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The comorbidity of myasthenia gravis (MG), with other autoimmune disorders like systemic lupus erythematosus (SLE), is relatively frequent but the co-occurrence with chronic inflammatory demyelinating polyneuropathy (CIDP) along with various autoimmune manifestations in the absence of thymoma is of extreme rarity. Our aim is to report a case of a woman who presented the concomitant appearance of MG, axonal sensory-motor polyneuropathy and hepatitis that may indicate an underlying pathogenetic link among the different autoimmune disorders. We present a case of a 54-year-old woman, with a generalized MG and a chronic sensory-motor polyneuropathy, hypothyroidism, anaemia, hepatitis, livedo reticularis and facial flush, of assumed autoimmune background, like SLE, although with persistent negative ANA antibodies, from the beginning and through the whole following years. The Human Leukocyte Antigen (HLA)-DRB1 genotyping showed a profile of alleles (DRB1*11:01/11:04) compatible with CIDP of mainly female gender in Greece and frequencies close to those of Sjogren's syndrome and scleroderma's in the Greek population. The diagnostic problems, the atypical clinical, electrophysiological and immunological features are discussed, along with the rarity of the case, with this exceptional combination of autoimmune manifestations, which could be truly associated under the clinical umbrella of a systemic disease, like SLE. However, our patient did not ever fulfil the SLE criteria. To raise awareness among clinicians about the exceptional combination of autoimmune manifestations driven by a specific HLA background. [ABSTRACT FROM AUTHOR]

Abstract Background Peroneal nerve is susceptible to injuries due to its anatomical course. Excessive weight loss, which reduces the fatty cushion protecting the nerve, is considered a common underlying cause of peroneal palsy. Other predisposing factors, such as prolonged postures, traumas of the region or concomitant pathologies (for example diabetes mellitus) contribute to the nerve damage. This study aims to reveal the multiple predisposing factors of peroneal nerve mononeuropathy after substantial weight loss that coexist in psychiatric patients and to make suggestions on their management. Methods Nine psychiatric inpatients, major depressive or schizophrenic, with foot drop underwent a complete clinical neurological and neurophysiological examination. All had excessive weight loss, which was completed in a short period of time and had not resulted from a well-balanced low-calorie diet, but was due to their psychiatric illness. Data regarding predisposing factors to peroneal nerve mononeuropathy were gathered, such as habitual leg crossing, squatting or other prolonged postures. Results The clinical examination and the neurophysiological evaluation in all patients were indicative of a focal lesion of the peroneal nerve at the fibular head. Conclusion Patients with major depressive and schizophrenic disorders gather multiple predisposing factors to peroneal palsy, adequate to classify them at a high risk group. The better focus of the attendant medical and nursing staff on this condition, the early clinical and neurophysiologic evaluation and surgical interventions may enable an improved management and prognosis of these patients.

Background: Little is known about how different outlier estimation methods affect cutoff limits for outliers in single fiber electromyography. Methods: We compared in a prospective fashion the established 18th jitter value (18thjv) method to three, whole‐distribution based, outlier detection methods: the interquartile range (IQR), the log‐normal, and the Z‐score method. The reference limits were probed in a normal cohort and in myasthenia gravis (MG) patients. Results: Differences in outlier cutoff values between the different methods were in the range of 2 μs. The number of abnormal muscles according to the computed criteria was similar for all four methods in the control group. Classification metrics (sensitivity, specificity, Youden's statistic, and predictive values) were also similar among the different methods. In the MG group, however, the Z‐score method failed to identify the abnormal jitter values. Accordingly, Kappa agreement was substantial to perfect (0.658 to 1) between the three methods (18thjv, IQR, and log‐normal), but was equivalent to chance between the three methods and the Z‐score in the MG group. Conclusions: The established 18thjv method proved largely robust when compared to whole‐distribution based methods, and its use in clinical practice is justified. Simple estimation of outlier limits by adding two SDs to the mean of the data, leads to unacceptable deviations from the true cutoff values. Moreover, in a clinical scenario in which the final electrodiagnosis depends only on the number of outliers, it is meaningful to accept a tolerance zone of about 2 μs, which is the approximate variation range among the different methods. [ABSTRACT FROM AUTHOR]

Despite its widespread use, little is known regarding the ability of the semi‐quantitative Rydel‐Seiffer tuning fork to designate peripheral nerve function. We sought to determine in a large sample of normal and abnormal nerves the relationship between vibration sense and compound sensory nerve action potential (SNAP) parameters recorded in a corresponding innervation area. Vibratory thresholds were determined on a scale of 0 to 8 with a 64 Hz Rydel‐Seiffer tuning fork placed on the lateral malleolus of 303 subjects. Sural nerve sensory neurography was employed to derive SNAP parameters, which were related to vibration sense by means of multiple linear regression. ROC curve analysis was performed to determine the classification efficacy of the tuning fork in distinguishing normal from abnormal sural nerve responses. SNAP amplitude was the most significant predictor in the whole subjects group and in the subgroup of subjects with normal SNAPs, whereas conduction velocity played a major role in subjects with abnormal SNAPs. Age was significantly associated with vibration perception, particularly in subjects with normal SNAPs. With an area under the curve of 0.730, vibration sense was a fair classifier for decreased SNAP amplitudes. The optimal vibratory cutoff was 4.2. Age is a major determinant of vibratory test results, highlighting the importance of aging of central and peripheral pathways in mediating vibration sense. Hence, neurophysiological testing cannot be omitted in the context of polyneuropathy work‐up, since even at the optimal cutoff threshold, vibratory examination still displays 40% false negative test results. [ABSTRACT FROM AUTHOR]