Citations

ABSTRACT Introduction Existing normal value references for pediatric nerve conduction studies (NCS) are based on limited sample sizes with uncertain reliability, suggesting a need for better normative data. Methods Electronic medical records were reviewed for pediatric patients (0 to <18 years) with normal findings on electromyography and NCS during the period from January 1, 1997 through September 20, 2017. Electrodiagnostic and demographic data were collected. Gaussian and descriptive statistics were used to establish normal values by age group. Results In this study we analyzed 1,918 normal NCS on 1,849 unique pediatric patients. Patients were stratified by age: 0 to <1 month; 1 to <6 months; 6 to <12 months; 12 to <24 months; 2 to <3 years; 3 to <4 years; 4 to <5 years; 5 to <10 years; 10 to <15 years; and 15 to <18 years. Normal reference ranges for amplitude, conduction velocity, and distal latency were established for each age group for 4 motor and 4 sensory nerves. Discussion The large sample size of this study provides reliable reference values for interpreting pediatric NCS. Muscle Nerve 60 : 155–160, 2019

Objective. To evaluate longitudinal cognitive/behavioral change over 12 months in participants enrolled in the ALS Multicenter Cohort Study of Oxidative Stress (ALS COSMOS). Methods. We analyzed data from 294 ALS participants, 134 of whom were studied serially. Change over time was evaluated controlling for age, sex, symptom duration, education, race, and ethnicity. Using multiple regression, we evaluated associations among decline in ALS Functional Rating Scale-Revised (ALSFRS-R) scores, forced vital capacity (FVC), and cognitive/behavioral changes. Change in cognitive/behavioral subgroups was assessed using one-way analyses of covariance. Results. Participants with follow-up data had fewer baseline behavior problems compared to patients without follow-up data. We found significant worsening of behavior (ALS Cognitive Behavioral Screen (ALS CBS) behavioral scale, p<0.001; Frontal Behavioral Inventory-ALS (FBI-ALS) disinhibition subscale, p=0.044). Item analysis suggested change in frustration tolerance, insight, mental rigidity, and interests (p<0.05). Changes in ALSFRS-R correlated with the ALS CBS. Worsening disinhibition (FBI-ALS) did not correlate with ALSFRS-R, FVC, or disease duration. Conclusion. We did not detect cognitive change. Behavioral change was detected, and increased disinhibition was found among patients with abnormal baseline behavioral scores. Disinhibition changes did not correlate with disease duration or progression. Baseline behavioral problems were associated with advanced, rapidly progressive disease and study attrition.

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

ABSTRACTIntroduction: Valosin containing protein (VCP) mutations cause a rare disorder characterized by hereditary inclusion body myopathy, Paget disease of bone (PDB), and frontotemporal dementia (FTD) with variable penetrance. VCP mutations have also been linked to amyotrophic lateral sclerosis and Charcot‐Marie‐Tooth disease type 2. Methods: Review of clinical, serological, electrophysiological, and myopathological findings of 6 VCP‐opathy patients from 4 unrelated families. Results: Patients manifested muscle weakness between ages 40 and 53 years and developed predominant asymmetric limb girdle weakness. One patient had distal weakness at onset and co‐existing peripheral neuropathy. Another patient had PDB, 1 had mild cognitive deficits, and 1 had FTD. All patients had myopathic and neurogenic electromyographic findings with predominant neurogenic changes in 2. Rimmed vacuoles were infrequent, while neurogenic changes were prominent in muscle biopsies. Conclusions: VCP‐opathy is a multifaceted disorder in which myopathy and peripheral neuropathy can coexist. The electrophysiological and pathological neurogenic changes raise the possibility of coexisting motor neuron involvement. Muscle Nerve, 2015 Muscle Nerve 54: 94–99, 2016 Muscle Nerve 54: 94–99, 2016