Amyotrophic Lateral Sclerosis (ALS), also known as Lou Gehrig’s disease, destroys nerve cells in the brain and the spinal cord and causes disability. In ALS patients, the wasting away of muscles results in nerve cell (neuron) destruction. This debilitating condition affects voluntary muscle movements such as chewing, walking, talking and breathing as well as overall functioning of the limbs.
ALS affects the upper and lower motor neurons located in the brain, spinal cord and brainstem. Degeneration of upper motor neurons causes tightness of the muscle resulting in spasticity, whereas degeneration of the lower motor neuron causes muscle weakness, muscle atrophy and twitching. Neurologist Jean-Martin Charcot, MD, observed clear signs of progressive neuronal damage stretching from upper motor neurons to the lower motor neurons and atrophy of neighbouring muscles after peering into the tissues of his patients suffering from ALS in 1865.
The Ice Bucket Challenge in the summer of 2014 aimed at raising awareness about this condition known as Amyotrophic Lateral Sclerosis.
Amyotrophic Lateral Sclerosis typically affects those between the ages of forty and seventy with the average age at diagnosis being 55. However, some individuals in their twenties and thirties may also develop the disease. Usually ALS occurs in higher percentages as men and women grow older. ALS occurrence is also twenty percent more common in men than in women.
However, with increasing age, the incidence of ALS becomes more equal between both men and women. The ALS Association suggests that the incidence rate of Amyotrophic Lateral Sclerosis to be 1.8 to 2 per 100,000 people, which implies 5,760 to 6,400 new diagnoses per year.
The incidence of ALS increases with age, usually starting in the 40s and continuing until the age of around 80 years. However, this does not cross out the probability of young people in their early 20s and 30s to get affected with ALS. ALS affects people from all races and ethnicities. Most people with ALS die due to respiratory failure, generally within 3 to 5 years of the first appearance of the symptoms. However, about only about 10% of the people with ALS survive for 10 or more years. Such a differential rate of disease progression makes prognosis difficult to predict and treatments challenging to develop.
According to the global estimates, there are around four to six people per 100,000 living with ALS at any given point in time. Approximately 6,000 people are diagnosed with ALS each year in the USA, according to the available statistics and around 93% of the patients in the U.S are Caucasian whereas 60 % are men. The incidence of ALS in the United States is estimated to be two per 100,000 people, and it is believed that there are more than 30,000 Americans who may be living with Amyotrophic Lateral Sclerosis at any given time.
The incidence or number of new cases per year is increasing, with an estimated two new ALS cases each year within a population of 100,000 people. Physicians have also noted reports that reflect increasing numbers of younger Amyotrophic Lateral Sclerosis patients, however these studies require further investigation.