What is amyotrophic lateral sclerosis?
Amyotrophic lateral sclerosis is a disease characterized by damage and death of cells in the brain, spinal cord responsible for muscle movement. As a result, muscle weakness and paralysis (lack of movement) develop. The manifestations of the disease are gradually increasing. Patients lose the ability to move independently, the activity of muscles, which are necessary for breathing, is disrupted, which leads to the death of patients.
The reasons for obtaining an ALS are not fully understood. There are several factors that, according to researchers, affect the onset of the disease. These include genetic mutations (changes in genetic material), imbalances of certain chemicals in the nervous system, disorders in the immune system (the system that protects the body from various infections), and others.
The disease is incurable. Taking drugs can slow down the development of amyotrophic lateral sclerosis.
The main manifestations of amyotrophic sclerosis in the early stages of ALS diagnosis include:
- weakness in the muscles of the arms or legs; decrease in muscle strength can begin in the foot, hand, fingers, and then spread to other muscles of the limbs, trunk
- slurred speech
- nasal speech sound
- difficulty swallowing food
- twitching in the muscles of the arms, legs, tongue
Over time, muscle weakness builds up, resulting in obtaining an ALS. In the later stages of the disease, the following manifestations occur:
- loss of ability to stand, walk
- lack of movement in the arms and legs
- loss of the ability to chew, swallow food
- pronounced speech difficulties
- loss of the ability to breathe spontaneously
ALS diagnosis is quite difficult, as it is necessary to exclude diseases that can cause similar symptoms. These include damage to the nervous system associated with exposure to heavy metals (for example, lead), infectious diseases, and others.
Laboratory ALS diagnosis plays an important role. Tests are carried out that reflect the general condition of the patient’s blood, indicators of the activity of the liver, kidneys. If abnormalities are detected, additional research may be required.
- General blood analysis. Allows you to determine the main indicators of blood, the number of erythrocytes, hemoglobin, leukocytes, platelets. An increase in the number of leukocytes is observed in various inflammatory processes.
- Total whey protein. A certain level of protein is required for the body to function properly. Proteins perform essential functions, carry out the transport of various substances in the body, ensure the retention of fluid in the bloodstream (colloidal-osmotic balance), and are an essential component of several body structures. When obtaining an ALS, eating difficulties arise. As a result, the level of total protein in the blood can be lowered.
- Alanine aminotransferase. An enzyme that is found in large quantities in liver cells. With the destruction of liver cells, the concentration of alanine aminotransferase in the blood increases. This analysis shows the severity of liver damage.
- Serum creatinine. Creatinine is produced in muscles during various energy processes and then released into the blood. It is excreted from the body by the kidneys; in several conditions accompanied by impaired renal function, the concentration of creatinine increases. The indicator is essential for assessing kidney function.
- Whey urea. Urea is the end product of protein metabolism in the body. It is excreted from the body by the kidneys. With kidney damage, impairment of their function, the level of urea increases.
Depending on the clinical situation, the following tests may be required:
- Determination of the concentration of heavy metals in the blood. Exposure to heavy metals in the human body can damage the nervous system. However, some of the manifestations may be similar to obtaining an ALS (for example, with lead exposure).
- Determination of the presence of heavy metals in urine. Heavy metals can damage the nervous system (e.g., lead, aluminum).
- Determination of antibodies to pathogens of infectious diseases. Antibodies are protein particles produced by the body’s immune system in response to the penetration of infection into the human body. Some infectious diseases (such as syphilis) can damage the nervous system.
- Electromyography. This ALS diagnosis method allows you to assess the electrical impulses that travel along the nerves to the muscles. To do this, special electrodes are applied to the muscle under study. The study is carried out in a calm state and with muscle contraction.
- Magnetic resonance imaging (MRI). An ALS diagnosis method based on the effect of a magnetic field on the human body. After processing the received signals, layer-by-layer images of the internal structures of the body are obtained. Allows exclusion of the presence of masses (for example, tumors) of the brain and spinal cord.
- Muscle biopsy. It can be performed if there is a suspicion of a disease in which muscles are affected, and not nerve cells, as in amyotrophic lateral sclerosis. For this, a small piece of muscle is taken, which is then examined in the laboratory.
How is ALS diagnosis made?
Amyotrophic lateral sclerosis is extremely difficult to diagnose for several reasons:
- It is a rare disease.
- Early symptoms are mild, such as clumsiness, awkwardness in the hands, or mildly plagued speech, all of which may be due to completely different causes.
- The disease affects each person differently; there is no specific symptom that clearly defines ALS.
If the therapist suspects that the patient is obtaining an ALS, they should refer them to a neurologist. Then the person may have to undergo a series of diagnostic examinations, which can be carried out both on an outpatient basis and in a hospital.
- Blood test. Research and ALS diagnosis will show whether the level of creatine kinase is elevated in the blood. This enzyme is produced when muscle tissue breaks down, and levels may be elevated in people with ALS. But this indicator is not a specific ALS sign since it can be an indicator of other diseases.
- Electroneuromyography. ENMG uses fine needles to record nerve impulses in individual muscles. The recording is usually done from each limb and bulbar (pharyngeal) muscles. Muscles that have lost their innervation are detected because their electrical activity is different from that of healthy muscles. ENMG results may differ from normal, even if the specific muscle is not already affected by the disease. With ENMG, the speed of the impulse along the nerve fibers is also checked. To do this, an electrical impulse is passed through a small pad in contact with the skin; this is a crucial research method for diagnostics.
- Transcranial magnetic stimulation. This is a new method that can be performed simultaneously with ENMG. It is designed to assess the state of motor neurons in the brain. TMS results can help with ALS diagnosis.
- Magnetic resonance imaging. MRI can detect damage in the nervous system caused by stroke, Alzheimer’s disease, Parkinson’s disease, multiple sclerosis, tumors, spinal cord injuries, and brain injuries. MRI does not reveal specific changes in ALS since the damage caused by this disease is not reflected in the images. This research method is used to rule out diseases with ALS-like symptoms.
The neurologist may decide to do additional tests, such as a lumbar puncture or muscle biopsy, if something indicates necessary. But these tests are not always used to diagnose ALS.