Motor Neurone Disease (MND)
This disease attacks the motor neurones in the brain and spinal cord with the symptoms gradually worsening over time. Motor neurones control important muscle activity like gripping, walking, speaking, swallowing and breathing. Eventually all of these activities will become impossible to do. Although not a painful disease, MND becomes very debilitating as it progresses. An individual will, eventually, be unable to move, with swallowing and breathing becoming extremely difficult.
There is no known cause for motor neurones to stop working, as MND is not attributed to a person’s lifestyle, race or diet. Diagnosis is mainly down to a neurologist, as a variety of tests are needed to rule out other conditions. Around 5% of diagnosed cases can be attributed to hereditary factors, either through MND, or associated Fronto temporal dementia (10%-15% of cases) – attributed to faulty genes.
There is no known cure at the present time, so people are made as comfortable as possible to ensure a good quality of life. Life expectancy is around 3-4 years from the onset of symptoms, although there have been reported cases of individuals living for 10 years or even longer. Fatalities are usually caused by the action of the breathing muscles, making the person more susceptible to chest infections and drowsiness. End of life is not usually distressing for the sufferer, therefore, as most people will pass away in their own homes, some even during the night in their sleep.
Motor neurone disease can be classified into 4 main types, although the symptoms may overlap and it is not always possible to be specific in diagnosis.
Amyotrophic lateral sclerosis (ALS) – This is the most common form of MND and it is characterized by wasting and weakness of the limbs. This type affects both upper and lower neurones, with typical symptoms including dropping objects unexpectedly and tripping over when walking for no reason. Life expectancy is approximately 2-5 years from onset.
Progressive bulbar palsy (PBP) – This type affects about a quarter of people diagnosed with MND. Both upper and lower neurones are affected, with symptoms consisting of slurred speech and difficulty swallowing. Life expectancy is around 6 months to 3 years from onset.
Progressive muscular atrophy (PMA) – Only a small proportion of sufferers are afflicted with this form of MND. Damage sustained in this type is mostly restricted to the lower neurones, symptoms being weakness and clumsiness in the hands. Life expectancy is around 5 years and over.
Primary lateral sclerosis (PLS) – This is the rarest form of MND, involving only the upper neurones. Weakness is normally only found in the lower limbs. There is the potential for this form of MND to develop into ALS, so, although life expectancy can be normal for PLS, if it progresses into ALS, this reduces to 2-5 years.