Diagnostic value of history and physical examination in patients suspected of lumbosacral nerve root compression

OBJECTIVE: To evaluate patient characteristics, symptoms, and examination findings in the clinical diagnosis of lumbosacral nerve root compression causing sciatica. METHODS: The study involved 274 patients with pain radiating into the leg. All had a standardised clinical assessment and magnetic resonance (MR) imaging. The associations between patient characteristics, clinical findings, and lumbosacral nerve root compression on MR imaging were analysed. RESULTS: Nerve root compression was associated with three patient characteristics, three symptoms, and four physical examination findings (paresis, absence of tendon reflexes, a positive straight leg raising test, and increased finger-floor distance). Multivariate analysis, analysing the independent diagnostic value of the tests, showed that nerve root compression was predicted by two patient characteristics, four symptoms, and two signs (increased finger-floor distance and paresis). The straight leg raise test was not predictive. The area under the curve of the receiver-operating characteristic was 0.80 for the history items. It increased to 0.83 when the physical examination items were added. CONCLUSIONS: Various clinical findings were found to be associated with nerve root compression on MR imaging. While this set of findings agrees well with those commonly used in daily practice, the tests tended to have lower sensitivity and specificity than previously reported. Stepwise multivariate analysis showed that most of the diagnostic information revealed by physical examination findings had already been revealed by the history items.     

Interrater reliability of the needle examination in lumbosacral radiculopathy

Low back pain and lumbar radiculopathy are among the most common painful disorders affecting the adult population. This study hypothesizes that there is good correlation between the diagnostic impression of an unblinded electromyographer, using clinical and electromyographic information, and an independent electromyographer, who uses the needle examination only to assess for lumbar radiculopathy. This is a prospective, single-blinded, observational pilot study. The needle examination was electronically recorded, reproduced, and shown to a second examiner, blinded to all clinical data. Diagnostic impressions from both examiners were recorded and evaluated for agreement. Six recorded cases were reviewed by 66 blinded examiners. Overall diagnostic agreement was 46.9% (60.5% faculty level, 28.5% resident level). Logistic regression shows a strong association between training level and agreement on diagnostic impression (odds ratio, 1.9; 95% confidence interval, 1.12-3.22; P = 0.019). This study shows that there is fair interrater reliability between faculty-level examiners and poor reliability among resident-level examiners when the needle examination is used to evaluate patients with lumbar radiculopathy.     

Paraspinal mapping: Quantified needle electromyography in lumbar radiculopathy

In the diagnosis of low back pain, the presence of a high percentage of false positive findings on radiologic imaging studies has lead to a more definitive role for electrodiagnosis as a confirmatory test. The paraspinal muscles are a crucial part of the electrodiagnostic examination for radiculopathy. To date, no technique for paraspinal evaluation has been validated. Based on previously documented anatomical techniques, we have designed a method of paraspinal examination termed “paraspinal mapping” (PM). Electromyographic (EMG) needles are placed in five carefully chosen locations and inserted in multiple directions. Individual scores for these insertions are added to determine a total PM sensitivity score. The first 50 studies using PM were compared to peripheral EMG, imaging studies, and pain drawings. Results indicate that the technique is easy to perform. Sensitivity scores relate well with these tests. In this limited and uncontrolled population, PM had higher sensitivity for abnormalities than either peripheral EMG or imaging studies. Because of the anatomical validity of PM, future studies may show it to be useful in localizing the level of radiculopathy independently from peripheral EMG, and to support clinical findings and imaging studies. © 1993 John Wiley & Soncs, Inc.     

神经电生理检查在腰骶神经根病中的诊断价值

腰骶神经根病是临床常见病、多发病,近年来,神经电生理检查在神经根病中的应用价值越来越受到关注.本文通过查阅近年来相关文献,对针电极肌电图、表面肌电图、神经传导速度测定、F波、H反射、体感诱发电位、磁刺激运动诱发电位等在腰骶神经根病中的诊断价值作一综述.     

Somatosensory evoked potentials (cutaneous nerve stimulation) and electromyography in lumbosacral radiculopathy.

In order to evaluate the usefulness of SEP with cutaneous nerve stimulation in lumbosacral radiculopathy, we investigated 19 patients by EMG including H-reflex and SEP. All patients had radiculopathy proven by myelography and/or CT scan and, if indicated, operative treatment. The findings by EMG and SEP were compared with operative and radiological findings. In this preliminary study, SEP was as sensitive as EMG in detecting lumbosacral radiculopathy. Further investigation seems justified.     

Diagnostic value of history and physical examination in patients suspected of sciatica due to disc herniation: a systematic review

We conducted a systematic review of the literature from 1965–1994 to assess the value of history and physical examination in the diagnosis of sciatica due to disc herniation; we also included population characteristics and features of the study design affecting diagnostic value. Studies on the diagnostic value of history and physical examination in the diagnosis of sciatica due to disc herniation are subject to important biases, and information on numerous signs and symptoms is scarce or absent. Our search revealed 37 studies meeting the selection criteria; these were systematically and independently read by three readers to determine diagnostic test properties using a standard scoring list to determine the methodological quality of the diagnostic information. A meta-analysis was performed when study results allowed statistical pooling. Few studies investigated the value of the history. Pain distribution seemed to be the only useful history item. Of the physical examination signs the straight leg raising test was the only sign consistently reported to be sensitive for sciatica due to disc herniation. However, the sensitivity values varied greatly, the pooled sensitivity and specificity values being 0.85 and 0.52, respectively. The crossed straight leg raising test was the only sign shown to be specific; the pooled sensitivity and specificity values were 0.30 and 0.84, respectively. There was considerable disagreement on the specificity of the other neurological signs (paresis, sensory loss, reflex loss). Several types of bias and other methodological drawbacks were encountered in the studies limiting the validity of the study results. As a result of these drawbacks it is probable that test sensitivity was overestimated and test specificity underestimated. Received: 8 September 1998 Received in revised form: 27 January 1999 Accepted: 17 March 1999     

Diagnostic value of electromyography in children and adolescents.

The diagnostic accuracy in pediatric neurology has been considerably improved by new methods such as magnetic resonance imaging and molecular genetic analysis. However, standard diagnostic techniques continue to play an important role. The authors analyzed the diagnostic value of electromyography (EMG) and nerve conduction studies (NCS) in a retrospective study of 498 pediatric patients. The overall consistency between EMG results and the final clinical diagnosis in all children examined was 98%. In myogenic diseases, the concordance between EMG and clinical findings was lower (80%), because some patients with congenital myopathies showed normal EMG findings in this group. Peripheral neurogenic diseases were in all but one of the cases diagnosed correctly (99.5%). No decrease in diagnostic reliability was found in the younger age group. EMG and NCS examinations have to be adapted to the needs of children by an experienced examiner, but continue to be valuable diagnostic methods in pediatric neurology.     

肌电图对糖尿病周围神经病的诊断价值

目的：探讨神经肌电图在糖尿病性周围神经病（DPN ）诊断中的应用价值。方法：选择我院2012年1月～2014年6月收治的200例DPN患者的临床资料,分析肌电诱发电位仪对患者的相关神经进行检测的结果。结果：在200例DPN患者中,神经电图总异常率高达71．5％。且随着病程的延长,其EM G异常率的发生逐渐增加。病程在1年以内的患者EM G异常率为40．8％,而病程在10年以上者异常率达到92．2％。病程在1年以内的患者H反射异常率为46．9％,而病程在10年以上者H反射异常率达到94％。其次是腓总神经运动传导速度（MCV）、腓浅神经感觉传导速度（SCV）异常率,分别是43．1％和58．8％,均超过40％。EM G结果提示：病程＜1年组拇短展肌、肱二头肌、胫前肌、趾总伸肌EM G异常率均为0,病程≥10年组异常率分别为17．6％、9．8％、21．5％、31．4％,同样随病程延长而异常率增加。结论：EM G在诊断DPN中具有较高的准确性,有利于早期发现和进行治疗。     

The electrodiagnosis of cervical and lumbosacral radiculopathy

This article reviews the usefulness of the electrodiagnostic examination in patients who have suspected cervical and lumbosacral radiculopathy. This study can verify the presence and severity of radiculopathy, determine which levels are involved, and provide an electrodiagnostic correlate to imaging abnormalities. A practical approach for conducting the nerve conduction portion and needle electrode examination in these patients is discussed.     

Diagnostic value of electromyography and muscle biopsy in arthrogryposis multiplex congenita

Arthrogryposis multiplex congenita (AMC), a clinical syndrome characterized by multiple congenital joint contractures, frequently is caused by lesions in the peripheral nervous system. Two standard tests for the evaluation of the motor unit are nerve conduction studies/electromyography (NCS/EMG) and muscle biopsy. We reviewed the diagnostic value of these two studies in the evaluation of AMC over a 23-year period, analyzing 38 patients with AMC who had NCS/EMG, muscle biopsy, or both. Final diagnoses were classified as neurogenic (8 patients), myopathic (10 patients), "other" (12 patients), or unknown (8 patients). Neither test alone had consistently high sensitivities, positive predictive values, or specificities. However, when NCS/EMG and muscle biopsy were concordant for neurogenic or myopathic findings, they were more accurate than either test alone, especially for neurogenic diseases. Test results were most commonly discordant in patients with "other" or unknown diagnoses. These findings suggest that when the clinical evaluation indicates a specific syndromic, developmental, or exogenous cause, NCS/EMG and muscle biopsy are not helpful and may not need to be performed. When the history, examination, and genetic evaluation are unrevealing, NCS/EMG and muscle biopsy together provide valuable diagnostic information.     

单纤维肌电图对糖尿病周围神经病的诊断价值

目的 探讨单纤维肌电图（SFEMG）在糖尿病周围神经病（DPN）中的应用。方法 采用Viking Ⅳ肌电图仪,测定36例2型糖尿病患者指总伸肌的颤抖和纤维密度（FD）,同时进行常规神经传导检测（NCS）并测量空腹血糖和糖化血红蛋白（HbA1C)。结果 颤抖和FD具有相关性,且均与HbA1C呈正相关。18例NCS异常者,颤抖值均超过正常范围（11例伴阻滞）,14例FD增加;18例NCS正常者,7例颤抖值增大（3例伴阻滞）,5例FD增加。结论 颤抖和FD所反映的失神经－神经再支配与代谢状况相关联;SFEMG是DPN早期诊断的敏感手段,可发现糖尿病亚临床周围神经病变。     

Diagnostic value of the electromyography of the extraocular muscles

ObjectiveThe electromyography (EMG) of the extraocular muscles (EOM) represents a special form of electrophysiological investigation techniques which can be offered only in a few centers with special ophthalmologic and neurophysiologic expertise due to its special characteristics. The diagnostic value of the EOM-EMG is especially apparent in neuromuscular diseases which occur with predominantly ocular manifestation.MethodsNeedle EMG examinations of EOM were performed in a cohort of 206 patients with a variety of relevant disorders mainly with a neurological focus. The results of these EMG examinations were assessed retrospectively. After local anaesthesia of the sclera and using a lid retractor to keep the eye open the EOM were identified visually by an experienced ophthalmologist and the needle was inserted. The EMG activity was registered in resting position, in mild volitional, and at maximum activation. The assessment was performed visually on a monitor by an experienced neurophysiologist.ResultsIn the group of neuromuscular (myopathic) diseases, the results of the EOM-EMG were compatible with the clinical diagnosis in 54 of 65 patients (83%) and in 69 of 85 patients (81%) in the group with peripheral lesions. In a “Varia” group (n = 56) no diagnosis could be established despite all further investigations in 31 patients. In the remaining patients, the EOM-EMG result was compatible with the diagnosis in 22 of 25 patients (88%). Subgroup analysis revealed that particularly in myositis (30 of 33 findings in 32 patients, one patient was examined twice; 91%), muscle dystrophy (7 of 8 patients; 88%) and in isolated nerve lesions (64 of 79 patients; 81%) the diagnosis could be positively proven by the EOM-EMG. Clinically relevant complications were not observed.ConclusionsThe EOM-EMG is safe and has a high diagnostic value especially in diseases such as myositis, muscular dystrophy and isolated peripheral nerve lesions.SignificanceWith better knowledge of the diagnostic value of the EOM-EMG in various diseases, less relevant diagnostic investigations can be avoided in the future. Moreover, a higher degree of trust in the method should facilitate the decision to perform this special diagnostic method.     

Prevalence of lumbosacral radiculopathy in two Sicilian municipalities

Objectives – As part of a door-to-door survey of neurologic diseases, we investigated the prevalence of lumbosacral radiculopathy (LR) in two Sicilian municipalities (N= 14,540, as of November 1, 1987). Material & methods – During phase 1, we administered a brief screening instrument to subjects in the study population. In phase 2, study neurologists using specified diagnostic criteria investigated those subjects who screened positive. Our case finding was restricted to subjects who manifested symptoms of LR in the six months preceding the prevalence day. Results – We found 143 subjects affected by LR (112 definite, 31 possible) yielding a crude prevalence of 9.8 cases per 1,000 population. Age-specific prevalence was generally higher in men; it increased to a peak at age 50–59 years and decreased steadily thereafter. At the peak, prevalence was higher in factory workers, housewives, and clerks compared to workers in other occupations. Conclusions – LR is a common neurologic disease in the general population.     

Diagnostic value of electrical stimulation of lumbosacral roots in radiculopathies*

Needle electrical stimulation of the lumbosacral roots at the laminar level of the Th12-L1 or L1-2 intervertebral spaces were performed in 24 normal subjects and 58 patients with various kinds of lumbar radiculopathy (unilateral L4, L5 and S1 herniated nucleus pulposus and lumber stenosis). The root stimulation method was compared with conventional needle EMG. Lumber electrical stimulation showed root abnormalities objectively in 80% of patients while the diagnostic value of needle EMG was 65%. Therefore, electrical root stimulation is superior to routine EMG for localizing lumbar root involvement. However, the only needle EMG demonstrated the root pathology in 7 cases (12%) and single electrophysiological abnormality was found by the root stimulation in 16 cases (27%). Thus, both electrophysiological methods should be complementary to each other in evaluation of the lumbar radiculopathy.     

Diagnostic value of quantitative electromyography. Its scope and limitations.

On the evidence of 951 cases of the 10,500 investigated with the aid of quantitative electromyography the author shows the value of the method for diagnosing muscle activity. Statistical analysis was applied to check the diagnostic value of EMG parameters separately and jointly in the identification of the pathology and its classification as either neurogenic or myogenic. Also surveyed are the sources of the discrepancies between the electromyographic and the histopathological results in very early and very advanced cases. Examples are given that show electromyographic findings as nosologically non-specific and the method as inferior to the morphological in this respect. On the other hand the method is stressed as one that permits it to (a) tell a malignant and rapid process from a slow one, (b) obtain evidence of repair and (c) prove generalization of processes considered to be local or the progressive character of processes considered to be non-progressive. The author also refers to the added scope given to electromyography by such developments as automatic recording, SFEMG, and determination of motor unit territory with the aid of multielectrodes.     

Single-fiber electromyography, examination technic and findings

Single-fibre electromyography has become much easier because of the advantages offered by modern computerised EMG equipment. Fibre density, jitter and the frequency of blockings can thus be examined with relative reliability. The technique allows a sensitive diagnosis of disturbances of neuromuscular stimulus transmission. Furthermore, different pathological results obtained in patients suffering from neuropathies or myopathies (12 controls, 65 patients) proved the diagnostic value of single-fibre EMG. The method is a valuable addition to conventional EMG. The examination technique is described and illustrated by various examples.     

The utility of F wave chronodispersion in lumbosacral radiculopathy

The sensitivity of F wave chronodispersion (Fc) in evaluating nerve root pathology is unknown. We compared Fc in 91 patients with clinical and EMG evidence of L5 or S1 radiculopathy with Fc in 81 controls in order to evaluate its sensitivity in lumbosacral radiculopathy. F waves were obtained by stimulating the peroneal and tibial nerves behind the knee and recording from the extensor digitorum brevis (L5 predominant) and flexor hallucis brevis (S1 predominant) muscles, respectively. Fc was calculated by subtracting the shortest F wave latency from the longest and, in controls, ranged from 0.2 to 23.4 ms in the peroneal nerve, and from 1.2 to 13.4 ms in the tibial nerve (95th percentile = 13 ms for the peroneal nerve and 9.2 ms for the tibial nerve). In the patient group, Fc also ranged from 0.2 to 23.4 ms in the peroneal nerve, and from 0.4 to 18.2 ms in the tibial nerve. Only 5 (5.5%) and 8 (11.3%) patients for the peroneal and tibial nerves, respectively, had Fc values which fell beyond the 95th percentile, a percentage far below the sensitivity of F wave latency measurement and not substantially different from chance. Thus we conclude that Fc has no substantial additional value in evaluating lumbosacral radiculopathy over that of F wave latency.