Motor Neurone Disease (MND)

 

MND was first described by Jean-Martin Charcot, a French Neurologist, in 1874.  

 

It is an umbrella term used to describe a number of diseases that progressively damage the motor nerves or neurons in the brain and spinal cord that transmit messages to the muscles.

 

In America it is known as Amyotrophic Lateral Sclerosis (ALS) or Lou Gehrig's disease.

 

MND and ALS refer to a fatal, progressive disease that can affect the ability to speak, move and breathe, of which there is no cure. It attacks the upper and lower motor neurons causing neurodegeneration.

 

Upper motor neurons carry messages from the brain to the spinal cord, and lower motor neurons carry messages from the spinal cord to the muscles. It is the lower motor neurons that directly influence the muscle. 

 

Neurodegeneration refers to the progressive distruction of nerve structure and function. Damage to upper motor neurons will cause spasticity (increased muscle tone) and exaggerated reflexes, because the intact spinal cord continues to conduct impulses, which can not be moderated by the brain. The area affected will depend upon the specific site of damage. 

 

Damage to lower motor neurons will result in weakness and paralysis. Muscles are usually flaccid (absent of tone), and reflexes absent.

 

Sensory nerves, cognitive functions and the nerves to the eyes are not affected. 

 

The cause remains unclear, but in 5% of cases there is a family history of MND or frontotemporal dementia. The majority of experts believe that it's a mixture of interrelated factors that eventually affect either the motor neurones or the supporting nerve cells.