Actress Sandra Bullock's longtime partner Bryan Randal, 57, passed away after battle with ALS

Bryan had been battling with ALS for the past three years

ALS, also called Lou Gehrig's disease is a progressive neurodegenerative disease affecting nerve cells in the brain and spinal cord

Lou Gehrig was a professional U. S. baseball player diagnosed with ALS in 1939, and died in 1941

ALS stands for Amyotrophic Lateral Sclerosis

ALS causes both groups of motor neurons to gradually deteriorate and then die

Damaged motor neurons stop sending messages to the muscle, hence the latter stops functioning

Though experts can't ascertain the cause of ALS, it's stated that a genetic cause can be identified in around 10% of the affected

Mayo clinic's website attributes some established risk factors to ALS: 1. Most common between the age group of 60 to 85 2. Before the age of 65 men are more prone than women 3. The gender based difference disappears after the age of 70

4. Other factors contributing to the ALS risk are smoking, toxin exposure, and military service 5. Exposure to certain chemicals, traumatic injuries, intense exertion during military service might trigger ALS

The good thing is that ALS is non-contagious i.e. it can't spread like the flu from person to person

Initial symptoms include weakness of limbs that develoos further over a period of days Or weeks

Moths later another limb gets affected. Some develop slurred speech and difficulty in swallowing

Can ALS be cured? No. There is no cure for ALS.

ALS treatments include: medicine, physical therapy, speech therapy, and devices like wheelchair, electri bed, etc.