Sural sensory nerve action potential, epidermal nerve fiber density, and quantitative sudomotor axon reflex in the healthy elderly.

INTRODUCTION: Polyneuropathy evaluation in older patients is often challenging due to conflicting data regarding normative values for peripheral nerve testing. METHODS: We characterized the results of sural nerve conduction studies, intraepidermal nerve fiber density (IENFD), and quantitative sudomotor axon reflex testing (QSART) in a prospective study of 50 healthy subjects aged ≥60 years. RESULTS: Of the 50 subjects, 48 (96%) had an obtainable sural sensory nerve action potential (SNAP). Using quantile regression, we estimated the lower limit of normal (LLN) for sural amplitudes to be 3 µV for patients 60-70 years, 1 µV for those 70-74 years, and <1 µV (absent) for those ≥75 years of age. IENFD and QSART volume were reduced with advancing age, although IENFD was lower in men and QSART volume was lower in women. CONCLUSIONS: We propose that an absent sural SNAP in patients up to 75 years of age should be considered abnormal. Our findings also support age- and gender-stratified normative data for IENFD and QSART.

Other median neuropathies.

Median mononeuropathy is common, with carpal tunnel syndrome the most frequently encountered acquired mononeuropathy in clinical practice. However, other disorders of the median nerve and many known anatomical variants can lead to misdiagnosis and unexpected surgical complications if their presence is not correctly identified. A number of inherited and acquired disorders can affect the median nerve proximal to the wrist, alone or accompanied by other affected peripheral nerves. Recognizing other disorders that can masquerade as median mononeuropathies can avoid misdiagnosis and misguided management. This chapter explores median nerve anatomical variants, disorders, and lesions, emphasizing the need for careful examination and electrodiagnostic study in the localization of median neuropathy.

Safety of repetitive nerve stimulation in patients with cardiac implantable electronic devices.

INTRODUCTION: Pacemakers and implantable cardioverter-defibrillators (ICDs) are vulnerable to inappropriate sensing of electromagnetic interference (EMI), such as from nerve conduction studies. We conducted a prospective study to assess the safety of repetitive nerve stimulation (RNS). METHODS: Fourteen patients undergoing insertion of 10 ICDs and 4 pacemakers under general anesthesia received RNS of the median, axillary, and spinal accessory nerves at 2 HZ and 50 HZ. We recorded detection of EMI and whether or not this resulted in an arrhythmia diagnosis or change in pacing output. RESULTS: EMI was visible in 2 ICDs, without spurious tachyarrhythmia detection. EMI was observed in 3 of the 4 pacemakers, which led to pacing inhibition and a pause in 2, both of which were programmed to a unipolar sensing configuration. CONCLUSIONS: RNS is safe in patients with ICDs. In pacemaker patients, RNS appears safe during bipolar sensing, but caution is recommended in pacemaker patients with unipolar sensing.

Electrodiagnostic Assessment of Radiculopathies.

This article discusses the electrodiagnostic assessment of radiculopathy. Relevant anatomy initially is reviewed followed by discussion surrounding the approach to nerve conduction studies and needle electrode examination when it comes to radiculopathy evaluation. Pitfalls of the electrodiagnosis versus clinical diagnosis of radiculopathy and the definitions of acute versus chronic, and active versus inactive, are reviewed.

Contemporary Neuroscience Core Curriculum for Medical Schools.

Medical students need to understand core neuroscience principles as a foundation for their required clinical experiences in neurology. In fact, they need a solid neuroscience foundation for their clinical experiences in all other medical disciplines also, because the nervous system plays such a critical role in the function of every organ system. Due to the rapid pace of neuroscience discoveries, it is unrealistic to expect students to master the entire field. It is also unnecessary, as students can expect to have ready access to electronic reference sources no matter where they practice. In the pre-clerkship phase of medical school, the focus should be on providing students with the foundational knowledge to use those resources effectively and interpret them correctly. This article describes an organizational framework for teaching the essential neuroscience background needed by all physicians. This is particularly germane at a time when many medical schools are re-assessing traditional practices and instituting curricular changes such as competency-based approaches, earlier clinical immersion, and increased emphasis on active learning. This article reviews factors that should be considered when developing the pre-clerkship neuroscience curriculum, including goals and objectives for the curriculum, the general topics to include, teaching and assessment methodology, who should direct the course, and the areas of expertise of faculty who might be enlisted as teachers or content experts. These guidelines were developed by a work group of experienced educators appointed by the Undergraduate Education Subcommittee (UES) of the American Academy of Neurology (AAN). They were then successively reviewed, edited, and approved by the entire UES, the AAN Education Committee, and the AAN Board of Directors.

Utility of electrodiagnostic testing in evaluating patients with lumbosacral radiculopathy: An evidence-based review.

This is an evidence-based review of electrodiagnostic (EDX) testing of patients with suspected lumbosacral radiculopathy to determine its utility in diagnosis and prognosis. Literature searches were performed to identify articles applying EDX techniques to patients with suspected lumbosacral radiculopathy. From the 355 articles initially discovered, 119 articles describing nerve conduction studies, electromyography (EMG), or evoked potentials in adequate detail were reviewed further. Fifty-three studies met inclusion criteria and were graded using predetermined criteria for classification of evidence for diagnostic studies. Two class II, 7 class III, and 34 class IV studies described the diagnostic use of EDX. One class II and three class III articles described H-reflexes with acceptable statistical significance for use in the diagnosis and confirmation of suspected S1 lumbosacral radiculopathy. Two class II and two class III studies demonstrated a range of sensitivities for use of muscle paraspinal mapping. Two class II studies demonstrated the utility of peripheral myotomal limb electromyography in radiculopathies.

Subspecialization in clinical neurophysiology: Development and current status.

OBJECTIVE: To describe the development and current status of training and certification in clinical neurophysiology (CNP); to explore the impact of the newer subspecialties in sleep medicine, neuromuscular medicine, and epilepsy; and to obtain information about aspects of practice in the subspecialty. METHODS: Information about training programs and certification was obtained from the records of the Accreditation Council for Graduate Medical Education and the American Board of Psychiatry and Neurology, and diplomates were surveyed about their CNP practice activities and attitudes toward certification/recertification. RESULTS: In the years since the first examination was administered, a robust number of CNP training programs developed, but recently, there has been a decrease in the number of programs and fellows, although the number of programs and fellows in the subspecialties of epilepsy, neuromuscular medicine, and sleep medicine has increased. A diplomate survey indicated that most respondents devoted significant practice time to CNP procedures, especially to EEGs and EMGs. Although more diplomates performed EEGs than EMGs, a substantial portion performed both. Most diplomates were planning to or had maintained certification in CNP. CONCLUSION: Over 3,000 neurologists, child neurologists, and psychiatrists have obtained certification in CNP, and the majority are participating in recertification. Although the newer and overlapping subspecialties of epilepsy, neuromuscular medicine, and sleep medicine may be having a negative impact on CNP, it continues to have a relatively large number of programs and attracts a relatively large number of fellows.

Age and sex differences in burnout, career satisfaction, and well-being in US neurologists.

OBJECTIVE: To examine age and sex differences in burnout, career satisfaction, and well-being in US neurologists. METHODS: Quantitative and qualitative analyses of men's (n = 1,091) and women's (n = 580) responses to a 2016 survey of US neurologists. RESULTS: Emotional exhaustion in neurologists initially increased with age, then started to decrease as neurologists got older. Depersonalization decreased as neurologists got older. Fatigue and overall quality of life in neurologists initially worsened with age, then started to improve as neurologists got older. More women (64.6%) than men (57.8%) met burnout criteria on univariate analysis. Women respondents were younger and more likely to work in academic and employed positions. Sex was not an independent predictive factor of burnout, fatigue, or overall quality of life after controlling for age. In both men and women, greater autonomy, meaning in work, reasonable amount of clerical tasks, and having effective support staff were associated with lower burnout risk. More hours worked, more nights on call, higher outpatient volume, and higher percent of time in clinical practice were associated with higher burnout risk. For women, greater number of weekends doing hospital rounds was associated with higher burnout risk. Women neurologists made proportionately more negative comments than men regarding workload, work-life balance, leadership and deterioration of professionalism, and demands of productivity eroding the academic mission. CONCLUSIONS: We identified differences in burnout, career satisfaction, and well-being in neurologists by age and sex. This may aid in developing strategies to prevent and mitigate burnout and promote professional fulfillment for different demographic subgroups of neurologists.

Nonsurgical interventions for spine pain.

Nonsurgical, conservative approaches to spine pain include medication and physical therapy. In addition, several invasive procedures have been developed to provide relief when conservative options fail. These include facet joint injection and radiofrequency ablation techniques, translaminar and transforaminal epidural corticosteroid injections, and intradiscal coagulation procedures. Controlled studies to assess the effectiveness of some of these therapeutic modalities have been performed.

Low Back Pain.

PURPOSE OF REVIEW: This article provides an overview of evaluating and treating low back pain in the outpatient setting. RECENT FINDINGS: As most cases of acute low back pain have a favorable prognosis, current guidelines on imaging studies recommend conservative treatment for 6 weeks prior to obtaining an MRI if no red flags are present. Of these red flags, a prior history of cancer is the strongest risk factor for a malignant etiology and requires urgent evaluation with MRI. Management of acute low back pain is mainly conservative with oral non-narcotic analgesics and mobilization as the initial recommendations. For patients with radiculopathy, epidural steroids may result in short-term pain relief, but long-term effects are still unclear. SUMMARY: A systematic, evidence-based approach to the patient with low back pain is key to providing safe and cost-efficient care.

Burnout, career satisfaction, and well-being among US neurology residents and fellows in 2016.

OBJECTIVE: To study prevalence of and factors contributing to burnout, career satisfaction, and well-being in US neurology residents and fellows. METHODS: A total of 938 US American Academy of Neurology member neurology residents and fellows were surveyed using standardized measures of burnout, career satisfaction, and well-being from January 19 to March 21, 2016. RESULTS: Response rate was 37.7% (354/938); about 2/3 of responders were residents and 1/3 were fellows. Median age of participants was 32 years and 51.1% were female. Seventy-three percent of residents and 55% of fellows had at least one symptom of burnout, the difference largely related to higher scores for depersonalization among residents. For residents, greater satisfaction with work-life balance, meaning in work, and older age were associated with lower risk of burnout; for fellows, greater satisfaction with work-life balance and effective support staff were associated with lower risk of burnout. Trainees experiencing burnout were less likely to report career satisfaction. Career satisfaction was more likely among those reporting meaning in work and more likely for those working in the Midwest compared with the Northeast region. CONCLUSIONS: Burnout is common in neurology residents and fellows. Lack of work-life balance and lack of meaning in work were associated with reduced career satisfaction and increased risk of burnout. These results should inform approaches to reduce burnout and promote career satisfaction and well-being in US neurology trainees.

Burnout, career satisfaction, and well-being among US neurologists in 2016.

OBJECTIVE: To study prevalence of and factors that contribute to burnout, career satisfaction, and well-being in US neurologists. METHODS: A total of 4,127 US American Academy of Neurology member neurologists who had finished training were surveyed using validated measures of burnout, career satisfaction, and well-being from January 19 to March 21, 2016. RESULTS: Response rate was 40.5% (1,671 of 4,127). Average age of participants was 51 years, with 65.3% male and nearly equal representation across US geographic regions. Approximately 60% of respondents had at least one symptom of burnout. Hours worked/week, nights on call/week, number of outpatients seen/week, and amount of clerical work were associated with greater burnout risk. Effective support staff, job autonomy, meaningful work, age, and subspecializing in epilepsy were associated with lower risk. Academic practice (AP) neurologists had a lower burnout rate and higher rates of career satisfaction and quality of life than clinical practice (CP) neurologists. Some factors contributing to burnout were shared between AP and CP, but some risks were unique to practice setting. Factors independently associated with profession satisfaction included meaningfulness of work, job autonomy, effectiveness of support staff, age, practicing sleep medicine (inverse relationship), and percent time in clinical practice (inverse relationship). Burnout was strongly associated with decreased career satisfaction. CONCLUSIONS: Burnout is common in all neurology practice settings and subspecialties. The largest driver of career satisfaction is the meaning neurologists find in their work. The results from this survey will inform approaches needed to reduce burnout and promote career satisfaction and well-being in US neurologists.

Diagnostic Accuracy of Single Fiber Electromyography for Myasthenia Gravis in Patients Followed Longitudinally.

INTRODUCTION: The literature lacks data on accuracy of single fiber electromyography (SFEMG) for myasthenia gravis (MG) patients followed longitudinally. METHODS: We included patients with a clinical suspicion of MG who received SFEMG and follow-up at our institution between 2003 and 2013. Data collected included demographics, symptom details, clinical deficits, other diagnostic testing results, MG medication regimen, duration on treatment, response to therapy, and ultimate diagnosis after follow-up. When available, information was also extracted from the MG-specific Activities of Daily Living, MG Quality of Life, and European Quality of Life assessments before and after SFEMG. RESULTS: Three hundred forty eight SFEMG patients met inclusion criteria. Myasthenia gravis was ultimately diagnosed in 31% (19% ocular, 12% generalized). A sensitivity of 78% was seen for MG regardless of subtype, 73% for ocular MG, and 85% for generalized MG. A specificity of 91% was obtained for MG of either ocular or generalized subtype. CONCLUSIONS: The diagnostic accuracy of SFEMG using this methodology minimizing incorporation bias is more reliable than that usually described in previous studies. There is utility in increasing diagnostic yield when SFEMG results are combined with clinical data and those from other diagnostic tests, particularly serology.

Bell palsy: Clinical examination and management.

Bell palsy is a common neurologic disorder characterized by acute facial mononeuropathy of unclear cause presenting with unilateral facial weakness. Careful examination and a detailed history are important in making an accurate diagnosis. Early recognition is essential, as treatment with corticosteroids within 72 hours of onset has been shown to hasten recovery. Fortunately, most patients recover spontaneously within 3 weeks, even if untreated.

Myelopathy due to degenerative and structural spine diseases.

PURPOSE OF REVIEW: This article reviews the current evaluation and treatment of patients with myelopathy due to cervical spondylotic disease and other structural disorders of the spine. RECENT FINDINGS: In patients with cervical spondylotic myelopathy, symptom duration, severity at baseline, and possibly age have been identified as key prognostic markers of clinical course and postsurgical outcome. Other potential markers include specific MRI and EMG findings. The diagnosis and monitoring of syringomyelia is enhanced by the addition of phase contrast MRI, which evaluates CSF flow dynamics. Flexion MRI is helpful in establishing the diagnosis of Hirayama disease, which is now attributed to a tightened dural sac that is displaced anteriorly on neck flexion, compressing the cord. SUMMARY: Advances in neuroimaging along with new insights into the pathophysiology of structural spine diseases can help guide clinical decision making and optimize patient outcomes.

Variants and mimics of Guillain Barré Syndrome.

BACKGROUND: The clinical and pathologic spectrum of Guillain Barre Syndrome (GBS) has expanded to include both demyelinating and axon loss forms. GBS may also have atypical presentations. For these reasons, clinicians are more likely to overlook unrelated disorders that mimic GBS. REVIEW SUMMARY: In this article, the classic presentation and variants of GBS are briefly reviewed. Disorders that mimic GBS are reviewed in detail, including those caused by neurotoxins, heavy metals, chemical toxins, drugs, vasculitis, hereditary disorders, infections, critical illness, and myelopathy. Illustrative case studies accompany a number of the descriptions. CONCLUSIONS: Failure to recognize the mimics of GBS can lead to erroneous diagnosis, inappropriate treatment, and significant morbidity. Appropriate diagnosis requires a combination of careful history and examination, and accurate interpretation of diagnostic testing.

Electrodiagnostic approach to the patient with suspected radiculopathy.

Cervical and lumbosacral radiculopathies are among the most common causes of referral to the electromyographic (EMG) laboratory. Among all the other electrodiagnostic studies (nerve conduction studies, late responses, somatosensory evoked potentials, root electrical and magnetic stimulation studies), the needle electrode (needle EMG) examination is the most specific and sensitive. A good grasp of the anatomic, clinical and electromyographic myotomal charts is essential to localize radiculopathies to single (or more) root lesions.