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Objectives: We sought to determine whether serial intraoperative laryngeal electromyography (L-EMG) or evoked L-EMG predicts vocal fold (VF) recovery following iatrogenic injury. Methods: Six beagles were sedated, and bipolar needle electrodes were inserted into each thyroarytenoid (TA) muscle. Endotracheal tube surface electrodes were also placed. As the sedation lightened. L-EMG activity was recorded from all electrodes with an intraoperative nerve monitoring system. The neck was opened, and direct recurrent laryngeal nerve (RLN) stimulation was performed. Subsequently, 4 animals underwent crush injury of the left RLN, and 2 animals underwent nerve transection. The L-EMG procedures were repeated every 1 to 2 weeks until left VF motion was observed in the dogs that suffered RLN crush injury. At each time point, the neck was opened and both RLNs were stimulated. Results: Fibrillation potentials were detected in ail animals after RLN injury. A change to electrical silence was seen in the animals in the crush injury group that were evaluated during the week preceding VF recovery. Fibrillation potentials and VF immobility persisted in the transection group throughout the complete time course of these experiments. The first appearance of an evoked response coincided with occurred after the return of left VF motion in the crush injury group. The threshold, latency, and amplitude differed from those of the controls and approached normal values over time. No response was detected in the transected nerves. Conclusions: The disappearance of fibrillations on intraoperative L-EMG was noted in the animals tested the week before the return of VF motion, and the return of motor unit action potentials was seen along with return of VF function. Evoked L-EMG was not helpful in predicting the return of VF mobility, but it may help quantify degrees of RLN injury and predict the speed of recovery. [ABSTRACT FROM AUTHOR]

Summary: Objectives: The primary objective of this study was to determine whether a simplified technique for intraoperative laryngeal electromyography was feasible using standard nerve integrity monitoring electrodes and audiovisual digital recording equipment. Our secondary objective was to determine if laryngeal electromyography data provided any additional information that significantly influenced patient management. Methods: Between February 2006 and February 2007, 10 children referred to our institution with vocal fold immobility underwent intraoperative laryngeal electromyography of the thyroarytenoid muscles. A retrospective chart review of these 10 patients was performed after institutional review board approval. Results: Standard nerve integrity monitoring electrodes can be used to perform intraoperative laryngeal electromyography of the thyroarytenoid muscles in children. In 5 of 10 cases reviewed, data from laryngeal electromyography recordings meaningfully influenced the care of children with vocal fold immobility and affected clinical decision-making, sometimes altering management strategies. In the remaining 5 children, data supported clinical impressions but did not alter treatment plans. Two children with idiopathic bilateral vocal fold paralysis initially presented with a lack of electrical activity on one or both sides but went on to develop motor unit action potentials that preceded recovery of motion in both vocal folds. Conclusions: Our findings suggest that standard nerve monitoring equipment can be used to perform intraoperative laryngeal electromyography and that electromyographic data can assist clinicians in the management of complex patients. Additionally, there may be a role for the use of serial intraoperative measurements in predicting recovery from vocal fold paralysis in the pediatric age group. [Copyright &y& Elsevier]

Abstract: A 49-year-old man developed simultaneously a Guillain Barré Syndrome (GBS) and a nephrotic syndrome (NS). The patient relapsed twice, despite treatment with intravenous immunoglobulins (IVIg) after a full or partial recovery, and became resistant to IVIg. Renal biopsy revealed focal segmental glomerulosclerosis (FSGS). He responded to plasmapheresis and corticosteroids with simultaneous recovery of his GBS and NS, suggesting a common pathogenesis of the two conditions. [Copyright &y& Elsevier]

Abstract: Objective: Cervical nerve root stimulation (CRS) is a technique of assessing the proximal segments of motor axons destined to upper extremity muscles. Few studies report normal values. The objective was to determine CMAP onset-latencies and CMAP amplitude, area, and duration changes in healthy controls for the abductor pollicis brevis (APB), abductor digiti minimi (ADM), biceps, and riceps muscles. In addition, to determine the tolerability of CRS, as measured by the visual analog scale (VAS). Methods: We studied 21 healthy volunteers prospectively with CRS using four target muscles (APB, ADM, biceps, and triceps) bilaterally. Collision studies were used in all APB recordings. VAS was obtained in all subjects. Results: Mean CMAP onset-latencies were: APB 14±1.5ms; ADM 14.2±1.5ms; biceps 5.4±0.6ms; triceps 5.4±1.0ms. Onset-latency significantly correlated with height for all nerves. The mean change in CMAP amplitude and area (%) between most distal stimulation and CRS was: APB reduction of 15.1±11.6 and 4.9±3.6%; ADM reduction of 21.1±10.7 and 17.2±8.8; biceps reduction of 10±11.5 and reduction of 8.7±6.8; triceps increase of 3.3±5.2 and 11.0±9.9% respectively. Mean CMAP duration change between most distal stimulation and CRS was: APB, increase of 20.4±7.4%; ADM, increase of 14.4±8.5%; biceps, increase of 13.9±10.8%; triceps, increase of 7.7±6.7%. The mean VAS score was 3.8±1.2, and all subjects completed the study. Conclusions: The present study establishes normative data and indicates that CRS is a well-tolerated technique. Significance: The normal values may be used as reference data for the needle CRS technique in the assessment of proximal conduction abnormalities. [Copyright &y& Elsevier]

Introduction: Phosphoglycerate mutase deficiency (PGAM) is a rare metabolic myopathy that results in terminal block in glycogenolysis. Clinically, patients with PGAM deficiency are asymptomatic, except when they engage in brief, strenuous efforts, which may trigger myalgias, cramps, muscle necrosis, and myoglobinuria. An unusual pathologic feature of PGAM deficiency is the association with tubular aggregates. Methods: We report an African-American patient from Panama with partial deficiency of PGAM who presented with asymptomatic elevation of creatine kinase levels and tubular aggregates on muscle biopsy. Results: Muscle biopsies showed subsarcolemmal and sarcolemmal tubular aggregates in type 2 fibers. Muscle PGAM enzymatic activity was decreased and gene sequencing revealed a heterozygous mutation in codon 78 of exon 1 of the PGAM2 gene, which is located on the short arm of chromosome 7. Conclusions: PGAM deficiency has been reported in 14 patients, 9 of whom were of African-American ethnicity, and in 5 (36%) tubular aggregates were seen on muscle biopsy. Contrary to previously reported cases, our patient was initially asymptomatic. This further expands the PGAM deficiency phenotype. Muscle Nerve, 2013 [ABSTRACT FROM AUTHOR]