Quantitative Neuromuscular Ultrasonography in Amyotrophic Lateral Sclerosis (ALS)

Amyotrophic Lateral Sclerosis (ALS) is a progressive and fatal neurological disease. Nonspecific symptoms lead to a delay in the diagnosis, only confirmed by the electrophysiologic study. Objectives. 1. To establish the diagnostic value of ultrasonography in ALS. 2. To evaluate the rate of muscle and nerve degeneration by ultrasonography in patients with ALS. 3. To check the relationship between ultrasound, clinical variables and functional tests in patients with ALS. Methods. A longitudinal observational study in a consecutive sample of patients diagnosed with ALS will be realized. All the patients will be examined 3 times during 6 months and capabilities associated with ALS and muscle strength will be assessed. Bilateral and cross sectional ultrasonography of several muscles and also median and tibial nerves will be performed. All the images will be processed and analyzed for obtaining morphometric variables (muscle thickness and nerve area) and textural ones (echogenic variation, entropy, homogeneity, textural contrast and correlation). Frequency of twitches will be also recorded. After longitudinal study, a survival study will be performed in relation to functional and sonographic variables.