A new research has revealed that some eye muscles have the unique capacity to stay unaffected by the crippling disease Amyotrophic Lateral Sclerosis or ALS.
The incurable, devastating neural disease affects muscles and paralyzes the body besides making breathing difficult.
However, unlike other muscles, no degeneration is affecting eye muscles. In many cases, it keeps functioning even at the terminal stages of the disease.
Researchers at Umeå University in Sweden studied mechanisms that revealed how ALS patients were able to maintain their eye functions and threw in clues on the treatment methods in their findings.
Unique Muscles
The study highlighted the specialized nature of the muscles in the eye and pointed out the variations vis-à-vis muscles of other parts of the body in many aspects. One example is the presence of neuromuscular junctions existing between nerve cells and muscle fibers.
Earlier research had suggested ALS as causing a breakdown at the nerve connection and invading into the brain and spinal cord affecting the nerve cells.
"We could see that the nerve connection to the eye muscles remaining intact even in stages of the disease where a large proportion of neuromuscular junctions had been lost in leg muscles," said Anton Tjust, the author and doctoral fellow at the Department of Integrative Medical Biology at Umeå University.
Power of Eye Muscle
However, an earlier study where Tjust was involved had shown a decrease in certain fiber types under the effect of ALS.
It was also mentioned in the study paper that some changes are shown by muscle fibers in the eye muscles toward the terminal stage of ALS.
This looks right with regard to multiply-innervated muscle fibers that fell one-third in some patients.
Role Of Stem Cells
The study examined muscle stem cells in eye muscles and in other muscles as well. Those in the eye were deemed more efficient compared with muscle stem cells in the arms and legs.
Tjust mentioned the high concentration of muscle stem cells in the front of the eye led to the perception that eye muscles are high on muscle stem cells.
His view is that the ability of the eye muscles to function during an ALS affliction means a protective mechanism is working.
One reason proffered by Pamela Shaw of the University of Sheffield in the UK attributes the resistance of eye muscles to gene difference. Comparing genes used by obliging neurons and resisting neurons, she said thousands of genes are "differentially expressed," implying that the use of gene by resistant neurons was significantly more or significantly less than the susceptible neurons.
Footballer's Trauma
ALS is also known as Lou Gehrig's disease. In the last stages, which is two to five years after diagnosis, it is fatal as patients lose most of their motor neurons.
Yet many patients, even in late stages, move their eyes and sometimes control the sphincter and a few other muscles.
An example of ALS patient is Steve Gleason, a former NFL player with the New Orleans Saints. Gleason was diagnosed with ALS in 2011 and is immobilized now as he cannot move or speak and needs assistance to breathe and eat.
However, Gleason's eye muscles are still functioning and allowing him to communicate. This is done by controlling a "speech-generating device" in a computer tablet that is attached to his wheelchair.
