/SA for almost all nerve roots studied. Patients with disc herniation showed a greater improvement in mean difference of MUR/SA (P < 0.05) (with a prognostic value of radicular LBP versus spinal stenosis in short- [VAS P = 0.042] and long-term improvement of pain [VAS P = 0.009]. The independent variables “MUR” and “SA” had a significant prognostic value for improvement of pain (VAS: R² = 0.287, P = 0.032 and VAS: R² = 0.277, P = 0.036 respectively). Electromyographic and clinical findings indicated a benefit from epidural steroid injections. Patients with disc herniation exhibited a better outcome, especially during the first 6 months post-treatment.

Evaluation of proximal and distal motor nerve conduction using the electrical root stimulation technique in the femoral and obturator nerves

Objectives: This study aimed to investigate the adaptability of the electrical root stimulation technique by achieving normative data from the obturator and femoral nerves of healthy dogs.

Methods: For this purpose, two stimulations and recordings were performed on both the obturator and femoral nerves in 40 dogs (22 males and 18 females). Electrical root stimulation was applied via monopolar needle electrodes between the sixth to seventh and fifth to sixth lumbar inter arcuate spaces to the obturator and femoral nerves, respectively. Muscle waves were recorded from the gracilis and sartorius muscles of the left and right pelvic limb.

Results: The proximal motor nerve conduction velocity was 60.89 ± 3.93 m/s and 59.87 ± 4.83 m/s in the obturator and femoral nerves, respectively.

Clinical significance: Our results showed that electrical root stimulation could be a useful method to test the integrity of the roots of obturator and femoral nerves and their proximal parts.

The Diagnostic Accuracy of Gluteal Trigger Points to Differentiate Radicular From Nonradicular Low Back Pain

OBJECTIVES

Low back pain (LBP) is highly prevalent and costly to the society. Previous studies have shown an association between radicular LBP and trigger points (TrPs) in the superior-lateral quadrant of the gluteal area (GTrP). The objective of current study was to evaluate the diagnostic value of GTrP to predict nerve root involvement among patients with LBP.

MATERIALS AND METHODS

In a prospective, diagnostic accuracy study 325 consecutive patients with LBP were recruited. At first step, patients were evaluated for the presence or absence of the GTrP. A different investigator, blinded to the GTrP findings, then performed history taking and physical examination. Subsequently, all patients underwent a lumbar spine magnetic resonance imaging and, when indicated, electrodiagnostic tests. On the basis of the clinical and ancillary tests findings, a multidisciplinary panel of experts (the "reference standard"), blinded to the GTrP evaluation, allocated patients to radicular versus nonradicular LBP groups. The agreement between the GTrP findings, as a diagnostic test and the reference standard allocation was evaluated in a 2 by 2 contingency table.

RESULTS

The specificity of the GTrP test was 91.4% and its sensitivity was 74.1%. The area under the receiver operating characteristic curve was 0.827 (0.781 to 0.874). Positive likelihood ratio was 8.62 and negative likelihood ratio was 0.28. Positive and negative predictive values were 91.9% and 72.7%, respectively.

DISCUSSION

As a clinical finding, TrPs in superior-lateral quadrant of gluteal area are highly specific indicators for radicular LBP. Incorporating these TrPs evaluation in routine physical examination of patients with LBP could decrease the need for more costly, time-consuming, and invasive diagnostic tests.

Relationships between the integrity and function of lumbar nerve roots as assessed by diffusion tensor imaging and neurophysiology

Purpose

Diffusion tensor imaging (DTI) has shown promise in the measurement of peripheral nerve integrity, although the optimal way to apply the technique for the study of lumbar spinal nerves is unclear. The aims of this study are to use an improved DTI acquisition to investigate lumbar nerve root integrity and correlate this with functional measures using neurophysiology.

Methods

Twenty healthy volunteers underwent 3 T DTI of the L5/S1 area. Regions of interest were applied to L5 and S1 nerve roots, and DTI metrics (fractional anisotropy, mean, axial and radial diffusivity) were derived. Neurophysiological measures were obtained from muscles innervated by L5/S1 nerves; these included the slope of motor-evoked potential input-output curves, F-wave latency, maximal motor response, and central and peripheral motor conduction times.

Results

DTI metrics were similar between the left and right sides and between vertebral levels. Conversely, significant differences in DTI measures were seen along the course of the nerves. Regression analyses revealed that DTI metrics of the L5 nerve correlated with neurophysiological measures from the muscle innervated by it.

Conclusion

The current findings suggest that DTI has the potential to be used for assessing lumbar spinal nerve integrity and that parameters derived from DTI provide quantitative information which reflects their function.

Magnetospinography visualizes electrophysiological activity in the cervical spinal cord

Diagnosis of nervous system disease is greatly aided by functional assessments and imaging techniques that localize neural activity abnormalities. Electrophysiological methods are helpful but often insufficient to locate neural lesions precisely. One proposed noninvasive alternative is magnetoneurography (MNG); we have developed MNG of the spinal cord (magnetospinography, MSG). Using a 120-channel superconducting quantum interference device biomagnetometer system in a magnetically shielded room, cervical spinal cord evoked magnetic fields (SCEFs) were recorded after stimulation of the lower thoracic cord in healthy subjects and a patient with cervical spondylotic myelopathy and after median nerve stimulation in healthy subjects. Electrophysiological activities in the spinal cord were reconstructed from SCEFs and visualized by a spatial filter, a recursive null-steering beamformer. Here, we show for the first time that MSG with high spatial and temporal resolution can be used to map electrophysiological activities in the cervical spinal cord and spinal nerve.

Failure of Intraoperative Monitoring to Detect Postoperative Neurologic Deficits: A 25-year Experience in 12,375 Spinal Surgeries

STUDY DESIGN

Retrospective.

OBJECTIVE

The purpose was to categorize and evaluate intraoperative monitoring (IOM) failure to detect neurologic deficits occurring during spinal surgery.

SUMMARY OF BACKGROUND DATA

The efficacy of spinal cord/nerve root monitoring regarding undetected neurologic deficits is examined in a large, single institution series involving all levels of the spinal column and all spinal surgical procedures.

METHODS

Multimodality IOM included somatosensory-evoked potentials (SSEPs), descending neurogenic-evoked potentials (DNEPs), transcranial motor-evoked potentials (MEPs), dermatomal somatosensory-evoked potentials (DSEPs), and spontaneous and triggered electromyography (spEMG, trgEMG). We reviewed 12,375 patients who underwent surgery for spinal pathology from 1985 to 2010. There were 7178 females (59.3%) and 5197 males (40.7%); 9633 (77.8%) primary surgeries and 2742 (22.2%) revisions. Procedures by spinal level were cervical 29.7% (3671), thoracic/thoracolumbar 45.4% (5624), and lumbosacral 24.9% (3080). Age at surgery was > 18 years - 72.7% (8993) and < 18 years - 27.3% (3382).

RESULTS

Forty-five of the 12,375 patients (0.36%) had false negative outcomes. False negative results by modality were as follows: spEMG (n = 22, 48.8%), trgEMG (n = 8, 17.7%), DSEP (n = 4, 8.8%), DNEP (n = 4, 8.8%), SSEP (n = 3, 6.6%), DSEP/spEMG (n = 3, 6.6%), and trgEMG/spEMG (n = 1, 2.2%). Thirty-seven patients had immediate postoperative deficits unidentified by IOM; 30 patients (81%) involved nerve root monitoring, four patients had spinal cord deficits, and three patients had peripheral sensory deficits. Eight patients had permanent neurologic deficits, six (0.048%) were nerve root and two (0.016%) were spinal cord in nature.

CONCLUSION

Despite correct application and usage, IOM data failed to identify 45 (0.36%) patients with false negative outcomes out of 12,375 surgical patients. Eight patients (0.064%) of these 45 patients had permanent neurologic deficits, six patients had nerve root deficits in nature and two patients had spinal cord deficits. Although admittedly small, this represents the risk of undetected neurologic deficits even when properly using IOM. Deficits are at a higher risk to remain unresolved when not detected by IOM.

LEVEL OF EVIDENCE

4.

Non-invasive electrical and magnetic stimulation of the brain, spinal cord, roots and peripheral nerves: Basic principles and procedures for routine clinical and research application. An updated report from an I.F.C.N. Committee

These guidelines provide an up-date of previous IFCN report on “Non-invasive electrical and magnetic stimulation of the brain, spinal cord and roots: basic principles and procedures for routine clinical application” (Rossini et al., 1994). A new Committee, composed of international experts, some of whom were in the panel of the 1994 “Report”, was selected to produce a current state-of-the-art review of non-invasive stimulation both for clinical application and research in neuroscience.

Since 1994, the international scientific community has seen a rapid increase in non-invasive brain stimulation in studying cognition, brain–behavior relationship and pathophysiology of various neurologic and psychiatric disorders. New paradigms of stimulation and new techniques have been developed. Furthermore, a large number of studies and clinical trials have demonstrated potential therapeutic applications of non-invasive brain stimulation, especially for TMS. Recent guidelines can be found in the literature covering specific aspects of non-invasive brain stimulation, such as safety (Rossi et al., 2009), methodology (Groppa et al., 2012) and therapeutic applications (Lefaucheur et al., 2014).

This up-dated review covers theoretical, physiological and practical aspects of non-invasive stimulation of brain, spinal cord, nerve roots and peripheral nerves in the light of more updated knowledge, and include some recent extensions and developments.

Abnormal flexor carpi radialis H-reflex as a specific indicator of C7 as compared with C6 radiculopathy

OBJECTIVE

The H-reflex of the flexor carpi radialis (FCR H-reflex) has not been commonly used for the diagnosis of cervical radiculopathy when compared with the routinely tested soleus H-reflex. Although both S1 and S2 roots innervate the soleus, the H-reflex is selectively related to S1 nerve root function clinically. Flexor carpi radialis is also innervated by two nerve roots which are C6 and C7. Although they are among the most common roots involved in cervical radiculopathy, few studies reported if the attenuation of the FCR H-reflex is caused by lesions affecting C7 or C6 nerve roots, or both. We aimed to identify whether an abnormal FCR H-reflex was attributed to the C7 or C6 nerve root lesion, or both. The sensitivities of needle electromyography, FCR H-reflex, and provocative tests in unilateral C7 or C6 radiculopathy were also compared in this study.

METHODS

A concentric needle electrode recorded bilateral FCR H-reflexes in 41 normal subjects (control group), 51 patients with C7 radiculopathy, and 54 patients with C6 radiculopathy. Clinical, radiological, and surgical approaches identified the precise single cervical nerve root involved in all patient groups. The H-reflex and M-wave latencies were measured and compared bilaterally. Abnormal FCR H-reflex was defined as the absence of the H-reflex or a side-to-side difference over 1.5 milliseconds which was based on the normal side-to-side difference of the H-reflex latency of 16.9 milliseconds (SD = 1.7 milliseconds) from the control group. We also determined standard median and ulnar conduction and needle electromyography. The provocative tests included bilateral determination of the Shoulder Abduction and Spurling's tests in all radiculopathy group patients.

RESULTS

Abnormal FCR H-reflexes were recorded in 45 (88.2%) of C7 radiculopathy group patients, and 2 (3.7%) of C6 radiculopathy group patients (P < 0.05). Needle electromyography was abnormal in 41 (80.4%) of C7 radiculopathy patients and 43 (79.6%) of C6 radiculopathy patients. Provocative tests were positive in 15 (29.4%) of C7 radiculopathy patients and 25 (46.3%) of C6 radiculopathy patients.

CONCLUSIONS

Flexor carpi radialis H-Reflex provides a sensitive assessment of evaluating the C7 spinal reflex pathway. Clinically, a combination of the FCR H-reflex with needle electromyography may yield the highest level of diagnostic information for evaluating clinical cases of C7 radiculopathy.

Potential advantages of the H-reflex of the biceps femoris-long head in documenting S1 radiculopathy

PURPOSE

A novel H-reflex method using the biceps femoris-long head (BF-LH) was investigated to collect the normative data for this reflex arc and assess its clinical utility for S1 radiculopathy evaluation. Comparability with conventional tibial and Sol H-reflex findings was also determined.

METHODS

BF-LH H-reflexes were recorded using surface electrodes to S1-root stimulation in 43 unilateral S1 radiculopathy patients (radiculopathy group) and 34 normal subjects (control group) from March 2009 to December 2011. H-M interval and peak-to-peak amplitudes were measured. The BF-LH H-reflex and the H-reflex from the soleus muscle (Sol H-reflex) to both tibial nerve stimulation (tibial H-reflex) and S1-root stimulation were used and compared for application in S1 radiculopathy evaluation.

RESULTS

BF-LH H-reflexes were reliably recorded for all control group subjects. Abnormal BF-LH H-reflexes were recorded for 40 (93.0%) radiculopathy group patients in the involved extremity, and abnormal involved side tibial H-reflexes and Sol H-reflexes were recorded in 31 (72.1%) and 41 (95.3%) radiculopathy group patients, respectively. The BF-LH H-reflex exhibited significantly higher sensitivity for evaluation of S1 radiculopathy, accurate in 40 (93.0%) radiculopathy group patients, than that provided by the conventional tibial H-reflex of only 31 (72.1%) (P < 0.05).

CONCLUSIONS

The BF-LH H-reflex is a highly sensitive and reliable clinical tool for evaluation of the S1 spinal reflex pathway in radiculopathy that is distinct from the Sol H-reflex and conventional tibial H-reflex arcs.

Electrical stimulation of lumbar spinal nerve roots in dogs

The aim of this study was to test the applicability of electrical stimulation of lumbar spinal nerve roots and obtain normative electrical root stimulation (ERS) data for L7 nerve root and sciatic nerve in dogs. For that purpose ERS and sciatic nerve stimulations were performed consecutively, in totally 40 healthy dogs. ERS was applied in the L7/S1 intervertebral space via monopolar needle electrodes. Muscle responses were recorded from the gastrocnemius muscles on the left and right hind limbs. Sciatic nerve stimulation was performed at the greater trochanter level on the left hind limb, with records obtained from the left gastrocnemius muscle. Mean root latencies of the left and right side were 5.22 ± 0.49 ms and 5.29 ± 0.53 ms, respectively. There was no significant difference in root latency between the right and left sides. The mean terminal latency was 3.82 ± 0.46 ms. The proximal motor nerve conduction velocity of the sciatic nerve was 63.15 ± 3.43 m/s. The results of this study show that ERS provides objective data about the integrity of lumbar spinal nerve roots by evaluating the entire population of motor fibres and total length of the motor axon in dogs. ERS can be considered a useful diagnostic method for confirmation of diagnoses of lumbosacral diseases.

The study of diagnostic efficacy of nerve conduction study parameters in cervical radiculopathy

BACKGROUND

Cervical Radiculopathy (CR) is a neurologic condition characterised by dysfunction of a cervical spinal nerve, the roots of the nerve, or both. Diagnostic criteria for CR are not well defined, and no universally accepted criteria for its diagnosis have been established. Clinical examination, radiological imaging and electrophysiologic evaluation are the different modalities to diagnose CR. The incidence of Cervical Spondylosis and related conditions is increasing in the present scenario and the use of radiologic examination is time consuming and uneconomical for the common Indian setup. Thus, there is a definite need to establish a cost effective, reliable, and accurate means for establishing the diagnosis of cervical radiculopathy. Electrodiagnostic tests are the closest to fulfill these criteria.

AIM

To evaluate diagnostic utility of various motor and sensory nerve conduction study parameters in cervical radiculopathy.

SETTING AND DESIGN

It was a cross-sectional study conducted on 100 subjects of age > 40 years.

MATERIAL AND METHODS

The consecutive patients clinically diagnosed to have cervical radiculopathy, referred from department of Orthopaedics were prospectively recruited for the motor and sensory nerve conduction study using RMS EMG EP Mark-II. Parameters studied were Compound Muscle Action Potential (CMAP), Distal Motor Latency (DML) and Conduction Velocity (CV) for motor nerves and Sensory Nerve Action Potential (SNAP) and CV for sensory nerves.

STATISTICAL ANALYSIS

Study observations and results were analysed to find the Specificity, Sensitivity, Positive Predictive Value and Negative Predictive Value using SPSS 16.0.

RESULTS

Among various motor nerve conduction parameters CMAP was found to be more sensitive with high positive predicative value. CV was found to have greater specificity and DML had least negative predictive value. Sensory nerve conduction parameters were found to have less sensitivity but higher specificity as compared to motor parameters.

CONCLUSION

Nerve conduction studies are useful supportive diagnostic tool for suspected cervical radiculopathy as they are found to have reliable sensitivity and specificity.

Shoulder hemiarthroplasty for proximal humeral fractures: comparisons between the deltopectoral and anterolateral deltoid-splitting approaches

BACKGROUND

Shoulder hemiarthroplasty is a widely accepted method for treating complex proximal humeral fractures, and the deltopectoral approach is the most popular route for this procedure. The purpose of the current study was to define and compare outcomes of shoulder hemiarthroplasty when using deltopectoral or anterolateral deltoid-splitting approaches.

MATERIALS AND METHODS

Two cohorts of patients were compared for clinical and radiographic outcomes at the same postoperative follow-up periods: a deltopectoral group (DP group) of 15 patients, from November 2004 to April 2007, and an anterolateral deltoid-splitting group (DS group) of 17 patients, from May 2007 to December 2009. Pain scores, goniometric measurements of the range of motion, and Constant scores were recorded for clinical assessment. Radiographic evaluations were recorded for stem osteolysis, tuberosity absorption, joint subluxation, and acromiohumeral distance.

RESULTS

The 2 groups did not differ significantly in demographic data, preoperative fracture classification, surgical timing, early postoperative radiographic findings, and 2-year radiographic results. The DS group had less immediate postoperative pain (P = .025). At the 2-year follow-up assessment, the groups did not difference significantly in shoulder abduction and forward flexion. All prostheses survived until the 2-year assessment.

CONCLUSION

When performing shoulder hemiarthroplasty for complex proximal humeral fractures, we found that the anterolateral deltoid-splitting approach provides an easier route for assessing posterior fracture fragments and managing rotator cuff tissue. The anterolateral deltoid-splitting approach was shown to be an acceptable alternative route for shoulder hemiarthroplasty than the standard deltopectoral approach.

Skin temperature changes in patients with unilateral lumbosacral radiculopathy

Objective

To clarify the relationship of skin temperature changes to clinical, radiologic, and electrophysiological findings in unilateral lumbosacral radiculopathy and to delineate the possible temperature-change mechanisms involved.

Methods

One hundred and one patients who had clinical symptoms and for whom there were physical findings suggestive or indicative of unilateral lumbosacral radiculopathy, along with 27 normal controls, were selected for the study, and the thermal-pattern results of digital infrared thermographic imaging (DITI) performed on the back and lower extremities were analyzed. Local temperatures were assessed by comparing the mean temperature differences (ΔT) in 30 regions of interest (ROIs), and abnormal thermal patterns were divided into seven regions. To aid the diagnosis of radiculopathy, magnetic resonance imaging (MRI) and electrophysiological tests were also carried out.

Results

The incidence of disc herniation on MRI was 86%; 43% of patients showed electrophysiological abnormalities. On DITI, 97% of the patients showed abnormal ΔT in at least one of the 30 ROIs, and 79% showed hypothermia on the involved side. Seventy-eight percent of the patients also showed abnormal thermal patterns in at least one of the seven regions. Patients who had motor weakness or lateral-type disc herniation showed some correlations with abnormal DITI findings. However, neither pain severity nor other physical or electrophysiological findings were related to the DITI findings.

Conclusion

Skin temperature change following lumbosacral radiculopathy was related to some clinical and MRI findings, suggesting muscle atrophy. DITI, despite its limitations, might be useful as a complementary tool in the diagnosis of unilateral lumbosacral radiculopathy.

Clinical findings and electrodiagnostic testing in 108 consecutive cases of lumbosacral radiculopathy due to herniated disc

STUDY AIM

This prospective study aim to examine whether clinical findings and electrodiagnostic testing (EDX) in patients with lumbosacral monoradiculopathy due to herniated disc (HD) differ as a function of root involvement level (L5 vs. S1) and HD zone (paramedian vs. intraforaminal).

PATIENTS AND METHODS

All patients with L4, L5 or S1 monoradiculopathy were prospectively enrolled at four electromyography (EMG) labs over a 2-year period. The diagnosis was based on a congruence between patient history and MRI evidence of HD. We compared the sensitivities of clinical findings and EDX with respect to both root involvement level and HD zone. Multivariate logistic regression was performed in order to verify the association between abnormal EMG, clinical, and neuroradiological findings.

RESULTS

One hundred and eight patients (mean age 47.7 years, 55% men) were consecutively enrolled. Sensory loss in the painful dermatome was the most frequent finding at physical examination (56% of cases). EMG was abnormal in at least one muscle supplied by femoral and sciatic nerves in 45 cases (42%). Inclusion of paraspinal muscles increased sensitivity to only 49% and that of proximal muscles was useless. Motor and sensory neurography was seldom abnormal. The most frequent motor neurographic abnormalities were a delay of F-wave minimum latency and decrease in the compound muscle action potential amplitude from extensor digitorum brevis and abductor hallucis in L5 and S1 radiculopathies, respectively. Sensory neurography was usually normal, the amplitude of sensory nerve action potential was seldom reduced when HD injured dorsal root ganglion or postganglionic root fibres. Multivariate logistic regression analysis showed that EMG abnormalities could be predicted by myotomal muscular weakness, abnormal deep reflexes, and paraesthesiae. The only clinical and electrophysiological differences with respect to root involvement level concerned deep reflexes and motor neurography of deep peroneal and tibial nerves.

CONCLUSIONS

Only some EDX parameters are helpful for the diagnosis of lumbosacral radiculopathy. EMG was abnormal in less than 50% of cases and its abnormalities could be predicted by some clinical findings. However, neurography is useful as a tool for differential diagnosis between radiculopathy and more diffuse disorders of the peripheral nervous system (polyneuropathy, plexopathy).

Electrophysiological diagnosis using sensory nerve action potential for the intraforaminal and extraforaminal L5 nerve root entrapment

BACKGROUND

The diagnosis of lumbar intraforaminal and extraforaminal stenosis (lumbar foraminal stenosis) is sometimes difficult. However, sensory nerve action potential (SNAP) decreases in amplitude when the lesion is at or distal to the dorsal root ganglion. Therefore, the amplitude of SNAP with lumbar foraminal stenosis should be decreased. In this cohort study, the usefulness of SNAP for the preoperative diagnosis of L5/S foraminal stenosis was assessed.

METHODS

In 63 patients undergoing unilateral L5 radiculopathy, bilateral SNAPs were recorded for the superficial peroneal nerve (L5 origin). The patients were divided into two groups according to the results of imaging examinations. Group A (37 patients) included patients whose lesion was located only at the intraspinal canal. In group B (26 patients), the lesion was located only at the intra- or extraforaminal area. All patients received surgery and the symptoms were diminished. The ratios of the amplitudes of SNAPs on the affected side to that on the unaffected side were compared between groups A and B.

RESULTS

SNAPs could not be elicited bilaterally in four patients. The amplitude ratio for group B (median 0.42, max 1.17, min 0) was significantly lower than that in group A (median 0.85, max 1.43, min 0) (p < 0.001 by Mann-Whitney U test). Using a cut-off value of 0.5 for the amplitude ratio, the sensitivity for the diagnosis of lumbar foraminal stenosis was 91.3 % with a specificity of 85.7 %.

CONCLUSIONS

Measurement of SNAP could be useful to diagnose a unilateral L5/S foraminal stenosis.

Extension traction treatment for patients with discogenic lumbosacral radiculopathy: a randomized controlled trial

OBJECTIVE

To investigate the effects of lumbar extension traction in patients with unilateral lumbosacral radiculopathy due to L5-S1 disc herniation.

DESIGN

A randomized controlled study with six-month follow-up.

SETTING

University research laboratory.

SUBJECTS

Sixty-four patients with confirmed unilateral lumbosacral radiculopathy due to L5-S1 disc herniation and a lumbar lordotic angle less than 39°, randomly assigned to traction or control group.

INTERVENTIONS

The control group (n = 32) received hot packs and interferential therapy, whereas the traction group (n = 32) received lumbar extension traction in addition to hot packs and interferential therapy.

MAIN OUTCOME MEASURES

Absolute rotatory angle, back and leg pain rating scale, Oswestry Disability Index, Modified Schober test, H-reflex (latency and amplitude) and intervertebral movements were measured for all patients three times (before treatment, after 10 weeks of treatment and at six-month follow-up).

RESULTS

There was a significant difference between the traction group and the control group adjusted to baseline values at 10 weeks post treatment with respect to: absolute rotatory angle (P < 0.001), Oswestry Disability Index (P = 0.002), back and leg pain (P = 0.009, P = 0.005), Modified Schober test (P = 0.002), latency and amplitude of H-reflex (P = 0.01, P < 0.001), intervertebral movements (P < 0.05). At six-month follow-up there were statistically significant differences between the study and control groups for all the previous variables (P < 0.05).

CONCLUSION

The traction group receiving lumbar extension traction in addition to hot packs and interferential therapy had better effects than the control group with regard to pain, disability, H-reflex parameters and segmental intervertebral movements.

Locked plating for proximal humeral fractures: differences between the deltopectoral and deltoid-splitting approaches

BACKGROUND

Locking proximal humerus plate (LPHP) fixation has recently become available for the treatment of proximal humeral fractures. However, the preliminary results were contradictory. The technical requirements for success when using LPHP remain to be defined. Maybe the approach to the proximal humerus plays an important role, not the implants. We analyzed two surgical approaches to proximal humeral fractures.

METHODS

Between April 2004 and October 2007, 63 consecutive patients with displaced proximal humeral fractures who underwent LPHP osteosynthesis in our institute were classified to two treatment groups retrospectively: the deltopectoral incision and the deltoid-splitting incision according to surgeon's preference. The Constant and Disabilities of the Arm, Shoulder and Hand scores were recorded for clinical assessment. Quality of reduction, fracture union, and radiographic complications were recorded for radiographic assessment. Electrophysiological abnormalities were also assessed.

RESULTS

There were no significant differences between the groups with regard to demographic data, preoperative radiographic findings, and duration of follow-up. There were also no significant differences between the groups with regard to operative time (p = 0.918), blood loss (p = 0.407), hospital stay (p = 0.431), postoperative head-shaft angle (p = 0.769), union time (p = 0.246), final head-shaft angle (p = 0.533), Constant score (p = 0.677), Disabilities of the Arm, Shoulder and Hand score (p = 0.833), radiographic complications (p = 1.000), and presence of electrophysiological abnormalities (p = 0.296). Avascular necrosis of the humeral head was found in three patients, all of whom in the deltopectoral approach group.

CONCLUSION

We found no statistically significant difference in clinical, radiographic, and electrophysiological outcomes between the deltopectoral approach and deltoid-splitting approach while surgical treatment of proximal humeral fractures.

Use of a multimodal conservative management protocol for the treatment of a patient with cervical radiculopathy

OBJECTIVE

The purpose of this study is to describe and discuss the treatment of a cervical disk herniation using a sequential multimodal conservative management approach.

CLINICAL FEATURES

A 40-year-old man had complaints of headache and severe sharp neck pain radiating to his left shoulder down to his arm, forearm, and hand. Results of electromyography/nerve conduction studies were abnormal. Magnetic resonance imaging revealed a large disk protrusion at C5-C6 with indentation of the thecal sac and a spur at the posterior margin. Moderate left neural foraminal narrowing was present at C5-C6 with narrowed intervertebral disk space at C5-C6 and C6-C7.

INTERVENTION AND OUTCOME

High-velocity, low-amplitude chiropractic manipulation; electrotherapy; ice; and exercise were used for treatment. The Neck Disability Index was used as a primary and electromyography/nerve conduction studies as a secondary outcome measurement. Based on the Neck Disability Index, there was an overall 89.65% symptoms improvement from the baseline.

CONCLUSIONS

This case study demonstrated possible beneficial effects of the multimodal treatment approach in a patient with cervical radiculopathy.

Magnetic resonance neurography for the evaluation of peripheral nerve, brachial plexus, and nerve root disorders

Object

Treatment of spinal and peripheral nerve lesions relies on localization of the pathology by the use of neurological examination, spinal MR imaging and electromyography (EMG)/nerve conduction studies (NCSs). Magnetic resonance neurography (MRN) is a novel imaging technique recently developed for direct imaging of spinal and peripheral nerves. In this study, the authors analyzed the role of MRN in the evaluation of spinal and peripheral nerve lesions.

Methods

Imaging studies, medical records, and EMG/NCS results were analyzed retrospectively in a consecutive series of 191 patients who underwent MRN for spinal and peripheral nerve disorders at the University of California, San Francisco between March 1999 and February 2005. Ninety-one (47.6%) of these patients also underwent EMG/NCS studies.

Results

In those who underwent both MRN and EMG/NCS, MRN provided the same or additional diagnostic information 32 and 45% of patients, respectively. Magnetic resonance neurograms were obtained at a median of 12 months after the onset of symptoms. The utility of MRN correlated with the interval between the onset of symptoms to MRN. Twelve patients underwent repeated MRN for serial evaluation. The decrease in abnormal signal detected on subsequent MRN correlated with time from onset of symptoms and the time interval between MRN, but not with resolution of symptoms. Twenty-one patients underwent MRN postoperatively to assess persistent, recurrent, or new symptoms; of these 3 (14.3%) required a subsequent surgery.

Conclusions

Magnetic resonance neurography is a valuable adjunct to conventional MR imaging and EMG/NCS in the evaluation and localization of nerve root, brachial plexus, and peripheral nerve lesions. The authors found that MRN is indicated in patients: 1) in whom EMG and traditional MR imaging are inconclusive; 2) who present with brachial plexopathy who have previously received radiation therapy to the brachial plexus region; 3) who present with brachial plexopathy and have systemic tumors; and 4) in patients under consideration for surgery for peripheral nerve lesions or after trauma. Magnetic resonance neurography is limited by the size of the nerve trunk imaged and the timing of the study.

Laser-evoked potentials: prognostic relevance of pain pathway defects in patients with acute radiculopathy

The radicular pain syndrome is a major problem in public health care that can lead to chronic back and leg pain in 30%. Ischalgia and back pain are the most prominent signs of dorsal root affection. Until now, no clinical or neurophysiological test procedure exists that evaluates the function of the dorsal root and predicts the prognosis of patients suffering from RPS. We have recently demonstrated that laser-evoked potentials (LEP) are able to demonstrate dorsal root damage. With this study, we investigated 54 patients with acute radicular symptoms and compared LEP parameters (side to side difference of latency and amplitude, transformed to a z-score) with their state of health after 3 months to calculate their predictive value for outcome prognosis. Most significantly, the latency difference between the LEP of the affected dermatome relative to the contralateral healthy dermatome was able to predict the prognosis. Latency z score above two demonstrates a 91% specificity (33% sensitivity) for a poor outcome at 3 months. A significant relation between amplitude changes and the main outcome measure could not be shown. Only extreme changes (z score >10) in amplitude show a high specificity for the persistence of ischialgia in particular (specificity 0.94; sensitivity 0.35). All other parameters, such as clinical scores or other LEP parameters, were not able to predict the outcome of patients. We propose that clinical testing using LEP with latency analysis is a useful tool for estimating the course of disease, so that patients with poor predictive parameters can be treated more invasively at early disease stages to avoid persistence of radiculopathy.

Ulnar nerve impairment at the wrist does not contribute to extramedian sensory symptoms in carpal tunnel syndrome

OBJECTIVE

Extramedian spread of sensory symptoms is frequent in carpal tunnel syndrome (CTS) but its mechanisms are unclear. We explored the possible role of subtle ulnar nerve abnormalities in the pathogenesis of extramedian symptoms.

METHODS

We recruited 350 CTS patients. After selection, 143 patients (225 hands) were included. The hand symptoms distribution was graded with a diagram into median (MED) and extramedian (EXTRAMED) pattern. We tested the correlation of ulnar nerve conduction measures with the distribution and the severity of symptoms involving the ulnar territory. The clinical significance of ulnar nerve conduction findings was explored with quantitative sensory testing (QST).

RESULTS

EXTRAMED distribution was found in 38.7% of hands. The ulnar neurographic measures were within normal values. Ulnar nerve sensory measures were significantly better in EXTRAMED vs MED hands and not significantly correlated to ulnar symptoms severity. Ulnar and median nerve sensory measures were significantly correlated. QST showed normal function of ulnar nerve alphabeta-fibers.

CONCLUSIONS

Ulnar nerve sensory abnormalities do not contribute to the spread of sensory symptoms into the ulnar territory.

SIGNIFICANCE

Our data favour the hypothesis that spinal and supraspinal neuroplastic changes may underlie extramedian spread of symptoms in CTS.

Motor conduction time along the cauda equina in patients with lumbar spinal stenosis

STUDY DESIGN

Magnetic lumbar stimulation was used to detect spinal nerve degeneration in patients with lumbar spinal stenosis (LSS).

OBJECTIVE

To evaluate delays in the motor conduction time in the cauda equina of patients with LSS.

SUMMARY OF BACKGROUND DATA

Previous studies suggested a bilateral slowing of motor conduction in the cauda equina in LSS. Among several methods, only magnetic stimulation is sufficiently sensitive for detecting potential degeneration in LSS. A recent study demonstrated the direct calculation of the cauda equina motor conduction time using magnetic stimulation at proximal and distal sites of the cauda equina. We used this technique to determine potential degeneration in patients with LSS.

METHODS

Twenty adult subjects and 15 patients with LSS were investigated. Lumbosacral roots were stimulated at intervertebral levels L1-L2 and L5-S1 by magnetic coil stimulation. The muscle responses to stimulation were recorded from the gastrocnemius-soleus, and anterior tibialis muscles on both sides with bipolar surface electrodes. The response latency from stimulations at the L5 spine level were subtracted from those at the L1 level on the same side. This value represented the conduction time from the proximal to distal ends of the cauda equina.

RESULTS

The mean conduction time along the cauda equina was significantly prolonged in patients with LSS compared with controls. The mean cauda equina motor conduction time was 1.97 +/- 0.67 milliseconds in controls and 3.57 +/- 2.22 milliseconds in patients with LSS (P = 0.00).

CONCLUSION

Determining the motor conduction time along the cauda equina using L1 and L5 magnetic stimulation provides an effective alternative method for evaluating the lumbar motor roots in patients with LSS.

Submaximal stimulation and f-wave parameters

PURPOSE

This study evaluates the effect of submaximal stimulation and varying stimulus rates on F-wave parameters.

METHODS

F-waves were recorded from the abductor pollicis brevis muscle from 3 normal subjects stimulating at 25%, 50%, and 75% intensity in comparison with supramaximal stimulation based on peak-to-peak compound muscle action potential amplitude. The effect of varying stimulus intensity (0.5, 1.0, and 2.0 Hz) at 30% stimulus intensity was also evaluated. Data were evaluated based on "true" values obtained after 100 stimuli. F-wave parameters studied included latencies (minimal and mean), amplitudes, persistences, durations, chronodispersions, and mean F amplitudes/maximum compound muscle action potential amplitudes.

RESULTS

For varying stimulus intensities and rates, the following results were obtained: (1) no meaningful change in F latencies or durations; (2) mean latency values were more reproducible than minimum; (3) amplitudes, persistence, and mean F amplitudes/maximum M-wave amplitude ratios increase linearly with increase in stimulus intensities; (4) chronodispersion increases with increase in stimulus intensity; (5) 20 stimuli appear adequate for true values at supramaximal stimulation but more are needed at submaximal levels; (6) varying stimulus frequency at submaximal stimulation did not meaningfully affect the results.

CONCLUSIONS

F-parameters require more stimuli at submaximal stimulation and, except for latencies and durations, would require different normal values than at supramaximal stimulation.

Routine electrodiagnosis and a multiparameter technique in lumbosacral radiculopathies

OBJECTIVE

This study compares Routine nerve conductions studies (NCS)/needle electromyography (nEMG) with a multiparameter recording method (NC-stat; NeuroMetrix Inc., Waltham, MA, USA) in patients with lumbosacral radiculopathies (LSR).

METHODS

Charts from 34 consecutive patients with a clinical history and/or examination consistent with an LSR were retrospectively reviewed. All underwent both Routine NCS/nEMG studies and NC-stat EDX. NC-stat testing included peroneal and posterior tibial nerve distal motor latencies and amplitudes and F-wave analysis. Twenty-eight patients had magnetic resonance imaging of the lumbosacral spine, and two had post-myelogram computerized tomography scan.

RESULTS

In the 24 patients with abnormal routine NCS/nEMG, NC-stat EDX was abnormal in 22. Raw agreement values between specific abnormal Routine and NC-stat EDX parameters ranged from 065 to 0.76. NC-stat amplitude and F-wave data provide reasonable electrodiagnostic 'rule in, rule out' information for LSR. Routine and NC-stat EDX had comparable positive and negative likelihood ratios with radiographic findings based on blinded neuroradiological evaluation. This included good 'stand alone' values for NC-stat F-wave and compound muscle action potential (CMAP) amplitude abnormalities in patients with spinal stenosis.

CONCLUSIONS

This report supports the value of multiparameter clinical neurophysiological evaluations in patients with LSR including CMAPs and F-waves.

The role of neurodiagnostic studies in nerve injuries and other orthopedic disorders

Neurodiagnostic techniques, such as nerve conduction studies, needle electromyography studies, intraoperative nerve monitoring, and evoked potentials provide useful information for practicing orthopedic surgeons to help localize central from peripheral nervous system lesions. For peripheral nerve lesions, it helps localize the level of the nerve dysfunction (for example, root versus plexus versus peripheral nerve). These techniques are well established and routinely used. Newer techniques have emerged that aim to simplify the technical process of performing these studies and help reduce the discomfort associated with these studies. Many of these newer techniques, however, are in their infancy, and their role in routine use for neurodiagnostic purposes is not clear. This review examines the various types of nerve injuries commonly encountered in orthopedic surgery practice and the role of electrodiagnostic (neurodiagnostic) techniques in diagnosing these conditions.

Cervical Radiculopathy

Cervical radiculopathy is a condition encountered commonly in the evaluation of neck pain that may result in significant discomfort and functional deficits. Although the long-term prognosis of this condition is favorable, a standardized approach to therapy is important to minimize unnecessary tests and identify patients who require more urgent intervention. Patient education, pain control, and physical therapy are the first line of therapy. Patients who have protracted pain or significant functional deficits may require a more thorough evaluation, including imaging, electrodiagnostic testing, and, possibly, surgical referral. This article outlines the basic clinical, diagnostic, and therapy considerations in the evaluation of cervical radiculopathy.

Lumbar Spinal Stenosis

Lumbar spinal stenosis may be congenital or acquired. A classic clinical presentation is described as neurogenic claudication. Physical signs of sensory loss, weakness, and attenuation of reflexes often are mild and limited in distribution. Neuroimaging of the lumbosacral spine with MRI and electrodiagnostic (electromyographic [EMG]) tests are the most informative diagnostic modalities. Conservative management often is successful, but surgical decompression may be indicated in refractory cases.