O'gorman, Cullen M

ABSTRACTIntroduction: Isolated musculocutaneous neuropathy is uncommon. In this study we aimed to determine its causes and clinical presentation and interpret the electrodiagnostic findings associated with this condition. Methods: Our investigation was a retrospective review of patients diagnosed with musculocutaneous neuropathy at the Mayo Clinic (Rochester, Minnesota) electromyography (EMG) laboratory between 1997 and 2015. Results: Thirty‐two patients with musculocutaneous neuropathy and 5 patients with lateral antebrachial cutaneous neuropathy were identified. The most common cause was acute trauma or surgery (65%). Fourteen percent of the cases were idiopathic and 14% were inflammatory. Pain and sensory disturbance were more common presentations than weakness. Weakness from nerve injury was not noted in 2 patients, suggesting that other muscles may provide adequate elbow flexion/supination. The bilateral absence of lateral antebrachial cutaneous nerve sensory responses suggests an inflammatory cause. Discussion: Musculocutaneous neuropathy usually results from trauma or iatrogenic injury. Nerve conduction studies alone are insufficient to confirm neuropathy, and needle EMG examination should be a routine part of the diagnostic evaluation. Muscle Nerve 58: 726–729, 2018

ABSTRACTIntroductionCranial muscle fasciculations may be difficult to detect in amyotrophic lateral sclerosis (ALS). Ultrasound (US) detection of fasciculations in these muscles may have clinical utility.MethodsPatients with suspected ALS were prospectively enrolled. Nerve conduction studies, needle electromyography (EMG), and US examination of cranial muscles were performed. Controls were examined by US only. Fasciculations were counted and scored for each muscle after 10 or 30 seconds.ResultsThere were 84 patients with ALS. Fasciculations were most frequently found in the genioglossus muscle. Overall, detection rates by US and EMG were similar, but US was more likely to detect frequent fasciculations. Fasciculations were rare in controls, seen in 7 of 1,090 (0.6%) muscles. No control had > 5 fasciculations in any muscle.DiscussionFasciculations were frequently detected in cranial muscles of patients with ALS. US was found to be a sensitive method, and was not impaired by factors such as anxiety and the inability of the patient to relax. Muscle Nerve 56: 1072–1076, 2017

ABSTRACTIntroductionPneumothorax is a potentially serious complication of electromyography (EMG). Data on the frequency of pneumothorax after EMG are lacking. The purpose of this study was to determine the frequency, timing, and risk factors for iatrogenic pneumothorax after EMG. Methods: Cases of pneumothorax after EMG were reviewed for clinical, electrophysiological, and radiological data. Results: Of 64,490 EMG studies, 7 patients had an association between the EMG and pneumothorax. All patients were symptomatic and presented within 24 hours of EMG. Sampling of serratus anterior and diaphragm was causative in 1 patient each. In 5 patients, multiple high‐risk muscles were sampled. The highest frequency of pneumothorax was observed with examination of serratus anterior (0.445%) and diaphragm (0.149%). Conclusions: The frequency of symptomatic iatrogenic pneumothorax after EMG appears to be low, and examinations of serratus anterior and diaphragm carry the highest risk. Electromyographers should be aware of the risk of pneumothorax and should counsel patients accordingly. Muscle Nerve 53: 518–521, 2016