Amyotrophic lateral sclerosis (ALS), better known in the United States as Lou Gehrig’s disease, is a neurodegenerative disease. ALS was first described by the French doctor Jean-Martin Charcot in 1869. The hallmarks are spasticity and progressive muscle weakness. This results in difficulty speaking, swallowing, walking and ultimately breathing. Depending on the form, the average age of onset is around 60 years. In 5-10% there is a hereditary factor. ALS has a high mortality, the average survival time is 3-4 years, 96% die within 10 years. In Europe, the disease occurs in about 2 in every 100,000 people.
Table of contents
- Symptoms
- Causes
- Diagnosis
- Therapy
- Etymology
- ALS Ice Bucket Challenge
Symptoms
The symptoms are mainly caused by atrophy of the muscles due to degeneration of the controlling motor neurons. In a large proportion of patients, cognitive functions and the muscles that control the bladder, intestines and eyes remain intact for a long time. Sensory nerves are largely spared, such as hearing, sight, sense of touch, smell and taste.
Initial symptoms
In the beginning, the disease can be very subtle. The first complaints usually consist of muscle weakness and/or atrophy. Other complaints include swallowing problems, cramps and muscle stiffness. About 75% of patients start with leg or arm related complaints. In the legs, these may include difficulty running, tripping or foot drop. In the arms, people may have difficulty with delicate actions such as buttoning buttons or turning a key.
Of the remaining 25%, the majority suffer from so-called bulbar complaints, which consist of more unclear speech than before and more nasal speech.
Progression
Although the first symptoms differ per patient, the severity of the muscle weakness increases in the majority of patients. Eventually they will no longer be able to walk, pick up anything with their hands and no longer be able to swallow properly. Since lung function is dependent on, among other things, the intercostal muscles, ALS patients frequently become dependent on chronic ventilation.
Most patients with ALS ultimately die from respiratory failure or pneumonia. Both long-term ventilation and swallowing problems increase the risk of developing this.
Causes
Genetic
About 5-10% of ALS patients inherit this directly from their parents. A number of hereditary gene mutations are known that confer a different increased risk and influence the age of onset of the condition.
Other
In this group, which consists of more than 90% of ALS patients, the exact cause is not yet known. There is a lot of speculation about possible causes, such as head trauma, drug use and food. However, no clear cause has emerged for this. The focus of studies is mainly on the role of glutamate, a neurotransmitter in the brain. This substance was found in relatively higher levels in the blood of people with ALS.
MRI brain research / Source: Frank Gaillard, Wikimedia Commons (CC BY-SA-3.0)
Diagnosis
There is no immediate test that can prove the diagnosis of ALS. In particular, the anamnesis (the patient’s story) in combination with findings during physical examination that indicate loss of the lower and upper motor neurons can indicate ALS. The progression (the worsening over time) is important.
Since a number of other conditions, such as multiple sclerosis, myasthenia gravis and viral infections, resemble ALS, it is important to rule them out with imaging and blood tests. Given the severity of the condition and the differential diagnosis, the diagnosis belongs to a neurologist.
Therapy
A drug that extends life expectancy by several months is Riluzole. This drug has an effect on the release of glutamate by the motor neurons. The drug no longer has an effect on already damaged cells and is therefore no longer effective in the later phase of the disease.
Maximum quality of life is paramount, a multidisciplinary team must strive for maximum comfort and mobility in consultation with the patient and family. The other treatment focuses mainly on the symptoms. There are medications for fatigue, spasms, pain, sleep disorders and constipation. Physiotherapy and logotherapy are important to allow the patient to be as mobile and independent as possible. People with ALS have an increased risk of malnutrition. In a later phase, forms of ventilation will play an important role.
Etymology
Amyotrophic lateral sclerosis is a combination of Greek words with the following meaning:
- “a” None
- “myo” Muscle
- “trophic” Growth
- “lateral” Reference to a part of the spinal cord
- “sclerosis” Connective tissue formation
The word amyotrophic describes the reduction of muscle tissue. Lateral sclerosis describes the formation of connective tissue in part of the spinal cord. This is based on the initial findings during autopsies of patients who had died of ALS.
ALS Ice Bucket Challenge
Source: Slgckgc, Wikimedia Commons (CC BY-2.0)
In mid-2014, a successful viral online event called the ice bucket challenge took place, with the aim of raising money for research into ALS. As of August 25, 2014, the ALS Association raised $79.7 million, compared to $2.5 million in 2013.
Want to know more? A website to find more information is the ALS foundation.
