Amyotrophic Lateral Sclerosis (ALS)

ALS is a neurodegenerative disease caused by the death of motor neurons in the brain and the spinal cord.

There are two types of motor neuron: upper and lower. The first are found in the motor cortex and establish connections with the lower motor neurons located in the brain stem and spinal cord, which innervate muscles. When the upper motor neurons die, spasticity, weakness and hyperreflexia appear.

When the lower motor neurons die, twitching, weakness and muscle atrophy occur. Other neuron populations can also be affected, such as the temporal and frontal behavioural and executive circuits.

Epidemiologically speaking, ALS has an incidence of 1.5-2 new cases a year per 100,000 people (3 new cases are diagnosed per day in Spain). The total number of cases (prevalence) is 2-5 per 100,000. According to this data, the total number of patient with ALS in Spain is approximately 4,000 cases. This is why it is included in the rare or minority disease group.

90% of cases of ALS are sporadic (no family history). Around 10% of ALS cases are familial, usually inherited as dominant traits. The incorporation of new molecular genetics techniques in the field of research has allowed more than 25 genes involved in ALS to be identified.

Symptoms

As a consequence of the continuous decrease in motor neurons, symptoms of the disease appear. These usually depend on the location of the motor neurons undergoing the most advanced processes of degeneration. In most patients (70%) the first symptom is loss of strength with muscular atrophy in the hands or clumsiness when walking, with frequent falls. In approximately 25% of patients, the first symptom is difficulty talking or swallowing, which indicates that degeneration of the bulbar motor neuron population is the most intense. There are also other possibilities for clinical presentation of this disease, although much less frequent: respiratory failure, weight loss or unexplained lack of energy (asthenia), cramps and twitches in the absence of muscle weakness, spasticity in legs, rapid mood changes or cognitive impairment.

In advanced phases, the disease can also paralyse the eye muscles. In the final stages of the disease, paralysis of the respiratory muscles leads to respiratory failure, which is often the cause of death.

Who is affected by the condition?

The condition particularly affects people aged between 40 and 70. The incidence is greater in men (3:2.2 per 100,000) in sporadic forms. The age of first onset of symptoms reaches its peak between 58 and 63 years old in sporadic cases and between 47 and 52 years in familial forms. Incidence decreases markedly after the age of 80. The risk of suffering ALS is 1:400 for women and 1:350 for men.

Diagnosis

The differing ways in which ALS manifests is one of the two reasons for a delay in suspected diagnosis of the disease, which can be up to 15 months. The other is that there is no test or biomarker to objectively confirm the diagnosis in the initial stages of the condition. A diagnosis of ALS is a diagnosis of exclusion, based on clinical criteria and conducting tests (MRI, clinical analysis, genetic tests, electromyography, EMTC, neuropsychological exam, nuclear medicine techniques and others) to rule out other illnesses with similar clinical findings. In most specialised ALS units, the disease diagnostic criteria used are the revised El Escorial criteria and the Awaji-shima criteria.

Typical treatment

There is currently no medication that can cure or stop the disease. Riluzole and Edaravone are the only medications approved for ALS treatment, although their effect on survival is moderate (months).

The European (EFNS) and American (ANA) associations of neurology recommend that patients with ALS be treated in specialised centres, where possible in multidisciplinary units, so that they might be prepared for any complications. These units should offer solutions to control the symptoms, including the use of a feeding tube, control of saliva secretions, cough assist devices, respirators for mechanical ventilation, technology to improve the patient’s ability to move around and facilitate communication in patients who have lost the ability to speak.

These multidisciplinary units are the centres preferred by those running new drug trials.

The reality is that there is currently no effective treatment, although patients and their relatives often desperately search online for miracle drugs that might cure the condition. ALSuntangled, a group made up of 80 international experts in ALS, was born with the aim of protecting these patients from the numerous products advertised. It mission is to review the veracity and safety of the alternative treatments offered online that have not gone through the proper regulatory channels. It publishes its results in the official magazine for the disease and on its website.

Typical tests

Diagnostic imaging techniques (MRI, CAT, PET), electrophysiology (electromyography, EMTC, PESs), laboratory analysis (haematology, biochemistry, antibodies, hormones, enzymes, serology, genetics), respiratory functional tests, gasometry, pulse oximetry, overnight pulse oximetry, capnography, BMI, calorimetry, lumbar puncture, functional scale for the disease (ALS-FRS-R). A muscular biopsy may be required in exceptional cases. It is advisable to admit the patient in order to arrange for testing and offer them a report on discharge detailing the ALS diagnostic category and degree of functional repercussion (ALS-FRS-R).

Prevention

Although various environmental risk factors have been suggested (geographic, occupational, dietary habits, proximity to electrical channels, contact with pesticides or other neurotoxins), there is no agreement on preventative measures to take.

In family forms, it is possible to offer genetic counselling to people with a desire for offspring.

During the natural course of the disease, complications often appear that may be prevented and treated. Among the most significant are malnutrition, respiratory failure, hypersalivation, spasticity, pain, loss of independent movement and communication, depression, anxiety, sleep disorders, bed sores, cognitive deficits and burden on carers.

Departments and professionals at Vall d’Hebron who treat this condition

The Multidisciplinary ALS Unit in the Neurology Department at Vall d’Hebron University Hospital is accredited by the Generalitat de Catalunya, Spanish Government (CSUR) and by the European Reference Network for Rare Neuromuscular Diseases (EURO-NMD).

Professionals from the following specialisms make up this unit: Case handling, nursing, social care, neurology, pneumology, rehabilitation, nutritional support, neuropsychology, physiotherapy, speech therapy, endoscopy, interventional radiology, technicians for increasing communication (UTAC).

The coordinator is Dr. Josep Gamez.