Epidemiology of amyotrophic lateral sclerosis in Minnesota: a year-long population based study.

This is the largest population based study of ALS in the U.S., encompassing the population of Minnesota (> 5.

Sensitivity and specificity of diagnostic ultrasound in the diagnosis of phrenic neuropathy.

Objectives: To determine the sensitivity and specificity of B-mode ultrasound in the diagnosis of neuromuscular diaphragmatic dysfunction, including phrenic neuropathy.

Methods: A prospective study of patients with dyspnea referred to the EMG laboratory over a 2-year time frame for evaluation of neuromuscular respiratory failure who were recruited consecutively and examined with ultrasound for possible diaphragm dysfunction. Sonographic outcome measures were absolute thickness of the diaphragm and degree of increased thickness with maximal inspiration.

B-mode ultrasound assessment of diaphragm structure and function in patients with COPD.

Background: Electromyographic evaluation of diaphragmatic neuromuscular disease in patients with COPD is technically difficult and potentially high risk. Defining standard values for diaphragm thickness and thickening ratio using B-mode ultrasound may provide a simpler, safer means of evaluating these patients.

Methods: Fifty patients with a diagnosis of COPD and FEV₁ < 70% underwent B-mode ultrasound.

Variability in diaphragm motion during normal breathing, assessed with B-mode ultrasound.

Study Design: Clinical measurement, cross-sectional.

Objectives: To establish a set of normal values for diaphragm thickening with tidal breathing in healthy subjects.

Background: Normal values for diaphragm contractility, as imaged sonographically, have not been described, despite the known role of the diaphragm in contributing to spinal stability.

Diaphragm depth in normal subjects.

Introduction: Needle electromyography (EMG) of the diaphragm carries the potential risk of pneumothorax. Knowing the approximate depth of the diaphragm should increase the test's safety and accuracy.

Methods: Distances from the skin to the diaphragm and from the outer surface of the rib to the diaphragm were measured using B mode ultrasound in 150 normal subjects.

Two-dimensional ultrasound imaging of the diaphragm: quantitative values in normal subjects.

Introduction: Real time ultrasound imaging of the diaphragm is an under-used tool in the evaluation of patients with unexplained dyspnea or respiratory failure.

Methods: We measured diaphragm thickness and the change in thickness that occurs with maximal inspiration in 150 normal subjects, with results stratified for age, gender, body mass index, and smoking history.

Results: The lower limit of normal diaphragm thickness at end expiration or functional residual capacity is 0.