Citations

ABSTRACT Introduction: The aim of this study was to create reference values for jitter measured with concentric needle electrodes. Methods: Operators worldwide contributed recordings from orbicularis oculi (OO), frontalis (FR), and extensor digitorum (ED) muscles in healthy controls. Criteria for acceptable signal quality were agreed upon in advance. Fifteen or 20 recordings of acceptable quality from each muscle were required for voluntary and electrical stimulation recordings, respectively. Results: Recordings from 59 to 92 subjects were obtained for each muscle and activation type. Outlier limits for mean consecutive difference and individual jitter data for voluntary activation were: OO, 31 and 45 µs; FR, 28 and 38 µs; ED, 30 and 43 µs; and for electrical stimulation they were: OO, 27 and 36 µs; FR, 21 and 28 µs; ED, 24 and 35 µs. Conclusion: Reference jitter values from concentric needle electrode recordings were developed from signals of defined quality while seeking to avoid creating supernormal values. Muscle Nerve 53: 351–362, 2016

IntroductionMuscle sympathetic nerve activity (MSNA) is an independent prognostic marker in patients with heart failure (HF). Therefore, its relevance to the treatment of HF patients is unquestionable.ObjectivesIn this study, we investigated the effects of cardiac resynchronization therapy (CRT) on MSNA response at rest and during exercise in patients with advanced HF.MethodsWe assessed 11 HF patients (51 ± 3.4 years; New York Heart Association class III–IV; left ventricular ejection fraction 27.8 ± 2.2%; optimal medical therapy) submitted to CRT. Evaluations were made prior to and 3 months after CRT. MSNA was performed at rest and during moderate static exercise (handgrip). Peak oxygen consumption (VO2) was evaluated by means of cardiopulmonary exercise test. HF patients with advanced NYHA class without CRT and healthy individuals were also studied.ResultsCRT reduced MSNA at rest (48.9 ± 11.1 bursts/min vs 33.7 ± 15.3 bursts/min, P < 0.05) and during handgrip exercise (MSNA 62.3 ± 13.1 bursts/min vs 46.9 ± 14.3 bursts/min, P < 0.05). Among HF patients submitted to CRT, the peak VO2 increased (12.9 ± 2.8 mL/kg/min vs 16.5 ± 3.9 mL/kg/min, P < 0.05) and an inverse correlation between peak VO2 and resting MSNA (r = –0.74, P = 0.01) was observed.ConclusionsIn patients with advanced HF and severe systolic dysfunction: (1) a significant reduction of MSNA (at rest and during handgrip) occurred after CRT, and this behavior was significantly superior to HF patients receiving only medical therapy; (2) MSNA reduction after CRT had an inverse correlation with O2 consumption outcomes.

Until recently, neuromyelitis optica (NMO) was considered to be a sub-type of multiple sclerosis (MS), which has a strong predilection for Caucasian populations, whereas NMO is more frequent in non-Caucasian individuals. The objective of this study was to compare the HLA-DRB profile in Brazilian Mulatto patients with NMO spectrum disorders (NMOSDs) with that observed for Mulatto MS patients and healthy Mulatto controls. Twenty seven NMOSD patients (20 women), all seropositive for NMO-IgG, 29 MS patients and 28 Mulatto healthy blood donors were evaluated for HLA-DRB allele groups. HLA-DRB1*03 allele group was overrepresented in NMO patients compared with healthy controls (p = 0.0401; OR = 3.23, 95%CI: 1.07—9.82). In contrast, the HLA-DRB1*15 allele group was overrepresented in Brazilian MS patients (OR = 15.89, 95%CI: 3.51—71.85; p < 0.0001). DRB3 was overrepresented in NMO (p = 0.0064), and DRB5 overrepresented in MS patients (p = 0.0001). The low frequency of HLA-DRB1*15 alleles was associated with the presence of long and central cord lesions at magnetic resonance. In addition, DRB1*15 alleles were associated with the fulfillment of the Barkhof criteria. In conclusion, these results indicate that the DRB profile of NMO patients is different from that observed for MS patients, further corroborating the distinction between NMO and MS.