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

Background: Posterior lumbar vertebral endplate fracture occurs with avulsion of the ring apophysis from the posterior vertebral body. Although this has been described in adolescents and young adults, proper diagnosis is often delayed or missed entirely. Surgery may be curative. Objective: To determine the common clinical features and treatment outcomes in youth and young adults with posterior lumbar vertebral endplate fractures. Design: Retrospective case series. Setting: Academic medical institution. Patients: Patients 10 to 25 years old from 2000 through 2012 with posterior vertebral endplate fracture diagnosis. Main Outcome Measurements: Demographic characteristics, diagnostic studies, interventions, and change in symptoms postoperatively.Results: A total of 16 patients had posterior vertebral endplate fractures (8 male patients; mean age, 15.2 years)-8.3% of 192 patients with inclusion age range undergoing spinal surgery for causes unrelated to trauma, scoliosis, or malignancy. The most common signs and symptoms were low back and radiating leg pain, positive straight leg raise, hamstring contracture, and abnormal gait. Cause was sports related for 12 patients (75%). Mean (range) time to diagnosis was 13.0 (3.0-63.0) months. Diagnosis was most commonly made with lumbar magnetic resonance imaging (n = 6). Most fractures occurred at L5 (n = 8, 50%) and L4 (n = 5, 31.3%). Conservative measures were trialed before surgery. Nine patients had "complete relief" following surgery and seven "improved." Conclusions: Posterior vertebral endplate fracture should be considered in differential diagnosis of a youth or young adult with back pain, radiating leg pain, and limited knee extension, regardless of symptom onset. For patients in whom conservative management fails, consultation with an experienced physician whose practice specializes in spine medicine is recommended.

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