Stephen Hawking visited a stem cell laboratory Tuesday to discuss Lou Gehrig's disease and the research efforts scientists are making. The 71-year-old was diagnosed with the disorder 50 years ago and struggled with depression as a result of it.

Nearly $18 million was received last year by Cedars-Sinai Medical Center to assist in its study of Lou Gehrig's disease. A patient at the hospital who was also a former student of Hawking urged doctors to invite the physicist to see their work with stem cells.

"We decided it was a great opportunity for him to see the labs and for us to speak to one of the preeminent scientists in the world," Dr. Robert Baloh, head of the ALS program at the hospital said.

Lou Gehrig's disease is also known as amyotrophic lateral sclerosis (ALS), a debilitating disease that affects motor neurons in the brain and causes muscle weakness. New York Yankee Baseball Hall of Fame inductee Lou Gehrig was diagnosed with ALS during the 1930s.

Hawkins, 71, is a long-term survivor of the disease, after being diagnosed at the age of 21. The famous physicist was able to focus on his education, as his condition didn't progress rapidly. The average life expectancy of people diagnosed with Lou Gehrig's disease is two to five years. For some people, progression of the disease either stops or reverses naturally.

Scientists at Cedars-Sinai are finding ways to slow the progression of Lou Gehrig's disease, although they have not discovered how to reverse or cure the disease.

"However difficult life may seem, there is always something you can do and succeed at," said Hawking, who relies on a computer to communicate. Hawking encouraged Cedars-Sinai to continue its support of stem cell research.