Facts about MND
French physician, J M Charcot, first identified Motor Neurone Disease (MND) in 1874. Despite intensive research, the cause remains unknown.
About one in every three hundred people are diagnosed with MND. There are approximately 400 people living with MND at any one time in Ireland. It usually affects those over 50 but can occur in people much younger.
The term MND describes a group of related diseases affecting the nerves in the brain and spinal cord that tell your muscles what to do. These nerves are known as motor nerves or motor neurones; the words nerves and neurones mean the same thing. As the nerves become damaged, the muscles they control weaken and waste. The muscles first affected tend to be those in the hands, feet or mouth and throat, depending on which type of the disease it is. It does not generally affect the senses so sight, smell, touch and hearing tend to remain intact, as do the sphincter muscles that control the bladder and bowel. Other areas that are not usually affected are sexual function and intellect. It is not contagious. MND is a progressive, life limiting disease and the rate of progression varies greatly from one person to another.
As yet, there is no specific treatment that will halt the progress of the disease. However, there is a lot that can be done in the way of symptom management and to slow the progression of the disease.
How is it diagnosed?
Usually it is not difficult for a Neurologist to diagnose MND on the basis of the history and signs. Early signs may cause some initial difficulty. There is no specific laboratory test. Sometimes special tests, possibly including a brain and spine MRI, are necessary to exclude other diseases. Usually, electrical tests on muscles and nerves are performed and a lumbar puncture and muscle biopsy may be done.
This is variable from three to five years (or occasionally longer) after onset, depending on the activity of the disease and the particular muscle groups affected.
MND presents itself in various ways, depending on the particular groups of muscle fibres which degenerate initially. Wasting and weakness of muscles of the hands, sometimes one side a first, stiffness in the legs with dragging of one leg or the development of marked weakness in the legs may be the initial symptom. Sometimes the muscles of the tongue and swallowing mechanism are affected early, with slurring of speech, difficulty in swallowing and coughing.
The disease may remain relatively stationary for some time or may progress to other limbs, to the tongue and to the breathing muscles. Motor Neurone Disease does not cause bladder or bower symptoms and does not cause sensory, visual or hearing disorders.
Is MND inherited?
Approximately 10% of people diagnosed with MND will have an inherited, or familial, form. This form of MND is extremely rare; the great majority of people diagnosed with MND (85%) have the sporadic form, occurring for no known reason.