New Delhi, Feb 26 : Canadian actor Kenneth Mitchell, known for roles in 'Star Trek' and 'Captain Marvel', on Monday passed away aged 49 due to Amyotrophic lateral sclerosis (ALS) -- a fatal motor neuron disease.

The disease, a slow degeneration of nerves of the brain, starts in mid-middle age, around 50s.

Ken battled the fatal disease, which affects nerve cells in the brain and spinal cord, for five and a half years, his family posted in a statement on Instagram.

'With heavy hearts we announce the passing of Kenneth Alexander Mitchell, beloved father, husband, brother, uncle, son and dear friend,' the post read.

'Ken was widely known as an actor in many films and television shows. He portrayed an Olympic hopeful, an apocalypse survivor, an astronaut, a superhero's dad, and four unique Star Trekkers,' it added.

Dr Ishu Goyal, Associate Consultant Neurologist, Sir HN Reliance Foundation Hospital, told IANS that no particular reason behind the disease is known yet, which makes it difficult to predict who can get the disease.

'While sometimes it is genetic, it does not run in families. So we cannot really predict who is going to get ALS,' Ishu said.

Muscle weakness, paralysis, and eventually respiratory failure are the main outcomes of ALS, which predominantly affects the motor neurons that regulate voluntary muscles -- used for chewing, talking and moving arms and legs.

Symptoms of ALS include muscle weakness, muscle cramps and twitches (fasciculations), impaired motor function, dysphagia, or slurred speech, increased muscular tone and stiffness and breathing issues.

'People with ALS may eventually lose their abilities to move, breathe, eat, and talk as the disease worsens,' Dr Vipul Gupta, chief of Neurointervention and co-chief of stroke unit, Artemis Hospital, Gurugram, told IANS.

'Insufficient oxygen delivery to the bloodstream by the lungs is the primary cause of death for most ALS patients. Breathing may become difficult or impossible with ALS. This is due to the fact that it affects the muscles in our lungs and chest. The diaphragm, which divides your chest from your abdomen, is one of these muscles. Other breathing muscles affected include those between your ribs,' he added.

A common clinical feature of the disease is its slow-growing process.

'It usually starts with weakness in one part of the body. It may start from the hand or leg. And gradually the weakness keeps on increasing, and it keeps on stepwise involving the other parts of the body. So the part of the body that gets affected loses its function,' Ishu said.

Over the years, the weakness keeps on increasing, making the patient wheelchair-bound. However, the patient remains mentally normal. They can think, communicate normally. Gradually it also affects speaking function, and ultimately turns fatal as it starts affecting respiration, as well as causes swallowing dysfunction.

Unfortunately, there is no particular cure for this disorder, but there are a few drugs which slow down the process of ALS to a certain extent, the doctors said. It may prolong the life of the patient by a few months.

The two drugs that are currently used are the Tarragon injections, which are given monthly, and Dialysol tablets, which have to be taken twice daily.

/IANS