ALS (Amyotrophic lateral sclerosis) is a fatal disease responsible for the progressive destruction of the motor neurons controlling voluntary movements. Motor neurons are nerve cells that extend from the brain throughout the spinal cord and to muscles all over the body. These motor neurons initiate and provide communication links between the brain and the voluntary muscles. In ALS, cell death occurs in both parts of the central nervous system. Loss of their innervation and, in part, lack of exercise, make muscles perish. ALS belongs to the motor neuron diseases, which are caused by gradual degeneration and death of motor neurons.
Other nerve cells are not affected, meaning that the consciousness and sensory part remain intact. The exact cause of cell damage is unknown. In some families, an accumulation of the disease is observed, suggesting genetic causes in about 10% of the cases. ALS is rare, about 1-2 cases out of 100,000 people occur.
Age of Onset
The disease mainly starts around the age of 50-60. However, ALS can occur at any age. Juvenile ALS onsets before the age of 25, but it is very rare. Only 1% of the ALS cases arise at such a young age. Stephen Hawking was diagnosed with ALS at the age of 21.
Amyotrophic lateral sclerosis Symptoms
The first symptoms are usually the clumsiness of the hand. Some movements become problematic such as writing. Later, due to atrophy, the muscles of the lower limbs and the tongue weaken.
Muscle cramps may occur, especially during the night. Muscle twitching and stiffness are common. They are becoming difficult to climb stairs, standing up from the chair. Also, 50% of patients have some difficulty thinking, and most of them experience pain, such as neck pain, back pain, and shoulder pain.
Regardless of where the symptoms first appear, muscle weakness and muscle atrophy spread to other parts of the body as the disease progresses. Patients may develop problems with moving.
Sooner or later, they will be unable to walk, use their hands, speak or form words, swallow and difficulty with breathing. Also, due to loss of muscle mass, patients experience weight loss and get tired fast when doing physical activity.
The patient’s muscular strength further decreases because of muscle waste and gradually becomes bed-ridden. Most eventually lose the ability to swallow and breathe. It will be required feeding through a tube and help to breathe with forced ventilation. This condition develops within 3 to 5 years, although in some cases, the course of the disease is slow to progress, and the severity of the symptoms increases more slowly.
However, with ALS, thinking, vision, hearing, sensation, sense of taste, touch will work to the end, and even though voluntary muscles are involved, eye movements, as well as a stool and urine output, remain normal.
ALS treatment and outcome
As of today, there is no cure for the disease. The result is death due to respiratory failure. About 50% of the patients die within three years after the diagnosis, and 20% live longer than ten years.
There are treatments available to slow down the progression of the disease. The first drug approved for the treatment of ALS is riluzole. The medication can prolong survival time by a few months.
Maintenance of ALS
Because the progression of ALS cannot be arrested, the goal of treatment is to maintain the quality of life as much as possible. The doctor prescribes medications to control muscle spasms, constipation, to reduce excessive salivation and fatigue. A physiotherapist can help maintain muscle strength so that the patient can maintain an independent lifestyle for a more extended period.
Reference: National Institute of Neurological Disorders and Stroke https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Fact-Sheets/Amyotrophic-Lateral-Sclerosis-ALS-Fact-Sheet