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The funduscopic examination is an essential component of the neurologic examination. However, examination of the ocular fundus with a direct ophthalmoscope is often difficult. Nonmydriatic ocular fundus photography allows direct visualization of the ocular fundus with high-quality photographs. We used nonmydriatic ocular fundus photography to improve patient care and funduscopy skills of residents in the Neurology Resident Clinic.At the time of triage, funduscopic photographs of all new neurology resident clinic patients were taken. The images were imported into the hospital's imaging software. The residents completed a full neurologic examination, including a funduscopic examination with a handheld ophthalmoscope. At the time of staffing the patients with the attendings, the residents received immediate feedback and teaching on retina photograph evaluation.A total of 255 patients were enrolled. Of those, 230 (90%) had at least one high-quality funduscopic photograph. Retinal photographs were normal in 161 (70%). Out of the 69 abnormal photographs, only 7% of abnormalities were detected by the residents. Ninety-three percent of residents found the retinal photographs useful.Nonmydriatic ocular fundus photography improved the care in patients presenting to a Neurology resident clinic and facilitated residents in recognizing funduscopic findings. Its benefits are clear when one considers (1) the high risk of negative patient outcomes and possible medicolegal consequences due to missed findings, (2) the ease of incorporating retinal photographs into the patients' medical records, and (3) the benefit of improving resident education in regard to the ophthalmologic examination.

INTRODUCTION/AIMS Previous studies have shown inconsistent data on the relationship between statin use and polyneuropathy (PN). The current systematic review and meta-analyses were conducted to comprehensively investigate the risk of incident PN among statin-users compared with non-users by identifying all available studies and summarizing their results. METHODS A systematic review was conducted from MEDLINE and EMBASE databases from inception to October 31, 2020. We included cohort and case-control studies that compared the risk of incident PN between statin-users and non-users. Point estimates and standard errors from eligible studies were pooled together using the generic inverse variance method. RESULTS Of 4968 retrieved articles, 6 studies in non-diabetic populations and 2 studies in diabetic populations fulfilled the inclusion criteria. Two meta-analyses were performed. The pooled analyses did not find a statistically significant association between the use of statins and risk of incident PN with the pooled odds ratio of 1.24 (95% confidence interval [CI], 0.88-1.76; I2 74%) and 0.82 (95% CI, 0.56-1.21; I2 80%) in non-diabetic and diabetic groups respectively. DISCUSSION No significant association between the use of statins and the risk of PN was observed in this systematic review and these two meta-analyses. However, there was a high degree of heterogeneity of the meta-analyses.

Item does not contain fulltext Neuromuscular ultrasound is a rapidly evolving specialty with direct application for patient care. Competency assessment is an essential standard needed to ensure quality for practitioners, particularly for those newly acquiring skills with the technique. Our aim was to survey experts' opinions regarding physician competency assessment of neuromuscular ultrasound and to identify minimal competency of knowledge and skills. The opinions of 18 experts were obtained through the Delphi method using two consecutive electronic surveys. A high degree of consensus was achieved on items regarding framework and the conduct of neuromuscular ultrasound assessment and the knowledge and skills that a candidate needs to attain minimal competency in neuromuscular ultrasound. In this study, a group of neuromuscular ultrasound experts developed a general framework for neuromuscular ultrasound competency assessment and recommended testable areas of knowledge and skills suitable for establishing minimal competency.

BACKGROUND Carpal tunnel syndrome (CTS) may be associated with structural lesions or anatomical variations at the wrist, especially in patients whose symptoms are more severe in, or limited to, the nondominant hand. The aims of this study were to identify the type and frequency of structural abnormalities and anatomical variations, and to demonstrate the contribution of ultrasound in this subgroup of CTS patients. METHODS A retrospective chart review was performed on all patients referred to the electromyography laboratory who fulfilled the diagnostic criteria for CTS and who underwent neuromuscular ultrasound. RESULTS Of 114 CTS patients with symptoms mainly in nondominant hand, 51 (44.7%) had structural abnormalities or anatomical variations detected by ultrasound. In multivariable analysis, symptoms mainly in the nondominant hand and a body mass index (BMI)

Introduction The aim of this study was to determine the value of high-resolution ultrasound (HRUS) in patients with ulnar neuropathy whose electrophysiology displayed an axonal, non-localizing pattern. Methods A prospective study of patients referred to an electromyography laboratory for ulnar neuropathy was performed. Of the 56 patients with clinical and electrodiagnostic (EDx) evidence of ulnar neuropathy, 12 were identified with non-localizing electrophysiology who subsequently underwent HRUS of the ulnar nerve. Results HRUS localized the ulnar neuropathy in all patients. In 2 patients, HRUS demonstrated structural lesions not at the elbow. Discussion HRUS often adds complementary information to standard EDx studies, including ulnar neuropathy. Thus, HRUS should be employed in patients with a non-localizing ulnar neuropathy on EDx studies. Muscle Nerve 58: 655-659, 2018.

Neuromuscular ultrasound has become an essential tool in the diagnostic evaluation of various neuromuscular disorders, and, as such, there is growing interest in neuromuscular ultrasound training. Effective training is critical in mastering this modality. Our aim was to develop consensus-based guidelines for neuromuscular ultrasound training courses. A total of 18 experts participated. Expert opinion was sought through the Delphi method using 4 consecutive electronic surveys. A high degree of consensus was achieved with regard to the general structure of neuromuscular ultrasound training; the categorization of training into basic, intermediate, and advanced levels; the learning objectives; and the curriculum for each level. In this study, a group of neuromuscular ultrasound experts established consensus-based guidelines for neuromuscular ultrasound training. These guidelines can be used in the development of the specialty and the standardization of neuromuscular ultrasound training courses and workshops.

Introduction: Hunter syndrome (mucopolysaccharidosis II) is a rare genetic disorder. Carpal tunnel syndrome (CTS) is a common finding in these patients. Methods: We report the ultrasound findings in a 40-year-old Hunter syndrome patient with severe CTS. Results: Marked abnormalities of the median nerve were present proximal to the carpal tunnel with an unusual area of increased echogenicity between enlarged fascicles separating the area of maximal enlargement and the normal median nerve proximally. Conclusions: This case demonstrated unique ultrasound findings in a Hunter syndrome with CTS. Ultrasound also localized the median nerve lesion in the setting of end-stage median neuropathy and nonlocalizing electrophysiology. Muscle Nerve 53: 147–150, 2016

Item does not contain fulltext Over the last two decades, dozens of applications have emerged for ultrasonography in neuromuscular disorders. We wanted to measure its impact on practice in laboratories where the technique is in frequent use. After identifying experts in neuromuscular ultrasound and electrodiagnosis, we assessed their use of ultrasonography for different indications and their expectations for its future evolution. We then identified the earliest papers to provide convincing evidence of the utility of ultrasound for particular indications and analyzed the relationship of their date of publication with expert usage. We found that experts use ultrasonography often for inflammatory, hereditary, traumatic, compressive and neoplastic neuropathies, and somewhat less often for neuronopathies and myopathies. Usage significantly correlated with the timing of key publications in the field. We review these findings and the extensive evidence supporting the value of neuromuscular ultrasound. Advancement of the field of clinical neurophysiology depends on widespread translation of these findings.

In the United States, the increasing cost of health care continues to be a serious medical, personal, and financial crisis for patients, doctors, and hospitals, as well as for businesses, insurers, and the government.1 On the therapeutic side, it is becoming commonplace for some new pharmaceuticals to cost tens to hundreds of thousands of dollars a year. On the diagnostic side, advanced imaging, especially MRI, is increasingly used. Although highly efficacious, its use is also driving up health care costs. These high costs have resulted in an increasing bureaucracy of insurance regulations, denials, appeals, and peer reviews. The increasing cost of health care has put the focus on value. Because value is defined as quality divided by cost, a test such as MRI, which has a high quality but also a high cost, has its value limited to certain situations. What one ideally wants in a diagnostic test is high quality and low cost. Neuromuscular ultrasound (NMUS) is such a diagnostic test whose time has come. In this issue of Neurology ®, Mandeville et al.2 report the robust cost-effectiveness of NMUS used in addition to electrodiagnostic testing in focal neuropathies.

Introduction: Multifocal pyomyositis is a rare inflammatory myopathy caused by bacterial infection and abscess formation in multiple skeletal muscles. To date, electromyography (EMG) of pyomyositis has not been reported. Methods: We describe the EMG findings of a patient with pathologically proven multifocal pyomyositis. Results and Conclusions: Muscles affected by pyomyositis demonstrate EMG features similar to those of other inflammatory myopathies. Other features such as acute entrapment neuropathy may exist concomitantly due to nerve compression from muscle abscess formation. Muscle Nerve 51: 293–296, 2015

Introduction: In ulnar neuropathy at the elbow (UNE), we determined how electrodiagnostic cutoffs [across-elbow ulnar motor conduction velocity slowing (AECV-slowing), drop in across-elbow vs. forearm CV (AECV-drop)] depend on pretest probability (PreTP). Methods: Fifty clinically defined UNE patients and 50 controls underwent ulnar conduction testing recording abductor digiti minimi (ADM) and first dorsal interosseous (FDI), stimulating wrist, below-elbow, and 6-, 8-, and 10-cm more proximally. For various PreTPs of UNE, the cutoffs required to confirm UNE (defined as posttest probability = 95%) were determined with receiver operator characteristic (ROC) curves and Bayes Theorem. Results: On ROC and Bayesian analyses, the ADM 10-cm montage was optimal. For PreTP = 0.25, the confirmatory cutoffs were >23 m/s (AECV-drop), and 14 m/s, and

Objective: To determine the incidence and mortality rates and predictors of death in myasthenia gravis (MG) and MG crisis in a large US cohort. Methods: Our cohort was identified from the Nationwide Inpatient Sample database for the years 2000 through 2005 using ICD-9-CM codes. MG crisis was identified by the principal diagnosis code or by the presence of respiratory failure. The incidence of MG was stratified by age, ethnicity, and gender. Multivariate logistic regression analysis was used to identify predictors of mortality in MG. For trend analyses of immune intervention, we used the Cochrane-Armitage test. Results: After data cleansing, 5,502 patients with MG were included. In women, the incidence of admission was two to three times higher during the first 5 decades. In men, the incidence of admission was higher during the sixth, seventh, and eighth decades. The annual incidence rate of MG was higher in black women (0.01 per 1,000 persons/year) compared to white women and white and black men (0.009, 0.008, and 0.007 per 1,000 persons/year). The overall in-hospital mortality rate was 2.2%, being higher in MG crisis (4.47%). Older age and respiratory failure were the predictors of death, with adjusted odds ratios of 9.28 (95% confidence interval [CI], 3.31, 26.0) and 3.58 (95% CI, 2.01, 6.38). The trend of IV immunoglobulin utilization has increased compared to plasma exchange and thymectomy ( p Conclusion: Myasthenia gravis (MG) is still a disease of young women and old men, as reflected by the hospital admission rates. In-hospital mortality of MG is low. Hospital utilization of IV immunoglobulin has significantly increased compared to plasma exchange and thymectomy.

Background Acute ischemic stroke (AIS) is common cause of hospital admission. The objective of this study was to determine the impact of the new Accreditation Council for Graduate Medical Education (ACGME) duty hour regulations on AIS outcomes including inhospital mortality. Methods Hospitalized patients with AIS were selected from the National Inpatient Sample database. Patients with AIS with a known mortality and hospital teaching status were included for the years 2000 through 2005. Inhospital mortality and predictors of mortality were stratified by the hospital teaching status. To determine the variability of mortality around the month of July (July phenomenon) the trend of mortality was determined in teaching hospitals stratified by the calendar month of each year. Results In all, 377,266 patients were included in this analysis; 43.0% were admitted to teaching hospitals. Overall inhospital mortality was 10.8%, slightly higher in teaching hospitals (11.4% v 10.3%, P < .0001). The trend in AIS mortality showed a decline during the 6 years included in this study in both hospital types (P < .0001). Adjusted analysis showed decline in mortality in both hospital types after July 1, 2003: odds ratio (OR) 0.91 (95% confidence interval [CI] 0.87, 0.94) in teaching hospitals and OR 0.81 (95% CI 0.78, 0.84) in nonteaching hospitals. Predictors of AIS-associated hospital mortality were similar in both hospital types except for sepsis, which was another independent predictor of death in nonteaching hospitals (OR 1.58, 95% CI 1.30, 1.94). There was no significant change in AIS mortality when stratified by each calendar month within the years included in this study (P value = .25-.93). Conclusion There was no difference in AIS mortality after the implementation of the new ACGME duty hour standards. In addition, data support the lack of July phenomenon in neurology residency programs in regard to AIS mortality.

The lumbrical-interossei comparison study is commonly employed in the electrodiagnosis of carpal tunnel syndrome. Placement of the recording electrodes relies on anatomic landmarks as the muscles being recorded cannot be seen or palpated. To determine the optimal active electrode location, 15 controls and 5 patients were studied using a grid of 12 electrodes placed over the lateral palm. Amplitudes, rise-times, and latencies of the responses at each location were measured. The lowest control latency difference was located in the lateral mid-proximal palm (mean 0 ms, upper range of 0.5 ms). This location also had the highest lumbrical amplitude and rise-time. More distal in the palm, the mean latency difference increased to 0.5 ms with an upper range of 0.9 ms. When performing the lumbrical-interossei comparison study, it is essential to place the active recording electrode in the optimal location. Failure to do so will result in an increased number of false-positive studies.

A 62-year-old man developed progressive gait instability, bladder dysfunction, proximal weakness, distal sensory loss, and mild cognitive impairment over 6 years. Neurologic examination revealed upper and lower motor neuron dysfunction in the lower extremities, with distal sensory loss. Electrodiagnostic studies, magnetic resonance imaging of the brain, and sural nerve biopsy were consistent with adult polyglucosan body disease. Biochemical and genetic analyses demonstrated reduced glycogen brancher enzyme levels associated with a heterozygous point mutation (Tyr329Ser or Y329S) in the glycogen brancher enzyme gene on chromosome 3. Mutational heterozygosity in the glycogen brancher enzyme gene has not been previously reported as a cause for this rare disease. A review of the clinical presentation, pathogenesis, etiology, and diagnosis of this disease is presented.

A variety of electrodiagnostic methods are used to confirm the diagnosis of acute inflammatory demyelinating polyneuropathy (AIDP), but difficulties are frequent during the first few weeks of weakness. We compared the nerve conduction studies (NCS) of patients with AIDP to those with critical illness polyneuropathy (CIP), a subacute axonal polyneuropathy. New electrodiagnostic criteria with graded certainty (normal, nondiagnostic, suggestive, highly suggestive, and definite) were designed and applied in a blinded manner to both groups. Among the AIDP patients, 64% met the highly suggestive and definite criteria (specificity 95-100%, P < 0.01), whereas 80% of the CIP group fell in the nondiagnostic criteria (P < 0.001). The relative preservation of the sural sensory response in spite of at least two abnormal sensory NCS in the upper limb suggested acute demyelination (sensitivity 48%, specificity 96%, P < 0.001) and was even more conclusive when associated with absent or prolonged F waves. Motor and sensory response amplitudes were lower in the CIP group, with comparable mean motor and sensory distal latencies and motor conduction velocities. Motor conduction blocks were present in 10% of nerves in AIDP and were not encountered in CIP. The frequency of absent or delayed F waves and absent H reflex was similar in both groups. The correlation coefficient of the cerebrospinal fluid protein concentration with the designed criteria was higher in the AIDP group (r = 0.9). We conclude that a new criterion with graded certainty is of higher specificity in the majority of patients with early AIDP.

Motor involvement in common peroneal neuropathy (CPN) frequently shows a selective pattern with regard to deep and superficial divisions of the peroneal nerve, by clinical examination and needle electromyography. The involvement of the sensory branch of the superficial peroneal nerve (SPN) has not been well established using nerve conduction studies. Among 42 cases of electrophysiologically defined CPN in 35 patients, 37 (88%) had clinical or electrophysiologic evidence for SPN involvement, but only 20 had diminished superficial peroneal sensory response (SPSR) amplitudes. Many of the cases involving normal SPSRs had significant axonal loss involving deep peroneal motor fibers. Sparing of the superficial peroneal sensory fibers provides further evidence for the selective vulnerability of different nerve fascicles to injury. This is an important pattern to recognize; from a practical standpoint, focal segmental conduction abnormalities in the motor nerve and EMG findings can help to differentiate these lesions from L-5 radiculopathy.

Piriformis syndrome is a controversial entrapment neuropathy in which the sciatic nerve is thought to be compressed by the piriformis muscle. Two patients developed severe left sciatic neuropathy after piriformis muscle release. One had a total sciatic nerve lesion, whereas the second had a predominantly high common peroneal nerve lesion. Follow-up studies showed reinnervation of the hamstrings only. We conclude that piriformis muscle surgery may be hazardous and result in devastating sciatic nerve injury.

There are many conflicting theories regarding the mechanism and prognosis of acute foot drop during labor. We report seven women who had arrested labor and foot drop. Six had short stature and one had a large newborn. All had weakness of ankle dorsiflexion, eversion, and inversion, and sensory loss in the L-5 dermatome. Superficial peroneal sensory nerve action potentials (SNAPs) were small or absent in six patients, and the sural SNAP was attenuated in one. Peroneal compound muscle action potential (CMAP) amplitude (recording from extensor digitorum brevis) was low in five, whereas the tibial CMAP was normal in all patients. Peroneal CMAP amplitude (recording from the tibialis anterior) was normal in three and small in three. Needle electromyography revealed decreased recruitment and fibrillation potentials in L-5-innervated muscles, mostly below the knee. We conclude that intrapartum foot drop occurs mostly in short women and is caused by lumbosacral trunk compression by the fetal head at the pelvic brim. The primary pathology is predominantly demyelination and recovery is complete in up to 5 months.

Compared to ulnar neuropathy at the elbow (UNE), ulnar neuropathy at the wrist (UNW) is rarer and more difficult to localize with routine electrophysiologic studies.By stimulating the ulnar nerve at the wrist and palm, and recording from first dorsal interosseous (FDI), the sensitivity and specificity of conduction block (CB) and slow conduction velocity (CV) of FDI fibers across the wrist was compared to traditional electrodiagnostic techniques for localization of UNW. Twenty patients with clinically defined UNW (due mainly to wrist trauma), 30 normal controls, and 20 disease controls with severe (n = 10) and mild (n = 10) UNE were evaluated prospectively. The upper (mean +2.5 SD) and lower (mean -2.5 SD) limits for all measurements were derived from the normal controls.The UNW patients showed: slow wrist-palm FDI CV (37 m/s) in 16 (80%); definite or probable CB in 14 (70%); prolonged distal latency (DL) to FDI (4.5 milliseconds) in 12 (60%), to ulnar-innervated palmar interosseous (PI) versus median-innervated lumbrical (L) in 12 (60%), and to abductor digiti minimi (ADM) in 11 (55%). However, only CB and slow wrist-palm FDI CV (37 m/s) were specific for UNW; prolonged DL to FDI was found in 4 patients (40%), to ADM in 4 patients (40%), and to PI in 1 patient (10%) with severe UNE. Overall, CB or slow wrist-palm FDI CV was present in 19 patients with UNW (95%). EMG failed to differentiate UNW from UNE, because forearm ulnar-innervated muscles were typically normal in UNW, but also often normal in mild UNE.In UNW, an additional palmar stimulation site improves electrodiagnostic yield, and demonstrates that CB is an important cause of muscle weakness.

Background Most peripheral neuropathies involve large as well as small-fiber dysfunction. A small subset of neuropathies present with restricted or predominant small-fiber involvement. Review summary In this review, we discuss the differential diagnosis, clinical presentation, evaluation, and treatment of small-fiber neuropathies. Although these neuropathies are rare, their differential diagnosis is broad, and includes many disorders, including metabolic, toxic, inflammatory, infectious, and genetic etiologies. As small fibers subserve pain and autonomic functions, these neuropathies usually present with pain and temperature loss, painful dysesthesias, autonomic dysfunction, or a combination. These neuropathies are especially challenging as nerve conductions and EMG, which help guide the evaluation of most peripheral neuropathies, may have normal findings in patients with small-fiber neuropathies. Other specialized studies, including tests of autonomic function, intraepidermal nerve fiber analysis, and quantitative sensory testing, are often required to confirm the presence of a small-fiber neuropathy. In some cases, the underlying etiology can be directly treated. In most, management is limited to symptomatic treatment of sensory and autonomic dysfunction. Conclusion Small-fiber neuropathies are a heterogeneous group of disorders. They vary in etiologies and require special attention, as many disorders are rare and the differential diagnosis is broad. Evaluation is often extensive and may need pathologic specimen. Many patients respond to symptomatic therapy, but some are difficult to treat.

Importance Fundoscopic examination is an essential component of the neurologic examination. Competence in its performance is mandated as a required clinical skill for neurology residents by the American Council of Graduate Medical Education. Government and private insurance agencies require its performance and documentation for moderate- and high-level neurologic evaluations. Traditionally, assessment and teaching of this key clinical examination technique have been difficult in neurology residency training. Objective To evaluate the utility of a simulation-based method and the traditional lecture-based method for assessment and teaching of fundoscopy to neurology residents. Design, Setting, and Participants This study was a prospective, single-blinded, education research study of 48 neurology residents recruited from July 1, 2015, through June 30, 2016, at a large neurology residency training program. Participants were equally divided into control and intervention groups after stratification by training year. Baseline and postintervention assessments were performed using questionnaire, survey, and fundoscopy simulators. Interventions After baseline assessment, both groups initially received lecture-based training, which covered fundamental knowledge on the components of fundoscopy and key neurologic findings observed on fundoscopic examination. The intervention group additionally received simulation-based training, which consisted of an instructor-led, hands-on workshop that covered practical skills of performing fundoscopic examination and identifying neurologically relevant findings on another fundoscopy simulator. Main Outcomes and Measures The primary outcome measures were the postintervention changes in fundoscopy knowledge, skills, and total scores. Results A total of 30 men and 18 women were equally distributed between the 2 groups. The intervention group had significantly higher mean (SD) increases in skills (2.5 [2.3] vs 0.8 [1.8], P = .01) and total (9.3 [4.3] vs 5.3 [5.8], P = .02) scores compared with the control group. Knowledge scores (6.8 [3.3] vs 4.5 [4.9], P = .11) increased nonsignificantly in both groups. Conclusions and Relevance This study supports the use of a simulation-based method as a supplementary tool to the lecture-based method in the assessment and teaching of fundoscopic examination in neurology residency.

Wegener granulomatosis (WG) is an uncommon, idiopathic disorder that is characterized by granulomatous inflammation of the upper and lower respiratory tract, disseminated vasculitis involving small and medium-sized vessels, and focal segmental glomerulonephritis. Approximately 25% to 50% of patients have nervous system involvement. The brain is less frequently involved. We report a case of a 74 year-old previously well woman who presented with rapidly progressing WG that culminated in subarachnoid hemorrhage. Only six cases of subarachnoid hemorrhage in the setting of WG have previously been reported. We review the common presenting signs and symptoms, diagnosis, treatment, and complications of WG.

Distal median neuropathy is the most common entrapment neuropathy affecting the upper extremity. Usually, the site of compression occurs in the wrist as the nerve passes under the flexor reticulatinum in the carpal tunnel. Rarely, pathology can occur more distally in the palm. Patients who have distal median neuropathy most often develop carpal tunnel syndrome (CTS), one of the most characteristic nerve entrapment syndromes. However, lesions of the proximal median nerve, brachial plexus, or C6-C7 may occasionally be confused clinically with the symptoms and signs of distal median neuropathy. In this regard, electrophysiologic testing plays an important role in the evaluation of suspected distal median neuropathy. A large variety of electrophysiologic tests are available, enabling the physician to study the median nerve. 7, 10, 14, 22 Electrophysiology not only can establish localization but can usually help assess severity and prognosis and help guide subsequent treatment.

The mechanism of motor nerve conduction slowing in amyotrophic lateral sclerosis (ALS) is thought primarily to be loss of large, fast-conducting motor fibers; this is less certain in axonal polyneuropathy. We compared motor conduction studies in 64 patients with axonal polyneuropathy with 72 patients with ALS. Compound motor action potential amplitude, distal motor latency, and conduction velocity were converted to a percentage of the upper or lower limit of normal and then represented as a square root (SQRT) transformation, plotted with SQRT amplitude as the independent variable and SQRT latency or SQRT conduction velocity as the dependent variables. Regression analysis of the lower extremity nerve data showed that prolongation of latency and slowing of velocity were amplitude-dependent and were virtually identical in ALS and polyneuropathy. In the upper extremity, amplitude-dependent prolongation of latency was similar in both groups, but amplitude-dependent slowing of velocity was seen in ALS and not in axonal polyneuropathy. Our data support the hypothesis that the major mechanism of slowing is similar in both polyneuropathy and ALS and is the loss of large, fast-conducting fibers. However, the presence of distal but not proximal slowing in the upper extremity of axonal polyneuropathy suggests that additional mechanisms may be contributory.

Entrapment neuropathies of the upper extremities, particularly the carpal tunnel syndrome and cubital tunnel syndrome, are commonly seen in clinical practice. This chapter discusses the clinical manifestations, diagnosis, and treatment of all entrapment and compressive neuropathies of the upper extremity.

Nerve conduction studies and needle electromyography are often crucial during the evaluation of patients with disorders of the anterior horn cells, spinal roots, sensory nerves, motor nerves, neuromuscular junctions, or muscles. The studies are performed with a guidance of the neurological examination, and the findings should be interpreted within the clinical context. In this chapter, basic principles of NCSs and needle EMG will be discussed, followed by a review of methodology, indications for performing NCS-EMG, and electrophysiologic findings in common neuromuscular disorders.