Diagnostic characteristics of nerve conduction study parameters for vasculitic neuropathy.

INTRODUCTION/AIMS: In vasculitic neuropathy (VN), a 50% side-to-side difference in the amplitude of compound muscle action potentials and sensory nerve action potentials is considered meaningful, but unequivocal evidence is lacking. The aim of this study is to characterize electrodiagnostic features that best distinguish VN from other axonal polyneuropathies. METHODS: We conducted a case-control study between January 2000 and April 2021. We reviewed the records of patients with VN who had bilateral nerve conduction studies (NCS) and evaluated different electrodiagnostic models to help distinguish VN from non-inflammatory axonal polyneuropathies. RESULTS: We identified 82 cases, and 174 controls with non-inflammatory axonal neuropathies. The amplitude percent difference Z-score model showed the best discriminatory capability between cases and controls (area under the curve [AUC] 0.87; 95% confidence interval [CI] 0.82, 0.93), and the number of nerves tested did not significantly influence the model. Individually, the ulnar motor nerve (AUC 0.86; 95% CI 0.77, 0.94) and median motor nerve (AUC 0.85; 95% CI 0.77, 0.94) showed the best discriminatory capability. A 50% amplitude difference between at least two bilateral nerves, either in the upper (AUC 0.85; 95% CI 0.77, 0.93) or lower (AUC 0.79; 95% CI 0.71, 0.87) extremity showed good discriminatory threshold for detecting VN. DISCUSSION: The best electrodiagnostic criteria for VN utilizes z-scores of percent differences in nerve amplitudes, but this approach may be difficult to implement at the bedside. Alternately, a 50% amplitude difference in at least two nerves is a reasonable approximation.

Distal symmetric polyneuropathy phenotype in patients with sensory neuronopathy at the time of electrodiagnosis.

INTRODUCTION/AIMS: It is unknown how often patients with sensory neuronopathy (SNN) present with a distal symmetric polyneuropathy (DSP) phenotype. In these cases, electrodiagnostic testing may discriminate SNN with a DSP phenotype from DSP. METHODS: We reviewed the records of patients who met SNN diagnostic criteria between January 2000 and February 2021 and identified patients with a DSP phenotype at the time of electrodiagnosis. RESULTS: Sixty-two patients fulfilled SNN diagnostic criteria. At symptom onset, 20 (32.2%) patients presented with distal symmetric sensory symptoms limited to the feet. However, most progressed rapidly over 6 months or developed asymmetric symptoms. At the time of electrodiagnosis, only seven (11.3%) patients had a DSP phenotype. Of these seven patients, four had cerebellar ataxia with neuropathy and vestibular areflexia syndrome, one had vitamin B6 deficiency, one was thought to be alcohol-induced, and one was idiopathic. DISCUSSION: Patients with SNN rarely present with a DSP phenotype at the time of electrodiagnosis. The finding that one third of cases resemble DSP at onset highlights the importance of clinical monitoring. In patients with a DSP phenotype, the presence of ataxia at onset or significant progression within 6 months may suggest the possibility of SNN and should prompt additional investigations, such as electrodiagnosis.

The neuromuscular fellowship portal and match.

For many years, Neuromuscular Medicine programs lacked a standardized means of handling fellowship applications and offering positions. Programs interviewed applicants and made offers as early as the first half of Post Graduate Year 3 (PGY3), a suboptimal timeline for applicants who may have had little prior exposure to neuromuscular or electrodiagnostic medicine. In 2021, the American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM) developed the Neuromuscular Fellowship Portal to standardize a later timeline and establish a process for fellowship applications and offers. In its first year, the Neuromuscular Fellowship Portal used a unique one-way match, in which the portal released serial offers to applicants based on rank order lists submitted by programs. Fifty-two Neuromuscular Medicine programs and seven electromyography (EMG)-focused Clinical Neurophysiology programs participated. Sixty-eight positions were filled, a similar number to previous years. A survey of fellowship directors and applicants following this process showed overwhelming support for the standardized timeline and application portal, but all program directors and most applicants favored moving to a traditional match. To maintain the existing application timeline and minimize costs for all parties, the AANEM Neuromuscular Fellowship Portal will host a two-way match, based on existing commercial match algorithms, in 2022. A match will afford a fair and efficient process for all involved. Both Neuromuscular Medicine and EMG-focused Clinical Neurophysiology programs will be encouraged to participate. The process undertaken by the AANEM can stand as an example for other neurologic subspecialties who are interested in standardizing their application timeline.

Patients who meet electrodiagnostic criteria for CIDP rarely present with a sensory predominant DSP phenotype.

INTRODUCTION: It is unknown how often patients with electrodiagnostic evidence of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), a potentially treatable condition, present with a distal symmetric polyneuropathy (DSP) phenotype. METHODS: We reviewed the records of patients who presented to our electrodiagnostic laboratory between January 1, 2011, to December 31, 2019, and fulfilled electrodiagnostic criteria for CIDP to identify those who presented with a sensory predominant DSP phenotype. RESULTS: One hundred sixty-two patients had a chronic acquired demyelinating neuropathy, of whom 138 met criteria for typical or atypical CIDP. Nine of these patients presented with a sensory predominant DSP phenotype, among whom six were eventually diagnosed with distal acquired demyelinating symmetric (DADS) neuropathy; one with Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal protein, Skin changes (POEMS) syndrome; and two with idiopathic DSP. The prevalence of acquired chronic demyelinating neuropathies among all patients presenting with a DSP phenotype was estimated to be 0.34%. DISCUSSION: Patients who meet electrodiagnostic criteria for CIDP rarely present with a sensory predominant DSP phenotype, and electrodiagnostic testing rarely identifies treatable demyelinating neuropathies in patients who present with a DSP phenotype.

Bilateral nerve conduction studies in the evaluation of distal symmetric polyneuropathy.

INTRODUCTION: Nerve conduction studies are used to aid in the diagnosis of distal symmetric polyneuropathy (DSP). It is unclear whether bilateral lower extremity nerve conduction studies (NCS) are needed when evaluating for suspected DSP. METHODS: We retrospectively analyzed NCS from patients who presented to the University of Michigan electromyography laboratory between July 1, 2016 and December 31, 2017 with symptoms of DSP to assess agreement and correlation between left and right lower extremity NCS parameters. RESULTS: We found significant agreement between abnormalities in individual nerve parameters of the left and right lower extremities of 105 patients, most notably in the sural nerve. In the 53 patients with bilateral sural, peroneal, and tibial studies, there was also significant agreement between whether the left and right met electrodiagnostic criteria for DSP (κ = 0.77). DISCUSSION: Bilateral lower extremity NCS may have limited utility in the evaluation of suspected DSP. Muscle Nerve, 2019.

Safety and pain in electrodiagnostic studies.

Discomfort is an unavoidable part of electrodiagnostic (EDX) studies. The most readily modifiable mediator of electromyography (EMG)-associated pain is muscle selection. Interventions that may reduce pain include vapocoolant spray, ibuprofen, and techniques such as slapping or stretching the skin. Needlestick injuries to health care workers carry the risk of transmitting bloodborne illnesses, but other infectious complications of EDX studies are very rare. EMG probably contributes to asymptomatic hemorrhage in approximately 1% of patients, but clinically significant bleeding has only been reported a few times. Therapeutic anticoagulation does not significantly increase this risk. With standard procedures, there have been no reports of patients developing cardiac arrhythmia from nerve conduction studies. No special precautions are necessary in patients with implantable cardiac devices or intravenous lines. There is a small risk of pneumothorax associated with EMG of the diaphragm and chest wall muscles. Several techniques have been suggested to improve the safety of diaphragm EMG. Muscle Nerve 55: 149-159, 2017.

Nerve conduction studies are safe in patients with central venous catheters.

INTRODUCTION: It is unknown if central venous catheters bypass the skin's electrical resistance and engender a risk of nerve conduction study-induced cardiac arrhythmia. The objective of this study is to determine if nerve conduction studies affect cardiac conduction and rhythm in patients with central venous catheters. METHODS: Under continuous 12-lead electrocardiogram monitoring, subjects with and without central venous catheters underwent a series of upper extremity nerve conduction studies. A cardiologist reviewed the electrocardiogram tracings for evidence of cardiac conduction abnormality or arrhythmia. RESULTS: Ten control subjects and 10 subjects with central venous catheters underwent the nerve conduction study protocol. No malignant arrhythmias or conduction abnormalities were noted in either group. CONCLUSIONS: Nerve conduction studies of the upper extremities, including both proximal stimulation and repetitive stimulation, do not appear to confer increased risk of cardiac conduction abnormality in those patients with central venous catheters who are not critically ill or have a prior history of arrhythmia. Muscle Nerve 56: 321-323, 2017.

Electromyography-related pain: muscle selection is the key modifiable study characteristic.

INTRODUCTION: The aim of this study was to estimate the effects of patient, provider, and study characteristics on electromyography (EMG)-related pain. METHODS: Patients undergoing EMG rated their EMG-related pain after each muscle was studied on a 100-point visual analog scale (VAS). Investigators recorded the order in which the muscles were sampled, the total time spent with the needle in each muscle, and whether electrical endplate noise was noted. RESULTS: A total of 1781 muscles were studied in 304 patients. Eleven muscles were associated with significantly more or less pain than the others. Endplate noise was associated with more pain (5.4 mm, 95% CI 2.8-7.0). There was a small, but significant effect from needling time (0.02 mm, 95% CI 0.00-0.04). CONCLUSIONS: Among factors that electromyographers can control, muscle selection has the greatest impact on pain. Our data include an extensive list of muscle-specific EMG-related pain scores. Provider and other study characteristics have little or no impact on EMG-related pain.

Altering electromyography studies: importance of the electromyographer's perception of patient pain.

OBJECTIVE: To determine the relation between the patient's actual pain, the electromyographer's perception of patient pain, and whether an electromyogram (EMG) is altered. DESIGN: Patients undergoing electromyography reported expected pain and procedure-related overall pain on a 100-mm visual analog scale (VAS). Blinded electromyographers estimated patient pain levels and indicated if they altered the study in any way because of this perception. Multivariable logistic regression was used to determine predictors of altering the EMG. Paired t tests were used to compare overall pain with expected pain and electromyographer perception of pain. SETTING: Tertiary referral center. PARTICIPANTS: Referred sample of adult subjects (N=304). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Patient pain, electromyographer perception of patient pain, and whether an EMG was altered because of the electromyographer's perception of patient pain. RESULTS: Mean VAS scores ± SD were 48±25mm for patient-expected pain (P<.001), 42±24mm for electromyographer perception of pain (P<.0001), and 36±25mm for actual overall pain. Electromyographers altered their study 31.7% of the time because of concerns about pain. For every 13-mm increase on the VAS (a prespecified clinically meaningful difference), the electromyographer perception of pain increased the odds of altering a study 2.36 times (95% confidence interval [CI], 1.71-3.26), whereas patient overall pain did not have a significant effect (odds ratio=1.12; 95% CI, .86-1.47). CONCLUSIONS: Patients expect EMGs to be more painful than they are. Electromyographers overestimate patient pain and are more likely to alter their studies when they believe patients are experiencing more pain, independently of whether patients actually have more pain. Improving the communication between electromyographers and patients may prevent unnecessary alterations.

The Neurology Fellowship Application Conundrum: Finding Common Ground.

For many neurologic subspecialties, the fellowship application process begins early in the first half of the second year of neurology-specific training (PGY3 for adult neurology residents and PGY4 for child neurology residents). In 2019, the American Academy of Neurology (AAN) published a position statement recommending communication between fellowship candidates and training programs begin no sooner than March 1 of the penultimate year of training and that programs offer fellowship positions no sooner than August 1 of the final year of training. A few pilot subspecialties adopted this timeline for 2021 recruitment for positions beginning in 2022. All United States-based AAN-affiliated neurology and child neurology residents who recently completed the fellowship application process received a survey about their fellowship application experience. Of the 291 residents who responded to the survey, 96% agree that applications should not be submitted before March 1 of the penultimate year of training and 72% believe that August 1 of the final year is a reasonable time to begin offering positions. Nearly half (49%) of residents believe that there is too little time for subspecialty/clinical exposure before applying for fellowship and 88% feel the current process and timeline are stressful. Residents who applied to programs in pilot subspecialties report more time to choose, less stress, and a lower number of time-pressured offers. A large majority of residents (89%) prefer to submit a single application through a centralized system. The survey results suggest that residents who just completed the fellowship application process agree with the AAN recommended timeline for all subspecialties and that all neurology subspecialties should consider adopting a fellowship match. Programs can help facilitate a better fellowship application experience by providing earlier exposure to a broad range of neurologic subspecialties and ensure that residents are given opportunities to attend national meetings and participate in appropriately scoped scholarly endeavors.

Declining use of neurological eponyms in cases where a non-eponymous alternative exists.

Eponyms are common in neurology, but their use is controversial. Recent studies have demonstrated increasing eponym use over time in the scientific literature, but it is unclear whether this is a result of authors choosing to use eponyms more frequently, or is merely a product of increasing rates of scientific publication. Our goal was to explore trends in decision-making pertaining to eponym usage. We identified cases where an eponym and a corresponding non-eponymous term existed, and assessed temporal trends in the relative usage of these terms using Google's n-gram viewer for each decade from 1900-2019. Relative to corresponding non-eponymous terms, the use of eponyms increased across the 20th century, peaking in the decade from 1980 to 1989, before sharply declining after the turn of the 21st century. This indicates that when faced with a choice between using an eponym and non-eponymous term, contemporary authors increasingly chose the non-eponymous term. This recent trend may reflect increased awareness of the limitations of eponyms, greater attention to the personal and political lives of namesakes, and a cultural shift toward viewing scientific advances as the result of collective and collaborative efforts rather than the solitary achievements of eminent individuals.

A Structured Approach to the Diagnosis of Peripheral Nervous System Disorders.

PURPOSE OF REVIEW: Neuroanatomic localization and pattern recognition can be used to diagnose both focal lesions and generalized disorders of the peripheral nervous system. This article describes the nature and pattern of sensory and motor deficits associated with lesions of specific spinal nerve roots, plexus, or peripheral nerves. It also describes the patterns of sensory and motor deficits that suggest multifocal or generalized disorders of the motor neurons, sensory neurons, and peripheral nerves. RECENT FINDINGS: The pattern of sensory and motor deficits may be used to distinguish lesions of the peripheral nervous system from those of the central nervous system. The spinal roots, nerve plexus, and peripheral nerves supply specific muscles and receive sensory input from distinctive cutaneous regions. Focal lesions of these structures therefore produce characteristic patterns of sensory and motor deficits. Multifocal or generalized disorders of the peripheral nervous system may be distinguished by categorizing their sensory and motor involvement, proximal and distal predominance, and degree of symmetry. Serum tests, CSF analysis, electrodiagnostic studies, MRI, ultrasound, nerve biopsy, and skin biopsy have unique roles in the diagnosis of suspected neuromuscular disorders. SUMMARY: A structured approach to the diagnosis of nerve and motor neuron disorders can lead to hypothesis-driven diagnostic testing. Ancillary tests should be reserved for cases in which confirming or refuting a diagnosis will change patient management.

2017 Program Director Survey: Feedback from your adult neurology residency leadership.

OBJECTIVE: To survey adult neurology program directors (PDs) and inform the future development of neurology training programs. METHODS: All US adult neurology PDs were invited to complete the survey. The goals were to determine the demographic makeup of residency programs, characterize curricula, understand PD and program needs, and compare results to those of a similar survey in 2007. RESULTS: The response rate was 70.6%. PD demographics for age, faculty track status, and academic rank remain unchanged over the last decade. The proportion of female PDs and assistant PDs has increased significantly. The mean number of residents per training program has also increased significantly. Female PDs are more likely to have a junior academic rank than their male colleagues. Disparities remain between the PDs' time spent on teaching/program administration and salary support. Most PDs support moving fellowship applications later in the training cycle. The majority of PDs find the Clinical Competency Committee process useful in assessing resident competence. A minority of PDs feel that the Accreditation Council for Graduate Medical Education Milestones meet their intended purpose. Half of programs include a curriculum to supplement the clinical experience on child neurology rotations. A third of programs include a supplemental curriculum for psychiatry rotations. The majority of programs offer a general fund for residents to use to support their education. CONCLUSION: Deficiencies exist in compensation for PDs' teaching and administrative time and for academic promotion for female PDs. These results serve as a benchmark for comparison across programs and the basis to advocate for further improvements and support for neurology residency training.

An Introductory, Computer-Based Learning Module for Interpreting Noncontrast Head Computed Tomography.

Introduction: New radiology and other residents must quickly assimilate a vast amount of anatomic and pathologic information when learning to interpret noncontrast head computed tomography (CT). No interactive, computer-based module using a search-pattern approach to provide new residents with the groundwork for interpretation of noncontrast head CT previously existed. Methods: We developed such a learning module using PowerPoint. First-year radiology residents completed the module prior to their neuroradiology rotation, and neurology residents completed it during orientation. Residents took 20-question pre- and posttests to assess knowledge and a postmodule survey. Each resident was randomized to one of two pretests and took the opposite as the posttest. Scores were collected over 5 years for radiology residents and 4 years for neurology residents. Statistical analysis of scores was performed using t tests. Results: Forty-seven first-year radiology residents and 31 neurology residents completed the module and the pre- and posttests. Scores for all residents either stayed the same or increased, regardless of the order of the versions of the pre- or posttests; the mean score increase was 4 (p < .0001) out of 20. Radiology residents had higher mean scores than neurology residents on the pre- and posttests, which were statistically significant (p < .04 and .0004, respectively). Feedback on the survey was overwhelmingly positive. Discussion: This computerized learning module is effective for teaching basic interpretation skills to new radiology and neurology residents. The module allows for asynchronous, programmed learning and the use of a step-by-step search-pattern approach.

Sex Differences in Academic Rank and Publication Rate at Top-Ranked US Neurology Programs.

Importance: Women are underrepresented in academic neurology, and the reasons for the underrepresentation are unclear. Objective: To explore potential sex differences in top-ranked academic neurology programs by comparing the number of men and women at each academic faculty rank and how many articles each group has published. Design, Setting, and Participants: Twenty-nine top-ranked neurology programs were identified by combining the top 20 programs listed on either the 2016 or 2017 Doximity Residency Navigator tool with the top 20 programs listed in the US News and World Report ranking of Best Graduate Schools. An internet search of the departmental websites was performed between December 1, 2015, and April 30, 2016. For each faculty member on a program site, the following biographical information was obtained: first name, last name, academic institution, sex, academic faculty rank, educational leadership (clerkship, fellowship, or residency director/assistant director), and year of medical school graduation. Main Outcomes and Measures: To compare the distribution of men vs women and the number of publications for men vs women at each academic faculty rank. Secondary analyses included Scopus h-index, book authorship, educational leadership (clerkship, residency, or fellowship director/assistant director), and clinical activity as inferred through Medicare claims data in men vs women after controlling for years since medical school graduation. Results: Of 1712 academic neurologists in our sample, 528 (30.8%) were women and 1184 (69.2%) were men (P < .001). Men outnumbered women at all academic faculty ranks, and the difference increased with advancing rank (instructor/lecturer, 59.4% vs 40.5%; assistant professor, 56.7% vs 43.3%; associate professor, 69.8% vs 30.2%; and professor, 86.2% vs 13.8%). After controlling for clustering and years since medical school graduation, men were twice as likely as women to be full professors (odds ratio [OR], 2.06; 95% CI, 1.40-3.01), whereas men and women had the same odds of being associate professors (OR, 1.04; 95% CI, 0.82-1.32). Men had more publications than women at all academic ranks, but the disparity in publication number decreased with advancing rank (men vs women after adjusting for years since medical school graduation: assistant professor [exponentiated coefficient, 1.85; 95% CI, 1.57-2.12]; associate professor [1.53; 95% CI, 1.22-1.91]; and full professor [1.36; 95% CI, 1.09-1.69]). Men had a higher log Scopus h-index than women after adjustment (linear coefficient, 0.44; 95% CI, 0.34-0.55). There was no significant association between sex and clinical activity (linear coefficient, 0.02; 95% CI, -0.10 to 0.13), educational leadership (OR, 1.09; 95% CI, 0.85-1.40), or book authorship (OR, 2.75; 95% CI, 0.82-9.29) after adjusting for years since medical school graduation. Conclusions and Relevance: Men outnumber women at all faculty ranks in top-ranked academic neurology programs, and the discrepancy increases with advancing rank. Men have more publications than women at all ranks, but the gap narrows with advancing rank. Other measures of academic productivity do not appear to differ between men and women.

A Self-Study Curriculum in Electromyography and Nerve Conduction Studies for Residents and Fellows.

INTRODUCTION: To our knowledge, there are no freely available curricula for a focused resident or fellow rotation in electromyography and nerve conduction studies that address the Accreditation Council for Graduate Medical Education (ACGME) milestones for neurology, physical medicine and rehabilitation, clinical neurophysiology, or neuromuscular medicine. Thus, we created this curriculum to help trainees develop a basic understanding of clinical electrodiagnostic studies. The program objectives map to many of the relevant ACGME milestones, primarily those pertaining to medical knowledge, patient care, and practice-based learning and improvement. METHODS: The curricular materials include an interactive, hyperlink-driven slide show with 19 educational modules, subdivided further into basic and advanced topics. We also created a 50-question multiple-choice test, paired each question with key concepts, and provided instructions on using the test results to develop a trainee-specific learning plan. RESULTS: Residents and fellows have been using this curriculum at the University of Michigan since 2007. The mean and median scores of 80 trainees who took the 50-item test between 2007 and 2016 were 80% and 82%, respectively, with a standard deviation of 10%. In annual surveys of neurology residents, this electromyography rotation has consistently had the highest mean approval rating of all clinical rotations in the training program. DISCUSSION: This curriculum is a complete, self-contained learning resource that may be used alone or to supplement a supervised apprenticeship for trainees who want to learn to perform electrodiagnostic studies independently. The content ensures that trainees demonstrate mastery of many of the ACGME milestones for their field.

Mentored peer review of standardized manuscripts as a teaching tool for residents: a pilot randomized controlled multi-center study.

BACKGROUND: There is increasing need for peer reviewers as the scientific literature grows. Formal education in biostatistics and research methodology during residency training is lacking. In this pilot study, we addressed these issues by evaluating a novel method of teaching residents about biostatistics and research methodology using peer review of standardized manuscripts. We hypothesized that mentored peer review would improve resident knowledge and perception of these concepts more than non-mentored peer review, while improving review quality. METHODS: A partially blinded, randomized, controlled multi-center study was performed. Seventy-eight neurology residents from nine US neurology programs were randomized to receive mentoring from a local faculty member or not. Within a year, residents reviewed a baseline manuscript and four subsequent manuscripts, all with introduced errors designed to teach fundamental review concepts. In the mentored group, mentors discussed completed reviews with residents. Primary outcome measure was change in knowledge score between pre- and post-tests, measuring epidemiology and biostatistics knowledge. Secondary outcome measures included level of confidence in the use and interpretation of statistical concepts before and after intervention, and RQI score for baseline and final manuscripts. RESULTS: Sixty-four residents (82%) completed initial review with gradual decline in completion on subsequent reviews. Change in primary outcome, the difference between pre- and post-test knowledge scores, did not differ between mentored (-8.5%) and non-mentored (-13.9%) residents (p = 0.48). Significant differences in secondary outcomes (using 5-point Likert scale, 5 = strongly agree) included mentored residents reporting enhanced understanding of research methodology (3.69 vs 2.61; p = 0.001), understanding of manuscripts (3.73 vs 2.87; p = 0.006), and application of study results to clinical practice (3.65 vs 2.78; p = 0.005) compared to non-mentored residents. There was no difference between groups in level of interest in peer review (3.00 vs 3.09; p = 0.72) or the quality of manuscript review assessed by the Review Quality Instrument (RQI) (3.25 vs 3.06; p = 0.50). CONCLUSIONS: We used mentored peer review of standardized manuscripts to teach biostatistics and research methodology and introduce the peer review process to residents. Though knowledge level did not change, mentored residents had enhanced perception in their abilities to understand research methodology and manuscripts and apply study results to clinical practice.