About 30,000 Americans now have A.L.S., which attacks nerve cells and ultimately leads to total paralysis, though the mind remains sharp. Life expectancy is typically two to five years from the time of diagnosis. The exact cause is not understood and there is no cure or treatment that stops or reverses the disease. One Food and Drug Administration-approved drug slows its progression, and other drugs are in clinical trials, according to the A.L.S. Association.

The flood of donations will be transformative for finding treatments and a cure for A.L.S. as well as for providing support to people with the disease, said Carrie Munk, a spokeswoman for the A.L.S. Association. The group now supports 98 global research projects and recently announced $3.5 million in financing for 21 others.

In addition, the Ice Bucket Challenge has raised awareness of the disease, which the A.L.S. Association said only half of Americans were aware of about a month ago.

Image In Augusta, Ga., Loreen Ingram-Moore gets doused at a fund-raiser for an A.L.S. clinic. Credit... Michael Holahan/Augusta Chronicle, via Associated Press

“While the monetary contributions are so absolutely incredible, and we’ll be able to really make a considerable difference in moving the mission of the A.L.S. Association forward, the real fortunate part of the Ice Bucket Challenge is the amount of awareness it has raised for the A.L.S. cause in general,” Ms. Munk said. “It puts us in a whole different ballgame to find treatments and cures for this disease.”