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An anti-IgG activity has previously been reported at the cellular level in patients with psoriasis. This activity was demonstrated by the so-called 'rheumatoid' rosette test. In the present work the nature of `rheumatoid' rosette-forming cells was studied in comparison with other EA rosette techniques. The use of purified cell populations showed that the lymphocytes participating in the 'rheumatoid' rosette phenomenon were lacking conventional T and B cell membrane markers, and were thus referred to as null cells. Such mononuclear cells bearing a receptor for the Fc part of IgG were able to act as killer cells to IgG-coated target cells. The cytotoxic activity was mainly restricted to a small proportion of lymphocytes forming 'rheumatoid' rosettes which had a high avidity for EA complexes. Such cytotoxicity could contribute to the ateiology of lesions in psoriasis. [ABSTRACT FROM AUTHOR]

Abstract Background Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal-dominant painless peripheral neuropathy characterized by episodes of repeated focal pressure neuropathies at sites of entrapment/compression, with a considerable variability in the clinical course. Electrodiagnostic and genetic testing are important in the diagnostic evaluation of these patients. Case presentation We report an unusual HNPP phenotype, five compression neuropathies in four nerves in a patient with bilateral hand numbness. A 42-year-old female, presented with acute bilateral paresthesias and weakness in her hands after starting yoga exercises requiring hyperextension of her hands at the wrists. Her presentation was complicated by: a) a remote history of acute onset foot drop and subsequent improvement, b) previous diagnoses of demyelinating peripheral neuropathy, possibly Charcot-Marie-Tooth disease, and c) exposure to leprosy. Electrodiagnostic testing showed 5 separate compression neuropathies in 4 nerves including: severe left and right ulnar neuropathies at the wrist, left and right median neuropathies at the wrist and left ulnar neuropathy at the elbow. There was a mild generalized, primarily demyelinating, peripheral polyneuropathy. Based on the clinical suspicion and electrodiagnostic findings, consistent with profound demyelination in areas of compression, genetic analysis was done which identified a deletion of the PMP-22 gene consistent with HNPP. Conclusion HNPP can present with unusual phenotypes, such as 5 separate mononeuropathies, bilateral ulnar and median neuropathies at the wrists and ulnar neuropathy at the elbow with mild peripheral demyelinating polyneuropathy associated with the PMP-22 gene deletion.

Background: There is substantial hospital-level variation in the use of Inpatient Rehabilitation Facilities (IRFs) versus Skilled Nursing Facilities (SNFs) among patients with stroke, which is poorly understood. Our objective was to quantify the net effect of the admitting hospital on the probability of receiving IRF or SNF care for individual patients with stroke., Methods: Using Medicare claims data (2011-2013), a cohort of patients with acute stroke discharged to an IRF or SNF was identified. We generated 2 multivariable logistic regression models. Model 1 predicted IRF admission (versus SNF) using only patient-level factors, whereas model 2 added a hospital random effect term to quantify the hospital effect. The statistical significance and direction of the random effect terms were used to categorize hospitals as being either IRF-favoring, SNF-favoring, or neutral with respect to their discharge patterns. The hospital's impact on individual patient's probability of IRF discharge was estimated by taking the change in individual predicted probabilities (change in individual predicted probability) between the 2 models. Hospital-level effects were categorized as small (<10%), moderate (10%-19%), or large (≥20%) depending on change in individual predicted probability., Results: The cohort included 135 415 patients (average age, 81.5 [SD=8.0] years, 61% female, 91% ischemic stroke) who were discharged from 1816 acute care hospitals to IRFs (n=66 548) or SNFs (n=68 867). Half of hospitals were classified as being either IRF-favoring (n=461, 25.4%) or SNF-favoring (n=485, 26.7%) with the remainder (n=870, 47.9%) considered neutral. Overall, just over half (n=73 428) of patients were treated at hospitals that had moderate or large independent effects on discharge settings. Hospital effects for neutral hospitals were small (ie, change in individual predicted probability <10%) for most patients (72.5%). However, hospital effects were moderate or large for 78.8% and 84.6% of patients treated at IRF- or SNF-favoring hospitals, respectively., Conclusions: For most patients with stroke, the admitting hospital meaningfully changed the type of rehabilitation care that they received., Competing Interests: None.

Objective: To inform the design of a potential future randomized controlled trial (RCT), we emulated 3 trials where patient-level outcomes were compared after stroke rehabilitation at inpatient rehabilitation facilities (IRFs) with skilled nursing facilities (SNFs)., Design: Trials were emulated using a 1:1 matched propensity score analysis. The 3 trials differed because facilities from rehabilitation networks with different case volumes were compared. Rehabilitation network case volumes were based on the number of patients with stroke that each hospital discharged to each specific IRF or SNF. Trial 1 included 60,529 patients from all networks, trial 2 included 34,444 patients from networks with medium and large case volumes (ie, ≥5 patients), and trial 3 included 19,161 patients from networks with large case volumes (ie, ≥10 patients). The E values were calculated to estimate the minimum strength that an unmeasured confounder would need to be to nullify the results., Setting: A national sample of IRFs and SNFs from across the United States., Participants: Fee-for-service Medicare patients with acute stroke who received IRF or SNF based rehabilitation., Interventions: Not applicable., Main Outcome Measures: One-year successful community discharge (home for >30 consecutive days) and all-cause mortality., Results: Overall, 29,500, 15,156, and 7450 patients were matched for trials 1, 2, and 3. For 1-year successful community discharge, absolute risk differences for IRF patients were 0.21 (95% CI, 0.20-0.22), 0.17 (95% CI, 0.16-0.19), and 0.12 (95% CI, 0.10-0.14) in trials 1, 2, and 3, respectively. For 1-year all-cause mortality, corresponding risk differences were -0.11 (95% CI, -0.12 to -0.11), -0.11 (95% CI, -0.12 to -0.09), and -0.08 (95% CI, -0.10 to -0.06). The E values indicated that a moderately sized unmeasured confounder, with a relative risk of 1.6-2.0 would nullify differences in successful community discharge., Conclusions: IRF patients had superior outcomes, but differences were attenuated when IRFs and SNFs from larger rehabilitation networks were compared. The vulnerability of the findings to unmeasured confounding supports the need for an RCT., (Copyright © 2022. Published by Elsevier Inc.)

In the United States, approximately 400,000 patients with acute stroke are discharged annually to inpatient rehabilitation facilities (IRFs) or skilled nursing facilities (SNFs). Typically, IRFs provide time-intensive therapy for an average of 2-3 weeks, whereas SNFs provide more moderately intensive therapy for 4-5 weeks. The factors that influence discharge to an IRF or SNF are multifactorial and poorly understood. The complexity of these factors in combination with subjective clinical indications contributes to large variations in the use of IRFs and SNFs. This has significant financial implications for health care expenditure, given that stroke rehabilitation at IRFs costs approximately double that at SNFs. To control health care spending without compromising outcomes, the Institute of Medicine has stated that policy reforms that promote more efficient use of IRFs and SNFs are critically needed. A major barrier to the formulation of such policies is the highly variable and low-quality evidence for the comparative effectiveness of IRF- vs SNF-based stroke rehabilitation. The current evidence is limited by the inability of observational data to control for residual confounding, which contributes to substantial uncertainty around any magnitude of benefit for IRF- vs SNF-based care. Furthermore, it is unclear which specific patients would receive the most benefit from each setting. A randomized controlled trial addresses these issues, because random treatment allocation facilitates an equitable distribution of measured and unmeasured confounders. We discuss several measurement, practical, and ethical issues of a trial and provide our rationale for design suggestions that overcome some of these issues., (Copyright © 2021 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Stroke often results in hemiparesis, leaving one side of the body "affected" relative to the other side. Prior research has shown that the affected arm has higher variability; however, the extent to which this variability can be modulated is unclear. Here we used a shared bimanual task to examine the degree to which participants could modulate the variability in the affected arm after stroke. Participants with chronic stroke ( n = 11) and age-matched controls ( n = 11) performed unimanual and bimanual reaching movements to move a cursor on a screen to different targets. In the unimanual condition, the cursor was controlled only by the movement of a single arm, whereas, in the bimanual condition, the cursor position was "shared" between the two arms by using a weighted average of the two hand positions. Unknown to the participants, we altered the weightings of the affected and unaffected arms to cursor motion and examined how the movement variability on each arm changed depending on its contribution to the task. Results showed that stroke survivors had higher movement variability on the affected arm; however, like age-matched controls, they were able to modulate the variability in both the affected and unaffected arms according to the weighting condition. Specifically, as the weighting on a particular arm increased (i.e., it became more important to the task), the movement variability decreased. These results show that stroke survivors are capable of modulating variability depending on the task context, and this feature may potentially be exploited for rehabilitation paradigms. NEW & NOTEWORTHY We show that chronic stroke survivors, similar to age-matched controls, are able to modulate variability in their affected and unaffected limbs in redundant bimanual tasks as a function of how these limbs contribute to the task. Specifically, in both affected and unaffected limbs, the variability of the limb increases as its contribution to the task decreases. This feature may potentially be exploited in rehabilitation paradigms using bimanual tasks.

Introduction: Research on neuromuscular disorders in sub-Saharan Africa is scarce. We aimed to delineate referral characteristics and the neuromuscular disorders observed among electrodiagnostic (EDX) consultations in a tertiary care setting in Zambia., Methods: EDX records were reviewed for all specialist-performed studies after the establishment of the laboratory. The frequency of demographic, medical characteristics, and final EDX impressions are presented., Results: Among 108 referrals, 52% were male, 84% were adults (mean age 44 years). Referrals were predominantly outpatients (85%) and sent by neurologists (68%). HIV infection was common (12%). Diabetes was rare (3%). Overall, 77% of studies were abnormal. Polyneuropathy was the most common abnormal EDX finding, followed by motor neuron disease., Discussion: A diverse range of neuromuscular diseases was evaluated among EDX referrals in Zambia. Though labor and expertise intensive, access to EDX consultation can enhance clinical care and facilitate research and surveillance of neuromuscular disorders in the region., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Purpose: Cadaveric palmar dissections reveal an ulnar sensory crossover (Berrettini anastomosis) to the third common palmar nerve so frequently that this crossover is considered a normal part of the anatomy. No literature has documented electrophysiologic evidence of the Berrettini anastomosis (BA). Presentation of third digit ulnar sensory crossover waveforms., Methods: Retrospective chart review case series. Clinical office. Nerve conduction waveforms and data., Results: Ulnar stimulation sensory crossover waveforms to digit three consistent with BA are presented., Conclusions: Third digit BA is measurable in routine electrodiagnostic nerve conduction study in some patients. The observed BA latency is the same and the amplitude is smaller (25% to 33%) than the ulnar sensory response. The clinical significance of the BA sensory response is unclear. The presence of a BA in severe carpal tunnel syndrome may give a small amplitude normal latency sensory response that could be misinterpreted and lead to a false negative result.

Introduction: There are not uniform standards for nerve conduction testing across the United States. The objective of this study is to present a set of methodologically sound criteria to evaluate the literature for the purpose of identifying high-quality normative nerve conduction studies (NCS) suitable for widespread use., Methods: The Normative Data Task Force (NDTF) was formed to review published studies on methodological issues related to NCS. A set of criteria was then developed to evaluate the literature. These criteria and their rationale are described., Results: We identified 7 key issues that reflect high quality in NCS. For each issue, specific review criteria were developed., Conclusion: Rigorous criteria enable identification of high-quality studies dealing with nerve conduction reference values. This represents the first step toward the overarching goal of recommending NCS techniques and reference values for electrodiagnostic medicine. Muscle Nerve 54: 366-370, 2016., (© 2016 American Association of Neuromuscular and Electrodiagnostic Medicine.)

Introduction: To address the need for greater standardization within the field of electrodiagnostic medicine, the Normative Data Task Force (NDTF) was formed to identify nerve conduction studies (NCS) in the literature, evaluate them using consensus-based methodological criteria derived by the NDTF, and identify those suitable as a resource for NCS metrics., Methods: A comprehensive literature search was conducted of published peer-reviewed scientific articles for 11 routinely performed sensory and motor NCS from 1990 to 2012., Results: Over 7,500 articles were found. After review using consensus-based methodological criteria, only 1 study each met all quality criteria for 10 nerves., Conclusion: The NDTF selected only those studies that met all quality criteria and were considered suitable as a clinical resource for NCS metrics. The literature is, however, limited and these findings should be confirmed by larger, multicenter collaborative efforts. Muscle Nerve 54: 371-377, 2016., (© 2016 American Association of Neuromuscular and Electrodiagnostic Medicine.)

Carpal tunnel syndrome (CTS) is the most common nerve entrapment. Electrodiagnostic (EDX) studies are a valid and reliable means of confirming the diagnosis. This monograph addresses the various EDX techniques used to evaluate the median nerve at the wrist. It also demonstrates the limitations of EDX studies with a focus on the sensitivity and specificity of EDX testing for CTS. The need to use reference values for populations such as diabetics and active workers, where normative values differ from conventional cutoffs used to confirm suspected CTS, is presented. The value of needle electromyography (EMG) is examined., (Copyright © 2011 Wiley Periodicals, Inc.)

Carpal tunnel syndrome (CTS) is a constellation of symptoms associated with compression of the median nerve at the wrist. The pathophysiology of CTS is not fully understood but mechanical aspects of injury within the carpal tunnel are most likely. The issues of ischemia, mechanical trauma, ectopic impulse generation, demyelination, tendonitis, elevated carpal tunnel pressure, mechanical factors, small and large fiber involvement and the variability of symptoms are presented. Documentation of neurophysiologic abnormalities in the median nerve is helpful to establish the diagnosis for CTS. There are several types of clinical neurophysiologic evaluations of the median nerve across the wrist. Sensory and motor nerve conduction studies (NCS) of the median nerve segment across the wrist compared to another nerve segment that does not go through the carpal tunnel (i.e. median, radial, or ulnar) are the most sensitive and accurate techniques. Other neurophysiologic techniques used to document CTS include vibrometry threshold testing, current perception testing, Semmes-Weinstein monofilament testing and two-point discrimination. These techniques have considerable subjective components and have not been found to be as sensitive as traditional NCS.

This article reviews nerve entrapments and cumulative trauma disorders of the upper limbs including a problematic carpal tunnel syndrome (CTS) patient case, idiopathic arm pain, and ulnar neuropathy. Major points of the discourse focus on the problems of treatment, especially as they relate to impairment and disability management.

We report two cases of postsurgical intramuscular meperidine injection with injury to the femoral nerve and subsequent vastus lateralis atrophy. The first case is a patient who had arthroscopic anterior cruciate ligament reconstruction; the second, a patient with a C6-C7 anterior fusion. Photographs, radiography, and electrodiagnostic studies clearly depict the nature of the injuries, and their etiology is discussed. These case reports describe a unique neuropathic injection injury that, to our knowledge, has never before been described in the literature.

Objective: To determine the effectiveness of medical history and physical examination in predicting electrodiagnostic outcome in patients with suspected cervical radiculopathy., Methods: Data on 183 subjects prospectively collected at five different electrodiagnostic laboratories were analyzed (96 cervical radiculopathies, 45 normal studies, and 42 abnormal electrodiagnostic findings other than radiculopathy). The sensitivity, specificity, positive predictive value, negative predictive value, and odds ratios were determined for symptoms and neurologic signs., Results: Symptoms of numbness, weakness, and tingling were associated with twice the probability of having abnormal electrodiagnostic study results in general, yet were not helpful in identifying a cervical radiculopathy. All single and combined physical examination components had poor sensitivities, with the exception of weakness, but much higher specificities. Patients with either weakness or reduced reflexes on physical examination were up to five times more likely to have abnormal electrodiagnostic findings. In subjects with any abnormal neurologic sign, the sensitivity improved to 84%, the positive predictive value was 79%, but the specificity was low (44%). Of those subjects with normal physical examination results, almost one half had an abnormal electrodiagnostic study result (negative predictive value 52%)., Conclusions: In a population of patients with suspected cervical radiculopathy, medical history and physical examination are helpful yet not sufficient to predict the electrodiagnostic outcome.