Amyotrophic lateral sclerosis (ALS) is an incurable progressive disease of the central nervous system, in which the patient has a lesion of the upper and lower motor neurons, which provokes muscle atrophy and paralysis. The frequency of this pathology is about 2-7 cases per 100 thousand people. Most often, the disease is diagnosed in patients older than 50 years.
The content of the article:
Classification of amyotrophic lateral sclerosis
Clinical picture of amyotrophic lateral sclerosis
Etiology and pathogenesis of amyotrophic lateral sclerosis
Diagnosis of amyotrophic lateral sclerosis
Differential diagnosis
Treatment of amyotrophic lateral sclerosis
Prognosis for amyotrophic lateral sclerosis
Amyotrophic lateral sclerosis (ALS)
Classification of amyotrophic lateral sclerosis
Scientists have not yet created a unified comprehensive classification of ALS. There are several approaches to the classification of the disease. For example, the North American approach provides for the allocation of the following types of ALS: sporadic, familial, sporadic endemic. The classification of amyotrophic lateral sclerosis provides for the following forms of the disease: bulbar, lumbosacral, cervical-thoracic and primary generalized. There are also several variants of the disease: mixed, pyramidal and segmental-nuclear.
Clinical picture of amyotrophic lateral sclerosis
The most common initial symptoms of the disease include cramps (painful muscle spasms), lethargy and weakness in the distal parts of the arms, bulbar disorders, atrophy of the leg muscles, weakness in the shoulder girdle. In addition, different variants of the disease are characterized by different clinical manifestations.
The classic version of the bass (with a neck opening). The first sign of the disease is the formation of an asymmetric paraparesis with pyramidal signs. In addition, spastic paraparesis appears, which is accompanied by hyperreflexia. Over time, the patient begins to show signs of bulbar syndrome.
Segmented-core version of the BASS (with a neck opening). This type of disease is manifested by the formation of asymmetric flaccid paraparesis, which is accompanied by hyporeflexia. At the same time, patients have the opportunity to move independently for some time.
The classic version of the bass (with a diffuse debut). This variant of pathology usually begins to manifest as a sluggish asymmetric tetraparesis. In addition, patients are also diagnosed with bulbar syndrome, which manifests itself in the form of dysphagia and dysphonia. The patient often has a sharp decrease in body weight, shortness of breath and rapid fatigue.
The classic version of the BASS (with lumbar debut). This variant of pathology begins with a lower flaccid paraparesis. Later, symptoms such as muscle hypertonia and hyperreflexia are added. At the beginning of the disease, patients can still move independently.
Pyramid version of the BASS (with lumbar debut). This type of disease begins with the occurrence of lower asymmetric paraparesis, which is then joined by upper spastic paraparesis.
The classic variant of ALS (bulbar paralysis is observed at the beginning of the disease). Dysphagia, dysphonia, dysarthria, upper and lower asymmetric paraparesis are characteristic of this disease. The patient is rapidly losing weight, he has respiratory disorders.
Segmented-core version of the BASS (with bulbar paralysis). For this variant of the disease, nasophonia, dysphagia, dysarthria are considered characteristic. As in the previous case, the patient loses body weight and respiratory pathologies appear.
Etiology and pathogenesis of amyotrophic lateral sclerosis
The exact causes of amyotrophic lateral sclerosis are still being investigated by scientists. However, there are several factors that provoke the disease. For example, about 5% of diseases have a hereditary etiology. At least 20% of cases are associated with mutations of the superoxide dismutase-1 gene. Scientists have proved that the high activity of the glutamatergic system plays an important role in the appearance of the disease. The fact is that an excess of glutamic acid provokes overexcitation and sudden death of neurons. The molecular genetic mechanism of the pathology has also been proved. It is caused by an increase in the level of DNA and RNA in cells, which eventually leads to a violation of protein synthesis.
Scientists also identify several predisposing factors that play an important role in the appearance of ALS. First of all, such factors include age. The fact is that the disease usually develops in patients aged 30-50 years. It is worth remembering that only about 5% of patients have a hereditary predisposition to ALS. In the overwhelming number of cases of ALS, the causes of pathology cannot be established.
The early course of the disease is characterized by symptoms such as convulsions, twitching, muscle numbness, difficulty speaking, weakness in the extremities. Since such symptoms are characteristic of many neurological diseases, it is difficult to diagnose ALS at an early stage. In most cases, it is possible to diagnose the disease at the stage of muscular atrophy.
Depending on the lesion of different parts of the body with the disease, limb bass and bulbar bass are distinguished. In the first case, the flexibility in the ankle worsens in patients, there is awkwardness when walking, they begin to stumble. Bulbar bass is manifested by difficult speech (nasal twang, difficulty swallowing). Soon it becomes difficult for the patient to move or he can no longer move independently at all. Usually, the disease does not adversely affect the mental abilities of the patient, but leads to severe depression. From the appearance of the first symptoms to death, in most cases, it takes about three to five years.
Diagnosis of amyotrophic lateral sclerosis
Since ALS is an incurable disease that rapidly shortens a person’s life, the patient’s examination should be comprehensive and accurate. It is extremely important to make the correct diagnosis to the patient in order to start relieving his main symptoms in time, as this can prolong the patient’s life. The examination plan usually includes the collection of anamnesis of life and disease, neurological and physical examination, MRI of the spinal cord and brain, EMG, laboratory tests.
Anamnesis collection and examination
Diagnosis of the disease begins with a detailed survey of the patient. Namely, the doctor needs to clarify whether the patient complains of muscle spasms and twitching, weakness and stiffness, impaired movement in the hands, speech, walking, swallowing, salivation, frequent lack of air, weight loss, fatigue, shortness of breath during exercise. In addition, the doctor should ask if the patient has noticed double vision, memory impairment, feelings of crawling goosebumps on the body, urination disorders. It is necessary to ask the patient about his family history — whether he has relatives with chronic movement disorders.
The main purpose of physical examination is to assess the patient’s constitution, weigh him, measure height, calculate body mass index. Neurological examination usually involves neuropsychological testing. During the assessment of bulbar functions, the doctor pays attention to the timbre of the voice, the speed of speech, the pharyngeal reflex, the presence of atrophy of the tongue, paresis of the soft palate. In addition, during the examination, the strength of the trapezius muscles is checked.
Instrumental research methods
Needle EMG is considered to be the main instrumental method of diagnosing the disease. This technique allows you to identify such signs of the disease as acute or chronic denervation. In the early stages of the disease, it is ineffective to use EMG stimulation, since it does not reveal noticeable signs of ALS.
In the process of diagnosing the disease, doctors also use neuroimaging methods. MRI of the spinal cord and brain plays a great role in the differential diagnosis of ALS. During MRI in 17-67% of patients, it is possible to detect symptoms of degeneration of the pyramidal tracts, atrophy of the motor cortex of the brain. However, it is worth noting that this technique is ineffective during the diagnosis of the disease in patients with bulbar syndrome.
During the diagnosis of ALS, many laboratory tests are performed. In particular, doctors can prescribe clinical and biochemical blood tests, a study of cerebrospinal fluid, serological studies. However, the only effective and reliable method of analysis is still considered to be molecular genetic analysis. The presence of superoxide dismutase-l mutations in the gene is considered suspicious for ALS.
Differential diagnosis
Since the symptoms of amyotrophic lateral sclerosis are similar in many respects to the manifestations of other neurological pathologies, doctors necessarily carry out differential diagnosis. The most accurate diagnosis can be made using an MRI of the brain and spine. First of all, ALS must be differentiated from muscle diseases, which include Rossolimo-Steinert-Kurschmann dystrophic myotonia, myositis with cellular abnormalities, oculopharengial myodystrophy.
It is also necessary to distinguish ALS from spinal cord pathologies:
chronic vertebrogenic ischemic myelopathy;
bulbospinal amyotrophy of Kennedy;
syringomyelia;
tumors;
familial spastic paraplegia;
chronic lymphocytic leukemia;
hexosaminidase deficiency;
lymphoma.
Differential diagnosis is also necessary in order to distinguish the disease from systemic pathologies, neuromuscular synapse lesions, brain pathologies such as multisystem atrophy, dyscirculatory encephalopathy, syringobulbia.
Treatment of amyotrophic lateral sclerosis
The main goals of the treatment of amyotrophic lateral sclerosis are considered to slow down the development of the disease, as well as the elimination of its symptoms, which significantly worsen the quality of life of the patient. It should be remembered that ALS is a serious incurable disease that shortens a person’s life expectancy. That is why the doctor has the right to inform the patient of the diagnosis only after a comprehensive and thorough examination.
Treatment of the disease includes medication and non-drug therapy. The latter implies regime measures. The patient should limit physical activity, which can accelerate the progression of ALS. In addition, it is very important to eat properly and fully. Drug therapy is divided into two types: pathogenetic and palliative.
Pathogenetic therapy
To date, the only drug that can slow the progression of ALS is riluzole. It has been proven that its reception is able to prolong the patient’s life by an average of three months. This drug is indicated for patients whose duration of the disease is less than 5 years. The patient should receive 100 mg of the drug daily. In order to avoid the risk of drug hepatitis, it is necessary to check the level of AST, ALT and LDH every three months. Since men and smokers have a lower concentration of riluzole in their blood, they should either limit themselves to smoking, or get rid of this bad habit altogether. You will need to take the drug for life.
Scientists have repeatedly tried to use other drugs for pathogenetic therapy. However, such experiments have not been effective. Among them were:
xaliproden;
metabolic agents;
anticonvulsants;
antiparkinsonian remedies;
antibiotics;
antioxidants;
calcium channel blockers;
immunomodulators.
The effectiveness of taking high doses of cerebrolysin has also not been proven, despite the fact that this drug is able to slightly improve the condition of patients.
Palliative care
Palliative therapy is designed to eliminate the complex of symptoms of the disease and thereby improve the quality of life of the patient. The following techniques are used to eliminate certain symptoms of ALS:
spasticity — baclofen and tizanidine are prescribed;
faculation (muscle twitching) — in addition to baclofen and tizanidine, carbamazepine is also prescribed;
depression and emotional lability — fluoxetine and amitriptyline;
walking disorder — walkers, canes and strollers are shown to eliminate this symptom;
deformity of the feet — the patient should wear orthopedic shoes;
neck paresis — a rigid or semi-rigid head holder is shown;
thrombosis of the veins of the lower extremities — elastic bandaging of the legs is prescribed;
rapid fatigue — performing gymnastic exercises, as well as taking amantadine and ethosuximide;
shoulder periarthrosis — compresses with procaine, dimethyl sulfoxide solution, hyaluronidase are prescribed;
oral hypersecretion syndrome — correction of dehydration, portable suction, mucolytics and bronchodilators are indicated to eliminate this symptom;
sleep apnea syndrome — fluoxetine;
respiratory disorders — periodic noninvasive ventilation is prescribed;
dysphagia — compliance with a special diet (exclusion of dishes with solid and dense components, preference for mashed dishes, souffles, porridges, purees);
dysarthria — taking muscle relaxants, the use of ice applications on the tongue, the use of electronic typewriters, a special computer typing system, compliance with speech recommendations compiled by the British Association of ALS;
salivation — regular sanitation of the oral cavity (it is necessary to brush your teeth three times a day, often rinse the cavity with antiseptic solutions), restriction of the use of fermented milk products, taking atropine and amitriptyline.
To improve muscle metabolism, the following medications can be prescribed to a patient with ALS: creatine, carnitine, levocarnitine solution, trimethylhydrazinium propionate. Multivitamin therapy is also indicated for patients, which involves taking multivitamins (neuromultivitis, milgamm) and thioctic acid.
In most patients with ALS, the disease is accompanied by serious motor disorders up to the limitation of mobility. Of course, this causes severe discomfort to the patient, who constantly needs the help of other people. Orthopedic correction techniques help to eliminate some motor disorders. The doctor needs to explain to the patient that the use of auxiliary means does not indicate his disability, but only reduces the difficulties caused by the disease.
The most life-threatening symptom of the disease is considered to be respiratory failure. The earliest symptoms of it will be morning fatigue, vivid dreams, daytime drowsiness, dissatisfaction with sleep. To detect respiratory failure at an early stage, polysomnography and spirography are performed. To eliminate apnea, medication and non-invasive ventilation of the lungs are indicated. It has been proven that these techniques can extend the patient’s life by one year. If the patient has a need for assisted breathing for more than 20 hours, the doctor raises the question of a complete transition to invasive ventilation.
Patients who have undergone an initial examination or repeated conclusion about the disease should be under outpatient supervision. As any new symptoms appear, they should also receive qualified advice. Patients should take most medications regularly. Only vitamins and myotropic drugs are taken in courses in stages.
Every three months, the patient needs to undergo a spirography procedure. If he regularly takes riluzole, he needs to determine the activity of LDH, AST and ALT every six months. If the patient has dysphagia, the blood glucose level and trophic status should be periodically measured. Patients have a choice of treatment regimen: they can stay both at home and stay in a hospice.
Prognosis for amyotrophic lateral sclerosis
The prognosis for ALS patients largely depends on the course of the disease. It has been proven that about 80-90% of patients with severe respiratory complications die within 3-5 years after the first signs of the disease. The remaining 10% of patients have a benign course of the disease. The duration of the disease is significantly reduced in the presence of the following factors: the patient’s age is less than 45 years, bulbar onset of ALS, rapid progression of the disease.