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.

Neurology podcast utilization during the COVID-19 pandemic.

BACKGROUND: As medical education shifted to a virtual environment during the early coronavirus disease 2019 (COVID-19) pandemic, we evaluated how neurology podcasting may have been utilized during this period, and which features of podcasts have been more highly sought by a medical audience. METHODS: We conducted a retrospective analysis of neurology-themed blogs and/or podcasts between April 2019 and May 2020. Programs were eligible if they reported mean monthly downloads > 2000, were affiliated with an academic society, or offered continuing medical education credit. Thirty-day download counts were compared between study months, with adjustment for multiple testing. Exploratory analyses were performed to determine which podcast features were associated with higher downloads. RESULTS: Of the 12 neurology podcasts surveyed, 8 completed the survey and 5 met inclusion criteria. The median monthly download count was 2865 (IQR 869-7497), with significant variability between programs (p < 0.001). While there was a 358% increase in downloads during April 2020 when compared to the previous month, this was not significant (median 8124 [IQR 2913-14,177] vs. 2268 [IQR 540-6116], padj = 0.80). The non-significant increase in overall downloads during April 2020 corresponded to an increase in unique episodes during that month (r = 0.48, p = 0.003). There was no difference in 30-day downloads among episodes including COVID-19 content versus not (median 1979 [IQR 791-2873] vs. 1171 [IQR 405-2665], p = 0.28). CONCLUSIONS: In this unique, exploratory study of academic neurology-themed podcasts, there was no significant increase in episode downloads during the early COVID-19 pandemic. A more comprehensive analysis of general and subspecialty medical podcasts is underway.

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.

Patient perception of pain versus observed pain behavior during a standardized electrodiagnostic test.

INTRODUCTION: Clinicians often assume that observations of pain behavior are adequate for assessment of patient pain perception during procedures. This has not been tested during a standardized electrodiagnostic experience. METHODS: During a prospective trial including extensive, standardized electrodiagnostic testing on persons with lumbar stenosis, vascular claudication, and asymptomatic volunteers, the subjects and an observer rated levels of pain. RESULTS: In 60 subjects, observers significantly under-rated pain (Visual Analog Scale 3.17 ± 2.23 vs. 4.38 ± 2.01, t = -4.577, df = 59, P < 0.001). Perceived pain during testing related to bodily pain as measured by the visual analog, McGill, Pain Disability, and Quebec scales, but not age, duration of symptoms, Tampa kinesiphobia, Center for Epidemiological Studies Depression scale, or SF-36 health quality of life. CONCLUSIONS: Persons with worse pain syndromes may perceive more pain during testing than others. Clinicians and researchers should understand that patients may have more pain than they recognize.

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.

Symmetry of paraspinal muscle denervation in clinical lumbar spinal stenosis: support for a hypothesis of posterior primary ramus stretching?

INTRODUCTION: Denervation of the paraspinal muscles in spinal disorders is frequently attributed to radiculopathy. Therefore, patients with lumbar spinal stenosis causing asymmetrical symptoms should have asymmetrical paraspinal denervation. METHODS: Seventy-three patients with clinical lumbar spinal stenosis, aged 55-85 years, completed a pain drawing and underwent masked electrodiagnostic testing, including bilateral paraspinal mapping and testing of 6 muscles on the most symptomatic (or randomly chosen) limb. RESULTS: With the exception of 10 subjects with unilateral thigh pain (P = 0.043), there was no relationship between side of pain and paraspinal mapping score for any subgroups (symmetrical pain, pain into 1 calf only). Among those with positive limb EMG (tested on 1 side), no relationship between side of pain and paraspinal EMG score was found. CONCLUSION: Evidence suggests that paraspinal denervation in spinal stenosis may not be due to radiculopathy, but rather due to stretch or damage to the posterior primary ramus.

The risk of hematoma following extensive electromyography of the lumbar paraspinal muscles.

INTRODUCTION: The purpose of this study is to provide a controlled trial looking at the risk of paraspinal hematoma formation following extensive paraspinal muscle electromyography. METHODS: 54 subjects ages 55-80 underwent MRI of the lumbar spine before or shortly after electromyography using the paraspinal mapping technique. A neuroradiologist, blinded to the temporal relationship between the EMG and MRI, reviewed the MRIs to look for hematomas in or around the paraspinal muscles. RESULTS: Two MRIs demonstrated definite paraspinal hematomas, while 10 were found to have possible hematomas. All hematomas were < 15 mm, and none were close to any neural structures. There was no relationship between MRI evidence of hematoma and either the timing of the EMG or the use of aspirin or other nonsteroidal anti-inflammatory drugs. CONCLUSIONS: Paraspinal electromyography can be considered safe in the general population and those taking nonsteroidal anti-inflammatory drugs.

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.

The impact of student debt on neurological practice.

The median cost of attending medical school is rising annually, and with it, student debt. Neurology residents have stepped up during the pandemic to answer the call of a health system at its breaking point. In this article, we outline how this escalating problem of student debt affects the neurology pipeline, the wellbeing and career decisions of current neurology trainees and practicing neurologists and through it, and the gap in healthcare. We describe currently available options for loan repayment and call for advocacy and legislation to address this mounting burden as a means to improve neurological care in the United States.

Multi-Residency Implementation of an Online Movement Disorders Curriculum Based on Real Patient Videos.

Background: In-person didactic education in residency has numerous challenges including inconsistent availability of faculty and residents, limited engagement potential, and non-congruity with clinical exposure. Methods: An online curriculum in movement disorders was implemented across nine neurology residency programs (six intervention, three control), with the objective to determine feasibility, acceptability, and knowledge growth from the curriculum. Residents in the intervention group completed ten modules and a survey. All groups completed pre-, immediate post-, and delayed post-tests. Results: Eighty-six of 138 eligible housestaff (62.3%) in the intervention group completed some modules and 74 completed at least half of modules. Seventy-four, 49, and 30 residents completed the pre-, immediate post-, and delayed post-tests respectively. Twenty-five of 42 eligible control residents (59.5%) completed at least one test. Mean pre-test scores were not significantly different between groups (6.33 vs. 6.92, p = 0.18); the intervention group had significantly higher scores on immediate post- (8.00 vs. 6.79, p = 0.001) and delayed post-tests (7.92 vs. 6.92, p = 0.01). Residents liked having a framework for movement disorders, appreciated the interactivity, and wanted more modules. Residents completed the curriculum over variable periods of time (1-174 days), and at different times of day. Discussion: This curriculum was feasible to implement across multiple residency programs. Intervention group residents showed sustained knowledge benefit after participating, and residents took advantage of its flexibility in their patterns of module completion. Similar curricula may help to standardize certain types of clinical learning and exposure across residency programs. Highlights: Interactive online tools for resident didactic learning are valuable to residents. Residents learn from interactive online curricula, find the format engaging, and take advantage of the flexibility of online educational tools. Beginner learners appreciate algorithms that help them to approach a new topic.

Education Research: NeuroBytes: A New Rapid, High-Yield e-Learning Platform for Continuing Professional Development in Neurology.

OBJECTIVE: To determine whether NeuroBytes is a helpful e-Learning tool in neurology through usage, viewer type, estimated time and cost of development, and postcourse survey responses. BACKGROUND: A sustainable Continuing Professional Development (CPD) system is vital in neurology due to the field's expanding therapeutic options and vulnerable patient populations. In an effort to offer concise, evidence-based updates to a wide range of neurology professionals, the American Academy of Neurology (AAN) launched NeuroBytes in 2018. NeuroBytes are brief (<5 minutes) videos that provide high-yield updates to AAN members. METHODS: NeuroBytes was beta tested from August 2018 to December 2018 and launched for pilot circulation from January 2019 to April 2019. Usage was assessed by quantifying course enrollment and completion rates; feasibility by cost and time required to design and release a module; appeal by user satisfaction; and effect by self-reported change in practice. RESULTS: A total of 5,130 NeuroBytes enrollments (1,026 ± 551/mo) occurred from January 11, 2019, to May 28, 2019, with a median of 588 enrollments per module (interquartile range, 194-922) and 37% course completion. The majority of viewers were neurologists (54%), neurologists in training (26%), and students (8%). NeuroBytes took 59 hours to develop at an estimated $77.94/h. Of the 1,895 users who completed the survey, 82% were "extremely" or "very likely" to recommend NeuroBytes to a colleague and 60% agreed that the depth of educational content was "just right." CONCLUSIONS: NeuroBytes is a user-friendly, easily accessible CPD product that delivers concise updates to a broad range of neurology practitioners and trainees. Future efforts will explore models where NeuroBytes combines with other CPD programs to affect quality of training and clinical practice.