Diagnostic criteria and outcome measurement of amyotrophic lateral sclerosis.

ALS is a most challenging disease. Accurate diagnostic criteria are well along in refinement, and experience with patients who are at the limits of the criteria should be presented to increase our comfort with the limits of ALS or motor neuron disease. As our understanding of the pathophysiology is further refined, there will be new drugs to test. It will be important to have sensitive clinical and electrophysiologic measures available to detect changes in the rate of progression. When effective drugs are identified, they will, in addition to helping patients, lend support to proposed mechanisms. Charcot would be impressed with our advances in the ability to detect and follow upper and lower motor neuron loss, but would urge us to press on in our clinical endeavors.