Dazzling friends with your most recent tongue-paralyzing diagnosis? Try dropping the name Amyotrophic Lateralizing Sclerosis -- often abbreviated to "ALS" by disease cognoscenti.

The initial symptoms are easy to miss -- weakness, muscle wasting, a certain stumbling twitchiness, swallowing problems and occasional slurred speech. Your spouse might blame it on too much TV -- but the real problem is a mysterious die-off of the motor nerve cells in your brain and spinal cord. Like high-powered transmission lines, these neurons normally send electric impulses to your muscles, stimulating them to move. Without them you become a brain trapped inside a useless husk of a body. If you happen to be a mathematical genius, you might be able to find a job as a theoretical physicist in the Lucasian Chair at Cambridge, like Stephen Hawking. However, if your career as a professional baseball player depends on perfect timing and reflexes like legendary Yankee hitter Lou Gehrig, then it's pretty much over for you.

ALS can strike anyone, and the causes are largely unknown. It is almost impossible to diagnose in the early stages -- but that might be a good thing. Since there's no treatment or cure, you are probably happier not knowing the truth.

Cheer up -- even though you may be frozen for the rest of your life on a ventilator getting nutrition through a feeding tube, in 90% of patients your intellectual life is likely to be unimpaired. You can watch all of Shakespeare plays again, work on chess problems, listen to classical music, or pass pleasurable hours re-reading this website. You can also righteously demand a certain amount of sympathy from friends and relatives.

However, if your neighbor tries to brag about having ALS, you also have some justification in being skeptical. Only 0.005 % of people ever get it -- and anybody that can pronounce the words "Amyotrophic Lateralizing Sclerosis" probably has something else!